Autism and Non-Antibiotic Properties of Common Beta-lactam Antibiotics

If you are looking for personalized medicine, you or your doctor need to be a good detective. Not to mention you need some clues.

If you are treating a condition like autism and certain things cause a marked change in the severity of the condition, these are pretty good places to start.

In the case of our reader in Delhi, it is Beta-lactam antibiotics (penicillin, amoxicillin etc), that consistently seem to improve her son’s autism. Improvement during treatment with antibiotics is reported quite often in autism, but with all kinds of different antibiotic.  Nothing is simple.

For non-medical readers, there are several categories of antibiotics; common types including:-

·        Beta-lactams (e.g. Penicillins)

·        Macrolides (e.g. Erythromycin, Azithromycin)

·        Fluoroquinolones (e.g. Ciprofloxacin) 

·        Tetracyclines (e.g. Minocycline) 

Macrolides have already had a dedicated post about their immunomodulatory effects, which did also cover some history about Poland from Monty's homework.

Macrolide Antibiotics for Some Autism? Or better still, Azithromycin analogue CSY0073, or just Nystatin?

Beta Lactam Antibiotics

In earlier posts we came across something called glutamate transporter GLT1 (also known as EAAT2).

Glutamate is the major excitatory neurotransmitter, and is inactivated by uptake via GLT-1 (EAAT2) and GLAST (EAAT1) transporters.

Many people given the observational diagnosis of autism appear to have an underlying imbalance between excitatory and inhibitory neurotransmitters (E/I imbalance). By correcting the specific type of E/I imbalance, even profound symptoms of autism including MR/ID and epilepsy can be moderated. If you have autism and/or epilepsy tuning your E/I imbalance is likely the most important step you can take.

Some drugs increase the expression of GLT-1 and so reduce the amount of glutamate. Macrolide antibiotics are one of these drugs.

So if a person has too much glutamate and this causes/contributes to their E/I imbalance then improved behaviour while taking penicillin antibiotics, who have a simple explanation.

Since you would not want to take penicillin forever you would then look for a non antibiotic drug that also increases the uptake of Glutamate. Once such drug, Riluzole, does exist and has already been trialed on children with OCD. 

But beta-lactams have other effects, so it is not certain that GLT-1 accounts for the beneficial effect sometimes found in autism. Fortunately some researchers have assembled most previous research into a single review paper. This paper does not mention autism and does miss some things out.

Review of Antibiotic and Non-Antibiotic Properties of Beta-lactam Molecules.

There are seven categories:-

·        Antibiotic

·        Epileptogenic

·        Neuroprotective

·        Analgesic

·        Immunomodulatory

·        Anxiolytic

·        Antineoplastic

Antibiotic Effect

We all know something about bacteria. If you have a bacterial infection like an ear infection your doctor might prescribe you an antibiotic.

As well as inflaming your ear, the bacteria may well affect gene expression. We saw in a previous post that bacteria and viruses change the expression of many genes, but the study of this is in its infancy. In autism we know that many genes are miss-expressed, but this varies from person to person. So a bacteria or virus has the potential to make autism worse (e.g. PANS and PANDAS), but also better. Bacteria are not always bad.

A person whose autism responds to an antibiotic might have bacteria that are worsening his autism. This is simplest of explanation of all.

The question then is where is the bacteria? If it is an intestinal bacterium this could be proven by using an antibiotic that only works there, like Vancomycin.

Epileptogenic effects

In this review they concluded the effects relate to GABA and here we are talking about negative effects. 

penicillin is a potent epileptogenic agent = it is capable of causing an epileptic attack

“This could mean that penicillin is a competitive GABA specific antagonist, which would further explain its epileptogenic properties.”

The paper omits to point out that in some people beta-lactams protect from epileptic seizures. The effect on Glutamate is likely at least sometimes what stops seizures.

Beta-Lactam Antibiotics as A Possible Novel Therapy for Managing Epilepsy and Autism, A Case Report and Review of Literature

The really clever thing in the above case report is that appears that the effect on glutamate may be by an epigenetic mechanism (via GLT1), since the effect is long lasting. Read later in this post about the epigenetic effects of beta-lactams.

Neuroprotective properties

“These results suggest that the neuroprotective effect induced by beta-lactam antibiotics is due to their capacity to stimulate GLT1 expression and thus regulate the concentration of glutamate in the synaptic cleft. GLT1 is a glutamate transporter inducing its reuptake by astrocytes preventing excessive glutamate concentration in the synaptic cleft

It was subsequently shown that the neuroprotective effect of BLMs was due not only to glutamate down regulation, but also to a diminished glutamate-induced intracellular Ca2+ concentration and an increased uptake of glutamate

Another probable mechanism of neuroprotection induced by BLMs is down-regulation of oxidative stress and modulation of apoptotic pathways shown in rat spinal cord when CFX was administered for 7 days prior to induction of constrictive neuropathy. This effect was apparently mediated by both a reduction in proapoptotic proteins Bax, and an increment in the antiapoptotic protein Bcl2.

CFX (Ceftiaxone) may induce neuroprotection by other mechanisms besides GLT1 overexpression. Yamada and Jinno [51] reported that the antibiotic reversed axotomy-induced up regulation of GFAP, a neuronal damage marker, and increased neuronal survival; apparently not only through glutamatergic regulation, but also by direct reduction of glial hypereactivity. Supplementary to this is the finding of an attenuation of microglial activation induced IL-1 expression in an ischemic injury model when CFX was administered as a pre-treatment [52]. This result may indicate a direct action on glial cells since partial reduction of astrocytes and microglia was observed.”

Analgesic (pain killing) Properties

“Interestingly, despite the widespread clinical use of BLMs (beta-lactams), some of their known non-antibiotic effects have been either disregarded or misinterpreted as resulting from bacterial microbiome regulation. For example, Caperton, Heim-Duthoy [54] hypothesized that chronic inflammatory arthritis could have a bacterial component and that therefore the clinical course of a patient could be affected by administration of CFX (Ceftriaxone).

Both the anti-inflammatory and neuromodulating effects exerted by BLMs either peripherally or centrally may be related to their analgesic properties in some pathologies that are difficult to treat such as the complex regional pain syndrome [65] or to the analgesic effect of a single preoperative dose of CFX in a clinical protocol [66].

Immunomodulatory Properties 

Not many people seem to have read this paper. They did not flesh out immunomodulation, so I draw on a different paper. People who write about immunomodulation usually say that beta-lactams do not have this effect, but that appears to be incorrect. 

Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin

Recent work has suggested that beta-lactam antibiotics might directly affect eukaryotic cellular functions. Here, we studied the effects of commonly used beta-lactam antibiotics on rodent and human T cells in vitro and in vivo on T-cell–mediated experimental autoimmune diseases. We now report that experimental autoimmune encephalomyelitis and adjuvant arthritis were significantly more severe in rats treated with cefuroxime and other beta-lactams. T cells appeared to mediate the effect: an anti-myelin basic protein T-cell line treated with cefuroxime or penicillin was more encephalitogenic in adoptive transfer experiments. The beta-lactam ampicillin, in contrast to cefuroxime and penicillin, did not enhance encephalomyelitis, but did inhibit the autoimmune diabetes developing spontaneously in non-obese diabetic mice. Gene expression analysis of human peripheral blood T cells showed that numerous genes associated with T helper 2 (Th2) and T regulatory (Treg) differentiation were down-regulated in T cells stimulated in the presence of cefuroxime; these genes were up-regulated in the presence of ampicillin. The T-cell protein that covalently bound beta-lactam antibiotics was found to be albumin. Human and rodent T cells expressed albumin mRNA and protein, and penicillin-modified albumin was taken up by rat T cells, leading to enhanced encephalitogenicity. Thus, beta-lactam antibiotics in wide clinical use have marked effects on T-cell behavior; beta-lactam antibiotics can function as immunomodulators, apparently through covalent binding to albumin.

 Anxiolytic effects (reduce anxiety)

“CA (Clavulanic acid) has proven effective as an anxiolytic drug, since it was reported that this drug diminished anxiety-like conduct in both rodent and primate models”

Antineoplastic effects (preventing tumors)

“CFX (Ceftriaxone) elicit antitumor activity both in vitro and in vivo models”

Addiction

Addiction did not appear in the chart above, but it gets a mention in the text 

“When tested in an opiate dependence model, both CFX [72] and CA [73] inhibited both physical dependence and withdrawal symptoms. This could mean that the effect shown by CFX is not due to its particular molecular structure, but can be reproduced by other BLMs (several BLMs effects shown on Fig. 3)

Other effects

“CA (Clavulanic acid) has been shown to increase dopamine release”

Epigenetic Effects

These were not mentioned in the paper, but I do think epigenetics is a fundamental part of many diseases, including much autism.

The paper really explains why short term use of beta-lactams can stop a person with epilepsy having seizures for a long time.

Off-Target drug effects resulting in altered gene expression events with epigenetic and"Quasi-Epigenetic" origins.

This review synthesizes examples of pharmacological agents who have off-target effects of an epigenetic nature. We expand upon the paradigm of epigenetics to include "quasi-epigenetic" mechanisms. Quasi-epigenetics includes mechanisms of drugs acting upstream of epigenetic machinery or may themselves impact transcription factor regulation on a more global scale. We explore these avenues with four examples of conventional pharmaceuticals and their unintended, but not necessarily adverse, biological effects. The quasi-epigenetic drugs identified in this review include the use of beta-lactam antibiotics to alter glutamate receptor activity and the action of cyclosporine on multiple transcription factors. In addition, we report on more canonical epigenome changes associated with pharmacological agents such as lithium impacting autophagy of aberrant proteins, and opioid drugs whose chronic use increases the expression of genes associated with addictive phenotypes. By expanding our appreciation of transcriptomic regulation and the effects these drugs have on the epigenome, it is possible to enhance therapeutic applications by exploiting off-target effects and even repurposing established pharmaceuticals. That is, exploration of "pharmacoepigenetic" mechanisms can expand the breadth of the useful activity of a drug beyond the traditional drug targets such as receptors and enzymes.

DAO inhibition

As our reader Agnieszka pointed out in the comments section, one commonly prescribed beta-lactam antibiotic called Augmentin contains a second antibiotic, Clavulanic acid, to boost its effectiveness; by chance is also a very potent DAO inhibitor. Diamine oxidase (DAO), also known as histaminase, is an enzyme in your body that is used to inactivate histamine. Histamine is found in food that you eat as well as being produced in your body and released by your mast cells during an allergic reaction.

DAO neutralizes the histamine in food so it does not enter your bloodstream.

So this particular antibiotic should be avoided by those people who are histamine intolerant and so do not produce enough DAO. This is about 1% of the general population, but might be more common in those with autism although there is no data on this subject.

Some people believe that ADHD is associated with a reduced level of DAO.

Indeed there is a patent to treat ADHD with a combination of DAO and caffeine.

Diamine oxidase for use in the treatment or prevention of attention deficit hyperactivity disorder (ADHD)

[0087] DAO can also be mixed with caffeine, strengthening the role of prevention and treatment of attention deficit hyperactivity disorder. Thus, also disclosed herein compositions comprising DAO and caffeine. 

[0088] Caffeine, a xanthine alkaloid group having stimulating properties for the treatment of attention deficit hyperactivity disorder. 

[0089] DAO content of the present invention per unit dose 0 · l-50mg, preferably 2-20mg. 

[0090] The present invention is caffeine content per unit dose 1-lOOmg, preferably 5-50mg. 

[0091] for the prevention and treatment of attention deficit hyperactivity disorder DAO or compositions comprising DAO may be before a meal or postprandial meal administration.

[0092] The use of DAO of the invention or compositions comprising DAO directly affect blood histamine levels, thus affecting the symptoms of attention deficit cumulative histamine levels induced hyperactivity disorder.

You can actually buy DAO supplements and of course caffeine.

Perhaps people consuming DAO inhibitors long term, such as NAC and Verapamil, and have chronic allergies or mast cell disorders might benefit from extra DAO. 

Evaluation of the inhibitory effect of various drugs / active ingredients on the activity of human diamine oxidase in vitro

Most DAO is actually in your digestive tract, where the dietary histamine is.

You can measure DAO levels in your blood.

Serum diamine oxidase (DAO) activity as a diagnostic test for histamine intolerance  

We can conclude that determination of DAO activity in serum is a useful diagnostic tool, together with detailed history to differentiate between food allergy and histamine intolerance.

We found that DAO activity was significantly lower in patients than in healthy control subjects.

Conclusion

I think there is plenty of food for thought here for parents of children whose autism and/or epilepsy improves when taking a beta-lactam antibiotic.  Hopefully some people will figure out which effect is the beneficial one and find something else to replicate it.

There is a lot previously written in this blog about upregulating GLT1, other than by a beta-lactam. My favoured option was Riluzole, but Bromocriptine will also do this, among its other actions. Riluzole is a drug for ALS, that has been trialed in children with OCD, without side effects.    

People technically without histamine intolerance (normal levels of DAO) who incidentally take large amounts of DAO inhibitors, may end up exacerbating an existing mast cell related problem. One potential solution for that small group might be taking an OTC DAO supplement.