Exposure to anti-seizure medications impact growth of gut bacterial species and subsequent host response

Gut microbiota in epilepsy: How antibiotics induce dysbiosis and influence seizure susceptibility

Epilepsy, a widespread chronic neurological disorder, has recently come under scrutiny for its potential association with the intricate dynamics of gut microbiota. Numerous investigations into the microbiota-gut-brain axis have revealed a close relationship between gut microbiota and epilepsy, suggesting gut microbiota as a potential treatment strategy. In clinical practice, a longstanding correlation has been observed between some kinds of antibiotics and the potential to induce seizures. Consequently, we have conceived a hypothesis that antibiotics might impact seizure activity by modulating the gut microbiota and influencing the physiological processes within the microbiota-gut-brain axis. In this review, our primary objective is to present the existing evidence and theoretical foundations supporting the hypothesis that dysbiosis within the gut microbiota may play a significant role in the pathophysiology of epilepsy. Furthermore, we aim to summarize the possible mechanisms between microbiota-gut-brain axis and epilepsy, offering insights into the selection of appropriate antibiotics for long-term epilepsy management and enhancing therapeutic efficacy through modulation of the gut microbiota. Further research is necessary to fully elucidate the intricate relationship between gut microbiota ecosystem and epilepsy. Exploring these connections holds promise for advancing our understanding of epilepsy pathogenesis and improving patient treatment and care.

The Influence of the Probiotics, Ketogenic Diets, and Gut Microbiota on Epilepsy and Epileptic Models: A Comprehensive Review

About one-third of epilepsies are resistant to antiepileptic drugs; thus, uncovering new pathways in the pathophysiology of epilepsy can reduce the global disease burden. Probiotics are live, non-pathogenic microorganisms that benefit the host by regulating the gut microbiome. This review aims to study the effect of probiotics and ketogenic diets on gut microbiota and their potential as a therapy for epilepsy. We conducted a systematic search of the databases PubMed, Scopus, Embase, and the Web of Science for pertinent studies that have been published. Our search methodology was meticulously structured to be exhaustive, integrating targeted keywords and Boolean operators to guarantee the acquisition of all potentially pertinent articles. Probiotics interact with the gut microbiome, balance its composition, and influence the gut-brain axis. Moreover, they reduce neuroinflammation and oxidative stress. The ketogenic diet (KD) affects gut bacteria, influencing neurotransmitter levels and short-chain fatty acids (SCFAs), which play a role in the gut-brain axis. Studies have shown the positive effects of various probiotics in animal models of epilepsy. They demonstrate improvements in seizure activity, anxiety, and neuroinflammation. In human studies, probiotics reduced seizure frequency and enhanced quality of life in patients with drug-resistant epilepsy. We believe using probiotics or dietary interventions like KD could be a promising therapeutic strategy for managing epilepsy. This could reduce seizure frequency and make life better for patients with epilepsy.

Intestinal microbiome alterations in pediatric epilepsy: Implications for seizures and therapeutic approaches

The intestinal microbiome plays a pivotal role in maintaining host health through its involvement in gastrointestinal, immune, and central nervous system (CNS) functions. Recent evidence underscores the bidirectional communication between the microbiota, the gut, and the brain and the impact of this axis on neurological diseases, including epilepsy. In pediatric patients, alterations in gut microbiota composition-called intestinal dysbiosis-have been linked to seizure susceptibility. Preclinical models revealed that gut dysbiosis may exacerbate seizures, while microbiome-targeted therapies, including fecal microbiota transplantation, pre/pro-biotics, and ketogenic diets, show promise in reducing seizures. Focusing on clinical and preclinical studies, this review examines the role of the gut microbiota in pediatric epilepsy with the aim of exploring its implications for seizure control and management of epilepsy. We also discuss mechanisms that may underlie mutual gut-brain communication and emerging therapeutic strategies targeting the gut microbiome as a novel approach to improve outcomes in pediatric epilepsy. PLAIN LANGUAGE SUMMARY: Reciprocal communication between the brain and the gut appears to be dysfunctional in pediatric epilepsy. The composition of bacteria in the intestine -known as microbiota- and the gastrointestinal functions are altered in children with drug-resistant epilepsy and animal models of pediatric epilepsies. Microbiota-targeted interventions, such as ketogenic diets, pre-/post-biotics administration, and fecal microbiota transplantation, improve both gastrointestinal dysfunctions and seizures in pediatric epilepsy. These findings suggest that the gut and its microbiota represent potential therapeutic targets for reducing drug-resistant seizures in pediatric epilepsy.

Carbamazepine-exposed earthworms are characterized by tissue-specific accumulation patterns and transcriptional profiles

Pharmaceutically active compounds enter soils via wastewater reuse and biosolid application. A ubiquitous drug present in wastewater is carbamazepine, a frequently prescribed anti-convulsant. Its mode of action is not species-specific and affects the nervous system of non-target organisms, including most likely the soil dwelling earthworms, which in turn has the potential to negatively impact soil quality. In this project, soils were amended with carbamazepine to explore uptake dynamics and resultant changes in molecular and life cycle endpoints of earthworms (Dendrobaena veneta). Earthworms were maintained, under laboratory conditions, for 28 days in soil spiked with either a solvent control, 0.6 mg/kg carbamazepine (encountered in the terrestrial system) or 10 mg/kg carbamazepine (significantly above an environmental hotspot). Carbamazepine concentrations were quantified in soils and worms by liquid chromatography tandem mass spectrometry (LC-MS/MS) which revealed tissue, dose and time-dependent differences in accumulation. Carbamazepine also modulated the make-up of the microbiome in the soil as well as the earthworm's gut. De novo RNA sequencing identified novel transcripts and complex tissue-specific transcriptomic changes, where, for example, the expression of the tubulin polymerisation promoting protein (tppp) was inhibited (9-fold) in the gut but induced (11-fold) in the cerebral ganglion of exposed earthworms. However, the notable absence of a strong cytochrome P450 response across all conditions suggests that the terrestrial earthworm also relies on detoxification pathways that differ to those observed in well-studied aquatic models. The novel finding that carbamazepine exposure triggers tissue-specific impacts in non-target soil organisms highlights the value and need for a more comprehensive understanding of how contaminants of emerging concern behave within an ecotoxicological context. This, in turn, will lead to informed and reliable risk assessments defining the consequences of wastewater and biosolid amendment practices on soil ecology and ecosystem function.

Persister Intestinal Bacteria, Epigenetics and Major Depression

The microbiota-gut-brain axis has been proposed as a potential modulator of mood disorders such as major depression. Complex bidirectional biochemical activities in this axis have been posited to participate in adverse mood disorders. Environmental and genetic factors have dominated recent discussions on depression. The prescription of antibiotics, antidepressants, adverse negative DNA methylation reactions and a dysbiotic gut microbiome have been cited as causal for the development and progression of depression. While research continues to investigate the microbiome-gut-brain axis, this review will explore the state of persistence of gut bacteria that underpins bacterial dormancy, possibly due to adverse environmental conditions and/or pharmaceutical prescriptions. Bacterial dormancy persistence in the intestinal microbial cohort could affect the role of bacterial epigenomes and DNA methylations. DNA methylations are highly motif driven exerting significant control on bacterial phenotypes that can disrupt bacterial metabolism and neurotransmitter formation in the gut, outcomes that can support adverse mood dispositions.

Role of gut dysbiosis in drug-resistant epilepsy: Pathogenesis and available therapeutic strategies

Over 70 million people worldwide suffer from epilepsy, a persistent brain disorder. Although there are more than 20 antiseizure drugs available for the symptomatic treatment of epilepsy, about one-third of patients with epilepsy experience seizures that show resistance to pharmacotherapy. Since patients with drug-resistant epilepsy are more prone to physical injuries, psychosocial dysfunction, early death, and deteriorated life quality, the development of safer and more effective treatments is a crucial clinical need. The gut-brain axis and microbiome research advances have provided new insights into the pathophysiology of epilepsy, the resistance to anti-seizure medicine, and potential treatment targets. Inflammation, disturbance of the blood-brain barrier, and altered neurotransmitters are key pathways linked to gut dysbiosis. The characterization of microbial species and functional pathways has advanced thanks to metagenomic sequencing and high-throughput analysis. In this review, we elaborate on the gut-mediated molecular pathways involved in drug-resistant epilepsy, the gut- modulatory therapeutic options, and their combination with antiseizure medications for drug-resistant epilepsy.

Gut microbiota as a potential therapeutic target for children with cerebral palsy and epilepsy

Gut microbiota (GM), the "second genome," exerts influence on human health by impacting brain function through the gut-brain axis. This interaction involves various mechanisms, including immune regulation, metabolites, and neuronal pathways. The application of the next-generation sequencing technology provides a revolutionary tool for the study of GM, which contributes to a deeper comprehension of the GM-host relationship. Children with cerebral palsy (CP), a common neurological disorder in children, are more likely to develop epilepsy, which can exacerbate CP symptoms, particularly those related to cognitive impairment and gastrointestinal tract, such as constipation. The current study identified specific changes in the GM of children with CP accompanied by epilepsy. Furthermore, both diet and oral microbiota have the potential to influence the composition of the GM. Interventions with probiotics and dietary fiber based on GM can improve constipation and cognition, and this approach may be a potential therapeutic strategy.

The Microbiota-Gut-Brain Axis and Neurological Disorders: A Comprehensive Review

Microbes have inhabited the earth for hundreds of millions of years longer than humans. The microbiota-gut-brain axis (MGBA) represents a bidirectional communication pathway. These communications occur between the central nervous system (CNS), the enteric nervous system (ENS), and the emotional and cognitive centres of the brain. The field of research on the gut-brain axis has grown significantly during the past two decades. Signalling occurs between the gut microbiota and the brain through the neural, endocrine, immune, and humoral pathways. A substantial body of evidence indicates that the MGBA plays a pivotal role in various neurological diseases. These include Alzheimer's disease (AD), autism spectrum disorder (ASD), Rett syndrome, attention deficit hyperactivity disorder (ADHD), non-Alzheimer's neurodegeneration and dementias, fronto-temporal lobe dementia (FTLD), Wilson-Konovalov disease (WD), multisystem atrophy (MSA), Huntington's chorea (HC), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), temporal lobe epilepsy (TLE), depression, and schizophrenia (SCZ). Furthermore, the bidirectional correlation between therapeutics and the gut-brain axis will be discussed. Conversely, the mood of delivery, exercise, psychotropic agents, stress, and neurologic drugs can influence the MGBA. By understanding the MGBA, it may be possible to facilitate research into microbial-based interventions and therapeutic strategies for neurological diseases.

A long journey to treat epilepsy with the gut microbiota

Epilepsy is a common neurological disorder that affects approximately 10.5 million children worldwide. Approximately 33% of affected patients exhibit resistance to all available antiseizure medications, but the underlying mechanisms are unknown and there is no effective treatment. Increasing evidence has shown that an abnormal gut microbiota may be associated with epilepsy. The gut microbiota can influence the function of the brain through multiple pathways, including the neuroendocrine, neuroimmune, and autonomic nervous systems. This review discusses the interactions between the central nervous system and the gastrointestinal tract (the brain-gut axis) and the role of the gut microbiota in the pathogenesis of epilepsy. However, the exact gut microbiota involved in epileptogenesis is unknown, and no consistent results have been obtained based on current research. Moreover, the target that should be further explored to identify a novel antiseizure drug is unclear. The role of the gut microbiota in epilepsy will most likely be uncovered with the development of genomics technology.

The impact of microbiota and ketogenic diet interventions in the management of drug-resistant epilepsy

AIM

Drug-resistant epilepsy (DRE) is a neurological disorder characterized by uncontrolled seizures. It affects between 10%-40% of the patients with epilepsy worldwide. Drug-resistant patients have been reported to have a different microbiota composition compared to drug-sensitive patients and healthy controls. Importantly, fecal microbiota transplantations (FMTs), probiotic and dietary interventions have been shown to be able to reduce seizure frequency and improve the quality of life in drug-resistant patients. The classic ketogenic diet (KD) and its modifications may reduce seizures in DRE in some patients, whereas in others they do not. The mechanisms mediating the dietary effects remain elusive, although it is known that gut microbes play an important role in transmitting dietary effects to the host. Indeed, specific commensal microbes differ even between responders and non-responders to KD treatment.

METHODS

In this narrative mini-review, we summarize what is known about the gut microbiota changes and ketogenic diets with special focus on patients with DRE.

RESULTS AND CONCLUSIONS

By highlighting unanswered questions and by suggesting future research directions, we map the route towards future improvement of successful DRE therapy.

Confounder or Confederate? The Interactions Between Drugs and the Gut Microbiome in Psychiatric and Neurological Diseases

The gut microbiome is emerging as an important factor in signaling along the gut-brain axis. The intimate physiological connection between the gut and the brain allows perturbations in the microbiome to be directly transmitted to the central nervous system and thereby contribute to psychiatric and neurological diseases. Common microbiome perturbations result from the ingestion of xenobiotic compounds including pharmaceuticals such as psychotropic drugs. In recent years, a variety of interactions between these drug classes and the gut microbiome have been reported, ranging from direct inhibitory effects on gut bacteria to microbiome-mediated drug degradation or sequestration. Consequently, the microbiome may play a critical role in influencing the intensity, duration, and onset of therapeutic effects, as well as in influencing the side effects that patients may experience. Furthermore, because the composition of the microbiome varies from person to person, the microbiome may contribute to the frequently observed interpersonal differences in the response to these drugs. In this review, we first summarize the known interactions between xenobiotics and the gut microbiome. Then, for psychopharmaceuticals, we address the question of whether these interactions with gut bacteria are irrelevant for the host (i.e., merely confounding factors in metagenomic analyses) or whether they may even have therapeutic or adverse effects.

Effect of dietary supplementation with Lactobacillus helveticus R0052 on seizure thresholds and antiseizure potency of sodium valproate in mice

OBJECTIVE

Both animal and human studies, though limited, showed that multi-strain probiotic supplementation may reduce the number of seizures and/or seizure severity. Here, we evaluated the effect of a single strain probiotic supplementation on seizure susceptibility, antiseizure efficacy of sodium valproate, and several behavioral parameters in mice.

METHODS

Lactobacillus helveticus R0052 was given orally for 28 days. Its influence on seizure thresholds was evaluated in the ivPTZ- and electrically-induced seizure tests. The effect on the antiseizure potency of valproate was assessed in the scPTZ test. We also investigated the effects of probiotic supplementation on anxiety-related behavior (in the elevated plus maze and light/dark box tests), motor coordination (in the accelerating rotarod test), neuromuscular strength (in the grip-strength test), and spontaneous locomotor activity. Serum and brain concentrations of valproate as well as cecal contents of SCFAs and lactate were determined using HPLC method.

RESULTS

L. helveticus R0052 significantly increased the threshold for the 6 Hz-induced psychomotor seizure. There was also a slight increase in the threshold for myoclonic and clonic seizure in the ivPTZ test. L. helveticus R0052 did not affect the threshold for tonic seizures both in the maximal electroshock- and ivPTZ-induced seizure tests. No changes in the antiseizure potency of valproate against the PTZ-induced seizures were reported. Interestingly, L. helveticus R0052 increased valproate concentration in serum, but not in the brain. Moreover, L. helveticus R0052 did not produce any significant effects on anxiety-related behavior, motor coordination, neuromuscular strength, and locomotor activity. L. helveticus R0052 supplementation resulted in increased concentrations of total SCFAs, acetate, and butyrate.

CONCLUSIONS

Altogether, this study shows that a single-strain probiotic - L. helveticus R0052 may decrease seizure susceptibility and this effect can be mediated, at least in part, by increased production of SCFAs. In addition, L. helveticus R0052 may affect bioavailability of valproate, which warrants further investigations.

New analytical method for the determination of endocrine disruptors in human faeces using gas chromatography coupled to tandem mass spectrometry

Endocrine-disrupting chemicals are environmental pollutants that can enter our bodies and cause diverse pathologies. Some bisphenols and parabens have been shown to be capable of modifying proper functioning of the endocrine system. Among other dysfunctions, endocrine-disrupting chemicals can cause changes in intestinal microbiota. Faeces are a convenient matrix that can be useful for identifying the quantity of endocrine disruptors that reach the intestine and the extent to which the organism is exposed to these pollutants. The present work developed a new analytical method to determine 17 compounds belonging to the paraben and bisphenol families found in human faeces. The extraction method was optimized using an ultrasound-assisted extraction technique followed by a clean-up step based on the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique. Optimization was performed using the design of experiments technique. In validation analysis, the method was proven to be linear over a wide range. R-squared outcomes were between 95 and 99%. Selectiveness and sensitivity outcomes were acceptable, with detection limits being between 1 and 10 ng g-1 in all cases, whilst quantification limits were between 3 and 25 ng g-1 in all instances, with the exception of bisphenol AF. The method was deemed accurate, with recovery values being close to 100% and relative standard deviations being lower than 15% in all cases. Applicability was examined by analysing 13 samples collected from volunteers (male and female). All samples were contaminated with at least one of the analytes studied. The most commonly found compounds were methylparaben and bisphenol A, which were detected in almost all samples and quantitatively determined in 11 and 12 samples, respectively. Of the 17 compounds analysed, 11 were found in at least one sample. Outcomes demonstrate that faeces can be a good matrix for the determination of exposure to contaminants of interest here.

A meta-analysis of the changes in the Gut microbiota in patients with intractable epilepsy compared to healthy controls

OBJECTIVE

To explore gut microbiota changes in intractable epilepsy patients compared to healthy control individuals through meta-analysis.

METHODS

PubMed, Web of Science, CNKI, Wanfang, medRxiv, bioRxiv, ilae.org, clinical trial databases, and papers from the International Epilepsy Congress (IEC) were searched, and the literature on the correlation between intractable epilepsy and the gut microbiota reported from database establishment to June 2023 was included. Literature meeting the inclusion criteria was screened, and meta-analysis of the included literature was performed using RevMan5.4 software.

RESULTS

Ten case-control studies were included in the meta-analysis. There were 183 patients with intractable epilepsy and 283 healthy control subjects. The analysis results indicated that Bacteroidetes (MD = -0.64, 95 %-CI = -1.21 to -0.06) and Ruminococcaceae (MD = -1.44, 95 % CI = -1.96 to -0.92) were less abundant in the patients with intractable epilepsy than in the normal population. Proteobacteria (MD = 0.53, 95 % CI = 0.02 to 1.05) and Verrucomicrobia (MD = 0.26, 95 % CI = 0.06 to 0.45) were more abundant in the patients with intractable epilepsy than in the normal population.

CONCLUSION

This meta-analysis indicated that the abundances of Bacteroidetes and Ruminococcaceae were reduced while those of Proteobacteria and Verrucomicrobia were significantly increased in patients with intractable epilepsy. The above changes in these four taxa of the gut microbiota may have been induced by intractable epilepsy, which may increase the risk of seizures. Their roles in the pathogenesis of intractable epilepsy need to be further explored, and related factors that influence microbiota changes should be considered in future studies.

The interplay between microbiota and brain-gut axis in epilepsy treatment

The brain-gut axis plays a vital role in connecting the cognitive and emotional centers of the brain with the intricate workings of the intestines. An imbalance in the microbiota-mediated brain-gut axis extends far beyond conditions like Irritable Bowel Syndrome (IBS) and obesity, playing a critical role in the development and progression of various neurological disorders, including epilepsy, depression, Alzheimer's disease (AD), and Parkinson's disease (PD). Epilepsy, a brain disorder characterized by unprovoked seizures, affects approximately 50 million people worldwide. Accumulating evidence suggests that rebuilding the gut microbiota through interventions such as fecal microbiota transplantation, probiotics, and ketogenic diets (KD) can benefit drug-resistant epilepsy. The disturbances in the gut microbiota could contribute to the toxic side effects of antiepileptic drugs and the development of drug resistance in epilepsy patients. These findings imply the potential impact of the gut microbiota on epilepsy and suggest that interventions targeting the microbiota, such as the KD, hold promise for managing and treating epilepsy. However, the full extent of the importance of microbiota in epilepsy treatment is not yet fully understood, and many aspects of this field remain unclear. Therefore, this article aims to provide an overview of the clinical and animal evidence supporting the regulatory role of gut microbiota in epilepsy, and of potential pathways within the brain-gut axis that may be influenced by the gut microbiota in epilepsy. Furthermore, we will discuss the recent advancements in epilepsy treatment, including the KD, fecal microbiota transplantation, and antiseizure drugs, all from the perspective of the gut microbiota.

Longitudinal exposure to antiseizure medications shape gut-derived microbiome, resistome, and metabolome landscape

The influence of chronically administered host-targeted drugs on the gut microbiome remains less understood compared to antibiotics. We investigated repetitive exposure effects of three common antiseizure medications [carbamazepine (CBZ), valproic acid, and levetiracetam] on the gut microbial composition, resistome, and metabolome using microcosms constructed from feces of young children. Microcosms were established by cultivating feces for 24 h (C0). These microcosms were daily transferred into fresh media for seven cycles (C1-C7) with antiseizure medications or carrier molecules, followed by four cycles without any drugs (C8-C11). The microbial dynamics and resistome of microcosms at C0, C1, C7, and C11 were assessed with 16S ribosomal ribonucleic acid gene sequencing or shotgun metagenome sequencing and real-time quantitative polymerase chain reaction analysis of the antimicrobial resistance genes, respectively. Metabolites of CBZ-treated and control microcosms at C0, C1, and C7 were evaluated using non-targeted metabolomics. Our findings revealed that the serial transfer approach longitudinally altered the microcosm composition. Among the medications, CBZ had the most substantial impact on the structure and metabolism of the feces-derived microcosms. The microbiome composition partially recovered during the drug-free period. Specifically, Bacteroides and Flavonifractor were depleted and Escherichia and Clostridium were enriched. Additionally, repetitive CBZ exposure increased the abundance and expression of genes related to various antibiotic resistance mechanisms, more specifically, efflux pumps and antibiotic target alteration. CBZ-induced changes in the microbiome were mirrored in the metabolome, with reductions in the citric acid cycle metabolites, glutamine, and spermidine, alongside increased levels of vitamin B6. Our study suggests that repetitive CBZ exposure may negatively impact gut microbial homeostasis and metabolism.

Noxious ramifications of cosmetic pollutants on gastrointestinal microbiome: A pathway to neurological disorders

On exposure to cosmetic pollutants, gastrointestinal dysbiosis, which is characterised by a disturbance in the gut microbiota, has come into focus as a possible contributor to the occurrence of neurotoxic consequences. It is normal practice to use personal care products that include parabens, phthalates, sulphates, triclosans/triclocarbans and micro/nano plastics. These substances have been found in a variety of bodily fluids and tissues, demonstrating their systemic dispersion. Being exposed to these cosmetic pollutants has been linked in recent research to neurotoxicity, including cognitive decline and neurodevelopmental problems. A vital part of sustaining gut health and general well-being is the gut flora. Increased intestinal permeability, persistent inflammation, and impaired metabolism may result from disruption of the gut microbial environment, which may in turn contribute to neurotoxicity. The link between gastrointestinal dysbiosis and the neurotoxic effects brought on by cosmetic pollutants may be explained by a number of processes, primarily the gut-brain axis. For the purpose of creating preventative and therapeutic measures, it is crucial to comprehend the intricate interactions involving cosmetic pollutants, gastrointestinal dysbiosis, and neurotoxicity. This review provides an in-depth understanding of the various hazardous cosmetic pollutants and its potential role in the occurrence of neurological disorders via gastrointestinal dysbiosis, providing insights into various described and hypothetical mechanisms regarding the complex toxic effects of these industrial pollutants.

Fecal transfers from children on the ketogenic diet mimic the anti-seizure effect in mice

The ketogenic diet (KD) mediates its anti-seizure effect through the gut microbiota in epilepsy mouse models.1 Lum et al.2 demonstrated that fecal microbiota from children with epilepsy treated with the KD decreases seizure susceptibility in mice after transfer.

The microbiome-gut-brain axis in epilepsy: pharmacotherapeutic target from bench evidence for potential bedside applications

The gut-brain axis augments the bidirectional communication between the gut and brain and modulates gut homeostasis and the central nervous system through the hypothalamic-pituitary-adrenal axis, enteroendocrine system, neuroendocrine system, inflammatory and immune pathways. Preclinical and clinical reports showed that gut dysbiosis might play a major regulatory role in neurological diseases such as epilepsy, Parkinson's, multiple sclerosis, and Alzheimer's disease. Epilepsy is a chronic neurological disease that causes recurrent and unprovoked seizures, and numerous risk factors are implicated in developing epilepsy. Advanced consideration of the gut-microbiota-brain axis can reduce ambiguity about epilepsy pathology, antiepileptic drugs, and effective therapeutic targets. Gut microbiota sequencing analysis reported that the level of Proteobacteria, Verrucomicrobia, Fusobacteria, and Firmicutes was increased and the level of Actinobacteria and Bacteroidetes was decreased in epilepsy patients. Clinical and preclinical studies also indicated that probiotics, ketogenic diet, faecal microbiota transplantation, and antibiotics can improve gut dysbiosis and alleviate seizure by enhancing the abundance of healthy biota. This study aims to give an overview of the connection between gut microbiota, and epilepsy, how gut microbiome changes may cause epilepsy, and whether gut microbiome restoration could be used as a treatment for epilepsy.

Topiramate alters the gut microbiome to aid in its anti-seizure effect

Introduction

There is a growing interest in the role of the gut microbiota in epilepsy, however, it is unclear if anti-seizure medications (ASMs) play a role in the gut-brain axis. To test this, we investigated the impact of the ASM topiramate on the gut microbiome of mice.

Methods

C57BL/6J mice were administered topiramate in their drinking water for 5 weeks. 16S ribosomal RNA gene sequencing was performed on fecal samples collected at 5 weeks. Analysis of alpha diversity, beta diversity, and differential abundance were performed. Cecal contents were analyzed for short-chain fatty acids (SCFAs) composition. Pentylenetetrazol (PTZ)-kindling was performed in saline, topiramate, Lactobacillus johnsonii, and topiramate and Lactobacillus johnsonii treated mice. Mice received PTZ injection every other day for a total of twelve injections, seizure activity was video monitored for 30 minutes and scored.

Results and discussion

Our study revealed that topiramate ingestion significantly increased Lactobacillus johnsonii in the gut microbiome of naïve mice. Treatment with topiramate and Lactobacillus johnsonii together, but not alone, reduced susceptibility to PTZ-induced seizures. Co-treatment also significantly increased the percent of butyrate and the abundance of butyrate-producing family Lachnospiraceae in the gut, and elevated the GABA/glutamate ratio in the cortex. Our results demonstrate that an ASM can alter the gut microbiome to aid in their anti-seizure effect in vivo and suggest the potential of the probiotic Lactobacillus johnsonii as an adjunct therapy with topiramate in reducing seizure susceptibility.

Microbiota-gut-brain axis and ketogenic diet: how close are we to tackling epilepsy?

The microbiota-gut-brain axis refers to the intricate bidirectional communication between commensal microorganisms residing in the digestive tract and the central nervous system, along neuroendocrine, metabolic, immune, and inflammatory pathways. This axis has been suggested to play a role in several neurological disorders, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, and epilepsy, paving the way for microbiome-based intervention strategies for the mitigation and treatment of symptoms. Epilepsy is a multifaceted neurological condition affecting more than 50 million individuals worldwide, 30% of whom do not respond to conventional pharmacological therapies. Among the first-hand microbiota modulation strategies, nutritional interventions represent an easily applicable option in both clinical and home settings. In this narrative review, we summarize the mechanisms underlying the microbiota-gut-brain axis involvement in epilepsy, discuss the impact of antiepileptic drugs on the gut microbiome, and then the impact of a particular dietary pattern, the ketogenic diet, on the microbiota-gut-brain axis in epileptic patients. The investigation of the microbiota response to non-pharmacological therapies is an ever-expanding field with the potential to allow the design of increasingly accessible and successful intervention strategies.

Microbiota-gut-brain axis mechanisms in the complex network of bipolar disorders: potential clinical implications and translational opportunities

Bipolar disorders (BD) represent a severe leading disabling mental condition worldwide characterized by episodic and often progressive mood fluctuations with manic and depressive stages. The biological mechanisms underlying the pathophysiology of BD remain incompletely understood, but it seems that there is a complex picture of genetic and environmental factors implicated. Nowadays, gut microbiota is in the spotlight of new research related to this kind of psychiatric disorder, as it can be consistently related to several pathophysiological events observed in BD. In the context of the so-called microbiota-gut-brain (MGB) axis, it is shown to have a strong influence on host neuromodulation and endocrine functions (i.e., controlling the synthesis of neurotransmitters like serotonin or mediating the activation of the hypothalamic-pituitary-adrenal axis), as well as in modulation of host immune responses, critically regulating intestinal, systemic and brain inflammation (neuroinflammation). The present review aims to elucidate pathophysiological mechanisms derived from the MGB axis disruption and possible therapeutic approaches mainly focusing on gut microbiota in the complex network of BD. Understanding the mechanisms of gut microbiota and its bidirectional communication with the immune and other systems can shed light on the discovery of new therapies for improving the clinical management of these patients. Besides, the effect of psychiatric drugs on gut microbiota currently used in BD patients, together with new therapeutical approaches targeting this ecosystem (dietary patterns, probiotics, prebiotics, and other novelties) will also be contemplated.

Epilepsy, gut microbiota, and circadian rhythm

In recent years, relevant studies have found changes in gut microbiota (GM) in patients with epilepsy. In addition, impaired sleep and circadian patterns are common symptoms of epilepsy. Moreover, the types of seizures have a circadian rhythm. Numerous reports have indicated that the GM and its metabolites have circadian rhythms. This review will describe changes in the GM in clinical and animal studies under epilepsy and circadian rhythm disorder, respectively. The aim is to determine the commonalities and specificities of alterations in GM and their impact on disease occurrence in the context of epilepsy and circadian disruption. Although clinical studies are influenced by many factors, the results suggest that there are some commonalities in the changes of GM. Finally, we discuss the links among epilepsy, gut microbiome, and circadian rhythms, as well as future research that needs to be conducted.

Health and Disease: Akkermansia muciniphila, the Shining Star of the Gut Flora

Akkermansia muciniphila (A. muciniphila) has drawn much attention as an important gut microbe strain in recent years. A. muciniphila can influence the occurrence and development of diseases of the endocrine, nervous, digestive, musculoskeletal, and respiratory systems and other diseases. It can also improve immunotherapy for some cancers. A. muciniphila is expected to become a new probiotic in addition to Lactobacillus and Bifidobacterium. An increase in A. muciniphila abundance through direct or indirect A. muciniphila supplementation may inhibit or even reverse disease progression. However, some contrary findings are found in type 2 diabetes mellitus and neurodegenerative diseases, where increased A. muciniphila abundance may aggravate the diseases. To enable a more comprehensive understanding of the role of A. muciniphila in diseases, we summarize the relevant information on A. muciniphila in different systemic diseases and introduce regulators of A. muciniphila abundance to promote the clinical transformation of A. muciniphila research.

Clinical significance of microbiota changes under the influence of psychotropic drugs. An updated narrative review

Relationship between drugs and microbiota is bilateral. Proper composition thus function of microbiota is a key to some medications used in modern medicine. However, there is also the other side of the coin. Pharmacotherapeutic agents can modify the microbiota significantly, which consequently affects its function. A recently published study showed that nearly 25% of drugs administered to humans have antimicrobial effects. Multiple antidepressants are antimicrobials,. and antibiotics with proven antidepressant effects do exist. On the other hand, antibiotics (e.g., isoniaside, minocycline) confer mental phenotype changes, and adverse effects caused by some antibiotics include neurological and psychological symptoms which further supports the hypothesis that intestinal microbiota may affect the function of the central nervous system. Here we gathered comprehensively data on drugs used in psychiatry regarding their antimicrobial properties. We believe our data has strong implications for the treatment of psychiatric entities. Nevertheless the study of ours highlights the need for more well-designed trials aimed at analysis of gut microbiota function.

Colonic drug delivery: Formulating the next generation of colon-targeted therapeutics

Colonic drug delivery can facilitate access to unique therapeutic targets and has the potential to enhance drug bioavailability whilst reducing off-target effects. Delivering drugs to the colon requires considered formulation development, as both oral and rectal dosage forms can encounter challenges if the colon's distinct physiological environment is not appreciated. As the therapeutic opportunities surrounding colonic drug delivery multiply, the success of novel pharmaceuticals lies in their design. This review provides a modern insight into the key parameters determining the effective design and development of colon-targeted medicines. Influential physiological features governing the release, dissolution, stability, and absorption of drugs in the colon are first discussed, followed by an overview of the most reliable colon-targeted formulation strategies. Finally, the most appropriate in vitro, in vivo, and in silico preclinical investigations are presented, with the goal of inspiring strategic development of new colon-targeted therapeutics.

Ketogenic and Low FODMAP Diet in Therapeutic Management of a Young Autistic Patient with Epilepsy and Dysmetabolism Poorly Responsive to Therapies: Clinical Response and Effects of Intestinal Microbiota

Autism spectrum disorder (ASD) is often associated with several intestinal and/or metabolic disorders as well as neurological manifestations such as epilepsy (ASD-E). Those presenting these neuropathological conditions share common aspects in terms of gut microbiota composition. The use of microbiota intervention strategies may be an approach to consider in the management of these cases. We describe the case of a 17-year-old girl affected by ASD, reduced growth, neurological development delay, mutations in the PGM1 and EEF1A2 genes (in the absence of clinically manifested disease) and, intestinal disorders such as abdominal pain and diarrhea associated with weight loss. As she demonstrated poor responsiveness to the therapies provided, we attempted two specific dietary patterns: a ketogenic diet, followed by a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, with the aim of improving her neurological, metabolic, and intestinal symptoms through modulation of the gut microbiota’s composition. The ketogenic diet (KD) provided a reduction in Firmicutes, Bacteroidetes, and Proteobacteria. Although her intestinal symptoms improved, KD was poorly tolerated. On the other hand, the passage to a low FODMAPs diet produced a significant improvement in all neurological, intestinal, and metabolic symptoms and was well-tolerated. The following gut microbiota analysis showed reductions in Actinobacteria, Firmicutes, Lactobacilli, and Bifidobacteria. The alpha biodiversity was consistently increased and the Firmicutes/Bacteroidetes ratio decreased, reducing the extent of fermentative dysbiosis. Gut microbiota could be a therapeutic target to improve ASD-related symptoms. Further studies are needed to better understand the correlation between gut microbiota composition and ASD, and its possible involvement in the physiopathology of ASD.

Topiramate-Induced Suicidal Ideation and Olfactory Hallucinations: A Case Report

Antiepileptic drugs prescribed in the context of migraine have been reported to be potentially linked with an increased risk of suicidal ideation and behavior. Meta-analyses support the evidence that amongst antiepileptic drugs, Topiramate has the greatest potential for facilitating the occurrence of suicidal ideation and behavior. Studies indicate that this occurs via the increased incidence of mood disorders amongst the population with migraines using Topiramate as a treatment, with a slow and progressive onset of suicidal ideation (if any). We discuss the unique case of a 43-year-old man known to have chronic migraines, who presented with intense rapid-onset suicidal ideation and olfactory hallucinations, three weeks after the introduction of Topiramate for chronic migraines. After a negative extensive investigation panel to rule out common organic diseases, Topiramate was ceased. The suicidal ideation and olfactory hallucinations resolved in less than 24 h without further interventions. This case report highlights that rapid-onset suicidal ideation and olfactory hallucinations could be linked as an unusual side effect to the introduction of Topiramate. The removal of Topiramate from the patient’s pharmacological treatments prevented further psychological distress linked to ego-dystonic suicidal ideation and a resolution of olfactory hallucinations. He was discharged 48 h later.