The beneficial effect of probiotics as a supplementary treatment in drug-resistant epilepsy: a pilot study

Various pharmacological agents in the pipeline against intractable epilepsy

Epilepsy is a noncommunicable chronic neurological disorder affecting people of all ages, with the highest prevalence in low and middle-income countries. Despite the pharmacological armamentarium, the plethora of drugs in the market, and other treatment options, 30%-35% of individuals still show resistance to the current medication, termed intractable epilepsy/drug resistance epilepsy, which contributes to 50% of the mortalities due to epilepsy. Therefore, the development of new drugs and agents is needed to manage this devastating epilepsy. We reviewed the pipeline of drugs in "ClinicalTrials. gov," which is the federal registry of clinical trials to identify drugs and other treatment options in various phases against intractable epilepsy. A total of 31 clinical trials were found regarding intractable epilepsy. Among them, 48.4% (15) are about pharmacological agents, of which 26.6% are in Phase 1, 60% are in Phase 2, and 13.3% are in Phase 3. The mechanism of action or targets of the majority of these agents are different and are more diversified than those of the approved drugs. In this article, we summarized various pharmacological agents in clinical trials, their backgrounds, targets, and mechanisms of action for the treatment of intractable epilepsy. Treatment options other than pharmacological ones, such as devices for brain stimulation, ketogenic diets, gene therapy, and others, are also summarized.

Saccharomyces Boulardii alleviates neuroinflammation and oxidative stress in PTZ-kindled seizure rat model

Previous research have reported that modulating the gut microbiome composition by fecal microbiota transplantation and probiotic administration can alleviate seizure occurrence and severity. Saccharomyces boulardii (SB) is a yeast probiotic that has demonstrated ameliorating effects on anxiety, memory and cognitive deficit, and brain amyloidogenesis. In this research, our goal was to examine the anti-seizure effects of SB on the pentylenetetrazole (PTZ)-kindled male Wistar rats. The animals were randomly categorized into four test groups. The rats were orally administered with saline (control and PTZ groups) or S. boulardii (SB + PTZ and SB groups) for 57 days. From the 29th day of the experiment, the animals received intraperitoneally saline (control and SB groups) or PTZ (PTZ and SB + PTZ groups) on alternate days for 30 days. The administration dose of SB and PTZ was 1010 CFU/ml/day and 35 mg/kg, respectively. We assessed animal seizure behavior, neuroinflammation, oxidative stress, and the levels of matrix metalloproteinase-9 (MMP-9) and brain-derived neurotrophic factor (BDNF) in the hippocampus tissue. S. boulardii hindered the PTZ-induced kindling development. SB treatment elevated glutathione (GSH) and total antioxidant capacity (TAC) and reduced malondialdehyde (MDA) levels. SB also lessened the hippocampal levels of BDNF and MMP-9. Following SB supplementation, proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-6 were lowered, and anti-inflammatory cytokine IL-10 was enhanced. Overall, our data indicated, for the first time, the positive impact of SB on the PTZ-kindled seizure rat model. The anti-seizure activity of SB was mediated by modulating oxidative stress, neuroinflammation, and MMP-9 and BDNF levels.

Is hepatic GABA transaminase a promising target for obesity and epilepsy treatments?

γ-Aminobutyric acid (GABA) transaminase (GABA-T) is a GABA-degrading enzyme that plays an essential role in regulating GABA levels and maintaining supplies of GABA. Although GABA in the mammalian brain was discovered 70 years ago, research on GABA and GABA-T has predominantly focused on the brain. Notwithstanding the high activity and expression of GABA-T in the liver, the exact functions of GABA-T in the liver remain unknown. This article reviews the up-to-date information on GABA-T in the liver. It presents recent findings on the role of liver GABA-T in food intake suppression and appetite regulation. Finally, the potential functions of liver GABA-T in other neurological diseases, natural GABA-T inhibitors, and future perspectives in this research area are discussed.

Overview of the Efficacy of Using Probiotics for Neurosurgical and Potential Neurosurgical Patients

This review delves into the emerging field of the gut microbiota-brain axis, emphasizing its bidirectional communication and implications for neurological health, particularly in trauma and neurosurgery. While disruptions in this axis can lead to dysbiosis and hinder neurological recovery, recent studies have highlighted the therapeutic potential of interventions like probiotics in targeting this axis. This review aims to focus on the efficacy of probiotic supplementation to support the gut microbiota-brain axis in trauma, neurosurgery, or pain based on the current clinical trials to assess the complex interplays among probiotics, the gut microbiota, and the central nervous system (CNS). This comprehensive literature review identified 10 relevant publications on probiotic interventions for various neurosurgical conditions across multiple countries. These studies demonstrated diverse outcomes, with significant improvements observed in gastrointestinal mobility, inflammatory responses, and infection rates, particularly in post-traumatic brain injury and spinal surgery. Probiotics also showed promise in mitigating antibiotic-associated diarrhea and modulating inflammatory cytokines. Despite the promising findings, the complex interplays among probiotics, the gut microbiota, and the central nervous system (CNS) call for cautious interpretation. Conflicting outcomes emphasize the need for better-designed trials to understand strain-specific and disease-specific effects accurately. In conclusion, probiotics offer a promising adjuvant therapy for neurosurgical patients, traumatic brain injuries, and post-spinal surgery. However, further well-designed randomized controlled trials are essential to elucidate the intricate relationship between microbiome-modulating interventions and the CNS via the gut microbiota-brain axis.

Early treatment with rifaximin during epileptogenesis reverses gut alterations and reduces seizure duration in a mouse model of acquired epilepsy

The gut microbiota is altered in epilepsy and is emerging as a potential target for new therapies. We studied the effects of rifaximin, a gastrointestinal tract-specific antibiotic, on seizures and neuropathology and on alterations in the gut and its microbiota in a mouse model of temporal lobe epilepsy (TLE). Epilepsy was induced by intra-amygdala kainate injection causing status epilepticus (SE) in C57Bl6 adult male mice. Sham mice were injected with vehicle. Two cohorts of SE mice were fed a rifaximin-supplemented diet for 21 days, starting either at 24 h post-SE (early disease stage) or at day 51 post-SE (chronic disease stage). Corresponding groups of SE mice (one each disease stage) were fed a standard (control) diet. Cortical ECoG recording was done at each disease stage (24/7) for 21 days in all SE mice to measure the number and duration of spontaneous seizures during either rifaximin treatment or control diet. Then, epileptic mice ± rifaximin and respective sham mice were sacrificed and brain, gut and feces collected. Biospecimens were used for: (i) quantitative histological analysis of the gut structural and cellular components; (ii) markers of gut inflammation and intestinal barrier integrity by RTqPCR; (iii) 16S rRNA metagenomics analysis in feces. Hippocampal neuronal cell loss was assessed in epileptic mice killed in the early disease phase. Rifaximin administered for 21 days post-SE (early disease stage) reduced seizure duration (p < 0.01) and prevented hilar mossy cells loss in the hippocampus compared to epileptic mice fed a control diet. Epileptic mice fed a control diet showed a reduction of both villus height and villus height/crypt depth ratio (p < 0.01) and a decreased number of goblet cells (p < 0.01) in the duodenum, as well as increased macrophage (Iba1)-immunostaining in the jejunum (p < 0.05), compared to respective sham mice. Rifaximin's effect on seizures was associated with a reversal of gut structural and cellular changes, except for goblet cells which remained reduced. Seizure duration in epileptic mice was negatively correlated with the number of mossy cells (p < 0.01) and with villus height/crypt depth ratio (p < 0.05). Rifaximin-treated epileptic mice also showed increased tight junctions (occludin and ZO-1, p < 0.01) and decreased TNF mRNA expression (p < 0.01) in the duodenum compared to epileptic mice fed a control diet. Rifaximin administered for 21 days in chronic epileptic mice (chronic disease stage) did not change the number or duration of seizures compared to epileptic mice fed a control diet. Chronic epileptic mice fed a control diet showed an increased crypt depth (p < 0.05) and reduced villus height/crypt depth ratio (p < 0.01) compared to respective sham mice. Rifaximin treatment did not affect these intestinal changes. At both disease stages, rifaximin modified α- and β-diversity in epileptic and sham mice compared to respective mice fed a control diet. The microbiota composition in epileptic mice, as well as the effects of rifaximin at the phylum, family and genus levels, depended on the stage of the disease. During the early disease phase, the abundance of specific taxa was positively correlated with seizure duration in epileptic mice. In conclusion, gut-related alterations reflecting a dysfunctional state, occur during epilepsy development in a TLE mouse model. A short-term treatment with rifaximin during the early phase of the disease, reduced seizure duration and neuropathology, and reversed some intestinal changes, strengthening the therapeutic effects of gut-based therapies in epilepsy.

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.

Diet composition and sterilization modifies intestinal microbiome diversity and burden of Theiler's virus infection-induced acute seizures

OBJECTIVE

Brain infection with Theiler's murine encephalomyelitis virus (TMEV) in C57BL/6J mice can induce acquired epileptogenesis. Diet alters acute seizure incidence in TMEV-infected mice; yet it is unclear whether intestinal dysbiosis may also impact acute or chronic behavioral comorbidities. This study thus assessed the impact of diet formulation and sterilization on acute seizure presentation, gut microbiome composition, and epilepsy-related chronic behavioral comorbidities.

METHODS

Baseline fecal samples were collected from male C57BL/6J mice (4- to 5-weeks-old; Jackson Labs) upon facility arrival. Mice were randomized to either autoclaved (AC) or irradiated diet (IR) (Prolab RMH 3000) or IR (Picolab 5053). Three days later, mice underwent intracerebral TMEV or phosphate-buffered saline (PBS) injection. Fecal samples were collected from a subset of mice at infection (Day 0) and Day 7 post-infection. Epilepsy-related working memory deficits and seizure threshold were assessed 6 weeks post-infection. Gut microbiome diversity was determined by 16S rRNA amplicon sequencing of fecal samples.

RESULTS

TMEV-infected mice displayed acute handling-induced seizures, regardless of diet: 28 of 57 IR Picolab 5053 (49.1%), 30 of 41 IR Prolab RMH 3000 (73.2%), and 47 of 77 AC Prolab RMH 3000 (61%) mice displayed seizures. The number of observed seizures differed significantly by diet: IR Picolab 5053 diet-fed mice had 2.2 ± 2.8 seizures (mean ± standard deviation), IR Prolab RMH 3000 diet-fed mice had 3.5 ± 2.9 seizures, and AC Prolab RMH 3000 diet-fed mice had 4.4 ± 3.8 seizures during the 7-day monitoring period. Gut microbiome composition differed significantly in TMEV-infected mice fed the AC Prolab RMH 3000 diet, with measured differences in gram-positive bacteria. These mice also displayed worsened long-term working memory deficits.

SIGNIFICANCE

Diet-induced differences in intestinal dysbiosis in the TMEV model are associated with marked changes in acute seizure presentation, symptomatic recovery, and onset of chronic behavioral comorbidities of epilepsy. Our study reveals a novel disease-modifying impact of dietary manipulation on intestinal bacterial species after TMEV-induced acute seizures.

Gamma-aminobutyric acid as a potential postbiotic mediator in the gut-brain axis

Gamma-aminobutyric acid (GABA) plays a crucial role in the central nervous system as an inhibitory neurotransmitter. Imbalances of this neurotransmitter are associated with neurological diseases, such as Alzheimer's and Parkinson's disease, and psychological disorders, including anxiety, depression, and stress. Since GABA has long been believed to not cross the blood-brain barrier, the effects of circulating GABA on the brain are neglected. However, emerging evidence has demonstrated that changes in both circulating and brain levels of GABA are associated with changes in gut microbiota composition and that changes in GABA levels and microbiota composition play a role in modulating mental health. This recent research has raised the possibility that GABA may be a potent mediator of the gut-brain axis. This review article will cover up-to-date information about GABA-producing microorganisms isolated from human gut and food sources, explanation why those microorganisms produce GABA, food factors inducing gut-GABA production, evidence suggesting GABA as a mediator linking between gut microbiota and mental health, including anxiety, depression, stress, epilepsy, autism spectrum disorder, and attention deficit hyperactivity disorder, and novel information regarding homocarnosine-a predominant brain peptide that is a putative downstream mediator of GABA in regulating brain functions. This review will help us to understand how the gut microbiota and GABA-homocarnosine metabolism play a significant role in brain functions. Nonetheless, it could support further research on the use of GABA production-inducing microorganisms and food factors as agents to treat neurological and psychological disorders.

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.

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.

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.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

Identification of disordered profiles of gut microbiota and functional component in stroke and poststroke epilepsy

AIMS

It is estimated that 11.5% of patients with stroke (STR) were at risk of suffering poststroke epilepsy (PSE) within 5 years. Gut microbiota is shown to affect health in humans by producing metabolites. The association between dysregulation of gut microbiota and STR/PSE remains unclear. The aim of this study was to identify potential gut microbiota and functional component in STR and PSE, which may provide a theoretical foundation for diagnosis and treatment of STR and PSE.

METHODS

The fresh stool samples were collected from 19 healthy controls, 27 STR patients, and 20 PSE patients for 16S rRNA gene sequencing. Analysis of amplicon sequence variant and community diversity was performed, followed by the identification of dominant species, species differences analysis, diagnostic, and functional analysis of species in STR and PSE.

RESULTS

Community diversity was decreased in STR and PSE. Some disordered profiles of gut microbiota in STR and PSE were identified, such as the increase of Enterococcus and the decrease of butyricicoccus in STR, the increase of Escherichia Shigella and Clostridium innocuum-group and the decrease of Faecalibacterium in PSE, and the decrease of Anaerostipes in both STR and PSE. Moreover, potential diagnostic biomarkers for STR (butyricicoccus), PSE (Faecalibacterium), STR, and PSE (NK4A214_group and Veillonella) were identified. Several significantly dysfunctional components were identified, including l-tryptophan biosynthesis in STR, fatty acid biosynthesis in PSE, and Stress_Tolerant and anaerobic in both STR and PSE.

CONCLUSION

The disturbed gut microbiota and related dysfunctional components are closely associated with the progression of STR and PSE.

Gut-Brain-axis: effect of basil oil on the gut microbiota and its contribution to the anticonvulsant properties

BACKGROUND

Epilepsy is a chronic neurological condition that disrupts the normal functioning of the brain and it is characterized by seizures. Research suggests the involvement of the Gut-Brain axis in epilepsy. This study seeks to determine the role of the gut microbiota in the anticonvulsant effect of basil oil (BO) using antibiotic-depleted and altered germ-free mice against naïve mice in Pentylenetetrazole (PTZ) induced seizure model. There is an ever growing interest in improvement of treatment outcomes in epilepsy and also in the development of newer therapeutic options, especially in the population of patients that do not attain seizure relief from available antiseizure medications (ASMs). According to research, gut microbiota can alter brain function and development. Increasing evidence suggests disrupting the delicate symbiotic balance existing between the gut and brain results in disease conditions. Also, the oil from Ocimum basilicum L., (BO) has been proven scientifically to significantly block clonic seizures induced by PTZ and picrotoxin in seizure models.

METHODS

The microbiota of mice were depleted or altered by administering cocktail antibiotics and individual antibiotics respectively. DNA was isolated from mouse stool, and then the 16S ribosomal ribonucleic acid (16S rRNA) gene was quantitatively amplified using reverse transcription-polymerase chain reaction (RT-PCR). Amplicons were sequenced to determine the phylogenetic make-up of the bacteria involved. Metabolic profiles of the serum and stool of mice were determined using Proton (1H) Nuclear Magnetic Resonance (NMR) spectroscopy.

RESULTS

Cocktail antibiotic pre-treatment significantly reversed the anticonvulsant effect of BO by increasing frequency and duration of seizures but did not affect latency to seizure. In mice pre-treated with single antibiotics, the anticonvulsant effect of BO was lost as latency to seizures, frequency and duration of seizures increased compared to mice that received only BO. Assessment of the phylogenetic make-up of the microbiota in antibiotic pre-treated mice showed a distorted composition of the microbiota compared to the control group.

CONCLUSION

Depletion of the microbiota significantly reversed the anticonvulsant actions of BO. The concentrations of short chain fatty acids (SCFAs) was higher in stool than in the serum of the mice. Administration of BO probably does not influence the microbial composition within the mouse microbiota. The elevated ratio of Firmicutes to Bacteroidetes in microbiota-depleted groups might have contributed to the reversal of anticonvulsant actions of BO.

Electrophysiological, histopathological, and biochemical evaluation of the protective effect of probiotic supplementation against pentylenetetrazole-induced seizures in rats

BACKGROUND AND PURPOSE

Research on the relationship between the gut microbiome and epilepsy is accumulating. The present study was conducted to evaluate the effect of probiotic supplementation on pentylenetetrazole (PTZ)-induced seizures in rats.

METHODS

Twenty-one adult male Wistar albino rats were included. The animals were divided into three groups of seven rats. Group 1 was a control group, whereas Group 2 rats received PTZ treatment and Group 3 rats had PTZ+PB (probiotic) treatment. For 6 weeks, Groups 1 and 2 were given saline (1 ml), whereas Group 3 had probiotic supplement. In the 5th week, tripolar electrodes were attached to the rats. Electrophysiological, behavioral, biochemical, and immunohistochemical evaluations were performed in the 6 weeks after the treatment.

RESULTS

PB treatment significantly reduced seizures. In the PTZ group, expression levels of brain-derived neurotrophic factor, nerve growth factor (NGF), and Sox2 (SRY sex-determining region Y-box 2) in rat brains decreased significantly compared to the control group, whereas the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), and nitric oxide (NO) levels increased. In the PTZ+PB group, NGF expression increased significantly compared to the PTZ group, whereas TNF-α, IL-6, TOS, and NO levels decreased. In histopathological examination, an abundance of necrotic neurons was notable in the PTZ group, which was less in the PTZ+PB group. In addition, body weight of the group supplemented with probiotics decreased after the treatment.

CONCLUSIONS

Our results suggest that probiotic supplementation may alleviate seizure severity and exert neuroprotective effects by reducing neuroinflammation and oxidative stress and altering the expression of neurotrophins in epileptogenic brains.

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.

Diet composition and sterilization modifies intestinal microbiome diversity and burden of Theiler's virus infection-induced acute seizures

Objective

Central nervous system infection with Theiler's murine encephalomyelitis virus (TMEV) in C57BL/6J mice can model acquired epileptogenesis. Diet alters the acute seizure incidence in TMEV-infected mice; yet it is unclear whether intestinal dysbiosis may also impact acute or chronic behavioral comorbidities. This study thus assessed the impact of diet sterilization in a specific pathogen-free vivarium on acute seizure presentation, the composition of the gut microbiome, and chronic behavioral comorbidities of epilepsy.

Methods

Baseline fecal samples were collected from male C57BL/6J mice (4-5 weeks-old; Jackson Labs) upon arrival. Mice were randomized to either autoclaved (AC) or irradiated (IR) diet (Prolab RMH 3000 - UU diets) or IR (Picolab 5053 - UW IR diet). Mice then underwent intracerebral TMEV or PBS injection three days later. Fecal samples were collected from a subset of mice at infection (Day 0) and Day 7 post-infection. Epilepsy-related working memory deficits and seizure threshold were assessed 6 weeks post-infection. Gut microbiome diversity was determined by 16S rRNA amplicon sequencing of fecal samples.

Results

TMEV-infected mice displayed acute handling-induced seizures, regardless of diet: 28/57 UW IR (49.1%), 30/41 UU IR (73.2%), and 47/77 UU AC (61%) mice displayed seizures. The number of observed seizures significantly differed: UW IR mice had 2.2±2.8 seizures (mean±standard deviation), UU IR mice had 3.5±2.9 seizures, and UU AC mice had 4.4±3.8 seizures during the 7-day monitoring period. The composition of the gut microbiome significantly differed in TMEV-infected mice fed the UU AC diet, with most measured differences occurring in Gram-positive bacteria. TMEV-infected mice fed the UU AC diet displayed worsened chronic working memory.

Significance

Intestinal dysbiosis evokes stark differences in acute seizure presentation in the TMEV model and vastly influences the trajectory of post-TMEV infection-induced behavioral comorbidities of epilepsy. Our study reveals a novel disease-modifying contribution of intestinal bacterial species after TMEV-induced acute seizures.

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.

Effects of probiotics on GABA/glutamate and oxidative stress in PTZ- induced acute seizure model in rats

Studies conducted in recent years have indicated a relationship between epilepsy and gut microbiota. Ion channels, excitatory/inhibitory balance and regulatory systems play a role in the pathophysiology of epilepsy. In addition, gut dysbiosis is also involved in the pathophysiology of epilepsy. This research investigated the impacts of probiotic mixture on epileptic seizures, Gamma aminobutyric acid (GABA), glutamate, and TAS and TOS levels in hippocampal tissue in the PTZ-induced acute seizure model in rats. Four groups were formed with male Wistar albino rats. The first and second groups were given 1 ml/day saline solution, and the other groups were given 0.05 mg/1 ml/day vehicle or 109cfu/1 ml/day probiotic supplementation, respectively via gavage for 21 days. A single-dose PTZ (45 mg/kg) was administered to induce seizure. The stages of seizure were analyzed according to the Racine scale. While ELISA was used to determine GABA and glutamate levels in the hippocampus, an automated colorimetric method was utilized to measure oxidant/antioxidant biomarkers. It was found that by delaying the first myoclonic jerk (FMJ), and the onset of the generalized tonic-clonic seizures, the probiotic mixture demonstrated anticonvulsant effects against seizures. The probiotic mixture was found to increase the inhibitory neurotransmitter GABA. It was also found to decrease TOS levels and increase TAS concentration. The findings of this study showed that probiotic mixture reduced oxidative stress with its positive effects against PTZ-induced epileptic seizures. Further studies are needed to reveal potentially related mechanisms.

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.

Neurotransmitter systems in the etiology of major neurological disorders: Emerging insights and therapeutic implications

Neurotransmitters serve as chemical messengers playing a crucial role in information processing throughout the nervous system, and are essential for healthy physiological and behavioural functions in the body. Neurotransmitter systems are classified as cholinergic, glutamatergic, GABAergic, dopaminergic, serotonergic, histaminergic, or aminergic systems, depending on the type of neurotransmitter secreted by the neuron, allowing effector organs to carry out specific functions by sending nerve impulses. Dysregulation of a neurotransmitter system is typically linked to a specific neurological disorder. However, more recent research points to a distinct pathogenic role for each neurotransmitter system in more than one neurological disorder of the central nervous system. In this context, the review provides recently updated information on each neurotransmitter system, including the pathways involved in their biochemical synthesis and regulation, their physiological functions, pathogenic roles in diseases, current diagnostics, new therapeutic targets, and the currently used drugs for associated neurological disorders. Finally, a brief overview of the recent developments in neurotransmitter-based therapeutics for selected neurological disorders is offered, followed by future perspectives in that area of research.

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.

Beneficial Effects of Probiotic Bifidobacterium longum in a Lithium-Pilocarpine Model of Temporal Lobe Epilepsy in Rats

Epilepsy is a challenging brain disorder that is often difficult to treat with conventional therapies. The gut microbiota has been shown to play an important role in the development of neuropsychiatric disorders, including epilepsy. In this study, the effects of Bifidobacterium longum, a probiotic, on inflammation, neuronal degeneration, and behavior are evaluated in a lithium-pilocarpine model of temporal lobe epilepsy (TLE) induced in young adult rats. B. longum was administered orally at a dose of 10⁹ CFU/rat for 30 days after pilocarpine injection. The results show that B. longum treatment has beneficial effects on the TLE-induced changes in anxiety levels, neuronal death in the amygdala, and body weight recovery. In addition, B. longum increased the expression of anti-inflammatory and neuroprotective genes, such as Il1rn and Pparg. However, the probiotic had little effect on TLE-induced astrogliosis and microgliosis and did not reduce neuronal death in the hippocampus and temporal cortex. The study suggests that B. longum may have a beneficial effect on TLE and may provide valuable insights into the role of gut bacteria in epileptogenesis. In addition, the results show that B. longum may be a promising drug for the comprehensive treatment of epilepsy.

Use of Integrative, Complementary, and Alternative Medicine in Children with Epilepsy: A Global Scoping Review

(1) Background: Epilepsy is one of the most common chronic neurological disorders in childhood. Complementary and alternative medicine (CAM) use is highly prevalent in patients with epilepsy. Despite CAM's widespread and increasing popularity, its prevalence, forms, perceived benefits, and potential risks in pediatric epilepsy are rarely explored. (2) Methods: We performed a scoping review of the available literature on the use of CAM in pediatric epilepsy. (3) Results: Overall, global cross-sectional studies showed a variable degree of CAM usage among children with epilepsy, ranging from 13 to 44% in prevalence. Popular types of CAMs reported were supplements, cannabis products, aromatherapy, herbal remedies, dietary therapy, massage therapy, and prayer. Families often report that CAM is effective, although there are limited objective measures of this. Potential risks lie in the use of CAM, such as herbal remedies, and/or unregulated, contaminated, or unpurified products. Studies also underscored inadequate patient-physician discussions regarding CAM. (4) Conclusions: A better understanding of this topic would aid clinicians in guiding patients/families on the use of CAM. Further studies on the efficacy of the different types of CAM used, as well as potential side effects and drug interactions are needed.

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial design to investigate the potential of psychobiotics on seizure semiology and comorbidities in canine epilepsy: study protocol

BACKGROUND

Epilepsy is the most common chronic neurological disease in dogs. More than two-thirds of these patients suffer from associated behavioural comorbidities. The latter could have their origin in partially overlapping pathomechanisms, with the intestinal microbiome as a potential key link between them. The current arsenal of drugs for epilepsy management remains limited. Most canine patients continue to have seizures despite treatment and the occurrence of comorbidities is not sufficiently addressed, limiting quality of life of affected dogs and owners. Therefore, novel additional epilepsy management options are urgently needed. The microbiome-gut-brain axis may serve as a new target for the development of innovative multimodal therapeutic approaches to overcome current shortcomings in epilepsy management.

METHODS

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial was designed to investigate the potential of the psychobiotic Bifidobacterium longum on behavioural comorbidities in canine epilepsy. Seizure semiology will be evaluated as a secondary outcome measure. Thirty-four privately owned dogs are planned to be included in the ongoing study meeting the following inclusion criteria: Dogs displaying increased anxiety/fear behaviour since the start of the idiopathic epilepsy. Tier II confidence level of the International Veterinary Epilepsy Task Force for the diagnosis of idiopathic epilepsy, with a maximum seizure interval of 3 month and a minimum of three generalised seizures within that period and chronically treated with at least one antiseizure drug without improvement in seizure frequency Each dog will receive the allocated supplement (probiotic vs. placebo) alongside its normal diet for a 3-month period. After a three-week wash out period, the second phase starts by administering the respective other supplement for another 3 months.

DISCUSSION

The current study considers modern high-quality standards for epilepsy medication trials. Common biasing effects should be limited to a possible minimum (regression-to-the mean effect, placebo effect, observer effect), ensuring a high validity and accuracy of the acquired results, thus enabling a representative nature of the efficacy of Bifidobacterium longum as add-on supplement for dogs suffering from epilepsy and its comorbidities. This publication should provide a description of the study procedure and data acquisition methods, including prognosed statistical analysis.

Immune Mechanisms in Epileptogenesis: Update on Diagnosis and Treatment of Autoimmune Epilepsy Syndromes

Seizures and epilepsy can result from various aetiologies, yet the underlying cause of several epileptic syndromes remains unclear. In that regard, autoimmune-mediated pathophysiological mechanisms have been gaining attention in the past years and were included as one of the six aetiologies of seizures in the most recent classification of the International League Against Epilepsy. The increasing number of anti-neuronal antibodies identified in patients with encephalitic disorders has contributed to the establishment of an immune-mediated pathophysiology in many cases of unclear aetiology of epileptic syndromes. Yet only a small number of patients with autoimmune encephalitis develop epilepsy in the proper sense where the brain transforms into a state where it will acquire the enduring propensity to produce seizures if it is not hindered by interventions. Hence, the term autoimmune epilepsy is often wrongfully used in the context of autoimmune encephalitis since most of the seizures are acute encephalitis-associated and will abate as soon as the encephalitis is in remission. Given the overlapping clinical presentation of immune-mediated seizures originating from different aetiologies, a clear distinction among the aetiological entities is crucial when it comes to discussing pathophysiological mechanisms, therapeutic options, and long-term prognosis of patients. Moreover, a rapid and accurate identification of patients with immune-mediated epilepsy syndromes is required to ensure an early targeted treatment and, thereby, improve clinical outcome. In this article, we review our current understanding of pathogenesis and critically discuss current and potential novel treatment options for seizures and epilepsy syndromes of underlying or suspected immune-mediated origin. We further outline the challenges in proper terminology.

Altered intestinal microbiota composition with epilepsy and concomitant diarrhea and potential indicator biomarkers in infants

Introduction

The diversity and dysregulation of intestinal microbiota is related to the pathology of epilepsy. Gut microbiota plays an important role in epilepsy, and regulating intestinal microbiota through exogenous intervention can alleviate symptoms. However, there are no studies about the effects of epilepsy-related diarrhea on gut microbiota.

Methods

The diversity and dysregulation of intestinal microbiota is related to the pathology of epilepsy. Gut microbiota plays an important role in epilepsy, and regulating intestinal microbiota through exogenous intervention can alleviate symptoms. However, there are no studies about the effects of epilepsy-related diarrhea on gut microbiota. To evaluate changes in gut microbiota structure and composition in patients with epilepsy and associated diarrhea, the structure and composition of the fecal microbiota among patients with epilepsy (EP, 13 cases), epilepsy with diarrhea (ED, 13 cases), and probiotic treatments (PT, 13 cases), and healthy controls (CK, seven cases) were investigated and validated by utilizing high-throughput 16S rRNA sequencing.

Results

The results showed that the α-diversity indexes indicated that richness and phylogenetic diversity had no significant differences among groups. However, the variation of β-diversity indicated that the structure and composition of intestinal microbiota were significantly different among the CK, EP, ED, and PT groups (permutational multivariate analysis of variance, p-value = 0.001). Normalized stochasticity ratio and β-nearest taxon index indicated that stochastic mechanisms exerted increasing influence on community differences with epilepsy and associated diarrhea. ED microbiome alterations include increased Proteobacteria and decreased Actinobacteria and Firmicutes at the phylum level. Bifidobacterium was the core microbe in CK, EP, and PT, whereas it decreased significantly in ED. In contrast, Escherichia/Shigella was the core microbe in CK and ED, whereas it increased significantly in ED (Tukey's multiple comparisons test, adjusted p-value <0.05). The association network in CK has higher complexity and aggregation than in the other groups. The EP network indicated high connectivity density within each community and high sparsity among communities. The bacterial community network of the ED had a more compact local interconnection, which was in contrast to that of PT. The top 7 microbial amplicon sequence variant-based markers that were selected by machine learning to distinguish the groups of epilepsy, probiotic treatments, and healthy infants had stronger discrimination ability. In addition, ASVs_1 (Escherichia/Shigella) and ASVs_3 (Bifidobacterium) had the most importance in the recognition.

Discussion

Our research finally showed that infants with epilepsy, epilepsy with diarrhea, and probiotic treatments exhibit substantial alterations of intestinal microbiota structure and composition, and specific intestinal strains are altered according to different clinical phenotypes and can therefore be used as potential biomarkers for disease diagnosis.

The different trends in the burden of neurological and mental disorders following dietary transition in China, the USA, and the world: An extension analysis for the Global Burden of Disease Study 2019

Introduction

The highly processed western diet is substituting the low-processed traditional diet in the last decades globally. Increasing research found that a diet with poor quality such as western diet disrupts gut microbiota and increases the susceptibility to various neurological and mental disorders, while a balanced diet regulates gut microbiota and prevents and alleviates the neurological and mental disorders. Yet, there is limited research on the association between the disease burden expanding of neurological and mental disorders with a dietary transition.

Methods

We compared the disability-adjusted life-years (DALYs) trend by age for neurological and mental disorders in China, in the United States of America (USA), and across the world from 1990 to 2019, evaluated the dietary transition in the past 60 years, and analyzed the association between the burden trend of the two disorders with the changes in diet composition and food production.

Results

We identified an age-related upward pattern in disease burden in China. Compared with the USA and the world, the Chinese neurological and mental disorders DALY percent was least in the generation over 75 but rapidly increased in younger generations and surpassed the USA and/or the world in the last decades. The age-related upward pattern in Chinese disease burdens had not only shown in the presence of cardiovascular diseases, neoplasms, and diabetes mellitus but also appeared in the presence of depressive disorders, Parkinson's disease, Alzheimer's disease and other dementias, schizophrenia, headache disorders, anxiety disorders, conduct disorders, autism spectrum disorders, and eating disorders, successively. Additionally, the upward trend was associated with the dramatic dietary transition including a reduction in dietary quality and food production sustainability, during which the younger generation is more affected than the older. Following the increase in total calorie intake, alcohol intake, ratios of animal to vegetal foods, and poultry meat to pulses, the burdens of the above diseases continuously rose. Then, following the rise of the ratios of meat to pulses, eggs to pulses, and pork to pulses, the usage of fertilizers, the farming density of pigs, and the burdens of the above disease except diabetes mellitus were also ever-increasing. Even the usage of pesticides was positively correlated with the burdens of Parkinson's disease, schizophrenia, cardiovascular diseases, and neoplasms. Contrary to China, the corresponding burdens of the USA trended to reduce with the improvements in diet quality and food production sustainability.

Discussion

Our results suggest that improving diet quality and food production sustainability might be a promising way to stop the expanding burdens of neurological and mental disorders.

Exposure to Antibiotics and Neurodevelopmental Disorders: Could Probiotics Modulate the Gut-Brain Axis?

In order to develop properly, the brain requires the intricate interconnection of genetic factors and pre-and postnatal environmental events. The gut-brain axis has recently raised considerable interest for its involvement in regulating the development and functioning of the brain. Consequently, alterations in the gut microbiota composition, due to antibiotic administration, could favor the onset of neurodevelopmental disorders. Literature data suggest that the modulation of gut microbiota is often altered in individuals affected by neurodevelopmental disorders. It has been shown in animal studies that metabolites released by an imbalanced gut-brain axis, leads to alterations in brain function and deficits in social behavior. Here, we report the potential effects of antibiotic administration, before and after birth, in relation to the risk of developing neurodevelopmental disorders. We also review the potential role of probiotics in treating gastrointestinal disorders associated with gut dysbiosis after antibiotic administration, and their possible effect in ameliorating neurodevelopmental disorder symptoms.

Ketogenic Diets in the Management of Lennox-Gastaut Syndrome-Review of Literature

Epilepsy is an important medical problem with approximately 50 million patients globally. No more than 70% of epileptic patients will achieve seizure control after antiepileptic drugs, and several epileptic syndromes, including Lennox-Gastaut syndrome (LGS), are predisposed to more frequent pharmacoresistance. Ketogenic dietary therapies (KDTs) are a form of non-pharmacological treatments used in attempts to provide seizure control for LGS patients who experience pharmacoresistance. Our review aimed to evaluate the efficacy and practicalities concerning the use of KDTs in LGS. In general, KDTs are diets rich in fat and low in carbohydrates that put the organism into the state of ketosis. A classic ketogenic diet (cKD) is the best-evaluated KDT, while alternative KDTs, such as the medium-chain triglyceride diet (MCT), modified Atkins diet (MAD), and low glycemic index treatment (LGIT) present several advantages due to their better tolerability and easier administration. The literature reports regarding LGS suggest that KDTs can provide ≥50% seizure reduction and seizure-free status in a considerable percentage of the patients. The most commonly reported adverse effects are constipation, diarrhea, and vomiting, while severe adverse effects such as nephrolithiasis or osteopenia are rarely reported. The literature review suggests that KDTs can be applied safely and are effective in LGS treatment.

Changes and significance of gut microbiota in children with focal epilepsy before and after treatment

Objective

To better understand the alterations in gut microbiota and metabolic pathways in children with focal epilepsy, and to further investigate the changes in the related gut microbiota and metabolic pathways in these children before and after treatment.

Methods

Ten patients with newly diagnosed focal epilepsy in Hunan Children’s Hospital from April, 2020 to October, 2020 were recruited into the case group. The case group was further divided into a pre-treatment subgroup and a post-treatment subgroup. Additionally, 14 healthy children of the same age were recruited into a control group. The microbial communities were analyzed using 16s rDNA sequencing data. Metastas and LEfSe were used to identify different bacteria between and within groups. The Kyoto Encyclopedia of Genes and Genomes database was used to KEGG enrichment analysis.

Results

There were significant differences in α diversity among the pre-treatment, post-treatment, and control groups. Besides, the differences in gut microbiota composition in 3 groups were identified by principal co-ordinates analysis (PCoA), which showed a similar composition of the pre-treatment and post-treatment subgroups. At the phyla level, the relative abundance of Actinobacteria in the pre-treatment subgroup was significantly higher than that in the control group, which decreased significantly after 3 months of treatment and showed no significant difference between the control group. In terms of the genus level, Escherichia/Shigella, Streptococcus, Collinsella, and Megamonas were enriched in the pre-treatment subgroup, while Faecalibacterium and Anaerostipes were enriched in the control group. The relative abundance of Escherichia/Shigella, Streptococcus, Collinsella, and Megamonas was reduced significantly after a three-month treatment. Despite some genera remaining significantly different between the post-treatment subgroup and control group, the number of significantly different genera decreased from 9 to 4 through treatment. Notably, we found that the carbohydrate metabolism, especially succinate, was related to focal epilepsy.

Conclusion

Children with focal epilepsy compared with healthy controls were associated with the statistically significant differences in the gut microbiota and carbohydrate metabolism. The differences were reduced and the carbohydrate metabolism improved after effective treatment. Our research may provide new directions for understanding the role of gut microbiota in the pathogenesis of focal epilepsy and better alternative treatments.

Epilepsy and the gut: Perpetrator or victim?

The brain and the gut are linked together with a complex, bi-path link known as the gut-brain axis through the central and enteric nervous systems. So, the brain directly affects and controls the gut through various neurocrine and endocrine processes, and the gut impacts the brain via different mechanisms. Epilepsy is a central nervous system (CNS) disorder with abnormal brain activity, causing repeated seizures due to a transient excessive or synchronous alteration in the brain’s electrical activity. Due to the strong relationship between the enteric and the CNS, gastrointestinal dysfunction may increase the risk of epilepsy. Meanwhile, about 2.5% of patients with epilepsy were misdiagnosed as having gastrointestinal disorders, especially in children below the age of one year. Gut dysbiosis also has a significant role in epileptogenesis. Epilepsy, in turn, affects the gastrointestinal tract in different forms, such as abdominal aura, epilepsy with abdominal pain, and the adverse effects of medications on the gut and the gut microbiota. Epilepsy with abdominal pain, a type of temporal lobe epilepsy, is an uncommon cause of abdominal pain. Epilepsy also can present with postictal states with gastrointestinal manifestations such as postictal hypersalivation, hyperphagia, or compulsive water drinking. At the same time, antiseizure medications have many gastrointestinal side effects. On the other hand, some antiseizure medications may improve some gastrointestinal diseases. Many gut manipulations were used successfully to manage epilepsy. Prebiotics, probiotics, synbiotics, postbiotics, a ketogenic diet, fecal microbiota transplantation, and vagus nerve stimulation were used successfully to treat some patients with epilepsy. Other manipulations, such as omental transposition, still need more studies. This narrative review will discuss the different ways the gut and epilepsy affect each other.

Diet-microbiome-gut-brain nexus in acute and chronic brain injury

In recent years, appreciation for the gut microbiome and its relationship to human health has emerged as a facilitator of maintaining healthy physiology and a contributor to numerous human diseases. The contribution of the microbiome in modulating the gut-brain axis has gained significant attention in recent years, extensively studied in chronic brain injuries such as Epilepsy and Alzheimer’s Disease. Furthermore, there is growing evidence that gut microbiome also contributes to acute brain injuries like stroke(s) and traumatic brain injury. Microbiome-gut-brain communications are bidirectional and involve metabolite production and modulation of immune and neuronal functions. The microbiome plays two distinct roles: it beneficially modulates immune system and neuronal functions; however, abnormalities in the host’s microbiome also exacerbates neuronal damage or delays the recovery from acute injuries. After brain injury, several inflammatory changes, such as the necrosis and apoptosis of neuronal tissue, propagates downward inflammatory signals to disrupt the microbiome homeostasis; however, microbiome dysbiosis impacts the upward signaling to the brain and interferes with recovery in neuronal functions and brain health. Diet is a superlative modulator of microbiome and is known to impact the gut-brain axis, including its influence on acute and neuronal injuries. In this review, we discussed the differential microbiome changes in both acute and chronic brain injuries, as well as the therapeutic importance of modulation by diets and probiotics. We emphasize the mechanistic studies based on animal models and their translational or clinical relationship by reviewing human studies.

Multi-omic Analysis of the Gut Microbiome in Rats with Lithium-Pilocarpine-Induced Temporal Lobe Epilepsy

Evidence supports that the gut microbiota and bacteria-dependent metabolites influence the maintenance of epileptic brain activity. However, the alterations in the gut microbiota between epileptic versus healthy individuals are poorly understood. We used a multi-omic approach to evaluate the changes in the composition of gut metagenome as well in the fecal metabolomic profile in rats before and after being submitted to status epilepticus (SE)-induced temporal lobe epilepsy (TLE). The 16S ribosomal RNA (rRNA) sequencing of fecal samples coupled to bioinformatic analysis revealed taxonomic, compositional, and functional shifts in epileptic rats. The species richness (Chao1 index) was significantly lower in the post-TLE group, and the β-diversity analysis revealed clustering separated from the pre-TLE group. The taxonomic abundance analysis showed a significant increase of phylum Desulfobacterota and a decrease of Patescibacteria in the post-TLE group. The DESEq2 and LEfSe analysis resulted in 18 genera significantly enriched between post-TLE and pre-TLE groups at the genus level. We observed that epileptic rats present a peculiar metabolic phenotype, including a lower concentration of D-glucose and L-lactic acid and a higher concentration of L-glutamic acid and glycine. The microbiota-host metabolic correlation analysis showed that the genera differentially abundant in post-TLE rats are associated with the altered metabolites, especially the proinflammatory Desulfovibrio and Marvinbryantia, which were enriched in epileptic animals and positively correlated with these excitatory neurotransmitters and carbohydrate metabolites. Therefore, our data revealed a correlation between dysbacteriosis in epileptic animals and fecal metabolites that are known to be relevant for maintaining epileptic brain activity by enhancing chronic inflammation, an excitatory-inhibitory imbalance, and/or a metabolic disturbance. These data are promising and suggest that targeting the gut microbiota could provide a novel avenue for preventing and treating acquired epilepsy. However, the causal relationship between these microbial/metabolite components and the SRS occurrence still needs further exploration.

Role of Short Chain Fatty Acids in Epilepsy and Potential Benefits of Probiotics and Prebiotics: Targeting “Health” of Epileptic Patients

The WHO’s definition of health transcends the mere absence of disease, emphasizing physical, mental, and social well-being. As this perspective is being increasingly applied to the management of chronic diseases, research on gut microbiota (GM) is surging, with a focus on its potential for persistent and noninvasive dietary therapeutics. In patients with epilepsy (PWE), a chronic lack of seizure control along with often neglected psychiatric comorbidities greatly disrupt the quality of life. Evidence shows that GM-derived short chain fatty acids (SCFAs) may impact seizure susceptibility through modulating (1) excitatory/inhibitory neurotransmitters, (2) oxidative stress and neuroinflammation, and (3) psychosocial stress. These functions are also connected to shared pathologies of epilepsy and its two most common psychiatric consequences: depression and anxiety. As the enhancement of SCFA production is enabled through direct administration, as well as probiotics and prebiotics, related dietary treatments may exert antiseizure effects. This paper explores the potential roles of SCFAs in the context of seizure control and its mental comorbidities, while analyzing existing studies on the effects of pro/prebiotics on epilepsy. Based on currently available data, this study aims to interpret the role of SCFAs in epileptic treatment, extending beyond the absence of seizures to target the health of PWE.

ProBioQuest: a database and semantic analysis engine for literature, clinical trials and patents related to probiotics

The use of probiotics to improve health via the modulation of gut microbiota has gained wide attention. The growing volume of investigations of probiotic microorganisms and commercialized probiotic products has created the need for a database to organize the health-promoting functions driven by probiotics reported in academic articles, clinical trials and patents. We constructed ProBioQuest to collect up-to-date literature related to probiotics from PubMed.gov, ClinicalTrials.gov and PatentsView. More than 2.8 million articles have been collected. Automated information technology-assisted procedures enabled us to collect the data continuously, providing the most up-to-date information. Statistical functions and semantic analyses are provided on the website as an advanced search engine, which contributes to the semantic tool of this database for information search and analyses. The semantic analytical output provides categorized search results and functions to enhance further analysis. A keyword bank is included which can display multiple tables of contents. Users can select keywords from different displayed categories to achieve easily filtered searches. Additional information on the searched items can be browsed via the link-out function. ProBioQuest is not only useful to scientists and health professionals but also to dietary supplement manufacturers and the general public. In this paper, the method we used to build this database-web system is described. Applications of ProBioQuest for several literature-based analyses of probiotics are included as examples of the various uses of this search engine. ProBioQuest can be accessed free of charge at http://kwanlab.bio.cuhk.edu.hk/PBQ/.

Effects of long-term supplementation of probiotics on cognitive function and emotion in temporal lobe epilepsy

Cognitive impairment and neuropsychiatric disorders are very common in patients with temporal lobe epilepsy (TLE). These comorbidities complicate the treatment of epilepsy and seriously affect the quality of life. So far, there is still no effective intervention to prevent the development of epilepsy-associated comorbidities. Gut dysbiosis has been recognized to be involved in the pathology of epilepsy development. Modulating gut microbiota by probiotics has shown an antiseizure effect on humans and animals with epilepsy. Whether this treatment strategy has a positive effect on epilepsy-associated comorbidities remains unclear. Therefore, this study aimed to objectively assess the effect of probiotics on cognitive function and neuropsychiatric performance of patients with TLE. Participants enrolled in an epilepsy clinic were randomly assigned to the probiotic and placebo groups. These two groups were treated with probiotics or placebo for 12 weeks, and then the cognitive function and psychological performance of participants were assessed. We enrolled 76 participants in this study, and 70 subjects were finally included in the study (35 in the probiotics group and 35 in the placebo group). Our results showed significant seizure reduction in patients with TLE treated with probiotics. No significant differences were observed on cognitive function (including intelligence and memory) between groups. For neuropsychiatric performances, supplementation of probiotics significantly decreased the Hamilton Anxiety Rating and Depression Scale scores and increased the 89-item Quality of Life in Epilepsy Inventory score in patients with TLE. In conclusion, probiotics have a positive impact on seizures control, and improve anxiety, depression, and quality of life in patients with TLE.

Targeted gut microbiota manipulation attenuates seizures in a model of infantile spasms syndrome

Infantile spasms syndrome (IS) is a devastating early-onset epileptic encephalopathy associated with poor neurodevelopmental outcomes. When first-line treatment options, including adrenocorticotropic hormone and vigabatrin, are ineffective, the ketogenic diet (KD) is often employed to control seizures. Since the therapeutic impact of the KD is influenced by the gut microbiota, we examined whether targeted microbiota manipulation, mimicking changes induced by the KD, would be valuable in mitigating seizures. Employing a rodent model of symptomatic IS, we show that both the KD and antibiotic administration reduce spasm frequency and are associated with improved developmental outcomes. Spasm reductions were accompanied by specific gut microbial alterations, including increases in Streptococcus thermophilus and Lactococcus lactis. Mimicking the fecal microbial alterations in a targeted probiotic, we administered these species in a 5:1 ratio. Targeted probiotic administration reduced seizures and improved locomotor activities in control diet–fed animals, similar to KD-fed animals, while a negative control (Ligilactobacillus salivarius) had no impact. Probiotic administration also increased antioxidant status and decreased proinflammatory cytokines. Results suggest that a targeted probiotic reduces seizure frequency, improves locomotor activity in a rodent model of IS, and provides insights into microbiota manipulation as a potential therapeutic avenue for pediatric epileptic encephalopathies.

Gut Microbes Regulate Innate Immunity and Epilepsy

Epilepsy is a common chronic brain disease. There are many clinical methods to control epileptic seizures, such as anti-seizure medications (ASMs) or surgical removal of epileptogenic lesions. However, the pathophysiology of epilepsy is still unknown, making it difficult to control or prevent it. The host’s immune system monitors gut microbes, interacts with microbes through pattern recognition receptors such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs) expressed by innate immune cells, and activates immune responses in the body to kill pathogens and balance the relationship between microbes and host. In addition, inflammatory responses induced by the innate immune system are seen in animal models of epilepsy and temporal lobe epilepsy brain tissue to combat pathogens or injuries. This review summarizes the potential relationship between gut microbes, innate immunity, and epilepsy based on recent research to provide more hints for researchers to explore this field further.

Current Principles in the Management of Drug-Resistant Epilepsy

Drug-resistant epilepsy is associated with poor health outcomes and increased economic burden. In the last three decades, various new antiseizure medications have been developed, but the proportion of people with drug-resistant epilepsy remains relatively unchanged. Developing strategies to address drug-resistant epilepsy is essential. Here, we define drug-resistant epilepsy and emphasize its relationship to the conceptualization of epilepsy as a symptom complex, delineate clinical risk factors, and characterize mechanisms based on current knowledge. We address the importance of ruling out pseudoresistance and consider the impact of nonadherence on determining whether an individual has drug-resistant epilepsy. We then review the principles of epilepsy drug therapy and briefly touch upon newly approved and experimental antiseizure medications.

Higher levels of Bifidobacteria and tumor necrosis factor in children with drug-resistant epilepsy are associated with anti-seizure response to the ketogenic diet

Background

Recently, studies have suggested a role for the gut microbiota in epilepsy. Gut microbial changes during ketogenic diet (KD) treatment of drug-resistant epilepsy have been described. Inflammation is associated with certain types of epilepsy and specific inflammation markers decrease during KD. The gut microbiota plays an important role in the regulation of the immune system and inflammation.

Methods

28 children with drug-resistant epilepsy treated with the ketogenic diet were followed in this observational study. Fecal and serum samples were collected at baseline and three months after dietary intervention.

Findings

We identified both gut microbial and inflammatory changes during treatment. KD had a general anti-inflammatory effect. Novel bioinformatics and machine learning approaches identified signatures of specific Bifidobacteria and TNF (tumor necrosis factor) associated with responders before starting KD. During KD, taxonomic and inflammatory profiles between responders and non-responders were more similar than at baseline.

Interpretation

Our results suggest that children with drug-resistant epilepsy are more likely to benefit from KD treatment when specific Bifidobacteria and TNF are elevated. We here present a novel signature of interaction of the gut microbiota and the immune system associated with anti-epileptic response to KD treatment. This signature could be used as a prognostic biomarker to identify potential responders to KD before starting treatment. Our findings may also contribute to the development of new anti-seizure therapies by targeting specific components of the gut microbiota.

Funding

This study was supported by the Swedish Brain Foundation, Margarethahemmet Society, Stiftelsen Sunnerdahls Handikappfond, Linnea & Josef Carlssons Foundation, and The McCormick Genomic & Proteomic Center.

Targeting the MGBA with -biotics in epilepsy: New insights from preclinical and clinical studies

BACKGROUND

Data accumulation reveals that the bidirectional communication between the gut microbiota and the brain, called the microbiota-gut-brain axis (MGBA), can be modulated by different compounds including prebiotics, probiotics, symbiotic (a fair combination of both), and diet, thus exerting a beneficial impact on brain activity and behaviors. This review aims to give an overview of the possible beneficial effects of the supplementation of -biotics in epilepsy treatment.

METHODS

A search on PubMed and ClinicalTrials.gov databases using the terms "probiotics", OR "prebiotics", AND "gut microbiota", AND "epilepsy" was performed. The search covered the period of the last eleven years (2010-2021).

CONCLUSIONS

Nowadays, studies analyzing the clinical impact of gut microbiota-modulating intervention strategies on epilepsy are limited and heterogenous due either to the different experimental populations studied (i.e., genetic vs lesional mouse models) or the various primary outcomes measure evaluated. However, positive effects have invariably been noticed; particularly, there have been improvements in behavioral comorbidities and associated gastrointestinal (GI) symptoms. More studies will be needed in the next few years to strictly evaluate the feasibility to introduce these new therapeutic strategies in the clinical treatment of highly refractory epilepsies.

Gut microbiota in various childhood disorders: Implication and indications

Gut microbiota has a significant role in gut development, maturation, and immune system differentiation. It exerts considerable effects on the child's physical and mental development. The gut microbiota composition and structure depend on many host and microbial factors. The host factors include age, genetic pool, general health, dietary factors, medication use, the intestine's pH, peristalsis, and transit time, mucus secretions, mucous immunoglobulin, and tissue oxidation-reduction potentials. The microbial factors include nutrient availability, bacterial cooperation or antagonism, and bacterial adhesion. Each part of the gut has its microbiota due to its specific characteristics. The gut microbiota interacts with different body parts, affecting the pathogenesis of many local and systemic diseases. Dysbiosis is a common finding in many childhood disorders such as autism, failure to thrive, nutritional disorders, coeliac disease, Necrotizing Enterocolitis, helicobacter pylori infection, functional gastrointestinal disorders of childhood, inflammatory bowel diseases, and many other gastrointestinal disorders. Dysbiosis is also observed in allergic conditions like atopic dermatitis, allergic rhinitis, and asthma. Dysbiosis can also impact the development and the progression of immune disorders and cardiac disorders, including heart failure. Probiotic supplements could provide some help in managing these disorders. However, we are still in need of more studies. In this narrative review, we will shed some light on the role of microbiota in the development and management of common childhood disorders.

The Beneficial Effect of Probiotics Supplementation on Penicillin-Induced Focal Seizure in Rats

The focal epilepsy is a chronic neurological brain disorder which affects millions of people in the world. There is emerging evidence that changes in the gut microbiota may have effects on epileptic seizures. In the present study, we examined the effect of probiotics on penicillin-induced focal seizure model in rats. Male Wistar Albino rats (n: 21) were randomly divided into three groups: control (no medication), penicillin and penicillin + probiotic. Probiotic VSL#3 (12.86 bn living bacteria/kg/day) was given by gavage for 30 days. The seizures were induced by intracortical injection of penicillin G (500 IU) into the cortex. An ECoG recordings were made for 180 min after penicillin G application. The spike frequency and the amplitude were used to assess the severity of seizures. Tumor necrosis factor (TNF-α), nitric oxide (NO) and interleukin (IL-6) levels in the brain were studied biochemically. Our results indicated that probiotic supplementation improved focal seizures through increasing the latency (p < 0.001) and decreasing the spike frequency (p < 0.01) compared to the penicillin group. Penicillin-induced seizure in rats significantly enhanced TNF-α (p < 0.01), NO (p < 0.01) and IL-6 (p < 0.05) compared to the control. Probiotic supplementation significantly decreased IL-6 (p < 0.05), TNF-α (p < 0.01) and NO (p < 0.001) compared to the penicillin group. When the body weights were compared before and after the experiment, there was no difference between the control and penicillin groups, but it was observed that the body weight decreased after probiotic supplementation in the penicillin + probiotic group. Probiotic supplementation may have anti-seizure effect by reducing proinflammatory cytokine and NO levels in epileptic rat brain.

Polysaccharides, Next Potential Agent for the Treatment of Epilepsy?

Epilepsy is a chronic neurological disorder. Current pharmacological therapies for epilepsy have limited efficacy that result in refractory epilepsy (RE). Owing to the limitations of conventional therapies, it is needed to develop new anti-epileptic drugs. The beneficial effects of polysaccharides from Chinese medicines, such as Lycium barbarum polysaccharides (COP) and Ganoderma lucidum polysaccharides (GLP), for treatment of epilepsy include regulation of inflammatory factors, neurotransmitters, ion channels, and antioxidant reactions. Especially, polysaccharides could be digested by intestinal microbial flora, referred as “intestinal brain organ” or “adult’s second brain”, may be the target for treatment of epilepsy. Actually, polysaccharides can effectively improve the type and quantity of intestinal flora such as bifidobacteria and lactic acid bacteria and achieve the purpose of treating epilepsy. Therefore, polysaccharides are hypothesized and discussed as potential agent for treatment of epilepsy.

Probiotic supplementation alleviates absence seizures and anxiety- and depression-like behavior in WAG/Rij rat by increasing neurotrophic factors and decreasing proinflammatory cytokines

AIM

Epilepsy is one of the most common chronic brain disorders that affect millions of people worldwide. In the present study, we investigated the effects of probiotic supplementation on absence epilepsy and anxiety-and depression-like behavior in WAG/Rij rats.

MATERIAL AND METHOD

Fourteen male WAG/Rij rats (absence-epileptic) and seven male Wistar rats (nonepileptic) were used. The effects of probiotic VSL#3 (12.86 bn living bacteria/kg/day for 30 day/gavage) on absence seizures, and related psychiatric comorbidities were evaluated in WAG/Rij rats. Anxiety-like behavior was evaluated by the open-field test and depression-like behavior by the forced swimming test. In addition, the brain tissues of rats were evaluated histopathologically for nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], SRY sex-determining region Y-box 2 [SOX2] and biochemically for nitric oxide [NO], tumor necrosis factor-alpha [TNF-α] ,and Interleukin-6 [IL-6].

RESULTS

Compared to Wistar rats, WAG/Rij rats exhibited anxiety- and depression-like behavior, and had lower BDNF, NGF and SOX2 immunoreactivity, and higher TNF-α, IL-6 levels in brain tissue. VSL#3 supplementation reduced the duration and number of spike-wave discharges (SWDs) and exhibited anxiolytic or anti-depressive effect. VSL#3 supplement also increased the NGF immunoreactivity while decreasing IL-6, TNF-α and NO levels in WAG/Rij rat brain.

CONCLUSION

The findings of the present study showed that neurotrophins, SOX2 deficiency, and pro-inflammatory cytokines may play a role in the pathogenesis of absence epilepsy. Our data support the hypothesis that the probiotics have anti-inflammatory effect. The present study is the first to show the positive effects of probiotic bacteria on absence seizures and anxiety- and depression-like behavior.