The role of the microbiome in aggression. Gut microbe imbalances that predict autism and ADHD. Biogaia trial for Autism.

 

By December 2020 7.3% of the Swedish cohort born in 1997-9 had been diagnosed with a Neurodevelopmental Disorder (ND). This can be predicted by samples previously collected.

Today’s post is all about the microbiome and covers three different areas covered recently in the research. Eight years after I wrote a post about our informal trial of Biogaia probiotics for autism, we now have a published paper.

Aggression and self injurious behavior (SIB) affects at least half of those diagnosed with level 3 autism at some point in their lives. SIB can become the overriding concern for care givers.

Our first paper looks at the role of the microbiome in aggression.

Gut-brain axis appears to play a critical role in aggression

A series of experiments on mice has found that they become more aggressive when their gut microbiome is depleted. Additionally, transplanting gut microbiota from human infants exposed to antibiotics led to heightened aggression in mice compared to those receiving microbiome transplants from non-exposed infants. The research was published in Brain, Behavior, and Immunity.

In the past decade, scientists have discovered a complex communication pathway linking gut microbiota—the trillions of microorganisms living in the human gut—with the brain. This pathway is called the microbiota-gut-brain axis. It regulates various physiological functions, including digestion and immunity, but also affects mood and behavior. The gut microbiota produces neurotransmitters and other metabolites that can influence brain function through neural, immune, and endocrine pathways.

Recent studies have demonstrated that symptoms of various disorders, once considered primarily psychological or neurological, can be transferred to rodents by transplanting gut microbiota from humans with these disorders. For example, researchers have shown that transplanting gut microorganisms from people with Alzheimer’s disease into mice (whose gut microbiota had been depleted to enhance transplant effectiveness) resulted in cognitive impairments in the mice. Similarly, symptoms of anxiety have been induced in mice by transplanting gut microbiota from humans with social anxiety.

For the humanized mice, the researchers obtained fecal samples from infants who had been exposed to antibiotics shortly after birth, as well as from unexposed infants. These samples were transplanted into five-week-old germ-free mice. The researchers then waited for four weeks before testing the mice for aggression.

To measure aggression, the researchers employed the resident-intruder test, a well-established behavioral assay in which a male mouse (the “resident”) is introduced to another unfamiliar male mouse (the “intruder”) in its home cage. Aggression was quantified based on the latency to the first attack (how quickly the resident mouse attacked the intruder) and the total number of attacks during a 10-minute period.

The results showed that mice raised without gut bacteria (germ-free) and those treated with antibiotics exhibited higher levels of aggression compared to the control group. These mice attacked more frequently and were quicker to initiate aggressive behavior in the resident-intruder test.

The researchers found that humanized mice receiving fecal microbiota from antibiotic-exposed infants were significantly more aggressive than those receiving transplants from non-exposed infants. Even though the infants’ microbiomes had a month to recover after antibiotic exposure, the aggressive behavior was still evident in the recipient mice.

Biochemical analyses revealed that aggressive mice (both germ-free and antibiotic-treated) had distinct metabolite profiles compared to control mice. Specifically, levels of tryptophan—a precursor to serotonin, a neurotransmitter associated with mood and behavior—were elevated in these mice. Additionally, the levels of certain metabolites associated with microbial activity, such as indole-3-lactic acid, were reduced in the aggressive mice, suggesting that the absence of a healthy microbiome might alter key biochemical pathways involved in aggression.

Here is the link to the original paper:

A gut reaction? The role of the microbiome in aggression

Recent research has unveiled conflicting evidence regarding the link between aggression and the gut microbiome. Here, we compared behavior profiles of control, germ-free (GF), and antibiotic-treated mice, as well as re-colonized GF mice to understand the impact of the gut microbiome on aggression using the resident-intruder paradigm. Our findings revealed a link between gut microbiome depletion and higher aggression, accompanied by notable changes in urine metabolite profiles and brain gene expression. This study extends beyond classical murine models to humanized mice to reveal the clinical relevance of early-life antibiotic use on aggression. Fecal microbiome transplant from infants exposed to antibiotics in early life (and sampled one month later) into mice led to increased aggression compared to mice receiving transplants from unexposed infants. This study sheds light on the role of the gut microbiome in modulating aggression and highlights its potential avenues of action, offering insights for development of therapeutic strategies for aggression-related disorders

Note the ABX means antibiotics

We include a study of humanized mice using unique fecal samples of 1-month-old infants, collected nearly a month after early-life ABX administration. In previous work (Uzan-Yulzari et al. 2021, Nat Comm), we have demonstrated that ABX in this critical period of life can have lasting effects of childhood growth. Here, we extend these findings using samples from the same cohort. Using fecal samples collected weeks after ABX administration also reduces the direct chemical effects of ABX on the host, highlighting the causative role of the dysbiotic host microbiome and associated metabolome in driving aggressive behavior. We demonstrate that infant microbiota, perturbed within the first 48 h of life, has a lasting signature through 1 month of age that, when transplanted into GF mice, results in increased aggression (3–5 weeks after transplant) when compared to effects of stools of infants not exposed to any early-life antibiotics. The findings are revolutionary as they show how ABX-altered microbiota during a critical development window can lead to persisting behavioral deficits.

 

Gut microbe imbalances could predict a child’s risk for autism, ADHD and speech disorders years before symptoms appear.

Study Identifies Gut Microbe Imbalances That Predict Autism And ADHD

We are researchers who study the role the microbiome plays in a variety of conditions, such as mental illness, autoimmunity, obesity, preterm birth and others. In our recently published research on Swedish children, we found that microbes and the metabolites they produce in the guts of infants – both found in poop and cord blood – could help screen for a child’s risk of neurodevelopmental conditions such as autism. And these differences can be detected as early as birth or within the first year of life. These markers were evident, on average, over a decade before the children were diagnosed. 

The imbalance in microbial composition – what microbiologists call dysbiosis – we observed suggests that incomplete recovery from repeated antibiotic use may greatly affect children during this vulnerable period. Similarly, we saw that repeated ear infections were linked to a twofold increased likelihood of developing autism.

Children who both repeatedly used antibiotics and had microbial imbalances were significantly more likely to develop autism. More specifically, children with an absence of Coprococcus comes, a bacterium linked to mental health and quality of life, and increased prevalence of Citrobacter, a bacterium known for antimicrobial resistance, along with repeated antibiotic use were two to four times more likely to develop a neurodevelopmental disorder.

Antibiotics are necessary for treating certain bacterial infections in children, and we emphasize that our findings do not suggest avoiding their use altogether. Parents should use antibiotics if they are prescribed and deemed necessary by their pediatrician. Rather, our study suggests that repeated antibiotic use during early childhood may signal underlying immune dysfunction or disrupted brain development, which can be influenced by the gut microbiome. In any case, it is important to consider whether children could benefit from treatments to restore their gut microbes after taking antibiotics, an area we are actively studying.

Another microbial imbalance in children who later were diagnosed with neurodevelopmental disorders was a decrease in Akkermansia muciniphila, a bacterium that reinforces the lining of the gut and is linked to neurotransmitters important to neurological health.

Even after we accounted for factors that could influence gut microbe composition, such as how the baby was delivered and breastfeeding, the relationship between imbalanced bacteria and future diagnosis persisted. And these imbalances preceded diagnosis of autism, ADHD or intellectual disability by 13 to 14 years on average, refuting the assumption that gut microbe imbalances arise from diet.

We found that lipids and bile acids were depleted in the cord blood of newborns with future autism. These compounds provide nutrients for beneficial bacteria, help maintain immune balance and influence neurotransmitter systems and signaling pathways in the brain.

The full paper is here: 

Infant microbes and metabolites point to childhood neurodevelopmental disorders 

Highlights

• Infant microbes and metabolites differentiate controls and future NDs

• Early-life otitis lowers Coprococcus and increases Citrobacter in future NDs

• Preterm birth, infection, stress, parental smoking, and HLA DR4-DQ8 increase ND risk

• Linolenic acid is lower and PFDA toxins higher in the cord serum of future ASD

Summary

This study has followed a birth cohort for over 20 years to find factors associated with neurodevelopmental disorder (ND) diagnosis. Detailed, early-life longitudinal questionnaires captured infection and antibiotic events, stress, prenatal factors, family history, and more. Biomarkers including cord serum metabolome and lipidome, human leukocyte antigen (HLA) genotype, infant microbiota, and stool metabolome were assessed. Among the 16,440 Swedish children followed across time, 1,197 developed an ND. Significant associations emerged for future ND diagnosis in general and for specific ND subtypes, spanning intellectual disability, speech disorder, attention-deficit/hyperactivity disorder, and autism. This investigation revealed microbiome connections to future diagnosis as well as early emerging mood and gastrointestinal problems. The findings suggest links to immune-dysregulation and metabolism, compounded by stress, early-life infection, and antibiotics. The convergence of infant biomarkers and risk factors in this prospective, longitudinal study on a large-scale population establishes a foundation for early-life prediction and intervention in neurodevelopment.

ABIS = All Babies in Southeast Sweden cohort

NDs = Neurodevelopmental disorders

Young children later diagnosed with ASD or exhibiting significant autistic traits tend to experience more ear and upper respiratory symptoms. In ABIS, infants who had otitis in their first year were found to be more prone to acquiring NDs if they lacked detectable levels of Coprococcus or harbored Citrobacter. The absence of Coprococcus, despite comparable levels in controls irrespective of otitis, raises questions about microbial community recovery. This potential failure of the microbiome to recover following such events may serve as a mechanism connecting otitis media to ND risk. Moreover, antibiotic-resistant Citrobacter was more prevalent in these infants. The presence of strains related  to Salmonella and Citrobacter, labeled in this investigation as SREB, was significantly higher in infants who later developed comorbid ASD/ADHD (21%), compared to controls (3%). This disruption may have consequences on neurodevelopment during a critical period. Salmonella and Citrobacter have shown the ability to upregulate the Wingless (Wnt) signaling. The Wnt pathway is vital for immune dysregulation and brain development, and its disruption has been implicated in ASD pathogenesis. 

Two fatty acid differences were notable in the stool of future ASD versus controls: omega-7 monounsaturated palmitoleic acid, (9Z)-hexadec-9-enoic acid (below the level of detection in 87.0% of future ASD but present in 43.5% of controls), and palmitic acid (elevated in future ASD). Palmitoleic acid has been associated with a decreased risk of islet and primary insulin autoimmunity. Conversely, palmitic acid, a saturated fatty acid, has been linked to neuronal homeostasis interference. Its effects are partially protected by oleic acid, which although approaching significance, was lower in the cord serum of future ASD.

Few metabolites were higher in stool of infants with future ASD, but there are a few notable examples: α-d-glucose, pyruvate, and 3-isopropylmalate. Coprococcus inversely correlated with 3-isopropylmalate, suggesting gut-brain connections and a possible imbalance in branched-chain amino acid (BCAA) pathways given the role of 3-isopropylmalate dehydrogenase in leucine and isoleucine biosynthesis. An increase in dehydroascorbate suggests potential disruptions in vitamin C metabolism, crucial for neurotransmitter synthesis and antioxidant defense, while elevated pyruvate suggests disturbance of neurotransmitter synthesis or energy production early in life. Pimelic acid elevation, found in disorders of fatty acid oxidation, suggests disruption of mitochondrial pathways for fatty acid oxidation.

Akkermansia and Coprococcus, absent or reduced in infants with future NDs, positively correlated with signals in stool representing neurotransmitter precursors and essential vitamins in stool. Specifically, Akkermansia correlated with tyrosine and tryptophan (i.e., catecholamine and serotonin precursors, respectively) and Coprococcus with riboflavin. Disruption of BCAA metabolism in ASD has been documented, involving coding variants in large amino acid transporters (LATs) and reduced utilization of trypotphan and large aromatic amino acids along with increased glutamate and decreases in tyrosine, isoleucine, phenylalanine, and tryptophan in children with ASD. Oxidative stress, a diminished capacity for efficient energy transport, and deficiencies in vitamins (like vitamin B2) essential for neurotransmitter synthesis and nerve cell maintenance have been implicated. Riboflavin as an antioxidant reduces oxidative stress and inflammation, demonstrating neuroprotective benefits in neurological disorders, possibly through maintenance of vitamin B6, which is necessary for glutamate conversion to glutamine and 5-hydroxytryptophan to serotonin.

Together, these findings support a hypothesis of early-life origins of NDs, mediated by gut microbiota. This provides a foundation for research and for developing early interventions for NDs.

 

Today’s final paper was highlighted recently in a comment on a post I wrote eight years ago, when we were trialing Biogaia probiotics. This original interest was prompted by a reader sharing her successful experiences of treating her son with severe autism. Perhaps she left the recent comment?

The two bacteria involved are both types of L. reuteri.

L. reuteri 6475 is sold as Biogaia Osfortis

L. reuteri 17938 is sold Biogaia Protectis

The combination of L. reuteri 17938 and L. reuteri 6475 is sold as Biogaia Gastrus.

My old post from 2016:-

Epiphany: Biogaia Trial for Inflammatory Autism Subtypes

The recently published trial:

Precision microbial intervention improves social behavior but not autism severity: A pilot double-blind randomized placebo-controlled trial -

Highlights

• L. reuteri (6475 + 17938) improves social functioning in children with autism

• L. reuteri does not improve overall autism severity or repetitive behaviors

• L. reuteri does not significantly alter microbiome composition or immune profile

•  Only the 6475 strain reverses the social deficits in a mouse model for autism

we performed a double-blind, randomized, placebo-controlled, parallel-design pilot trial in children with ASD. Importantly, we found that L. reuteri, compared with placebo, significantly improved social functioning, both in terms of reducing social deficits, as measured by the social responsiveness scale (SRS^31,32), and increasing adaptive social functioning, as measured by the social adaptive composite score of the Adaptive Behavior Assessment System, Second Edition (ABAS-2³³). L. reuteri did not improve overall autism severity, restricted and repetitive behaviors, and co-occurring psychiatric and behavioral problems, nor did it significantly modulate the microbiome or immune response. Thus, this safe microbial manipulation has the potential for improving social deficits associated with ASD in children.

I had to amend my old post with a warning long ago.

UPDATE: A significant minority of parents report negative reaction to Bio Gaia, this seems to relate to histamine; but more than 50% report very positive effects without any side effects; so best to try a very small dose initially to see if it is not well tolerated. 

Histamine Reaction to BioGaia gastrus

Conclusion

The gut microbiota does indeed play a key role in how your brain functions, but the gut-brain axis works in both directions. What goes on in your brain can affect your gut and not just the other way around. It is called bidirectional signaling.

Antibiotics taken during pregnancy, or during early childhood, will have unintended consequences. Often there is no choice, like for those readers whose baby experienced sepsis at birth (bacterial blood stream infection); you have to give antibiotics to avoid death.

In today’s second paper we see that the researchers are thinking about therapeutical implications. Perhaps the newborn’s gut flora should be repopulated during the weeks after the antibiotic treatment?

I receive many questions about how to treat self injurious behavior that does not respond to anything the doctor has prescribed. Rifaximin, an antibiotic used to treat irritable bowel syndrome with diarrhea, is one therapy that does help some types of SIB (and SIBO, small intestinal bacterial overgrowth, of course). This probably would not surprise the authors of today’s first paper.

Biogaia Gastrus (L. reuteri 6475 + 17938) from today’s third paper worked wonders for the SIB of one reader’s child.

Not surprisingly fecal microbiota transplantation (FMT) can improve SIB in some people.

The Swedish data shows interesting insights such as that lipids and bile acids were depleted in the cord blood of newborns with future autism. The researchers think they can predict the diagnosis of autism or ADHD. The question is and then what? Even when there is a diagnosis of autism, not much changes for most children.

FMT (Fecal Microbiota Transplantation) Super-donors and Abandoning the “One Stool Fits All” Approach

Not all stools were created equal

There was a comment recently left on this blog posing the question of what makes a good donor for FMT (Fecal Microbiota Transplantation), or a “poop transplant” in plain English.

FMT is actually an approved therapy for Clostridioides difficile infection (CDI). Research has shown  FMT to be more effective than the antibiotic vancomycin. To quote from the research, “The infusion of donor feces was significantly more effective for the treatment of recurrent C. difficile infection than the use of vancomycin”.

FMT might not be for discussion at the dinner table, but it is highly effective in some instances.

FMT is actually far more widely used than you might imagine.  In one of today’s papers from China they had treated 1,387 people using 20 donors, for a wide variety of conditions.

In the US, autism researchers at Arizona State University showed a benefit that was maintained after a period of two years.

Autism symptoms reduced nearly 50 percent two years after fecal transplant

At two years post-treatment, most of the initial improvements in gut symptoms remained. In addition, parents reported a slow steady reduction of ASD symptoms during treatment and over the next two years. A professional evaluator found a 45% reduction in core ASD symptoms (language, social interaction and behavior) at two years post-treatment compared to before treatment began.

An earlier study with only vancomycin (an antibiotic) had found major temporary improvements in GI and autism symptoms, but the benefits were lost a few weeks after treatment stopped despite use of over-the-counter probiotics.

The obvious question to ask is whether FMT has a potential benefit to people with autism who do not have GI dysfunction.  I think this question is far from being answered.

We have seen in earlier posts that modifying the microbiome has great potential to fine-tune the function of the brain.  Researchers at UCLA showed that the high fat ketogenic diet controls epileptic seizures not through the action of ketones in the brain, but via the high fat intake changing the mix of bacteria in the gut.

The Gut Microbiota Mediates the Anti-Seizure Effects of the Ketogenic Diet

FMT is just one way to modify the microbiome.  The UCLA researchers are developing a medical food to produce similar effects on the microbiome as the ketogenic diet.

Very likely a personalized bacteria transfer, customized to the symptoms of the person, might effectively treat many more conditions than just GI problems.  

It does look likely that for some conditions there may be super-donors, people whose microbiome is particularly effective, when transferred to others.

But the research cautions against what is called the “One Stool Fits All” Approach.  The donor and recipient need to be “compatible”.

The Super-Donor Phenomenon in Fecal Microbiota Transplantation

The microbial diversity of the donor is a good predictor of FMT success in the recipient. However, donor-recipient compatibility also plays an influential role in determining FMT success. Donor-recipient compatibility can stem from genetic factors such as differences in innate immune responses, or environmental factors including diet, xenobiotic exposure, and microbial interactions.

FMT for Inflammatory Bowel Disease (IBD): The Emergence of the FMT Super-Donor

IBD encompasses both Crohn's disease and ulcerative colitis; two debilitating disorders characterized by chronic relapsing inflammation of the intestinal. In contrast to CDI, there is no evidence that IBD results from an overgrowth of one specific pathogen. Rather, the disease is likely brought on by complex interactions involving the host's genetics, immune system, and gut microbiota. Both Crohn's disease and ulcerative colitis are broadly characterized by a reduced diversity of the gut microbiota with lower relative abundances of the Bacteroidetes and Firmicutes phyla and higher proportions of Proteobacteria. A specific reduction in the abundance of butyrate-producing bacterial species, particularly Faecalibacterium prausnitzii, has been observed for both Crohn's disease and ulcerative colitis. Meanwhile, for Crohn's disease, an increase in a pro-inflammatory form of Escherichia coli has also been reported.

The first successful case report of an FMT for the treatment of IBD was published in 1989 when a male with refractory ulcerative colitis achieved clinical remission for 6 months following a retention enema with healthy donor stool. Subsequently, a large number of FMT studies have been conducted on IBD patients with variable clinical outcomes, remission rates, and longevity of effect. Recently, Paramsothy et al. performed a systematic review and meta-analysis of 53 studies (four RCT, 30 cohort, 19 case studies) of FMT in IBD patients. Avoiding publication bias, their analysis of cohort studies revealed FMT was more effective at inducing remission in Crohn's disease patients when compared to patients with ulcerative colitis (52 vs. 33%, respectively). With regard to ulcerative colitis, a larger number of FMT infusions and a lower gastrointestinal tract administration were associated with improved rates of remission.

In contrast to studies of CDI, FMT studies conducted on IBD patients have frequently identified differential recipient responses that have been associated with variability in the donor stool. Currently, the stool used for FMT is not standardized in terms of donor selection (related vs. unrelated), preparation (fresh vs. frozen, aerobic vs. anaerobic), or the dose that is administered (single vs. multiple doses). While inconsistencies in FMT protocols make it difficult to compare different studies, there is a large degree of variability in clinical responses to FMT between recipients who have been subjected to the same study design. It is unfortunate that information on a recipient's genetic background or dietary intake is not yet routinely assessed, particularly given that some instances of IBD have an underlying genetic component. Due to the lack of genetic information, investigators have instead focused on the donor-dependent effect and proposed the existence of so called super-donors to explain the variation in recipient responses.

The first study to record the super-donor effect was a randomized control trial that was investigating the efficacy of FMT for inducing clinical remission in patients with ulcerative colitis. Moayyedi et al. assigned 75 patients with active disease to weekly enemas containing either fecal material or water (placebo) for a period of 6 weeks. FMT was shown to be superior to the placebo, resulting in significantly higher rates of endoscopic and clinical remission, albeit of modest effect (24 vs. 5%, respectively), after 7 weeks. Of the nine patients who entered remission, seven had received FMT from the same donor. Thus, it was argued that FMT success was donor-dependent.

Currently, it is not possible to predict the clinical efficacy of a donor before FMT in IBD patients. It has been suggested that remission rates could be improved by pooling donor's stool together, limiting the chances a patient will receive only ineffective stool. This stool pooling approach was recently investigated on an Australian cohort of 85 mild to moderate ulcerative colitis patients, in the largest randomized control trial of FMT for IBD to date. Rather than receiving FMT from just one donor, patients in the treatment arm were administered a stool mixture that contained contributions from up to seven different donors with the hope that donor-dependent effects could be homogenized. In addition to this, a far more intensive dosing program was adopted with an initial FMT delivered by colonoscopy that was followed by fecal enemas, five times a week for 8 weeks. Despite the multi-donor and intensive dosing approach, Paramsothy et al. achieved post-FMT remission rates (FMT, 27% vs. placebo, 8%, p = 0.02) that were similar to those reported previously. Notably, however, both clinical and endoscopic remission were required for primary outcome achievement in this study, whereas previous studies have mostly focused on either endoscopic or clinical remission rates alone. The pooled stool mixture was demonstrated to have higher microbial diversity than individual stool alone based on OTU count and phylogenetic diversity measures. Subsequent analysis of the different stool batches discovered that one donor appeared to exhibit a super-donor effect. Specifically, patients that received FMT batches that contained stool from this one donor exhibited a higher remission rate than those whose FMT batches did not include the super-donor (37 vs. 18%, respectively).

FMT for Other Disorders: Is There Also a Super-Donor Effect?

Evidence of FMT super-donors in other disorders outside of IBD is currently lacking. Case series and reports limit the capacity to identify super-donor effects because of limited sample sizes. However, despite the lack of large cohort studies, several studies have hinted at the possibility of a donor-dependent effect on FMT outcome. For example, in a short-term FMT pilot trial on 18 middle-aged men with metabolic syndrome, FMTs from lean donors (allogenic FMT) were found to correspond with a 75% increase in insulin sensitivity and a greater diversity of intestinal bacteria in the recipient compared to autologous FMTs (recipient-derived). It was later noted that the patients who experienced a more robust improvement of insulin sensitivity post-FMT had all been in receipt of the same donor. In a subsequent study on 38 Caucasian men with metabolic syndrome, lean donor FMT also resulted in a significant improvement in peripheral insulin sensitivity at 6 weeks. However, this effect was lost by the 18 week follow up. For the allogenic FMT, 11 lean donors were used, seven of which were used for more than one recipient. Whilst donor-dependent effects were not reported, the authors noted that the “multiple fecal donors might explain the transient and variable effects seen in the allogenic group.” As FMT research in this field progresses from small-scale case series to larger-scale randomized placebo controlled clinical trials, it remains to be seen whether the super-donor phenomenon generalizes to other conditions outside of IBD.

Abandoning the “One Stool Fits All” Approach

Microbial dysbiosis is a blanket term for an unhealthy or imbalanced gut community. As such, the population structure that is considered to represent microbial dysbiosis is variable between different disorders. Moreover, the microbiome deficit of one individual may not necessarily mirror that of another individual and therefore it is not surprising that patients respond differently to FMT. As more FMT-related clinical and microbial data are generated, it is becoming clear that “one stool does not fit all” in the context of treating chronic diseases with microbial dysbiosis. Equally so, the selection of donors based solely on clinical screening guidelines provides no guarantee of FMT success. It appears a patient's response to FMT predominantly depends on the capability of the donor's microbiota to restore the specific metabolic disturbances associated with their particular disease phenotype. If this is true, a donor-recipient matching approach, where a patient is screened to identify the functional perturbations specific to their microbiome, may be the best way forward. The patient could then be matched to a specific FMT donor known to be enriched in taxa associated with the metabolic pathway that needs to be restored. Immune tolerance screening would also be beneficial for reducing the impact of donor-recipient incompatibilities stemming from underlying differences in innate immune responses.

Framework for rational donor selection in fecal microbiota transplant clinical trials

Early clinical successes are driving enthusiasm for fecal microbiota transplantation (FMT), the transfer of healthy gut bacteria through whole stool, as emerging research is linking the microbiome to many different diseases. However, preliminary trials have yielded mixed results and suggest that heterogeneity in donor stool may play a role in patient response. Thus, clinical trials may fail because an ineffective donor was chosen rather than because FMT is not appropriate for the indication. Here, we describe a conceptual framework to guide rational donor selection to increase the likelihood that FMT clinical trials will succeed. We argue that the mechanism by which the microbiome is hypothesized to be associated with a given indication should inform how healthy donors are selected for FMT trials, categorizing these mechanisms into four disease models and presenting associated donor selection strategies. We next walk through examples based on previously published FMT trials and ongoing investigations to illustrate how donor selection might occur in practice. Finally, we show that typical FMT trials are not powered to discover individual taxa mediating patient responses, suggesting that clinicians should develop targeted hypotheses for retrospective analyses and design their clinical trials accordingly. Moving forward, developing and applying novel clinical trial design methodologies like rational donor selection will be necessary to ensure that FMT successfully translates into clinical impact.

Association Between the Clinical Efficacy of Fecal Microbiota Transplantation in Recipients and the Choice of Donor

Objective: To examine the association between the clinical efficacy of fecal microbiota transplantation (FMT) in recipients and the choice of donor, and to observe the characteristics of intestinal flora and metabolites among different donors. 

Methods: A retrospective case-control study was conducted. Donor whose feces was administrated for more than 30 recipients was enrolled. Data of 20 FMT donors and corresponding recipients at Intestinal Microecology Diagnosis and Treatment Center of the Tenth People's Hospital from October 2018 to December 2019 were collected retrospectively.

During follow-up, the efficacy of each recipient 8-week after FMT treatment was recorded and analyzed. Based on the efficacy of each donor, the donors were divided into three groups.Association of the efficacy of each donor group with the morbidity of complications, and association of efficacy of recipients with donors were analyzed. The evaluation indicators of FMT efficacy included objective clinical effectiveness and/or subjective effectiveness. Objective effectiveness indicated clinical cure plus clinical improvement, and subjective effectiveness indicated marked effectiveness plus medium effectiveness through questionnaire during follow-up. 

Results: A total of 1387 recipients were treated by 20 donors, including 749 cases of chronic constipation, 141 cases of chronic diarrhea, 107 cases of inflammatory bowel disease (IBD), 121 cases of irritable bowel syndrome (IBS), 83 cases of autism, and 186 cases of other diseases, such as radiation bowel injury, intestinal pseudo-obstruction, paralytic intestinal obstruction, functional bloating and allergic diseases. There were 829 cases, 403 cases, and 155 cases in high efficacy group, moderate efficacy group and low efficacy group respectively. Baseline data among 3 groups were not significantly different (all P> 0.05).

In comparison of bacterial abundance (operational taxonomic unit, OTU) among different effective donor groups, the high efficacy group was the highest (330.68±57.28), the moderate efficacy group was the second (237.79±41.89), and the low efficacy group was the lowest (160.60±49.61), whose difference was statistically significant. 
In comparison of butyric acid content among three groups, the high efficacy group had the highest [(59.20±9.00) μmol/g], followed by middle efficacy group [(46.92±9.48) μmol/g], and the low efficacy group had the lowest [(37.23±5.03) μmol/g], whose difference was statistically significant (F=10.383, P=0.001). The differences of acetic acid and propionic acid among three groups were not statistically significant (all P>0.05). A total of 418 cases developed complications (30.1%). Morbidity of complication in low efficacy group, moderate efficacy group and high efficacy group was 40.6% (63/155), 30.0% (121/403) and 28.2% (243/829) respectively, and the difference was statistically significant (χ(2)=9.568, P=0.008). The incidence of diarrhea in low efficacy group, moderate efficacy group and high efficacy group was 7.1% (11/155), 4.0% (16/403) and 2.8% (23/829) respectively, and the difference was statistically significant (χ(2)=7.239, P=0.027). Comparing the incidences of other types of complications, no statistically significant differences were found (all P>0.05). Follow up began 8 weeks after the FMT treatment. The total follow-up rate was 83.6% (1160/1387). The overall effective rate 58.3% (676/1160). Effective rates of various diseases were as follows: chronic constipation 54.3% (328/604), chronic diarrhea 88.5% (115/130), IBD 56.1% (55/98), IBS 55.1% (59/107), autism 61.6% (45/73), and other diseases 50.0% (74/148). Comparing the effective rate of three groups of donors for different diseases, there was no statistically significant difference in chronic diarrhea (P>0.05); there was a positive correlation trend in IBD, IBS and autism, but the differences were not statistically significant (all P>0.05). For chronic constipation and other diseases, high efficacy group had the highest effective rate [65.0% (243/374) and 63.2% (55/87)], followed by moderate efficacy group [49.4% (86/174) and 38.1% (16/42)], and low efficacy group had the lowest [16.1% (9/56) and 15.8% (3/19)], whose differences were significant (all P

Conclusions: Different donors have different efficacy in different diseases. Chronic constipation, radiation bowel injury, etc. need to choose donors with high efficacy. IBD, IBS and autism may also be related to the effectiveness of donors, while chronic diarrhea is not associated to the donor. The efficiency of the donor is negatively correlated to the morbidity of complications. The abundance and diversity of intestinal flora and the content of butyric acid may affect the efficacy of the donor.

Conclusion

FMT in practice today does look rather primitive, but seems to be beneficial more than half of the time, even in autism in the Chinese study.

As expected, different donors have different efficacy in different diseases.  As FMT becomes more popular you would expect that more super-donors will be stumbled upon and then clinicians will have a better chance to match the donor to the recipient.

For certain GI conditions that do not respond well to current drug therapy, FMT does look a good option to investigate.  The level of success is likely to vary depending on the availability and selection of the donor.

It does seem that orally ingested bacteria in the form of probiotics often do not colonize the gut as hoped for, and just past straight through, with only a limited and transient effect.  The fact that FMT can have a very long-lasting effect is remarkable and likely due to the fact that these bacteria are direct from another human.

Modifying the microbiome is only now emerging as a treatment idea and it will take many decades to fully develop it.

Ingesting a mix of another human’s bacteria is not without risk.  

Massachusetts General Hospital oversaw trial that led to the first death from a fecal transplant, a new paper shows

This spring, a 73-year-old man with a rare blood condition became the first person to die from drug-resistant bacteria found in a fecal transplant. New details about that unprecedented incident emerged on Wednesday.

The man was a participant in a clinical trial run at Massachusetts General Hospital and received fecal transplant capsules made in November with fecal material from one stool donor, according to a paper published Wednesday in the New England Journal of Medicine. Tests after the man’s death revealed that material contained a rare type of E. coli bacteria.

FMT seems to be becoming fashionable, with all kinds of people offering it.  The American Journal of Gastroenterology even published a study on Do-it-Yourself FMT. "Almost all indicated that they would perform DIY FMT again, though many would have preferred to have FMT in a clinical setting."  I would vote for the clinical setting and a carefully selected/screened donor. 

Dietary Autism Therapy? It clearly works for some

Diet can affect behaviour - but in some people much more so than others.

As the threshold for a diagnosis of autism, and indeed ADHD, is reduced more and more people may find a dietary solution.

Even people with a more severe neurological disorder may find dietary modification provides a benefit.

The big mistake is to think that all you can/need to do to treat disorders like autism is modify diet and pop a few vitamins and supplements.

In today’s post I grouped together causes, or contributors, to autism that fall in my “dietary” category.

• Food allergy
• Food intolerance
• Gluten related disorders
• Histamine intolerance
• Pesticides
• SIBO
• Propionic and Butyric acid (SCFAs)
• Probiotics and Fiber 
• Low Glycemic Diet
• Ketogenic Diet
• FMT/MTT
• Fragile Gut
• Pancreatic Insufficiency

I do not dwell too much on diet in this blog probably because I have one son who has always had a near perfect diet, has no GI issues, but has autism and yet my other son, with an arguably poor self-restricted diet, is healthy, again with no GI issues and is totally neurotypical. Yes, perhaps if the son with autism had the restricted diet, he would have fared worse – we will never know.

Many people with severe autism have restricted diets, somewhat reinforced by their parents wanting to keep the peace.  

People with autism are prone to auto-immune conditions and that will include food allergies (wheat, milk etc).  Restricted diets lead to a microbiome that is equally restricted. Eating large amounts of pro-inflammatory junk food (chicken nuggets, french fries, sugar (sucrose and fructose), refined carbohydrate, processed meat etc) is a poor choice for anyone, autistic or not.

Improving diet does hold potential for many with autism and/or ADHD.

You have to choose for yourself what is relevant and what is a distraction in your N=1 case.

                                                                  

Food intolerance vs Food Allergy

Food intolerance refers to difficulty in digesting certain foods. It is important to note that food intolerance is different from food allergy.
Food allergies trigger the immune system, while food intolerance does not. Some people suffer digestive problems after eating certain foods, even though their immune system has not reacted - there is no histamine response.

Foods most commonly associated with food intolerance include dairy products, grains that contain gluten, and foods that cause intestinal gas build-up, such as beans and cabbage.

Here are some key points about food intolerance.

·        Symptoms of food intolerance tend to take longer to appear than symptoms of allergies

• The symptoms are varied and can include, migraine, cough, and stomach ache
• Some food intolerance is caused by the lack of a particular enzyme

According to James Li, M.D., Ph.D., when it is an allergy, even small amounts result in symptoms, as may be the case with peanuts. Whereas, with food intolerance, tiny amounts will usually have no effect.

The symptoms of food intolerance generally take longer to emerge, compared to food allergies.

Onset typically occurs several hours after ingesting the offending food or compound and may persist for several hours or days. In some cases, symptoms may take 48 hours to arrive.

Some people are intolerant to several groups of foods, making it harder for doctors to determine whether it might be a chronic illness or food intolerance. Identifying which foods are the culprits can take a long time.

Enzyme deficiencies are a common cause of food intolerance.

People who are lactose intolerant do not have enough lactase, an enzyme that breaks down milk sugar (lactose) into smaller molecules that the body can break down further and absorb through the intestine. If lactose remains in the digestive tract, it can cause spasm, stomach ache, bloating, diarrhea, and gas.

People with an allergy to milk protein have similar symptoms to those with lactose intolerance; that is why lactose intolerant individuals are commonly misdiagnosed as allergic.

Histamine Intolerance

Many foods and drinks contain histamine.

Usually, the enzyme DAO, and to a lesser extent HNMT, breaks down ingested histamine, preventing it from being absorbed in the gut and entering the bloodstream.  Within the brain histamine acts as a neurotransmitter.

Some factors can interfere with how DAO and HMNT work, or how much of these enzymes are present in the gut.

The common food additive Sodium Benzoate (E211) is a DAO-inhibitor. It is widely used in carbonated drinks, jams, fruit juice, pickles and condiments.  Someone who is histamine intolerant will need to learn to avoid such foods.

Other common factors that interfere with DAO and HMNT levels include many prescription drugs, for example:

• airway medications, such as theophylline
• heart medications
• antibiotics
• antidepressants
• antipsychotics
• diuretics
• muscle relaxants
• pain medications
• gastrointestinal medicines
• nausea and gastroesophageal reflux disease, GERD
• malaria drugs
• tuberculosis medications

  

Pesticides

I think it is hardly surprising that pesticides can affect a developing brain, just like the lead that used to be added to petrol/gasoline.

The key time to avoid pesticides and toxic chemical is during pregnancy and early childhood.

Once you have got autism with MR/ID, it is probably rather late to worry about a small risk from a tiny exposure to pesticides from supermarket fruit and vegetables.

Early exposure to pesticides linked to small increased risk of autism spectrum disorder

Exposure to common agricultural pesticides before birth and in the first year of life is associated with a small to moderately increased risk of autism spectrum disorder (ASD) compared with infants of women without such exposure, finds a study published in The BMJ today.

The researchers say their findings support efforts to prevent exposure to pesticides during pregnancy to protect a child's developing brain.

Experimental studies have suggested that common pesticides can affect normal brain development, and environmental exposures during early brain development are suspected to increase risk for autism spectrum disorders in children.

But studies examining pesticide exposure in the real world and risk of ASD are rare.

So, researchers at the University of California used registry records to identify 2,961 patients with a diagnosis of ASD -- including 445 with ASD with accompanying intellectual disability -- and 35,370 healthy ("control") patients of the same birth year and sex.

Participants were born between 1998 and 2010 in California's Central Valley, a heavily agricultural region, and 80% of cases were male.

Data from the California state-mandated Pesticide Use Registry were then integrated into a geographic information system tool to assess prenatal (before birth) and infant exposures to 11 commonly used pesticides (measured as pounds of pesticides applied per acre/month within 2 km of their mother's residence during pregnancy and exposure during developmental periods defined as yes vs no).

These pesticides were selected because of their high use and evidence indicating toxic effects on brain development.

After adjusting for potentially influential factors, the researchers found modest increases in ASD risk among offspring exposed to several pesticides (including glyphosate, chlorpyrifos, diazinon, malathion, permethrin, bifenthrin and methyl-bromide) before birth and during the first year of life, compared with controls.

Associations were strongest in those with ASD and intellectual disability, which represents the more severe end of the autism spectrum.

This is an observational study, and as such, can't establish cause, and the researchers point to some limitations, such as relying on patient records for details about diagnoses, and being unable to examine clinical outcomes.

Nevertheless, they say their study is by far the largest investigating pesticides and autism spectrum disorder to date and their findings back up earlier work in this field.

"Our findings suggest that ASD risk may increase with prenatal and infant exposure to several common ambient pesticides that impacted neurodevelopment in experimental studies," they write.

They call for further research to explore underlying mechanisms in the development of autism. However, from a public health and preventive medicine perspective, they say their findings "support the need to avoid prenatal and infant exposure to pesticides to protect the developing child's brain."

Gluten Free?

One long-known feature of autism is the loss of Purkinje cells, these cells are involved in motor skills and this probably contributes to clumsiness and poor handwriting in many people with autism. For good motor skills you need plenty of Purkinje cells, with plenty of myelin coating their axons.

An extreme cause of Purkinje cell loss in some people is a reaction to gluten, mainly in those with Celiac Disease (CD).  The process is not fully understood but results in antibodies selectively destroying Purkinje cells and leading to a condition called Cerebellar Ataxia.

People sensitive to gluten, but not having Celiac disease, may also experience some ataxia as well as a wide range of auto-immune disorders that can include psychiatric manifestations.

I think a small number of people with autism do have non celiac gluten sensitivity (NCGS).  Those people should feel better on a gluten free diet.  A small number of people with severe autism may have undiagnosed Celiac disease.

Gluten related disorders

Gluten-related disorders is the term for the diseases triggered by gluten, including celiac disease (CD), non-celiac gluten sensitivity (NCGS), gluten ataxia, dermatitis herpetiformis (DH) and wheat allergy. The umbrella category has also been referred to as gluten intolerance. 

If you have one of the above conditions then avoid gluten.

If you do not have one of the above conditions, you are in the great majority and there is no point spending extra money to avoid gluten.

There is no reliable data, but an estimate is that 10-15% of people have some kind of gluten related disorder.

It is not surprising that a minority of people with autism respond to a gluten free diet, but the majority do not.  Your N=1 case of autism could fall in either camp.

 Source:- Dr Schär AG

Cerebellar Ataxia, Celiac Disease and Non-Celiac Gluten Sensitivity

Cerebellar ataxia (CA) is one of the most frequent neurological manifestations related to celiac disease (CD) (1), and may be the only and initial clinical manifestation of this disease (2) without any association with gastro-intestinal symptoms or malabsorption signs.

Gluten ataxia is purely cerebellar and involves the entire cerebellum (9). The clinical signs of CA are gait ataxia, limb ataxia, dysarthria, pyramidal signs, altered eyes motions, and progressive impairment of stability and erect position

The prolonged gluten consumption in patients with gluten ataxia leads to a progressive loss of Purkinje cells in the cerebellum. Patients with celiac disease and CA have a blood deficit of vitamin E

Non celiac gluten sensitivity (NCGS) is defined by clinical evidence of improvement of symptoms, following the introduction of GFD in the absence of enteropathy (22). Autoantibodies, such as TG2, are absent in NCGS. The presence of Anti Gliadin Antibodies (AGA) and particularly IgG AGA may be an indicator of NCGS in more than 50% of patients that refer to the gastroenterologist (23). Hadjivassiliou et al. (15) reported on 114 patients with NCGS and gluten ataxia (GA), 68 of which had circulating TG6 antibodies.

An early diagnosis of CA and gluten related disorders (GRD) increases the possibility to improve the neurological process (8); the clinical improvement is usually seen 1 year after starting the GFD (9) and continues for a period of about 2 years.

Cerebellar Ataxia is equally responsive to GFD in CD and NCGS patients.

Extra-intestinal manifestations of non-celiac gluten sensitivity: An expanding paradigm

Non celiac gluten sensitivity (NCGS) is a syndrome characterized by a cohort of symptoms related to the ingestion of gluten-containing food in subjects who are not affected by celiac disease (CD) or wheat allergy. The possibility of systemic manifestations in this condition has been suggested by some reports. In most cases they are characterized by vague symptoms such as ‘foggy mind’, headache, fatigue, joint and muscle pain, leg or arm numbness even if more specific complaints have been described. NCGS has an immune-related background. Indeed there is a strong evidence that a selective activation of innate immunity may be the trigger for NCGS inflammatory response. The most commonly autoimmune disorders associated to NCGS are Hashimoto thyroiditis, dermatitis herpetiformis, psoriasis and rheumatologic diseases. The predominance of Hashimoto thyroiditis represents an interesting finding, since it has been indirectly confirmed by an Italian study, showing that autoimmune thyroid disease is a risk factor for the evolution towards NCGS in a group of patients with minimal duodenal inflammation. On these bases, an autoimmune stigma in NCGS is strongly supported; it could be a characteristic feature that could help the diagnosis and be simultaneously managed. A possible neurological involvement has been underlined by NCGS association with gluten ataxia, gluten neuropathy and gluten encephalopathy. NCGS patients may show even psychiatric diseases such as depression, anxiety and psychosis. Finally, a link with functional disorders (irritable bowel syndrome and fibromyalgia) is a topic under discussion. In conclusion, the novelty of this matter has generated an expansion of literature data with the unavoidable consequence that some reports are often based on low levels of evidence. Therefore, only studies performed on large samples with the inclusion of control groups will be able to clearly establish whether the large information from the literature regarding extra-intestinal NCGS manifestations could be supported by evidence-based agreements.

SIBO

Small intestinal bacterial overgrowth (SIBO) is a serious condition affecting the small intestine. It occurs when bacteria that normally grow in other parts of the gut start growing in the small intestine. That causes pain and diarrhea. It can also lead to malnutrition as the bacteria start to use up the body’s nutrients.

If you have severe autism and live in rural China the study below suggests you have a 50:50 chance of having SIBO. 

SIBO is measurable and treatable using mainstream medicine.

Don’t treat SIBO, if you do not have SIBO.

Hydrogen breath test to detect small intestinal bacterial overgrowth: a prevalence case- in autism.

 

The aim of this study is to assess the prevalence of small intestinal bacterial overgrowth (SIBO) by hydrogen breath test in patients with autism spectrum disorders (ASD) with respect to a consistent control group. From 2011 to 2013, 310 children with ASD and 1240 sex- and age-matched typical children were enrolled in this study to undergo glucose breath test. The study participants were considered to exhibit SIBO when an increase in H₂ of ≥20 ppm or CH₄ of ≥10 ppm with respect to the fasting value was observed up to 60 min after the ingestion of glucose. Ninety-six children with autism suffered from SIBO, giving a prevalence rate of SIBO was 31.0% (95% CI 25.8-36.1%). In contrast, 9.3% of the typical children acknowledged SIBO. The difference between groups was statistically significant (P < 0.0001). The median Autism Treatment Evaluation Checklist (ATEC) score in the children with autism and with SIBO was significantly high when compared with the children without autism and without SIBO [98 (IQR, 45-120) vs. 63 (32-94), P < 0.001]. For the autism group, the 6-GI Severity Index (6-GSI) score was found to be strongly and significantly correlated with the total ATEC score (r = 0.639, P < 0.0001). SIBO was significantly associated with worse symptoms of autism, demonstrating that children with SIBO may significantly contribute to symptoms of autism.

Diarrhea was the most common SIBO symptom (71.0% of ASD patients), followed by abdominal pain (37.1%), and abnormal feces (30.0%). Children with autism and with SIBO were more likely from the rural area.

Furthermore, we found that SIBO was associated with worse symptoms of autism. However, it is difcult to establish whether the changes seen play a causative role or are merely a consequence of the disease. Interestingly, the effectiveness of oral, non-absorbable antibiotics in temporarily reducing symptoms of autism [28] suggests that the relationship may be causal, that is, we hypothesize that SIBO may significantly contribute to symptoms of autism in some children. Several possible mechanisms can be inferred. First, propionate has severe neurological effects in rats and Clostridia species are propionate producers. Studies by MacFabe et al. [29] have demonstrated that injecting propionate directly into specific regions of rat brains in vivo can cause significant behavioral problems. Second, differences in the microbiota may also result in altered microbial metabolism of aromatic amino acids, with consequent changes in systemic metabolites (as reflected in urinary metabolite profiles), which could lead to neurological symptoms [30]. Third, the microbiota could also be involved in the disease etiology via interactions with the immune system [31]. Some of the possible mechanisms outlined above are more likely to involve changes within the overall balance of the whole microbial community, while others may be exerted by specific bacteria. Fourth, SIBO leads to steatorrhea, vitamin B12 absorptive impairment and also injury to the small intestinal microvilli which itself causes malabsorption [32]. Zhang et al. [33] suggested that decrease in brain vitamin B12 status across the lifespan that may reflect an adaptation to increasing antioxidant demand, while accelerated deficits due to GSH deficiency may contribute to neurodevelopmental and neuropsychiatric disorders. Finally, many pathogenic Gram-negative bacteria contain lipopolysaccharide (LPS) in their cell walls, which can cause damage in various tissues including the brain [3]. LPS-induced inflammation in the brain increases permeability of the blood–brain barrier and facilitates an accumulation of high levels of mercury in the cerebrum, which may aggravate ASD symptoms.

 

SIBOTreatment Options

There are different levels and types of SIBO. These distinctions matter when determining the most appropriate treatment. Depending on the extent of your condition, treatment may vary. 

·         hydrogen-predominant SIBO: The primary treatment is the antibiotic rifaximin.

·         methane-predominant SIBO: This type of SIBO is harder to treat, and it may take longer to respond to treatment. Use rifaximin plus neomycin for these cases.

·         recurrent SIBO: formulations of antimicrobial herbs can be used to treat recurrences and as an alternative for initial treatment of hydrogen- or methane-predominant SIBO.

As part of treatment follow a FODMAP (low fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet.

People taking acid reducing drugs for reflux/GERD/GORD might note that PPI-induced dysbiosis is considered a type of SIBO.  PPIs are proton pump inhibitors like Nexium that are now more popular than Histamine H2 blockers like Zantac/Ranitidine.

Interestingly apple cider vinegar (ACV) can counter  PPI-induced dysbiosis. Your small intestines need some acid. Your body relies on Sodium bicarbonate released by the pancreas to maintain pH levels, but it can only reduce acidity, not increase it. I imagine a swig of anything acidic would likely have a similar effect, although ACV has non acid-related effects.

If it is SIBO, get a genuine diagnosis, treat it and avoid it reoccurring

Propionic and Butyric Acids and SCFAs (Short Chained fatty Acids)

SCFAs are produced when dietary fiber is fermented in the colon. Acetate, propionate, and butyrate are the three most common SCFAs.

Avoid dysbiosis in your colon

You need fiber and butyrate-producing bacteria for a healthy colon.

Epithelial metabolism shapes the colonic microbiota.

Left: During gut homeostasis, obligate anaerobic bacteria convert fiber into fermentation products (butyrate) to maintain the epithelium in a metabolic state characterized by high oxygen consumption. This metabolic polarization of differentiated colonocytes (C2) maintains epithelial hypoxia (<1 oxygen="" span="" style="background: yellow; mso-highlight: yellow;" to="">limit the amount of oxygen (O

₂) diffusing into the gut lumen. Right: A metabolic reorientation of terminally differentiated colonocytes toward low oxygen consumption (C1) increases the concentration of respiratory electron acceptors (O₂ and NO₃^–) emanating from the epithelial surface, thereby causing a shift in the microbial community from obligate to facultative anaerobic bacteria. The color scale at the bottom indicates O₂ levels. SC, stem cell; TA, undifferentiated transit-amplifying cell; C2, terminally differentiated C2-skewed colonocyte; C1, terminally differentiated C1-skewed colonocyte; GC, goblet cell; NO, nitric oxide.

Source:- Colonocyte metabolism shapes the gut microbiota

Propionic acid leads to PTEN↓ Inflammation↑ Gliosis↑ Mitochondrial dysfunction ↑

We saw in an earlier post that propionic acid is used to cause reversible autism in a mouse model. When propionic acid is infused directly into rodents' brains, it produces reversible behaviors (e.g., hyperactivity, dystonia, social impairment, perseveration) and brain changes (e.g., innate neuroinflammation, glutathione depletion). In the mouse model, you just feed them some NAC and they switch back to regular happy mice.

We now know the details of what is happening to those mice.  To a lesser extent if you produce a lot of propionic acid in your human gut some may well make it to your brain and produce a similar effect.

High prevalence of self‐reported autism spectrum disorder in the Propionic Acidemia Registry

Propionic Acidemia (PA) is an inborn error of metabolism caused by mutations in propionyl‐CoA carboxylase (PCC). The disease is characterized by the systemic accumulation of propionic acid (PPA) and its toxic derivatives. Children with PA are at high risk of developing low muscle tone, cardiomyopathy, neutropenia, pancreatitis, and ultimately death.PA also has neurological manifestations that include a high risk of seizures and stroke, and a wide range of chronic psychological and cognitive sequelae, with intellectual disability and language impairments being the most frequently reported.

We know that in autism increasing PTEN is generally a good thing. Gliosis includes things like activating the brains immune cells (microglia) which we know is bad.

Propionic Acid Induces Gliosis andNeuro-inflammation through Modulation of PTEN/AKT Pathway in Autism Spectrum Disorder

PPA is believed to cause systematic mitochondrial dysfunction (MD), as evidenced by increased free acyl-carnitine (cofactor used to transport long-chain and very-long-chain fatty-acids into the mitochondria) in rats exposed to PPA16.

PPA promotes gliosis and Pro-Inflammatory cytokines release

PTEN was reported to regulate radial glia cell proliferation in the early stages of neural development through inhibition of Akt pro-survival pathway26. Recent studies reported that PTEN is downregulated in autistic glial cells26^,27, however, what triggers PTEN inhibition in ASD remains uncertain. In this study, data suggest that PPA binding to its receptor may lead to GPR41-induced PTEN inhibition, thereof allowing Akt survival pathway to proceed. As we demonstrated in Fig. 5, PPA seems to tamper with both PTEN and activated p-Akt levels. PTEN expression decreased with increased PPA concentration and vice versa for p-Akt. Noteworthy, PPA interfered with the amount of activated p-Akt but not Akt expression. This result further validates that PPA has no direct effect on Akt expression but rather downregulates PTEN expression. Consequently, this allows p-Akt to remain active which results in over-proliferation of glia-committed neural progenitor cells.

There are many studies on this subject and the one below is from December 2019.

The Probiotics and Fructo-Oligosaccharide Intervention Modulate Gut Microbiome, Short-Chain Fatty Acids and a Hyper-Serotonergic State in Children with ASD

Background: Autism spectrum disorders (ASD) prevalence is increasing, but its etiology remains elusive and its satisfactory effective treatment is not available. The microbiota-gut-brain axis can contribute to ASD pathology and may supply an effective and promising way for ameliorating the ASD symptoms. Herein, we explore the differences of the gut microbiota profiles, fecal short-chain fatty acids (SCFAs) and peripheral neurotransmitters between ASD children and typical development children, and whether the probiotics + fructo-oligosaccharide (FOS) intervention alters the gut microbiota profiles, SCFAs and neurotransmitters in ASD children.

Methods: This study was divided into two stages. At the discovery stage, we compared the difference of the gut microbiota profiles (using 16S rRNA sequencing), faecal SCFAs (using GC-MS) and plasma neurotransmitters (using UHPLC-MS/MS) between 26 ASD children and 24 TD children. Then, all the 26 ASD children participated into the intervention stage, and we measured the gut microbiota profiles, SCFAs and neurotransmitters at before and after probiotics + FOS (n = 16) or placebo supplementation (n = 10) for ASD children.

Findings: Firstly, the gut microbiota were in a state of dysbiosis and significantly lower levels of Bifidobacteriales and Bifidobacterium longum in ASD subjects found at the discovery stage. Compared with TD children, the significantly lower levels of acetic acid, propionic acid, and butyric acid, and a hyperserotonergic state (the increased 5-HT) and dopamine metabolism disorder (the decreased homovanillic acid) were observed in ASD children. Secondly, the increasing growth of beneficial bacteria (Bifidobacteriales and B. longum) and suppressing the growth of suspected pathogenic bacteria (Clostridium) emerged after the probiotics + FOS intervention, with significant improvements in the severity of autism (assessed by the ATEC), and gastrointestinal symptoms (assessed by the 6-GSI). With probiotics + FOS intervention, the above SCFAs in children with autism significantly elevated and approached to that of the typical development children. However, the levels of concentrations in fecal isobutyric acid and caproic acid after probiotics + FOS intervention were markedly higher than TD children, and the plasma zonulin downregulation as an intestinal permeability marker. Interestingly, our data demonstrated that the decreased 5-HT and 5-hydroxyindolacetic acid, as well as the increased kynurenine and homovanillic acid emerged after probiotics + FOS intervention. Our analysis of Spearman's rank correlation showed that Clostridium were significantly positive associated with 5-HT. However, the above-mentioned changes did not show in the placebo group for ASD children.

Interpretation: Our data suggest that gut microbiome is closely correlated with SCFAs and some neurotransmitters. The probiotics + FOS intervention can modulate the gut microbiome, SCFAs and some neurotransmitters in association with improved ASD symptoms, including a hyper-serotonergic state and dopamine metabolism disorder.                                         

Medical Food (Probiotics) from one end and FMT from the other

There is some very clever research that will lead to medical food, containing specific bacteria, as a means of promoting specific chemical reactions in your gut, which then effect other parts of your body.

In earlier posts we saw how you could mimic the effect of the ketogenic diet in reducing seizures by using medical food.

The Gut Microbiota Mediates the Anti-Seizure Effects of the Ketogenic Diet

We saw how one kind of childhood leukaemia can be prevented by taking a particular bacteria in medical food or yoghurt.

Missing microbes 'cause' childhood cancer

But Prof Greaves adds: "The most important implication is that most cases of childhood leukaemia are likely to be preventable." 

His vision is giving children a safe cocktail of bacteria - such as in a yoghurt drink - that will help train their immune system. 

Even some expensive drugs have been found to be effective only in the presence of specific gut bacteria.  So, alongside the drug give that bacteria?

Local bacteria affect the efficacy of chemotherapeutic drugs

Of 30 drugs examined in vitro, the efficacy of 10 was found to be significantly inhibited by certain bacteria, while the same bacteria improved the efficacy of six others

Conceivably, there is potential for direct interaction between systemically administered drugs at various body sites in the course of infection or in the case of orally administered drugs and microbiota of the small intestine.

In conclusion, our data bring attention to the fact that internal bacteria can interact with a drug therapy and could under certain circumstances influence treatment efficacy and/or side effects.

The microbiota comes from the mother and ideally involves natural delivery and mother’s milk.

Early use and overuse of antibiotics will disrupt the microbiota.

The body’s immune system is calibrated very early in life, if mis-calibrated it will over/under-react for the rest of your life.  Early exposure to bacteria is part of the calibration process, this is why having a pet indoors during pregnancy reduces the chance of a child having allergies. Also, good to be exposed to the other animals’ humans have evolved alongside (domesticated farmyard animals).

This takes us back to the idea of the Halogenone/Holobiont.

Secretome,Microbiome/Hologenome, Proteome, Epigenome, Exome and Genome

 This can be summed up as give your body the bugs it evolved to expect, or don’t be surprised when things start going wrong (aberrant immune responses etc).

FMT/MTT

Another way of colonizing your gut with beneficial bacteria is repopulate it with someone else’s, so called microbiota transfer therapy (MTT), better known as fecal microbiota therapy (FMT) or more simply a poop transplant (PT, I suppose).

Trials show that taking probiotics orally often has little impact on what is growing in your gut.  The effect is often short term and the new bacteria do not colonize their new host.

The idea of taking someone else’s feces/poo and inserting into a child with GI problems and autism may not sound very high tech, but in small trials it has shown to be beneficial.

Clearly there is potential to transfer things that might not be beneficial.

In the end I think someone will develop a synthesized lab-made product containing the many billions of “good” bacteria.  Ultimately this could be a personalized medical product, tailored to the individual needs of the patient.

Autism symptoms reduced nearly 50 percent two years after fecal transplant

In a new study, researchers demonstrate long-term beneficial effects for children diagnosed with ASD through a revolutionary fecal transplant technique known as microbiota transfer therapy (MTT).

"It is very unusual to see steady gradual improvement after the conclusion of any treatment," said Adams. "We only conducted the long-term follow-up study after several families told us that their child was continuing to improve significantly." Krajmalnik-Brown stated that the data suggests that the MTT intervention transformed the gut environment into a healthier status, leading to long-term benefit on both GI and ASD symptoms.

Does this only work in people with autism who have GI symptoms? I would suspect it does, but would like to see some evidence.

Low Glycemic Diet

Hypoglycemia is low blood sugar that can cause headaches, weakness, and anxiety. Hyperglycemia refers to high levels of sugar, or glucose, in the blood.

Low blood sugar (hypoglycemia) can also mimic the symptoms of ADHD. Hypoglycemia in children may cause uncharacteristic aggression, hyperactivity, the inability to sit still, and the inability to concentrate. 

High blood sugar (hyperglycemia) also negatively affects behavior.

Eating foods with a low Glycemic Index (GI) avoids spikes in blood sugar.  Your body responds to blood glucose spikes by producing more insulin.  This kind of diet is used by people with diabetes, but is actually good for everyone.

Anecdotal evidence from comments in this blog and elsewhere does give some support for this diet in humans.  We also now have some scientific research that also looks inside the brain.

Low glycemic index diet reduces symptoms of autism in mice

The number of people diagnosed with autism - a spectrum of disorders characterized by social avoidance, repetitive behaviors and difficulty communicating - has risen dramatically over the past two decades for reasons that are unclear. A diet recommended for diabetics ameliorated signs of autism in mice, researchers have found. Although preliminary and not yet tested in humans, the findings might offer clues to understanding one potential cause of autism.

Intriguingly, in the new study, the brains of mice modeling autism that were fed the high-glycemic index diet had drastically less doublecortin, a protein indicator of newly developing neurons, compared to predisposed mice on the low-glycemic index diet. The deficiency was especially obvious in a part of the brain that controls memory.

In addition, the brains of the high-glycemic index diet mice appeared to have greater numbers of activated microglia, the resident immune cells of the brain. Their brains also expressed more genes associated with inflammation, compared to the mice fed the low-glycemic index diet.

Other studies of human mothers and their children with autism have implicated the activation of the immune system. For the most part, these studies have focused on infection, which causes a bout of inflammation -- as opposed to a high-glycemic index diet, which causes chronic, low-level inflammation, Maher says.

The new study found that the diet might directly influence the ecosystem of bacteria in the gut. More complex starches are broken down by bacteria that live in the lower part of the gut, the large intestine. The group saw some evidence of that in the blood, detecting metabolites that could only have come from the gut in larger amounts in the animals fed the high-glycemic index diet.

'We were really surprised when we found molecules in the blood that others had reported could only be generated by gut bacteria,' Maher says. 'There were big differences in some of these compounds between the two diets.'

The Ketogenic Diet

I think the Ketogenic Diet (KD) is the cleverest diet because it will genuinely help a small number of people, but for entirely different reasons.

We saw that in people with seizures, the beneficial effect does not come from ketones, it comes from the high fat diet changing the microbiome and causing different bacteria to thrive. The researchers at UCLA then showed how this effect final reaches the brain where it affects GABA and Glutamate levels, and so prevents epileptic seizures.

In some people with a problem transporting glucose across the blood brain barrier (as in Alzheimer’s) or a problem with converting that glucose into ATP in mitochondria (someone with mitochondrial disease) the ketone BHB becomes an alternative fuel for cells.  These people would benefit from the ketones produced naturally in your body, when you follow the high fat Ketogenic Diet.  

Pancreatic Insufficiency

Pancreatic insufficiency is actually one of the few things I did actually test for a few years ago.

It has been suggested that some people with autism cannot digest proteins properly and that this results in a lack of amino acids that are needs to produce neurotransmitters and build other new proteins.

This might occur if the pancreas was not doing its job of producing the required digestive enzymes.  The medical term is pancreatic insufficiency.

Almost 10 years ago a special digestive cocktail called CM-AT was entering the “final stage of testing”.  It is still being tested.

The developer of CM-AT initially suggested that a biomarker existed for responders.  They wanted to use chymotrypsin as a measure of pancreatic function. This test is an old one and in children is best known for cystic fibrosis.

Many other conditions lead to pancreatic insufficiency. It can be caused by pancreatitis, other causes of insufficiency may include celiac disease, Crohn disease, Zollinger-Ellison syndrome and Shwachman-Diamond Syndrome (SDS). I guess any condition causing too much stomach acid would also lead to pancreatic insufficiency (that is what Zollinger-Ellison syndrome does). What about just “Fragile Gut”, which seems common in autism?

First evidence on Chymotrypsin:-

Chymotrypsin : Evidence of a Novel Pancreatic Insufficiency in Children with ASD?

Background:

Emerging research has suggested that some children with ASD appear to be at high risk for gastrointestinal concerns. It has also been noted that many children with ASD have diets that are highly self- selective, e.g., having a preference for carbohydrates. Although it remains unclear what the basis for GI disruption is, it may be the case that some children with ASD have insufficient levels of digestive enzymes needed to process some food types, e.g., protein. If a child has this deficiency, they cannot optimally digest a class of food (e.g., protein), their food avoidance may be related to unpleasant sequelae associated with its ingestion (e.g., under-digested meat feeling like “lead shot” in the stomach). The enzyme chymotrypsin digests protein into its component amino acids. Amino acids, especially essential amino acids, play a crucial role in the production of neurotransmitters (e.g., dopamine and serotonin), are regulators of gene expression, and form the building blocks for new proteins.

Objectives:

The objectives of this study were: 1) determine the prevalence of abnormal levels of the enzyme fecal chymotrypsin (FCT) in children with autism, and 2) to determine whether FCT levels are associated with severity of autistic symptomatology.

Methods:

Participants were 323 children between the ages of 3 and 8 years (261 boys; mean age: 5.8 yrs.) who met DSM-IV criteria for Autistic Disorder, as screened by the Social Communication Questionnaire (SCQ) and confirmed by Autism Diagnostic Interview-Revised (ADI-R) and clinical interview. FCT levels were assessed using photometric assay of stool samples (performed by Quest Diagnostics); FCT levels ≤ 12.6 U/g are considered abnormally/pathologically low. Severity of autistic symptomatology was assessed using the total score of the Social Communication Questionnaire (SCQ) and the ADI-R subscale scores.

Results:

Of the 323 children, 198 (61.3%) had abnormally low/pathological levels of FCT activity (<12.6 U/g; mean FCT level=7.34), while 38.7% had normal levels (>12.6 U/g; mean FCT level=18.92). Comparison of FCT level and autism symptom level (i.e., ADI-R subscale scores, SCQ total score) in all participants revealed no statistically significant associations between FCT level and severity of autistic symptoms. This finding suggests that lower FCT levels in children with autism are not associated with more severe autistic symptomatology.

Conclusions:

The presence of low FCT levels in a large subset of children with autism suggests that chymotrypsin deficiency may be a key feature in some children with ASD. This enzymatic deficiency may place these at higher risk for a suboptimal supply of amino acids, which may in turn possibly undermine their ability to produce neurotransmitters, regulate gene expression, and synthesize new proteins. These findings may inspire further research into the role of the pancreas and amino acid deficiency in autism, and in a broader sense, into the physiology and biochemistry of a subset of children with autism. It also provides rationale for investigating chymotrypsin replacement therapy in children with autism who exhibit FCT deficiency.

Fragile Gut in Autism

Robust vs. Fragile Gut Function in Children with ASD. (A) Robust Gut: the healthy gut displays robust digestion of proteins and simple sugars by the small intestine brush border enzymes that make these nutrients absorbable. After digestion, very few intact nutrients remain and indigestible polysaccharides (fiber) remain. This fiber is consumed by saccharolytic bacteria, which line most of the large intestine, and produce beneficial byproducts (such as short chain fatty acids). Undigested proteins or amino acids are consumed by putrefactive bacteria, which are few in number, and produce potentially harmful putrefactive metabolites that are easily detoxified. The blood and lymphatics in the villi do not directly interact with the lumen of the small intestine, preventing the interaction of antigenic food molecules with the underlying immune tissue. (B) Fragile Gut: the fragile gut of children with autism displays reduced digestive capacity. The inflammation and deterioration of the gut lining may cause reduced expression and activity of brush border disaccharidases and peptidases and greater amounts of intact simple sugars and proteinaceous substrates and less fermentable fiber. This proteinaceous substrate is consumed by the more prevalent putrefactive bacteria producing greater amounts of putrefactive metabolites, such as ammonia, phenols, and sulfides. The blood and lymphatics in the villi are in contact with the lumen due to the excessive inflammation and the undigested proteins in the intestine are able to directly pass. This process allows for interaction of antigenic proteins with immune tissue leading to an aberrant immune response and subsequent autoantibody production

Source:   Dietary Considerations in Autism Spectrum Disorders: The Potential Role of Protein Digestion and Microbial Putrefaction in the Gut-Brain Axis

   

Treatment of Pancreatic Insufficiency

Pancreatic enzymes are widely used to treat pancreatic insufficiency. A common product is Creon.

Pancreatin is used for pancreatic enzyme replacement therapy - it contains varying amounts of protease (trypsin, chymotrypsin, elasase), lipase and amylase, which help with the digestion of protein, fat and starch respectively.

In the above study it was important that there was NO correlation between lower Chymotrypsin and more severe autism.

I suspect that the best treatment is to treat “Fragile Gut” and then perhaps chymotrypsin will go back to normal all by itself.

Conclusion

There is no single therapy for autism applicable to all.  There can never be, because many hundreds, if not thousands, of dysfunctions can lead to an autism diagnosis.  You need to treat the dysfunction, not the vague observational diagnosis. 

You do not need to treat someone else's dysfunction, perhaps in vogue on Facebook, or the holistic therapist's pet dysfunction, you need to treat your specific person's actual dysfunction.

It is clear that some people, from all parts of the autism spectrum, can/do benefit from dietary intervention, but you have to match the dietary intervention to the underlying dysfunction (autism is not the dysfunction).

Buying organic chicken nuggets is unlikely to help anyone’s autism.  Stopping eating fried food might indeed do some marginal good, in some cases.

My son loves fish soups and meat-based soups, made the old-fashioned way, making a stock by boiling up the bones.  It makes very tasty soup, but it did not make autism go away. Some people apparently buy bone broth to "heal the gut".  If you regularly eat non-farmed oily fish there is no need for expensive fish oil supplements.  

Identifying any genuine food allergies, food intolerance and unusual chemical allergies/intolerances, like histamine, should reduce the occurrence of autism flare-ups/exacerbations.  Not all commercial food allergy testing is reliable, even though it might be expensive, it is just a business.  It is another case of buyer beware, like all exotic tests.

You will find anecdotes of wonderful improvement using dietary intervention, but you will struggle to find peer-reviewed clinical trials showing similar results. This just shows that only a sub-group, at most, are responders.

Only a dietary therapy that matches a genuine underlying dysfunction can be beneficial.  The same is equally true for all drug interventions for autism.

If your only therapies are dietary, you have really only scratched the surface of ways to potentially treat autism.  If you live in a country with no science-based autism MDs, you will have to do plenty of homework yourself.

For most people the best source of gut bacteria is likely a varied diet and this should be accompanied by a diet rich in fiber.

The many people with autism who have a very restricted diet and GI issues would seem the most likely to benefit from dietary interventions; but that might be stating the obvious.  Can people with severe autism, but a varied diet and no GI problems benefit from dietary intervention?  This is certainly possible and so should be considered, but looks less likely.

Commercially available probiotics range from quite potent ones that do have immunomodulatory effects, to mild ones to treat stomach upsets, to others that do very little.  Some people respond negatively to specific probiotics that might be beneficial to another person. 

Modifying the microbiome is the target of many new medical products in development.  These products are not related to GI problems, they are using the microbiome to produce chemicals in the gut that then get absorbed and act just like a drug does. A slow sustained release of such chemicals inside the gut can be more beneficial that taking a drug by mouth, or nose or vein.  Oxytocin produced in the gut is a good example.

I think dietary autism therapies require even more trial and error than pharmaceutical autism therapies.  The bigger the effort and cost, the bigger the potential placebo effect becomes.  

On the plus side, dietary therapy is easy to access, which is why it is so popular.

This post was not overly complicated, but it was long.