Cross talk between drug-resistant epilepsy and the gut microbiome

Microbiome's Universe: Impact on health, disease and cancer treatment

The human microbiome is a diverse ecosystem of microorganisms that reside in the body and influence various aspects of health and well-being. Recent advances in sequencing technology have brought to light microbial communities in organs and tissues that were previously considered sterile. The gut microbiota plays an important role in host physiology, including metabolic functions and immune modulation. Disruptions in the balance of the microbiome, known as dysbiosis, have been linked to diseases such as cancer, inflammatory bowel disease and metabolic disorders. In addition, the administration of antibiotics can lead to dysbiosis by disrupting the structure and function of the gut microbial community. Targeting strategies are the key to rebalancing the microbiome and fighting disease, including cancer, through interventions such as probiotics, fecal microbiota transplantation (FMT), and bacteria-based therapies. Future research must focus on understanding the complex interactions between diet, the microbiome and cancer in order to optimize personalized interventions. Multidisciplinary collaborations are essential if we are going to translate microbiome research into clinical practice. This will revolutionize approaches to cancer prevention and treatment.

Microglia in Microbiota-Gut-Brain Axis: A Hub in Epilepsy

There is growing concern about the role of the microbiota-gut-brain axis in neurological illnesses, and it makes sense to consider microglia as a critical component of this axis in the context of epilepsy. Microglia, which reside in the central nervous system, are dynamic guardians that monitor brain homeostasis. Microglia receive information from the gut microbiota and function as hubs that may be involved in triggering epileptic seizures. Vagus nerve bridges the communication in the axis. Essential axis signaling molecules, such as gamma-aminobutyric acid, 5-hydroxytryptamin, and short-chain fatty acids, are currently under investigation for their participation in drug-resistant epilepsy (DRE). In this review, we explain how vagus nerve connects the gut microbiota to microglia in the brain and discuss the emerging concepts derived from this interaction. Understanding microbiota-gut-brain axis in epilepsy brings hope for DRE therapies. Future treatments can focus on the modulatory effect of the axis and target microglia in solving DRE.

Probiotics and the microbiota-gut-brain axis in neurodegeneration: Beneficial effects and mechanistic insights

Neurodegenerative diseases (NDs) are a group of heterogeneous disorders with a high socioeconomic burden. Although pharmacotherapy is currently the principal therapeutic approach for the management of NDs, mounting evidence supports the notion that the protracted application of available drugs would abate their dopaminergic outcomes in the long run. The therapeutic application of microbiome-based modalities has received escalating attention in biomedical works. In-depth investigations of the bidirectional communication between the microbiome in the gut and the brain offer a multitude of targets for the treatment of NDs or maximizing the patient's quality of life. Probiotic administration is a well-known microbial-oriented approach to modulate the gut microbiota and potentially influence the process of neurodegeneration. Of note, there is a strong need for further investigation to map out the mechanistic prospects for the gut-brain axis and the clinical efficacy of probiotics. In this review, we discuss the importance of microbiome modulation and hemostasis via probiotics, prebiotics, postbiotics and synbiotics in ameliorating pathological neurodegenerative events. Also, we meticulously describe the underlying mechanism of action of probiotics and their metabolites on the gut-brain axis in different NDs. We suppose that the present work will provide a functional direction for the use of probiotic-based modalities in promoting current practical treatments for the management of neurodegenerative-related diseases.

Gut microbiota profile in CDKL5 deficiency disorder patients

CDKL5 deficiency disorder (CDD) is a neurodevelopmental condition characterized by global developmental delay, early-onset seizures, intellectual disability, visual and motor impairments. Unlike Rett Syndrome (RTT), CDD lacks a clear regression period. Patients with CDD frequently encounter gastrointestinal (GI) disturbances and exhibit signs of subclinical immune dysregulation. However, the underlying causes of these conditions remain elusive. Emerging studies indicate a potential connection between neurological disorders and gut microbiota, an area completely unexplored in CDD. We conducted a pioneering study, analyzing fecal microbiota composition in individuals with CDD (n = 17) and their healthy relatives (n = 17). Notably, differences in intestinal bacterial diversity and composition were identified in CDD patients. In particular, at genus level, CDD microbial communities were characterized by an increase in the relative abundance of Clostridium_AQ, Eggerthella, Streptococcus, and Erysipelatoclostridium, and by a decrease in Eubacterium, Dorea, Odoribacter, Intestinomonas, and Gemmiger, pointing toward a dysbiotic profile. We further investigated microbiota changes based on the severity of GI issues, seizure frequency, sleep disorders, food intake type, impairment in neuro-behavioral features and ambulation capacity. Enrichment in Lachnoclostridium and Enterobacteriaceae was observed in the microbiota of patients with more severe GI symptoms, while Clostridiaceae, Peptostreptococcaceae, Coriobacteriaceae, Erysipelotrichaceae, Christensenellaceae, and Ruminococcaceae were enriched in patients experiencing daily epileptic seizures. Our findings suggest a potential connection between CDD, microbiota and symptom severity. This study marks the first exploration of the gut-microbiota-brain axis in subjects with CDD. It adds to the growing body of research emphasizing the role of the gut microbiota in neurodevelopmental disorders and opens doors to potential interventions that target intestinal microbes with the aim of improving the lives of patients with CDD.

Idiopathic Generalized Epilepsy: Misunderstandings, Challenges, and Opportunities

The idiopathic generalized epilepsies (IGE) make up a fifth of all epilepsies, but <1% of epilepsy research. This skew reflects misperceptions: diagnosis is straightforward, pathophysiology is understood, seizures are easily controlled, epilepsy is outgrown, morbidity and mortality are low, and surgical interventions are impossible. Emerging evidence reveals that patients with IGE may go undiagnosed or misdiagnosed with focal epilepsy if EEG or semiology have asymmetric or focal features. Genetic, electrophysiologic, and neuroimaging studies provide insights into pathophysiology, including overlaps and differences from focal epilepsies. IGE can begin in adulthood and patients have chronic and drug-resistant seizures. Neuromodulatory interventions for drug-resistant IGE are emerging. Rates of psychiatric and other comorbidities, including sudden unexpected death in epilepsy, parallel those in focal epilepsy. IGE is an understudied spectrum for which our diagnostic sensitivity and specificity, scientific understanding, and therapies remain inadequate.

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.

Oral microbiome alterations in epilepsy and after seizure control

Background

The existing diagnostic methods of epilepsy such as history collection and electroencephalogram have great limitations in practice, so more reliable and less difficult diagnostic methods are needed.

Methods

By characterizing oral microbiota in patients diagnosed with epilepsy (EPs) and patients whose seizures were under control (EPRs), we sought to discover biomarkers for different disease states. 16S rRNA gene sequencing was performed on 480 tongue swabs [157 EPs, 22 EPRs, and 301 healthy controls (HCs)].

Results

Compared with normal individuals, patients with epilepsy exhibit increased alpha diversity in their oral microbiota, and the oral microbial communities of the two groups demonstrate significant beta diversity differences. EPs exhibit a significant increase in the abundance of 26 genera, including Streptococcus, Granulicatella, and Kluyvera, while the abundance of 14 genera, including Peptostreptococcus, Neisseria, and Schaalia, is significantly reduced. The area under the receiver operating characteristic curve (AUC) of oral microbial markers in the training cohort and validation cohort was 98.85% and 97.23%, respectively. Importantly, the AUC of the biomarker set achieved 92.44% of additional independent validation sets. In addition, EPRs also have their own unique oral community.

Conclusion

This study describes the characterization of the oral microbiome in EP and EPR and demonstrates the potential of the specific microbiome as a non-invasive diagnostic tool for epilepsy.

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.

Pathophysiology of drug-resistant canine epilepsy

Drug resistance continues to be a major clinical problem in the therapeutic management of canine epilepsies with substantial implications for quality of life and survival times. Experimental and clinical data from human medicine provided evidence for relevant contributions of intrinsic severity of the disease as well as alterations in pharmacokinetics and -dynamics to failure to respond to antiseizure medications. In addition, several modulatory factors have been identified that can be associated with the level of therapeutic responses. Among others, the list of potential modulatory factors comprises genetic and epigenetic factors, inflammatory mediators, and metabolites. Regarding data from dogs, there are obvious gaps in knowledge when it comes to our understanding of the clinical patterns and the mechanisms of drug-resistant canine epilepsy. So far, seizure density and the occurrence of cluster seizures have been linked with a poor response to antiseizure medications. Moreover, evidence exists that the genetic background and alterations in epigenetic mechanisms might influence the efficacy of antiseizure medications in dogs with epilepsy. Further molecular, cellular, and network alterations that may affect intrinsic severity, pharmacokinetics, and -dynamics have been reported. However, the association with drug responsiveness has not yet been studied in detail. In summary, there is an urgent need to strengthen clinical and experimental research efforts exploring the mechanisms of resistance as well as their association with different etiologies, epilepsy types, and clinical courses.

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.

Can the Gut Microbiota Serve as a Guide to the Diagnosis and Treatment of Childhood Epilepsy?

BACKGROUND

To investigate the activity of the gut-brain axis in the pathogenesis of childhood epilepsy and to define biomarkers capable of assisting with determining new strategies in that context.

METHODS

Twenty children with epilepsy of "unknown etiology" and seven healthy controls in the same age group were included in the study. The groups were compared using a questionnaire. Stool samples were stored in tubes containing DNA/RNA Shield (Zymo Research) with a sterile swab. Sequencing was carried out using the MiSeq System (Illumina). The 16S rRNA sequencing of samples using next-generation sequencing involved V4 variable region polymerase chain reaction amplification concluded by 2 × 250-bp paired-end sequencing of amplicons and at least 50,000 reads (>Q30) per sample. DNA sequences were classified at the genus level using the Kraken program. Bioinformatics and statistical analysis were then performed.

RESULTS

Individuals' gut microbiota relative abundance values differed between the groups at the genus, order, class, family, and phylum levels. Flavihumibacter, Niabella, Anoxybacillus, Brevundimonas, Devosia, and Delftia were seen only in the control group, whereas Megamonas and Coriobacterium were observed only in the epilepsy group. The linear discriminant analysis effect size method identified 33 taxa as important in differentiating the groups.

CONCLUSIONS

We think that bacterial varieties (such as Megamonas and Coriobacterium) that differ between the two groups can be employed as useful biomarkers in the diagnosis and follow-up of epileptic patients. We also predict that, in addition to epilepsy treatment protocols, the restoration of eubiotic microbiota may increase the success of treatment.

Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis

Billions of years of co-evolution has made mitochondria central to the eukaryotic cell and organism life playing the role of cellular power plants, as indeed they are involved in most, if not all, important regulatory pathways. Neurological disorders depending on impaired mitochondrial function or homeostasis can be caused by the misregulation of "endogenous players", such as nuclear or cytoplasmic regulators, which have been treated elsewhere. In this review, we focus on how exogenous agents, i.e., viral pathogens, or unbalanced microbiota in the gut-brain axis can also endanger mitochondrial dynamics in the central nervous system (CNS). Neurotropic viruses such as Herpes, Rabies, West-Nile, and Polioviruses seem to hijack neuronal transport networks, commandeering the proteins that mitochondria typically use to move along neurites. However, several neurological complications are also associated to infections by pandemic viruses, such as Influenza A virus and SARS-CoV-2 coronavirus, representing a relevant risk associated to seasonal flu, coronavirus disease-19 (COVID-19) and "Long-COVID". Emerging evidence is depicting the gut microbiota as a source of signals, transmitted via sensory neurons innervating the gut, able to influence brain structure and function, including cognitive functions. Therefore, the direct connection between intestinal microbiota and mitochondrial functions might concur with the onset, progression, and severity of CNS diseases.

Potential relationship between Tourette syndrome and gut microbiome

OBJECTIVE

In this article, the author aims to discuss and review the relationship between gut microbiota and Tourette syndrome, and whether the change in gut microbiota can affect the severity of Tourette syndrome.

SOURCES

Literature from PubMed, Google Scholar, and China National Knowledge Infrastructure was mainly reviewed. Both original studies and review articles were discussed. The articles were required to be published as of May 2022.

SUMMARY OF THE FINDINGS

Current studies on the gut microbiome have found that the gut microbiome and brain seem to interact. It is named the brain-gut-axis. The relationship between the brain-gut axis and neurological and psychiatric disorders has been a topic of intense interest. Tourette syndrome is a chronic neurological disease that seriously affects the quality of life of children, and there appears to be an increase in Ruminococcaceae and Bacteroides in the gut of patients with Tourette syndrome. After clinical observation and animal experiments, there appear to be particular gut microbiota changes in Tourette syndrome. It provides a new possible idea for the treatment of Tourette syndrome. Probiotics and fecal microbial transplantation have been tried to treat Tourette syndrome, especially Tourette syndrome which is not sensitive to drugs, and some results have been achieved.

CONCLUSIONS

The relationship between gut microbiota and Tourette syndrome and how to alleviate Tourette syndrome by improving gut microbiota are new topics, more in-depth and larger sample size research is still needed.

A framework for health equity in people living with epilepsy

Epilepsy is a disease where disparities and inequities in risk and outcomes are complex and multifactorial. While most epilepsy research to date has identified several key areas of disparities, we set out to provide a multilevel life course model of epilepsy development, diagnosis, treatment, and outcomes to highlight how these disparities represent true inequities. Our piece also presents three hypothetical cases that highlight how the solutions to address inequities may vary across the lifespan. We then identify four key domains (structural, socio-cultural, health care, and physiological) that contribute to the persistence of inequities in epilepsy risk and outcomes in the United States. Each of these domains, and their core components in the context of epilepsy, are reviewed and discussed. Further, we highlight the connection between domains and key areas of intervention to strive towards health equity. The goal of this work is to highlight these domains while also providing epilepsy researchers and clinicians with broader context of how their work fits into health equity.

Genetically proxied gut microbiota, gut metabolites with risk of epilepsy and the subtypes: A bi-directional Mendelian randomization study

Background

An increasing number of observational studies have revealed an association among the gut microbiota, gut metabolites, and epilepsy. However, this association is easily influenced by confounders such as diet, and the causality of this association remains obscure.

Methods

Aiming to explore the causal relationship and ascertain specific gut microbe taxa for epilepsy, we conducted a bi-directional Mendelian randomization (MR) study based on the genome-wide association study (GWAS) data of epilepsy from the International League Against Epilepsy, with the gut microbiota GWAS results from MiBioGen, and summary-level GWAS data of gut microbiota-dependent metabolites trimethylamine N-oxide and its predecessors.

Results

Nine phyla, 15 classes, 19 orders, 30 families, and 96 genera were analyzed. A suggestive association of host-genetic-driven increase in family Veillonellaceae with a higher risk of childhood absence epilepsy (odds ratio [OR]: 1.033, confidential interval [CI]: 1.015–1.051, P_IVW = 0.0003), class Melainabacteria with a lower risk of generalized epilepsy with tonic-clonic seizures (OR = 0.986, CI = 0.979–0.994, P_IVW = 0.0002), class Betaproteobacteria (OR = 0.958, CI = 0.937–0.979, P_IVW = 0.0001), and order Burkholderiales (OR = 0.960, CI = 0.937–0.984, P_IVW = 0.0010) with a lower risk of juvenile myoclonic epilepsy were identified after multiple-testing correction. Our sensitivity analysis revealed no evidence of pleiotropy, reverse causality, weak instrument bias, or heterogeneity.

Conclusion

This is the first MR analysis to explore the potential causal relationship among the gut microbiota, metabolites, and epilepsy. Four gut microbiota features (two class levels, one order level, and one family level) were identified as potential interventional targets for patients with childhood absence epilepsy, generalized epilepsy with tonic-clonic seizures, and juvenile myoclonic epilepsy. Previous associations in numerous observational studies may had been interfered by confounders. More rigorous studies were needed to ascertain the relationship among the gut microbiota, metabolites, and epilepsy.

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/.

Screening of Risk Factors for Poor Prognosis in Patients with Refractory Epilepsy Secondary to Encephalomalacia

Objective

The study was aimed at screening the independent prognostic risk factors for refractory epilepsy associated with encephalomalacia (REAE).

Methods

Patients with REAE treated in the First People's Hospital of Linping District from January 2018 to December 2019 were selected. The prognosis was represented by Engel grading. Clinical data of the patients were collected, including age, sex, BMI, lesion sites, number of lesion sites, lesion size, seizure frequency, epilepsy type, and treatment methods. Independent risk factors for poor prognosis were screened by logistic regression analysis. The receiver operating characteristic curve (ROC) was used to evaluate the prognostic efficacy of independent risk factors.

Results

A total of 48 patients were included in this study, including 31 patients (64.58%) in the good prognosis group and 17 patients (35.42%) in the poor prognosis group. The mean age of the poor prognosis group was higher than that of the good prognosis group (P = 0.002). The proportion of patients with multisite lesions in the poor prognosis group was higher than that in the good prognosis group (P = 0.016). The proportion of patients with cerebral malacia lesion diameter ≥ 3 cm in the poor prognosis group was higher than that in the good prognosis group (P = 0.002). The proportion of patients with attack frequency ≥ 2 times/month in the poor prognosis group was higher than in the good prognosis group (P = 0.002). The proportion of patients receiving surgical treatment in the poor prognosis group was lower than that in the good prognosis group (P < 0.001). Age, number of lesion sites, size of encephalomalacia, and seizure frequency were independent risk factors for the prognosis of patients with REAE (OR > 1, P < 0.05). Surgical treatment was an independent protective factor associated with the prognosis of patients with REAE (OR < 1, P < 0.05). The area under the ROC curve of surgical treatment was 0.83 (P = 0.004). The area under the ROC curve of the size of encephalomalacia was 0.72 (P = 0.008). There was a positive correlation between age and size of encephalomalacia and Engel grade (r > 0, P < 0.05). Surgical treatment was negatively correlated with Engel grade (r < 0, P < 0.05). The number of lesion sites and seizure frequency had no significant correlation with Engel (P > 0.05). The proportion of Engel I patients treated with surgery was higher than that treated with drugs (P = 0.001). The ratio of Engel III and IV patients treated with surgery was lower than that treated with medications (P < 0.05).

Conclusion

Age, number of lesion sites, size of encephalomalacia, and seizure frequency are independent risk factors for the prognosis of patients with REAE. Surgical treatment is an independent prognostic factor for patients with REAE. Surgical treatment can significantly improve patient outcomes.

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.

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.

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.

The Microbiota-Gut-Brain Axis and Epilepsy

Honoured as the second genome in humans, the gut microbiota is involved in a constellation of physiological and pathological processes, including those related to the central nervous system. The communication between the gut microbiota and the brain is realized by a complex bidirectional connection, known as the "microbiota-gut-brain axis", via neuroendocrine, immunological, and direct neural mechanisms. Recent studies indicate that gut dysfunction/dysbiosis is presumably involved in the pathogenesis of and susceptibility to epilepsy. In addition, the reconstruction of the intestinal microbiome through, for example, faecal microbiota transplantation, probiotic intervention, and a ketogenic diet, has exhibited beneficial effects on drug-resistant epilepsy. The purposes of this review are to provide a brief overview of the microbiota-gut-brain axis and to synthesize what is known about the involvement of the gut microbiota in the pathogenesis and treatment of epilepsy, to bring new insight into the pathophysiology of epilepsy and to present a preliminary discussion of novel therapeutic options for epilepsy based on the gut microbiota.

About gladiators and a sacred disease

In this special edition of the Biomedical Journal the reader gains an insight into drug-resistant epilepsy and according treatment approaches involving deep brain stimulation, the ketogenic diet and fecal microbiota transplant. Another emphasis is put on personalized medicine strategies, and covered in articles about the use of natriuretic peptides against cancer, along with an article about companion diagnostics involving extracellular vesicles. Recurrent infection with Clostridium difficile, associated risk factors and therapeutic options are discussed. We learn about a mechanism that helps Leishmania evade a host control mechanism, receive an update about human adenovirus and are presented with characteristic magnetic resonance neuroimaging in COVID-19 pediatric patients. An advanced assessment in pediatric septic shock and an improved model for a pediatric early warning system are proposed. Some of the genetic causes of renal hypomagnesemia are explored, the impact of air pollution on children is examined, and an antisiphon device is described for surgical treatment of hydrocephalus. The relation between energy metabolism, circadian rhythm and its influence on the ATPase in the SCN are investigated, and among others some of the genetics influencing smoking duration and lung cancer. Finally it is discussed how embryo quality can be improved in in vitro fertilization, and what impact high estradiol has on blastocyst implantation. The outcome of surgery to correct mandibular deficiency is assessed, and in two letters the inclusion of observational studies in the evaluation of clinical trials related to COVID-19 is elaborated.

DL-3-n-butylphthalide promotes hippocampal neurogenesis and reduces mossy fiber sprouting in chronic temporal lobe epilepsy rats

Background

A decrease in hippocampal neurogenesis is considered an important cause of cognitive impairment, while changes in mossy fiber sprouting are closely related to development of spontaneous recurrent seizures in chronic temporal lobe epilepsy (TLE). Racemic l-3-n-butylphthalide (DL-NBP) can alleviate cognitive impairment in ischemic stroke and Alzheimer’s disease by promoting neurogenesis. DL-NBP treatment can also improve cognitive function and reduce seizure incidence in chronic epileptic mice. However, the mechanisms of action of DL-NBP remain unclear. The aim of the present study was to examine the effects of DL-NBP on mossy fiber sprouting, hippocampal neurogenesis, spontaneous epileptic seizures, and cognitive functioning in the chronic phase of TLE.

Methods

Nissl staining was used to evaluate hippocampal injury, while immunofluorescent staining was used to analyze hippocampal neurogenesis. The duration of spontaneous seizures was measured by electroencephalography. The Morris water maze was used to evaluate cognitive function. Timm staining was used to assess mossy fiber sprouting.

Results

TLE animals showed reduced proliferation of newborn neurons, cognitive dysfunction, and spontaneous seizures. Treatment with DL-NBP after TLE increased the proliferation and survival of newborn neurons in the dentate gyrus, reversed the neural loss in the hippocampus, alleviated cognitive impairments, and decreased mossy fiber sprouting and long-term spontaneous seizure activity.

Conclusions

We provided pathophysiological and morphological evidence that DL-NBP might be a useful therapeutic for the treatment of TLE.

Is Gut Microbiota a Key Player in Epilepsy Onset? A Longitudinal Study in Drug-Naive Children

Microbiota alterations have been recently investigated in individuals with epilepsy and in other neurological diseases as environmental factors that play a role, by acting through the gut-brain axis, in the pathological process. Most studies focus on the contribution of bacterial communities in refractory epilepsy and suggest a beneficial role of ketogenic diet in modulating the gut microbiota and seizure occurrence. However, they do not evaluate whether epilepsy itself alters the gut microbiota in these patients or if the gut microbial communities could contribute as a seizure trigger. In this pilot study, we performed 16S rRNA sequencing and investigated the gut microbial communities of eight children at their seizure onset and after anti-seizure was started (one year follow-up) and we compared microbial data with seven healthy children, age- and sex-matched. In drug-naive subjects, we observed a microbial signature that shared several features with those reported in refractory epilepsy, such as an increased abundance in Akkermansia spp. and Proteobacteria and a decreased relative abundance in Faecalibacterium spp.We suggest that a bacterial-mediated proinflammatory milieu could contribute to seizure occurrence in children with new onset of epilepsy, as already reported for individuals with drug-resistant epilepsy, and that it could vary during treatment in those who are drug-responsive.

Analysis of gut microbiota in patients with epilepsy treated with valproate: Results from a three months observational prospective cohort study

BACKGROUND

Growing evidence implicates the potential effect of microbiota on the pathogenesis and course of epilepsy. However, the effects of valproate (VPA), a broad spectrum anti-epileptic drugs, on gut microbiota have not been investigated in humans. This study aimed to analyze fecal microbiota in patients with epilepsy treated with valproate.

METHODS

A total of 10 participants, who were newly diagnosed of cryptogenic epilepsy with treatment naïve and received 1000 mg daily doses of VPA, were recruited in our prospective study. Microbiota compositions were evaluated at baseline and after three months of VPA treatment using 16S rDNA sequencing.

RESULTS

VPA treatment was associated with clinical improvements in all patients, but not changes in gut microbiota richness and complexity (Shannon: p = 0.82). Microbiome composition structure differences also revealed no statistical difference in dissimilarity (Adonis: p = 0.90). No statistical difference taxa were found between two groups. However, the ratio of phyla Firmicutes to Bacteriodetes (ANOVA: p = 0.037) markedly raised after three months of VPA-treatment. A correlation matrix based on the spearman correlation distance confirmed associations between specific fecal taxa and VPA-related clinical metabolic parameters, including drug concentration in the blood, total cholesterol, triglyceride, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase and weight gain. (p < 0.05) CONCLUSIONS: Among those patients treated with VPA, characterization of the gut microbiota altered, and gut microbiota associated with weight gain and clinical biochemical indexes, suggesting that microbiome composition data might involve in the mechanisms of VPA induced metabolic disorder.

The role of microbiota-gut-brain axis in neuropsychiatric and neurological disorders

Emerging evidence indicates that the gut microbiota play a crucial role in the bidirectional communication between the gut and the brain suggesting that the gut microbes may shape neural development, modulate neurotransmission and affect behavior, and thereby contribute to the pathogenesis and/or progression of many neurodevelopmental, neuropsychiatric, and neurological conditions. This review summarizes recent data on the role of microbiota-gut-brain axis in the pathophysiology of neuropsychiatric and neurological disorders including depression, anxiety, schizophrenia, autism spectrum disorders, Parkinson's disease, migraine, and epilepsy. Also, the involvement of microbiota in gut disorders co-existing with neuropsychiatric conditions is highlighted. We discuss data from both in vivo preclinical experiments and clinical reports including: (1) studies in germ-free animals, (2) studies exploring the gut microbiota composition in animal models of diseases or in humans, (3) studies evaluating the effects of probiotic, prebiotic or antibiotic treatment as well as (4) the effects of fecal microbiota transplantation.

Ciprofloxacin for treatment of drug-resistant epilepsy

PURPOSE

To investigate the efficacy of short-term treatment with ciprofloxacin in alteration of gut microbiota pattern and reduction of seizure frequency in adult patients with drug-resistant epilepsy.

METHODS

In a prospective study, we investigated the effect of a 5-day course of treatment with ciprofloxacin on gut microbiota pattern and seizure frequency of 23 adults with drug-resistant epilepsy. Fecal samples were collected before and after treatment and were analyzed for microbial load and species. Changes in seizure frequency were registered for 12 weeks. Responders were defined as patients who experienced ≥50 % seizure reduction in comparison to baseline. Outcome measures were specified as alteration in fecal microbial burden in days 5-7 and responder rate in 4th and 12th weeks.

RESULTS

The mean baseline frequency of seizures was5.6 ±7.7 per week. All patients were on polytherapy with a mean of 3 ± 1.2 anti-seizure medications. Microbial analysis showed a considerable increase in Bacteroidetes/Firmicutes ratio after treatment. Seizure frequency significantly decreased at the end of first week and the therapeutic effect continued to week 12 (P < 0.001). The responder rate at 4th and 12th weeks were 69.6 % and 73.9 % respectively with a more prominent response in patients with symptomatic generalized epilepsy (P:0.06).

CONCLUSION

Alteration of abnormal gut microbiota pattern by methods such as short-course antibiotic therapy, prescription of probiotics and fecal microbiota transplant might be effective in treatment of drug-resistant epilepsy.

The varying effects of antibiotics on gut microbiota

Antibiotics are lifesaving therapeutic drugs that have been used by human for decades. They are used both in the fight against bacterial pathogens for both human and for animal feeding. However, of recent, their effects on the gut microbial compositions and diversities have attracted much attention. Existing literature have established the dysbiosis (reduced diversity) in the gut microbiota in association with antibiotic and antibiotic drug doses. In the light of spelling out the varying effects of antibiotic use on gut microbiota, this review aimed at given an account on the degree of gut microbial alteration caused by common antibiotics. While some common antibiotics are found to destroy the common phyla, other debilitating effects were observed. The effects can be attributed to the mode of mechanism, the class of antibiotic, the degree of resistance of the antibiotic used, the dosage used during the treatment, the route of administration, the pharmacokinetic and pharmacodynamics properties and the spectrum of the antibiotic agent. Health status, stress or the type of diet an individual feeds on could be a great proportion as confounding factors. While it is understood that only the bacterial communities are explored in the quest to establishing the role of gut in health, other gut microbial species are somehow contributing to the dysbiosis status of the gut microbiota. Until now, long term natural fluctuations like diseases outbreaks and mutations of the strain might as well rendered alteration to the gut independent of antibiotic treatments.

Understanding mechanisms of drug resistance in epilepsy and strategies for overcoming it

INTRODUCTION

The present evidence indicates that approximately 70% of patients with epilepsy can be successfully treated with antiepileptic drugs (AEDs). A significant proportion of patients are not under sufficient control, and pharmacoresistant epilepsy is clearly associated with poor quality of life and increased morbidity and mortality. There is a great need for newer therapeutic options able to reduce the percentage of drug-resistant patients.

AREAS COVERED

A number of hypotheses trying to explain the development of pharmacoresistance have been put forward. These include: target hypothesis (altered AED targets), transporter (overexpression of brain efflux transporters), pharmacokinetic (overexpression of peripheral efflux transporters in the intestine or kidneys), intrinsic severity (initial high seizure frequency), neural network (aberrant networks), and gene variant hypothesis (genetic polymorphisms).

EXPERT OPINION

A continuous search for newer AEDs or among non-AEDs (blockers of efflux transporters, interleukin antagonists, cyclooxygenase inhibitors, mTOR inhibitors, angiotensin II receptor antagonists) may provide efficacious drugs for the management of drug-resistant epilepsy. Also, combinations of AEDs exerting synergy in preclinical and clinical studies (for instance, lamotrigine + valproate, levetiracetam + valproate, topiramate + carbamazepine) might be of importance in this respect. Preclinically antagonistic combinations must be avoided (lamotrigine + carbamazepine, lamotrigine + oxcarbazepine).

Evidences for a Role of Gut Microbiota in Pathogenesis and Management of Epilepsy

Epilepsy as a chronic neurological disorder is characterized by recurrent, unprovoked epileptic seizures. In about half of the people who suffer from epilepsy, the root cause of the disorder is unknown. In the other cases, different factors can cause the onset of epilepsy. In recent years, the role of gut microbiota has been recognized in many neurological disorders, including epilepsy. These data are based on studies of the gut microbiota–brain axis, a relationship starting by a dysbiosis followed by an alteration of brain functions. Interestingly, epileptic patients may show signs of dysbiosis, therefore the normalization of the gut microbiota may lead to improvement of epilepsy and to greater efficacy of anticonvulsant drugs. In this descriptive review, we analyze the evidences for the role of gut microbiota in epilepsy and hypothesize a mechanism of action of these microorganisms in the pathogenesis and treatment of the disease. Human studies revealed an increased prevalence of Firmicutes in patients with refractory epilepsy. Exposure to various compounds can change microbiota composition, decreasing or exacerbating epileptic seizures. These include antibiotics, epileptic drugs, probiotics and ketogenic diet. Finally, we hypothesize that physical activity may play a role in epilepsy through the modulation of the gut microbiota.

The gut microbiome in drug-resistant epilepsy

Drug-resistant epileptic patients make up approximately one-third of the global epilepsy population. The pathophysiology of drug resistance has not been fully elucidated; however, current evidence suggests intestinal dysbiosis, as a possible etiopathogenic factor. Ketogenic diet, whose effect is considered to be mediated by alteration of gut microbiota synthesis, has long been administered in patients with medically refractory seizures, with positive outcomes. In this review, we present data derived from clinical studies regarding alterations of gut microbiome profile in drug-resistant epileptic patients. We further attempt to describe the mechanisms through which the gut microbiome modification methods (including ketogenic diet, pre- or probiotic administration) improve drug-resistant epilepsy, by reporting findings from preclinical and clinical studies. A comprehensive search of the published literature on the PubMed, Embase, and Web of science databases was performed. Overall, the role of gut microbiome in drug-resistant epilepsy is an area which shows promise for the development of targeted therapeutic interventions. More research is required to confirm the results from preliminary studies, as well as safety and effectiveness of altering gut bacterial composition, through the above-mentioned methods.