A Comprehensive Review on the Role of the Gut Microbiome in Human Neurological Disorders

Altered gut microbial profiles in drug-treated rats with alcoholic heart disease

Introduction. Alcohol abuse can lead to significant cardiac injury, resulting in Alcoholic heart disease (AHD). The interplay between cardiac health and gut microbiota composition in the context of alcohol consumption is not well understood.Hypothesis. Shen Song Yang Xin (SSYX) capsule and amiodarone are common drugs used to treat alcoholic heart disease, but little is known about their microbial regulatory mechanisms in alcoholic heart disease.Aim. To investigate the effects of SSYX and amiodarone on cardiac injury and gut microbiota composition in a rat model of AHD induced by alcohol consumption.Methodology. We evaluated body weight, cardiac function, changes in gut morphology, and gut microbiota composition to assess the effects of SSYX and amiodarone on AHD.Results. Alcohol consumption significantly reduced body weight and aggravated cardiac fibrosis. However, SSYX attenuated fibrosis and improved cardiac function. SSYX also improved intestinal morphological changes caused by chronic alcoholism and activated the expression of ZO-1 and occludin, which are important in maintaining intestinal barrier function. The gut microbiota composition was altered in rats with AHD, with an increase in Actinobacteria abundance. Both SSYX and amiodarone affected the gut microbiota composition, and their effects were positively correlated. SSYX plays a protective role against heart injury caused by alcohol consumption. It improves cardiac function, intestinal morphological changes and gut microbiota composition.Conclusion. SSYX and amiodarone may have potential therapeutic options for AHD. Actinobacteria/Firmicutes ratio and the abundance of Christensenellaceae R7 group, norank_flachnospiraceae and Roseburia may serve as potential biomarkers for detecting alcoholic heart disease.

Characterization of Gut Microbiota in Rats and Rhesus Monkeys After Methamphetamine Self-administration

Methamphetamine (MA) is one of the most abused drugs globally, but the mechanism of its addiction remains unclear. Several animal studies have shown that the gut microbiota (GM) influences addictive behaviors, but the pattern of GM changes during addiction in animals of different species remains unclear. The aim of this study was to explore the association between dynamic changes in GM and MA self-administration acquisition among two classical mammals, rhesus monkeys (Macaca mulatta) and rats, MA self-administration models. Male Sprague-Dawley rats and male rhesus monkeys were subjected to classical MA self-administration training, and fecal samples were collected before and after MA self-administration training, respectively. 16S rRNA sequencing was used for GM analyses. We found that GM changes were more pronounced in rats than in rhesus monkeys, as evidenced by more GM taxa producing significant differences before and after MA self-administration training in rats than in monkeys. We also found that the expression of the genus Clostridia_vadinBB60_group significantly decreased after MA self-administration training in both rats and rhesus monkeys. Lactobacillus changes were significantly negatively correlated with total MA uptake in rats (Pearson R =  - 0.666, p = 0.035; Spearman R =  - 0.721, p = 0.023), whereas its change was also highly negatively correlated with total MA uptake in rhesus monkeys (Pearson R =  - 0.882, p = 0.118; Spearman R =  - 1.000, p = 0.083), although this was not significant. These findings suggest that MA causes significant alterations in GM in both rhesus monkeys and rats and that the genus Lactobacillus might be a common therapeutic target for MA uptake prevention across the species.

Understanding the Impact of the Gut Microbiome on Mental Health: A Systematic Review

Mental health is a serious issue, with mental health disorders affecting millions of people globally. Gut microbiota has received considerable attention because of its potential role in the pathogenesis of mental health disorders. This systematic review synthesized 15 studies exploring the effects of the gut microbiome on depression, anxiety, schizophrenia, and bipolar disorder, with qualitative and quantitative insights. The studies were conducted in different countries and employed various methods including 16S rRNA sequencing and metagenomic analysis with sample sizes varying from 50 to 600. Some of the key findings were that depression was associated with reduced microbial diversity and high levels of Firmicutes, and anxiety was associated with low levels of short-chain fatty acid (SCFA)-producing bacteria and high levels of Proteobacteria. Schizophrenia was related to endotoxemia and a reduction in the Lactobacillus count whereas bipolar disorder displayed a shift in the Firmicutes/Bacteroidetes ratio. Of interest, probiotics and dietary changes were as effective as drug treatment leading to symptom alleviation in many patients. It was found that depression was linked to less diverse gut bacteria while anxiety was associated with an increase in inflammatory bacteria. People with bipolar disorder were also found to have different gut bacteria patterns. This review also emphasizes the importance of the gut microbiota in the pathophysiology of mental disorders and the promising value of targeting microbiomes in pharmacological treatment approaches.

Microbiota-Gut-Brain Axis in Age-Related Neurodegenerative Diseases

BACKGROUND

Age-related neurodegenerative diseases (NDs) pose a formidable challenge to healthcare systems worldwide due to their complex pathogenesis, significant morbidity, and mortality. Scope and Approach: This comprehensive review aims to elucidate the central role of the microbiotagut- brain axis (MGBA) in ND pathogenesis. Specifically, it delves into the perturbations within the gut microbiota and its metabolomic landscape, as well as the structural and functional transformations of the gastrointestinal and blood-brain barrier interfaces in ND patients. Additionally, it provides a comprehensive overview of the recent advancements in medicinal and dietary interventions tailored to modulate the MGBA for ND therapy.

CONCLUSION

Accumulating evidence underscores the pivotal role of the gut microbiota in ND pathogenesis through the MGBA. Dysbiosis of the gut microbiota and associated metabolites instigate structural modifications and augmented permeability of both the gastrointestinal barrier and the blood-brain barrier (BBB). These alterations facilitate the transit of microbial molecules from the gut to the brain via neural, endocrine, and immune pathways, potentially contributing to the etiology of NDs. Numerous investigational strategies, encompassing prebiotic and probiotic interventions, pharmaceutical trials, and dietary adaptations, are actively explored to harness the microbiota for ND treatment. This work endeavors to enhance our comprehension of the intricate mechanisms underpinning ND pathogenesis, offering valuable insights for the development of innovative therapeutic modalities targeting these debilitating disorders.

Fecal microbiota transplantation in severe pneumonia: a case report on overcoming pan-drug resistant Klebsiella pneumoniae infection

Objective

To evaluate the therapeutic potential of fecal microbiota transplantation (FMT) in treating severe pneumonia patients with concurrent pan-drug resistant Klebsiella pneumoniae infection.

Methods

A case report of a 95-year-old female patient with severe pneumonia, complicated by pan-resistant bacterial infections, is presented. The patient was diagnosed with severe pneumonia caused by COVID-19, along with co-infections of Staphylococcus hominis, Enterococcus faecalis, Candida tropicalis, Pseudomonas aeruginosa, ESBL-producing pan-drug resistant Klebsiella pneumoniae and pan-resistant Acinetobacter baumannii. During hospitalization, the patient underwent comprehensive treatments, including antimicrobials, mechanical ventilation, and fiberoptic bronchoscopic alveolar lavage. FMT was administered following the failure of conventional treatments to resolve recurrent diarrhea, increased sputum production, and persistent pan-drug resistant Klebsiella pneumoniae infection.

Results

Post-FMT, the patient exhibited significant clinical improvement, including reduced sputum production, cessation of diarrhea, and the normalization of respiratory symptoms. Gut microbiota analysis revealed that FMT enhanced the abundance of beneficial microbiota and suppressed Klebsiella pneumoniae, and the patient was successfully discharged after 133 days of hospitalization.

Conclusion

FMT emerged as a pivotal intervention in the management of this severe pneumonia case, suggesting its efficacy in restoring gut microbiota balance and aiding recovery from multi-drug-resistant infections. This case underscores the potential of FMT as a therapeutic option in severe pulmonary infections, especially in the context of antibiotic resistance in severe pneumonia patients.

Increased levels of Escherichia-Shigella and Klebsiella in the gut contribute to the responsivity of placebo analgesia

Placebo analgesia is observed in both humans and animals. Given the complexity of placebo analgesia involving a variety of neurobiological, psychological, and psychosocial processes, further investigation into its underlying mechanisms is essential. Gut microbiota has been implicated in the responsivity of placebo analgesia, but its precise role remains unknown and warrants further investigations. Here, we conducted a conditioning training model with chronic inflammatory pain induced by complete Freund's adjuvant (CFA) in mice, associating parecoxib with different cues. Hierarchical clustering analysis of placebo analgesia behaviors was employed to classify mice into responders and non-responders phenotypes. Approximately 40% of CFA mice undergoing conditioning training exhibited placebo analgesia. Notably, placebo analgesia responders displayed reduced anxiety-like behaviors. 16S rRNA results revealed a distinct composition of gut microbiota composition among the control, placebo analgesia non-responders and responders groups. Notably, levels of Escherichia Shigella and Klebsiella in the gut were increased considerably in the placebo analgesia responders as compared to both control and non-responders groups. In conclusion, placebo analgesia responders demonstrated marked analgesia, reduced anxiety-like behaviors, and increased levels of Escherichia-Shigella and Klebsiella, implying a potential linkage between gut microbiota and placebo analgesia.

The mechanisms, hallmarks, and therapies for brain aging and age-related dementia

Age-related cognitive decline and dementia are significant manifestations of brain aging. As the elderly population grows rapidly, the health and socio-economic impacts of cognitive dysfunction have become increasingly significant. Although clinical treatment of dementia has faced considerable challenges over the past few decades, with limited breakthroughs in slowing its progression, there has been substantial progress in understanding the molecular mechanisms and hallmarks of age-related dementia (ARD). This progress brings new hope for the intervention and treatment of this disease. In this review, we categorize the latest findings in ARD biomarkers into four stages based on disease progression: Healthy brain, pre-clinical, mild cognitive impairment, and dementia. We then systematically summarize the most promising therapeutic approaches to prevent or slow ARD at four levels: Genome and epigenome, organelle, cell, and organ and organism. We emphasize the importance of early prevention and detection, along with the implementation of combined treatments as multimodal intervention strategies, to address brain aging and ARD in the future.

Bee Pollen as a Source of Biopharmaceuticals for Neurodegeneration and Cancer Research: A Scoping Review and Translational Prospects

Bee Pollen (BP) has many advantageous properties relying on its multitargeting potential, a new tendency in managing many challenging illnesses. In cancer and neurodegeneration, the multiple effects of BP could be of unequaled importance and need further investigation. Although still limited, available data interestingly spotlights some floral sources with promising activities in line with this investigation. Adopting scoping review methodology, we have identified many crucial bioactivities that are widely recognized to individual BP compounds but remain completely untapped in this valuable bee cocktail. A wide range of these compounds have been recently found to be endowed with great potential in modulating pivotal processes in neurodegeneration and cancer pathophysiology. In addition, some ubiquitous BP compounds have only been recently isolated, while the number of studied BPs remains extremely limited compared to the endless pool of plant species worldwide. We have also elucidated that clinical profits from these promising perspectives are still impeded by challenging hurdles such as limited bioavailability of the studied phytocompounds, diversity and lack of phytochemical standardization of BP, and the difficulty of selective targeting in some pathophysiological mechanisms. We finally present interesting insights to guide future research and pave the way for urgently needed and simplified clinical investigations.

Gut-Microbiota-Derived Butyric Acid Overload Contributes to Ileal Mucosal Barrier Damage in Late Phase of Chronic Unpredictable Mild Stress Mice

Intestinal mucosal barrier damage is regarded as the critical factor through which chronic unpredictable mild stress (CUMS) leads to a variety of physical and mental health problems. However, the exact mechanism by which CUMS induces intestinal mucosal barrier damage is unclear. In this study, 14, 28, and 42 d CUMS model mice were established. The indicators related to ileal mucosal barrier damage (IMBD), the composition of the ileal microbiota and its amino acid (AA) and short-chain fatty acid (SCFA) metabolic functions, and free amino acid (FAA) and SCFA levels in the ileal lumen were measured before and after each stress period. The correlations between them are analyzed to investigate how CUMS induces intestinal mucosal barrier damage in male C57BL/6 mice. With the progression of CUMS, butyric acid (BA) levels decreased (14 and 28 d) and then increased (42 d), and IMBD progressively increased. In the late CUMS stage (42 d), the degree of IMBD is most severe and positively correlated with significantly increased BA levels (p < 0.05) in the ileal lumen and negatively correlated with significantly decreased FAAs, such as aspartic, glutamic, alanine, and glycine levels (p < 0.05). In the ileal lumen, the abundance of BA-producing bacteria (Muribaculaceae, Ruminococcus, and Butyricicoccus) and the gene abundance of specific AA degradation and BA production pathways and their related enzymes are significantly increased (p < 0.05). In addition, there is a significant decrease (p < 0.05) in the abundance of core bacteria (Prevotella, Lactobacillus, Turicibacter, Blautia, and Barnesiella) that rely on these specific AAs for growth and/or are sensitive to BA. These changes, in turn, promote further colonization of BA-producing bacteria, exacerbating the over-accumulation of BA in the ileal lumen. These results were validated by ileal microbiota in vitro culture experiments. In summary, in the late CUMS stages, IMBD is related to an excessive accumulation of BA caused by dysbiosis of the ileal microbiota and its overactive AA degradation.

Investigating the bacterial profiles of Lactobacillus, Bifidobacterium, Actinobacteria, Fusobacterium, Firmicutes, and Bacteroides in stool samples from patients with severe depression and healthy individuals

Depression is a multifaceted mental health disorder with complex etiology and significant global burden. Recent research indicates that the gut microbiota plays a role in the pathophysiology of depression, highlighting the potential role of specific bacterial species in influencing mood and cognitive function. In this study, we aimed to investigate the presence, copy numbers, and Ct values of selected bacterial species in stool samples from depressed patients (n=50) compared to control subjects (n=50). Our findings revealed significant differences in the abundance of Fusobacterium spp., Bifidobacterium spp., Lactobacillus spp., Bacteroidetes phylum, Firmicutes phylum, and Actinobacteria spp. between the two groups. Dysregulation of the gut microbiota, characterized by decreased presence of beneficial bacteria (e.g., Bifidobacterium spp., Lactobacillus spp.) and altered abundance of potentially pathogenic bacteria (e.g., Fusobacterium spp.), may contribute to the development or exacerbation of depression. These findings support the emerging concept of the gut-brain axis and its role in mental health. However, further research is needed to better understand the underlying mechanisms and explore the therapeutic potential of microbiota-targeted interventions for depression. Understanding the intricate interplay between the gut microbiota and depression could pave the way for novel treatment strategies and personalized approaches in mental health care.

Drug-Resistant Epilepsy and Gut-Brain Axis: an Overview of a New Strategy for Treatment

Drug-resistant epilepsy (DRE), also known as intractable epilepsy or refractory epilepsy, is a disease state with long-term poorly controlled seizures attack. Without effective treatment, patients are at an elevated risk of injury, premature death, mental disorders, and poor quality of life, increasing the need for a fresh perspective on the etiology and treatment of DRE. The gut is known to harbor a wide variety of microorganisms that can regulate the host's response to exogenous signals and participate in various physiological and pathological processes in the human body. Interestingly, emerging evidence has uncovered the changes in gut microbiota in patients with epilepsy, particularly those with DRE. In addition, both dietary interventions and specific antibiotic therapy have been proven to be effective in restoring the microecological environment and, more importantly, reducing seizures. Here, we reviewed recent studies on DRE and the involvement of gut microbiota in it, describing changes in the gut microflora composition in patients with DRE and corresponding animal models. Furthermore, the influence of the ketogenic diet, probiotics, fecal microbiota transplantation (FMT), and antibiotics as microbiome-related factors on seizure control and its possible mechanisms are broadly discussed. Finally, we highlighted the significance of gut microbiome in DRE, in order to provide a new prospect for early identification and individualized treatment of patients with DRE.

Characterizing the role of the microbiota-gut-brain axis in cerebral small vessel disease: An integrative multi‑omics study

BACKGROUND

Prior efforts have revealed changes in gut microbiome, circulating metabolome, and multimodal neuroimaging features in cerebral small vessel disease (CSVD). However, there is a paucity of research integrating the multi-omic information to characterize the role of the microbiota-gut-brain axis in CSVD.

METHODS

We collected gut microbiome, fecal and blood metabolome, multimodal magnetic resonance imaging data from 37 CSVD patients with white matter hyperintensities and 46 healthy controls. Between-group comparison was performed to identify the differential gut microbial taxa, followed by performance of multi-stage microbiome-metabolome-neuroimaging-neuropsychology correlation analyses in CSVD patients.

RESULTS

Our data showed both depleted and enriched gut microbes in CSVD patients. Among the differential microbes, Haemophilus and Akkermansia were associated with a range of metabolites enriched for Aminoacyl-tRNA biosynthesis pathway. Furthermore, the affected metabolites were associated with neuroimaging measures involving gray matter morphology, spontaneous intrinsic brain activity, white matter integrity, and global structural network topology, which were in turn related to cognition and emotion in CSVD patients.

CONCLUSION

Our findings provide an integrative framework to understand the pathophysiological mechanisms underlying the interplay between gut microbiota dysbiosis and CSVD, highlighting the potential of targeting the microbiota-gut-brain axis as a therapeutic strategy in CSVD patients.

Making waves: From tap to gut- exploring the impact of drinking water on gut microbiota

Drinking water (DW) harbours diverse microbial species and chemical attributes. Water comprises the greatest portion of our daily diet, ingested both on its own and used in the preparation of food. DW is our major source of liquids, which is vital to maintaining homeostasis, and can also supply essential minerals. Limited evidence suggests that DW plays a role in shaping the gut microbiome, which implies that it may impact human health. Despite its significant contribution to diet, DW is often overlooked in studies examining dietary influences on the gut microbiota. This perspective explores our current understanding of the link between DW and the gut microbiota - an area of human microbiome science that has been surprisingly understudied. Existing studies reveal links between DW source, microbiota composition, and gut health, emphasizing the need for comprehensive investigations. Understanding the interplay between DW and gut microbiota holds potential for tailored interventions to enhance human health.

Gut commensal Agathobacter rectalis alleviates microglia-mediated neuroinflammation against pathogenesis of Alzheimer disease

Gut microbiota plays a crucial role in the pathogenesis of Alzheimer disease (AD). Here, we found that AD patients had significantly lower abundance of Agathobacter, which were negatively correlated with cognitive impairment. Animal experiments showed that Agathobacter rectalis (A. rectalis) supplementation increased beneficial commensal bacteria, significantly improved pathological damage, and suppressed microglial activation in APP/PS1 mice. We further demonstrated that butyric acid, a metabolite of A. rectalis, reduced microglial activation and pro-inflammatory factor production via Akt/ nuclear factor κB (NF-κB) signal pathway in vitro. Meanwhile, we revealed that A. rectalis effectively inhibited activation of microglia in the APP/PS1 mice by regulating Akt/ NF-κB pathway. This finding highlights the role of A. rectalis and its metabolite butyrate in mitigating neuroinflammation in AD by modulating the Akt/NF-κB pathway.

Research Hotspots and Frontiers of Alzheimer's Disease and Gut Microbiota: A Knowledge Mapping and Text Mining Analysis

Gut microbiota has been confirmed to be closely related to Alzheimer's disease (AD). Research on gut microbiota and AD has also increased significantly. This study aimed to conduct a bibliometric and visual analysis of published studies related to gut microbiota and AD. Based on the Web of Science Core Collection SCI-Expanded database, we utilize Excel 2019 and visualization analysis tools VOSviewer, Co-Occurrence13.2 (COOC13.2), Citespace, HistCite, and Bibliometrix (R-Tool of R-Studio) for analysis. A total of 1093 related kinds of literature were included, and the number of papers presented an overall increasing trend. The country/region with the most publications is China, the institution is Zhejiang University, the author is Walter J Lukiw from the USA, and the journal is the Journal of Alzheimer's Disease. Hotspot research areas include the relationship between gut microbiota metabolism and AD, AD treatments related to the gut microbiota, and diseases related to AD and gut microbiota. The future research direction may be T cells, NLRP3 inflammasome, and Porphyromonas gingivalis. Studies on AD and gut microbiota have grown rapidly in recent years. Our research results may provide valuable references for readers and help researchers better find new research directions in the future.

The potential role of mitochondria in the microbiota-gut-brain axis: Implications for brain health

Mitochondria are crucial organelles that regulate cellular energy metabolism, calcium homeostasis, and oxidative stress responses, playing pivotal roles in brain development and neurodegeneration. Concurrently, the gut microbiota has emerged as a key modulator of brain physiology and pathology through the microbiota-gut-brain axis. Recent evidence suggests an intricate crosstalk between the gut microbiota and mitochondrial function, mediated by microbial metabolites that can influence mitochondrial activities in the brain. This review aims to provide a comprehensive overview of the emerging role of mitochondria as critical mediators in the microbiota-gut-brain axis, shaping brain health and neurological disease pathogenesis. We discuss how gut microbial metabolites such as short-chain fatty acids, secondary bile acids, tryptophan metabolites, and trimethylamine N-oxide can traverse the blood-brain barrier and modulate mitochondrial processes including energy production, calcium regulation, mitophagy, and oxidative stress in neurons and glial cells. Additionally, we proposed targeting the mitochondria through diet, prebiotics, probiotics, or microbial metabolites as a promising potential therapeutic approach to maintain brain health by optimizing mitochondrial fitness. Overall, further investigations into how the gut microbiota and its metabolites regulate mitochondrial bioenergetics, dynamics, and stress responses will provide valuable insights into the microbiota-gut-brain axis in both health and disease states.

Socioeconomic adversity, maternal nutrition, and the prenatal programming of offspring cognition and language at two years of age through maternal inflammation

Increasing rates of child neurodevelopmental vulnerability are a significant public health challenge. The adverse effect of socioeconomic adversity on offspring cognition may be mediated through elevated prenatal maternal systemic inflammation, but the role of modifiable antecedents such as maternal nutrition has not yet been clarified. This study aimed to examine (1) whether prenatal factors, with an emphasis on maternal nutrition, were associated with prenatal maternal systemic inflammation at 28 weeks' gestation, including the metabolomic marker glycoprotein acetyls (GlycA); (2) the extent to which the association between prenatal maternal nutrition and child cognition and language at age two years was mediated by elevated maternal inflammation in pregnancy; (3) the extent to which the associations between prenatal socioeconomic adversity and child neurodevelopment were mediated through prenatal maternal nutrition and GlycA levels. We used a prospective population-derived pre-birth longitudinal cohort study, the Barwon Infant Study (Barwon region of Victoria, Australia), where 1074 mother-child pairs were recruited by 28 weeks' gestation using an unselected sampling frame. Exposures included prenatal factors such as maternal diet measured by a validated food frequency questionnaire at 28 weeks' gestation and dietary patterns determined by principal component analysis. The main outcome measures were maternal inflammatory biomarkers (GlycA and hsCRP levels) at 28 weeks' gestation, and offspring Bayley-III cognition and language scores at age two years. Results showed that the 'modern wholefoods' and 'processed' maternal dietary patterns were independently associated with reduced and elevated maternal inflammation respectively (GlycA or hsCRP p < 0.001), and also with higher and reduced offspring Bayley-III scores respectively (cognition p ≤ 0.004, language p ≤ 0.009). Associations between dietary patterns and offspring cognition and language were partially mediated by higher maternal GlycA (indirect effect: cognition p ≤ 0.036, language p ≤ 0.05), but were less evident for hsCRP. The maternal dietary patterns mediated 22 % of the association between socioeconomic adversity (lower maternal education and/or lower household income vs otherwise) and poorer offspring cognition (indirect effect p = 0.001). Variation in prenatal GlycA levels that were independent of these dietary measures appeared less important. In conclusion, modifiable prenatal maternal dietary patterns were associated with adverse child neurocognitive outcomes through their effect on maternal inflammation (GlycA). Maternal diet may partially explain the association between socioeconomic adversity and child neurocognitive vulnerability. Maternal diet-by-inflammation pathways are an attractive target for future intervention studies.

Gut Microbiome variation in patients with early-stage mild-to-moderate intracerebral hemorrhage: A pilot study exploring therapeutic targets

BACKGROUND

The significant morbidity and mortality rates of acute intracerebral hemorrhage (ICH) are well-known around the world. The link between gut microbiota and different types of strokes is becoming more studied. The goal of this study was to look at the relationships between intestinal flora and early-stage mild-to-moderate ICH (emICH), and to provide a new perspective for adjunctive treatment of emICH.

METHODS

Fecal samples from 100 participants with emICH (n=50) and healthy individuals (n=50) in this study were collected as well as analyzed utilizing 16S rRNA gene amplicon sequencing in order to characterize the gut microbial community.

RESULTS

Distinct microbial communities are present within each group, with emICH patients exhibiting a diminished diversity and uniformity in their microbial profiles. A notable shift in the gut microbiota composition of emICH patients has been observed, characterized by an upsurge in pro-inflammatory microbes belonging to the Euryarchaeota phylum and a concurrent decline in beneficial Bacteroidetes species. Concurrently, significant associations and patterns among operational taxonomic units (OTUs) were identified in emICH patients. A panel of biomarkers (WAL_1855D, Methanobrevibacter, Streptococcus, Bacteroides, Coprococcus, Lachnospira) has been effectively utilized to distinguish emICH patients from healthy individuals, with an area under the curve (AUC) of 0.845. Additionally, an analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation uncovered several perturbed pathways in emICH patients, predominantly those related to metabolic processes and the inflammatory response. Moreover, predictive profiling of the microbiome's phenotypic traits suggests that emICH patients are likely to harbor a higher prevalence of Gram-negative bacteria and potential opportunistic pathogens compared to healthy controls.

CONCLUSIONS

The gut microbiota ecosystem of emICH patients is disrupted, characterized primarily by an increase in pro-inflammatory microbiota, elevated inflammatory signaling pathways, and metabolic dysregulation. Furthermore, microbiota modulation may be seen as a novel approach for the adjunctive treatment of emICH.

Use of Caenorhabditis elegans to Unravel the Tripartite Interaction of Kynurenine Pathway, UPRmt and Microbiome in Parkinson's Disease

The model organism Caenorhabditis elegans and its relationship with the gut microbiome are gaining traction, especially for the study of neurodegenerative diseases such as Parkinson's Disease (PD). Gut microbes are known to be able to alter kynurenine metabolites in the host, directly influencing innate immunity in C. elegans. While the mitochondrial unfolded protein response (UPRmt) was first characterized in C. elegans in 2007, its relevance in host-microbiome interactions has only become apparent in recent years. In this review, we provide novel insights into the current understanding of the microbiome-gut-brain axis with a focus on tripartite interactions between the UPRmt, kynurenine pathway, and microbiome in C. elegans, and explore their relationships for PD remediations.

Modulation of the gut microbiota by dietary intervention with Acanthocereus tetragonus improves the health status of Wistar rats with metabolic syndrome

The gastrointestinal tract is an ecosystem with heterogeneous patterns, distributions, and environments, resulting in different microbial compositions in each gut segment. The relationship between diet and microbiota determines this heterogeneity. Consumption of diets high in fat and carbohydrates (HLHC) is associated with gut dysbiosis, low microbial diversity, and metabolic syndrome (MetS). Functional fiber consumption improves the profile and diversity of the gut microbiota (GM); it stimulates the production of short-chain fatty acids (SCFAs), which act as signaling molecules that maintain the gut barrier integrity and induce hormone synthesis that regulates satiety and glucose metabolism, reducing some MetS parameters. The effect of a dietary intervention with Acanthocereus tetragonus (At), a cactus rich in fiber, antioxidants, amino acids, and minerals traditionally consumed by the Mexican population, is reported here. For this purpose, Wistar rats were randomly divided into three study groups: a control (C) group, a MetS group, and an At-supplemented group. In the MetS and At groups, an HLHC was administered for 12 weeks, inducing MetS. After 18 weeks, stool samples were collected for microbiota sequencing. HLHC administration favored Firmicutes and decreased the abundance of Bacteriodetes at the phylum level in the MetS group. At the genus level, the dietary intervention with At increased the presence of Roseburia, Ruminococcus, Blautia, Bacteroides, and Christensenella, reflecting the effect of A. tetragonus consumption on GM. At diet administration reduced body weight; the plasma glucose, insulin, and lipid levels; and insulin resistance.

The effect of synbiotics in the treatment of drug-resistant epilepsy and the parental burden of caregivers: a single-arm pretest-posttest trial

BACKGROUND

In patients with drug-resistant epilepsy (DRE), the composition of the gut microbiome changes compared to drug-sensitive patients and healthy individuals. Synbiotics, a mixture of probiotics and prebiotics, aim to improve the balance of bacteria in the gut microbiome. This study aimed to assess the effect of synbiotics on the treatment of DRE and the burden on caregivers.

METHODS

This one-group pretest-posttest quasi-experimental study was conducted in Arak, Iran. Thirty children with DRE, diagnosed by a pediatric neurologist and meeting the inclusion criteria in 2021-22, were included in the study. In addition to anticonvulsant drugs, infants were administered PediLact at a dose of 5-15 drops per day for eight weeks, and KidiLact at a dose of one sachet per day for eight weeks for children aged 2-15 years. Both PediLact and KidiLact are synbiotics. To investigate the burden on caregivers (parents), the Zarit Caregiver Burden Interview was conducted. In addition, the number of epileptic seizures was assessed from mothers before and immediately after the intervention over one month.

RESULTS

The mean age of the participants in the study was 8.6 years (SD: 3.4). Eighteen participants (60%) were boys, and 12 (40%) were girls. The results of the study showed a statistically significant decrease in the mean burden on caregivers, from 34.20 (SD: 14.4) before the intervention to 30.26 (SD: 15.8) after the intervention (P = 0.017). The mean frequency of seizures decreased significantly, from 15.83 (SD: 12.9) before the intervention to 12.73 (SD: 12.8) after the intervention (P = 0.001). Following the intervention, the seizure frequency stopped in two patients, decreased by 50% in six patients, increased in one patient, and remained unchanged in 21 patients.

CONCLUSION

The results suggest that Symbiotics in DRE patients are associated with a lower parental burden of caregivers and seizure frequency. Well-designed randomized clinical trial studies are recommended to generate rigorous causal evidence and conclusions.

Investigating the mechanisms of inflammation and immune alterations in Parkinson's disease using spatial transcriptomics techniques

In recent years, overwhelming evidence has emphasized the crucial role of inflammation in the pathogenesis of PD. However, the exact mechanisms by which inflammation damages dopaminergic neurons in PD are still unclear. Therefore, we generated a MPTP-induced PD mouse model and performed spatial transcriptomic sequencing to provide more insight into the process of PD development at specific brain regions. Our results indicate that the pathological changes of PD are mainly manifested in the midbrain, especially in the substantia nigra region, with significant reductions in oligodendrocytes and Agt-labeled astrocytes and an increase in Gfap-labeled astrocytes. Macrophages displayed an increasing trend in the PD environment, indicating a pattern of immune modulation induced by PD. Moreover, pathway analysis revealed significant impairments in ion migration ability, abnormal Ca2+ channels, cAMP signaling, and synaptic damage in PD. Significant downregulation of Mt1 and Mt2 and upregulation of Atp1b2, Gpi1, and Cox6a1 in PD further underscored the occurrence of intense inflammation and immune alterations. On the basis of these findings, we have validated the significant accumulation of Ca2+ in the midbrain tissue in the PD environment by measuring its content. Additionally, we have demonstrated a close association between the reduction of dopaminergic neurons, represented by the midbrain region, and ferroptosis by evaluating the iron content, malondialdehyde (MDA) levels, and the protein expression of GPX4 and TH in the tissue. We propose the hypothesis that PD-related inflammation and immune changes can induce neuronal and oligodendrocyte damage through the induction of ferroptosis, thereby further accelerating the progression of PD.

Efficacy of bifidobacterium-related preparations on depression: the first meta-analysis

Currently, depression-induced suicide has emerged as the primary contributor to the worldwide burden of disability. However, the prevailing drug treatment not only suffers from delayed effectiveness and limited efficacy, but also there are withdrawal symptoms and rebound phenomenon. Consequently, there is an imperative to investigate safer and more efficient treatments to ameliorate the clinical manifestations of depression. At present, there is increased evidence that probiotics can improve the symptoms of depression, but the existing studies use many and mixed types of probiotics, and it is impossible to determine the specific efficacy of bifidobacteria in the treatment of depression. This review will systematically review the effects of bifidobacteria on the treatment effect of depression, Meta-analysis showed that Bifidobacterium-related preparations effectively improved depressive symptoms in patients with depression. This study represents the initial meta-analysis conducted on the use of bifidobacteria-related agents for treating depression. The objective was to determine the effect of bifidobacteria-related preparations on improving depressive symptoms. We found that Bifidobacterium and its related agents can effectively reduce depression scale scores in patients with depression, suggesting the need for further research into this potential strategy for the prevention and treatment of depression.

Microbiota-gut-brain axis in perioperative neurocognitive and depressive disorders: Pathogenesis to treatment

An increasing number of people undergo anesthesia and surgery. Perioperative neurocognitive and depressive disorders are common central nervous system complications with similar pathogeneses. These conditions pose a deleterious threat to human health and a significant societal burden. In recent years, numerous studies have focused on the role of the gut microbiota and its metabolites in the central nervous system via the gut-brain axis. Its involvement in perioperative neurocognitive and depressive disorders has attracted considerable attention. This review aimed to elucidate the role of the gut microbiota and its metabolites in the pathogenesis of perioperative neurocognitive and depressive disorders, as well as the value of targeted interventions and treatments.

Multi-omics insights into anti-colitis benefits of the synbiotic and postbiotic derived from wheat bran arabinoxylan and Limosilactobacillus reuteri

Exploring nutritional therapies that manipulate tryptophan metabolism to activate AhR signaling represents a promising approach for mitigating chronic colitis. Arabinoxylan is a bioactive constituent abundant in wheat bran. Here, we comprehensively investigated anti-colitis potentials of wheat bran arabinoxylan (WBAX), its synbiotic and postbiotic derived from WBAX and Limosilactobacillus reuteri WX-94 (i.e., a probiotic strain exhibiting tryptophan metabolic activity). WBAX fueled L. reuteri and promoted microbial conversion of tryptophan to AhR ligands during in vitro fermentation in the culture medium and in the fecal microbiota from type 2 diabetes. The WBAX postbiotic outperformed WBAX and its synbiotic in augmenting efficacy of tryptophan in restoring DSS-disturbed serum immune markers, colonic tight junction proteins and gene profiles involved in amino acid metabolism and FoxO signaling. The WBAX postbiotic remodeled gut microbiota and superiorly enhanced AhR ligands (i.e., indole metabolites and bile acids), alongside with elevation in colonic AhR and IL-22. Associations between genera and metabolites modified by the postbiotic and colitis in human were verified and strong binding capacities between metabolites and colitis-related targets were demonstrated by molecular docking. Our study advances the novel perspective of WBAX in manipulating tryptophan metabolism and anti-colitis potentials of WBAX postbiotic via promoting gut microbiota-dependent AhR signaling.

The Gut Microbiota Modulates Neuroinflammation in Alzheimer's Disease: Elucidating Crucial Factors and Mechanistic Underpinnings

BACKGROUND AND PURPOSE

Alzheimer's disease (AD) is characterized by progressive cognitive decline and neuronal loss, commonly linked to amyloid-β plaques, neurofibrillary tangles, and neuroinflammation. Recent research highlights the gut microbiota as a key player in modulating neuroinflammation, a critical pathological feature of AD. Understanding the role of the gut microbiota in this process is essential for uncovering new therapeutic avenues and gaining deeper insights into AD pathogenesis.

METHODS

This review provides a comprehensive analysis of how gut microbiota influences neuroinflammation and glial cell function in AD. A systematic literature search was conducted, covering studies from 2014 to 2024, including reviews, clinical trials, and animal studies. Keywords such as "gut microbiota," "Alzheimer's disease," "neuroinflammation," and "blood-brain barrier" were used.

RESULTS

Dysbiosis, or the imbalance in gut microbiota composition, has been implicated in the modulation of key AD-related mechanisms, including neuroinflammation, blood-brain barrier integrity, and neurotransmitter regulation. These disruptions may accelerate the onset and progression of AD. Additionally, therapeutic strategies targeting gut microbiota, such as probiotics, prebiotics, and fecal microbiota transplantation, show promise in modulating AD pathology.

CONCLUSIONS

The gut microbiota is a pivotal factor in AD pathogenesis, influencing neuroinflammation and disease progression. Understanding the role of gut microbiota in AD opens avenues for innovative diagnostic, preventive, and therapeutic strategies.

Explore the mechanisms of triterpenoids from Ganoderma lucidum in the protection against Alzheimer's disease via microbiota-gut-brain axis with the aid of network pharmacology

Ganoderma lucidum (Curtis) P. Karst.(G. lucidum) is a kind of fungi, which also a traditional Chinese medicine used for "wisdom growth" in China. Triterpenoids from G. lucidum (GLTs) are one of the main active ingredients. Based on the strategy of early intervention on Alzheimer's disease (AD) and the inextricable association between disordered gut microbiota and metabolites with AD, this study aimed to explore the mechanisms of GLTs in the protection against AD via microbiota-gut-brain axis with the aid of network pharmacology. In this study, LC-MS/MS was used to identify the main active ingredients of GLTs. Network pharmacology was used to predict the potential target and validated with Caco-2 cell model. D-galactose was used to induce the slow-onset AD on rats. Metabolomics methods basing on GC-MS combined with 16S rRNA sequencing technology was used to carry out microbiota-gut-metabolomics analysis in order to reveal the potential mechanisms of GLTs in the protection of AD. As results, GLTs showed a protection against AD effect on rats by intervening administration. The mechanisms were inextricably linked to GLTs interference with the balance of gut microbiota and metabolites. The main fecal metabolites involved were short-chain fatty acids and aromatic amino acid metabolites.

A comprehensive review on the pharmacological role of gut microbiome in neurodegenerative disorders: potential therapeutic targets

Neurological disorders, including Alzheimer and Parkinson's, pose significant challenges to public health due to their complex etiologies and limited treatment options. Recent advances in research have highlighted the intricate bidirectional communication between the gut microbiome and the central nervous system (CNS), revealing a potential therapeutic avenue for neurological disorders. Thus, this review aims to summarize the current understanding of the pharmacological role of gut microbiome in neurological disorders. Mounting evidence suggests that the gut microbiome plays a crucial role in modulating CNS function through various mechanisms, including the production of neurotransmitters, neuroactive metabolites, and immune system modulation. Dysbiosis, characterized by alterations in gut microbial composition and function, has been observed in many neurological disorders, indicating a potential causative or contributory role. Pharmacological interventions targeting the gut microbiome have emerged as promising therapeutic strategies for neurological disorders. Probiotics, prebiotics, antibiotics, and microbial metabolite-based interventions have shown beneficial effects in animal models and some human studies. These interventions aim to restore microbial homeostasis, enhance microbial diversity, and promote the production of beneficial metabolites. However, several challenges remain, including the need for standardized protocols, identification of specific microbial signatures associated with different neurological disorders, and understanding the precise mechanisms underlying gut-brain communication. Further research is necessary to unravel the intricate interactions between the gut microbiome and the CNS and to develop targeted pharmacological interventions for neurological disorders.

The Association of the Oral Microbiota with Cognitive Functioning in Adolescence

Background: A growing body of research supports the role of the microbial communities residing in the digestive system in the host's cognitive functioning. Most of these studies have been focused on the gut microbiome and its association with clinical phenotypes in middle-aged and older adults. There is an insufficiency of population-based research exploring the association of normative cognitive functioning with the microbiome particularly with the oral microbiota. Methods: In this study, using metagenomics and metabolomics, we characterized the salivary microbiome diversity in a sample of 51 males of Hispanic and African American origin aged 12-18 years and explored the associations between the microbiome and the youths' cognitive performance captured with the Kaufman Assessment Battery for Children II (KABC-II). Results: Several bacterial species of the oral microbiota and related metabolic pathways were associated with cognitive function. In particular, we found negative associations between indicators of general intelligence and the relative abundance of Bacteroidetes and Lachnospiraceae and positive associations with Bifidobacteriaceae and Prevotella histicola sp. Among metabolic pathways, the super pathways related to bacterial cell division and GABA metabolism were linked to cognitive function. Conclusions: The results of our work are consistent with the literature reporting on the association between microbiota and cognitive function and support further population work to elucidate the potential for a healthy oral microbiome to improve cognitive health.

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

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

A systematic framework for understanding the microbiome in human health and disease: from basic principles to clinical translation

The human microbiome is a complex and dynamic system that plays important roles in human health and disease. However, there remain limitations and theoretical gaps in our current understanding of the intricate relationship between microbes and humans. In this narrative review, we integrate the knowledge and insights from various fields, including anatomy, physiology, immunology, histology, genetics, and evolution, to propose a systematic framework. It introduces key concepts such as the 'innate and adaptive genomes', which enhance genetic and evolutionary comprehension of the human genome. The 'germ-free syndrome' challenges the traditional 'microbes as pathogens' view, advocating for the necessity of microbes for health. The 'slave tissue' concept underscores the symbiotic intricacies between human tissues and their microbial counterparts, highlighting the dynamic health implications of microbial interactions. 'Acquired microbial immunity' positions the microbiome as an adjunct to human immune systems, providing a rationale for probiotic therapies and prudent antibiotic use. The 'homeostatic reprogramming hypothesis' integrates the microbiome into the internal environment theory, potentially explaining the change in homeostatic indicators post-industrialization. The 'cell-microbe co-ecology model' elucidates the symbiotic regulation affecting cellular balance, while the 'meta-host model' broadens the host definition to include symbiotic microbes. The 'health-illness conversion model' encapsulates the innate and adaptive genomes' interplay and dysbiosis patterns. The aim here is to provide a more focused and coherent understanding of microbiome and highlight future research avenues that could lead to a more effective and efficient healthcare system.

Distinguishing bipolar depression, bipolar mania, and major depressive disorder by gut microbial characteristics

BACKGROUND

Gut microbial disturbance has been widely confirmed in mood disorders. However, little is known about whether gut microbial characteristics can distinguish major depressive disorder (MDD), bipolar depression (BP-D), and bipolar mania (BP-M).

METHODS

This was a prospective case-control study. The composition of gut microbiota was profiled using 16S ribosomal RNA (rRNA) gene sequencing of fecal samples and compared between healthy controls (HC; n = 46), MDD (n = 51), BP-D (n = 44), and patients with BP-M (n = 45).

RESULTS

Gut microbial compositions were remarkably changed in the patients with MDD, BP-D, and BP-M. Compared to HC, distinct gut microbiome signatures were found in MDD, BP-D, and BP-M, and some gut microbial changes were overlapping between the three mood disorders. Furthermore, we identified a signature of 7 operational taxonomic units (OUT; Prevotellaceae-related OUT22, Prevotellaceae-related OUT31, Prevotellaceae-related OTU770, Ruminococcaceae-related OUT70, Bacteroidaceae-related OTU1536, Propionibacteriaceae-related OTU97, Acidaminococcaceae-related OTU34) that can distinguish patients with MDD from those with BP-D, BP-M, or HC, with area under the curve (AUC) values ranging from 0.910 to 0.996.

CONCLUSION

Our results provide the clinical rationale for the discriminative diagnosis of MDD, BP-D, and BP-M by characteristic gut microbial features.

Bile acid modulation by gut microbiota: a bridge to understanding cognitive health

The gut microbiota plays an important role in regulating the body's physiological system, and more recently its impact on bile acid metabolism and cognitive function has been investigated by many studies. In addition to their conventional function in fat digestion and absorption, bile acids are now considered crucial signaling molecules that control several metabolic processes and immunological responses. For this purpose, the authors conducted comprehensive research using relevant terms in an attempt to understand more about the gut microbiota and its impact on bile acid metabolism and cognitive health. The gut-brain axis refers to the network of routes through which gut bacteria communicate with the brain. Through its capacity to bio-transform primary bile acids into secondary bile acids, the gut microbiota plays a significant role in bile acid metabolism. Bile acids function as signaling molecules and act on the brain through nuclear and membrane-bound receptors, influencing neurotransmitter production, neuroinflammation, and neuroplasticity to modify this communication. Any dysregulation in this axis can result in cognitive dysfunction. The link between gut microbiota, bile acids, and cognitive health cannot be ignored. It is imperative to explore this link further by conducting large-scale trials to improve the cognitive health of patients with multiple comorbidities, especially those involving the gastrointestinal tract and nervous system.

Microbiome and metabolome analyses indicate variations in the gut microbiota that disrupt regulation of appetite

The mechanism connecting gut microbiota to appetite regulation is not yet fully understood. This study identifies specific microbial community and metabolites that may influence appetite regulation. In the initial phase of the study, mice were administered a broad-spectrum antibiotic cocktail (ABX) for 10 days. The treatment significantly reduced gut microbes and disrupted the metabolism of arginine and tryptophan. Consequently, ABX-treated mice demonstrated a notable reduction in feed consumption. The hypothalamic expression levels of CART and POMC, two key anorexigenic factors, were significantly increased, while orexigenic factors, such as NPY and AGRP, were decreased. Notably, the levels of appetite-suppressing hormone cholecystokinin in the blood were significantly elevated. In the second phase, control mice were maintained, while the ABX-treated mice received saline, probiotics, and short-chain fatty acids (SCFAs) for an additional 10 days to restore their gut microbiota. The microbiota reconstructed by probiotic and SCFA treatments were quite similar, while microbiota of the naturally recovering mice demonstrated greater resemblance to that of the control mice. Notably, the abundance of Akkermansia and Bacteroides genera significantly increased in the reconstructed microbiota. Moreover, microbiota reconstruction corrected the disrupted arginine and tryptophan metabolism and the abnormal peripheral hormone levels caused by ABX treatment. Among the groups, SCFA-treated mice had the highest feed intake and NPY expression. Our findings indicate that gut microbes, especially Akkermansia, regulate arginine and tryptophan metabolism, thereby influencing appetite through the microbe-gut-brain axis.

The gut microbiota improves the efficacy of immune-checkpoint inhibitor immunotherapy against tumors: From association to cause and effect

Immune-checkpoint inhibitors (ICIs), including anti-PD-1/PD-L1 therapeutic antibodies, have markedly enhanced survival across numerous cancer types. However, the limited number of patients with durable benefits creates an urgent need to identify response biomarkers and to develop novel strategies so as to improve response. It is widely recognized that the gut microbiome is a key mediator in shaping immunity. Additionally, the gut microbiome shows significant potential in predicting the response to and enhancing the efficacy of ICI immunotherapy against cancer. Recent studies encompassing mechanistic analyses and clinical trials of microbiome-based therapy have shown a cause-and-effect relationship between the gut microbiome and the modulation of the ICI immunotherapeutic response, greatly contributing to the establishment of novel strategies that will improve response and overcome resistance to ICI treatment. In this review, we outline the current state of research advances and discuss the future directions of utilizing the gut microbiome to enhance the efficacy of ICI immunotherapy against tumors.

Intestinal mycobiota dysbiosis associated inflammation activation in chronic schizophrenia

The microbiome-gut-brain axis is related to schizophrenia (SCZ). The role of intestinal mycobiota in SCZ has been under investigated. We present a half-year follow-up study involving 109 chronic SCZ patients and 77 healthy controls. Intestinal mycobiota was tested by internal transcribed spacer (ITS). Untargeted liquid chromatography-mass spectrometry (LC-MS) was used to measure fecal metabolites. Symptom severity was assessed using the Positive and Negative Syndrome Scale. Enterotype analysis showed that Candida-type patients exhibited severer positive symptoms and depression factors than Saccharomyces-type patients. Candida and its top species and operational taxonomic units (OTUs) were positively correlated with depression factors (all p=0.001). Fecal metabolites analysis showed that upregulated metabolites were associated with chronic inflammation (NF-κB pathway and T helper cell differentiation), downregulated metabolites were associated with glutamate metabolism, serotonergic and dopaminergic synapse. Procrustes analysis revealed significant correlation between intestinal mycobiota and fecal metabolites (M2=0.937, p<0.001). Metabolic module analysis showed that the top module, MEturquoise (associated with Th1 and Th2 cell differentiation), was negatively correlated with SCZ (r=-0.783, p<0.0001), positively correlated with Candida, Aspergillus, Trichosporon and Talaromyces (decreased in SCZ) and negatively correlated with Saccharomyces (increased in SCZ). We also found impairments of intestinal barrier in SCZ, characterized by increased in blood D-lactate (mucosa impairment marker) and decreased in blood mucin 2 (mucosal barrier protective protein). Serum levels of TNF-α was increased and showed stable high levels during treatment. This study suggests that mycobiota dysbiosis-related chronic inflammation and an impaired intestinal mucosal barrier are associated with chronic SCZ.

Impacts of microbiota and its metabolites through gut-brain axis on pathophysiology of major depressive disorder

Major depressive disorder (MDD) is characterized by a high rate of recurrence and disability, which seriously affects the quality of life of patients. That's why a deeper understanding of the mechanisms of MDD pathology is an urgent task, and some studies have found that intestinal symptoms accompany people with MDD. The microbiota-gut-brain axis is the bidirectional communication between the gut microbiota and the central nervous system, which was found to have a strong association with the pathogenesis of MDD. Previous studies have focused more on the communication between the gut and the brain through neuroendocrine, neuroimmune and autonomic pathways, and the role of gut microbes and their metabolites in depression is unclear. Metabolites of intestinal microorganisms (e.g., tryptophan, kynurenic acid, indole, and lipopolysaccharide) can participate in the pathogenesis of MDD through immune and inflammatory pathways or by altering the permeability of the gut and blood-brain barrier. In addition, intestinal microbes can communicate with intestinal neurons and glial cells to affect the integrity and function of intestinal nerves. However, the specific role of gut microbes and their metabolites in the pathogenesis of MDD is not well understood. Hence, the present review summarizes how gut microbes and their metabolites are directly or indirectly involved in the pathogenesis of MDD.

The breath volatilome is shaped by the gut microbiota

The gut microbiota is widely implicated in host health and disease, inspiring translational efforts to implement our growing body of knowledge in clinical settings. However, the need to characterize gut microbiota by its genomic content limits the feasibility of rapid, point-of-care diagnostics. The microbiota produces a diverse array of xenobiotic metabolites that disseminate into tissues, including volatile organic compounds (VOCs) that may be excreted in breath. We hypothesize that breath contains gut microbe-derived VOCs that inform the composition and metabolic state of the microbiota. To explore this idea, we compared the breath volatilome and fecal gut microbiomes of 27 healthy children and found that breath VOC composition is correlated with gut microbiomes. To experimentally interrogate this finding, we devised a method for capturing exhaled breath from gnotobiotic mice. Breath volatiles are then profiled by gas-chromatography mass-spectrometry (GC-MS). Using this novel methodology, we found that the murine breath profile is markedly shaped by the composition of the gut microbiota. We also find that VOCs produced by gut microbes in pure culture can be identified in vivo in the breath of mice monocolonized with the same bacteria. Altogether, our studies identify microbe-derived VOCs excreted in breath and support a mechanism by which gut bacterial metabolism directly contributes to the mammalian breath VOC profiles.

A relationship between intestinal microbiome and epilepsy: potential treatment options for drug-resistant epilepsy

Background. According to the World Health Organization, about 50 million people worldwide suffer from epilepsy. Almost 1/3 of patients are diagnosed with drug-resistant epilepsy (DRE). A relationship between intestinal microbiome (IM) and the central nervous system carried out throughout life via bidirectional dynamic network exists. It has been evidenced that IM profile becomes altered in patients with DRE.

Objective: to summarize the current literature data on the role for microbiome-gut-brain axis in DRE, as well as to assess an importance of IM composition changes as a prognostic marker for developing DRE.

Material and methods. The authors conducted a search for publications in the electronic databases PubMed/MEDLINE and eLibrary, as well as Google Scholar search engine. The evaluation of the articles was carried out in accordance with the PRISMA recommendations. Based on the search, 4,158 publications were retrieved from PubMed/MEDLINE database, 173 – from eLibrary, and 1,100 publications found with  Google Scholar. After the selection procedure, 121 studies were included in the review.

Results. The review provides convincing evidence about a correlation between IM and DRE demonstrating overt differences in IM composition found in patients with epilepsy related to drug sensitivity. IM dysbiosis can be corrected by exogenous interventions such as ketogenic diet, probiotic treatment and fecal microbiota transplantation subsequently resulting in altered brain neurochemical signaling and, therefore, alleviating epileptic activity.

Conclusion. A ketogenic diet, probiotics and antibiotics may have some potential to affect epilepsy by correcting IM dysbiosis, but the current studies provide no proper level of evidence. Future clinical multicenter trials should use standardized protocols and a larger-scale patient sample to provide more reliable evidence. Moreover, further fundamental investigations are required to elucidate potential mechanisms and therapeutic targets.

The impact of altered dietary adenine concentrations on the gut microbiota in Drosophila

The gut microbiota influences host metabolism and health, impacting diseases. Research into how diet affects gut microbiome dynamics in model organisms is crucial but underexplored. Herein, we examined how dietary adenine affects uric acid levels and the gut microbiota over five generations of Drosophila melanogaster. Wild-type W1118 flies consumed diets with various adenine concentrations (GC: 0%, GL: 0.05%, and GH: 0.10%), and their gut microbiota were assessed via Illumina MiSeq sequencing. Adenine intake significantly increased uric acid levels in the GH group > the GC group. Despite no significant differences in the alpha diversity indices, there were significant disparities in the gut microbiota health index (GMHI) and dysbiosis index (MDI) among the groups. Adenine concentrations significantly altered the diversity and composition of the gut microbiota. High adenine intake correlated with increased uric acid levels and microbial population shifts, notably affecting the abundances of Proteobacteria and Firmicutes. The gut microbiota phenotypes included mobile elements, gram-positive bacteria, biofilm-forming bacteria, and gram-negative bacteria. The significantly enriched KEGG pathways included ageing, carbohydrate metabolism, and the immune system. In conclusion, adenine intake increases uric acid levels, alters gut microbiota, and affects KEGG pathways in Drosophila across generations. This study highlights the impact of dietary adenine on uric acid levels and the gut microbiota, providing insights into intergenerational nutritional effects.

Healing from Within: How Gut Microbiota Predicts IBD Treatment Success-A Systematic Review

Recent research indicates that the microbiome has a significant impact on the progression of inflammatory bowel disease (IBD) and that creating therapies that change its composition could positively impact the outcomes of IBD treatment. This review summarizes the results of extensive studies that examined IBD patients undergoing several therapies, including anti-TNF medication, vedolizumab, ustekinumab, probiotics, and fecal microbiota transplantation (FMT), and the alterations in their gut microbiota's composition and function. The objective was to investigate the variety and effectiveness of microbial species in order to discover new biomarkers or therapeutic targets that could improve the outcome of treatment for these patients. This research aimed to offer useful insights into personalized medicine techniques for managing IBD. Beneficial bacteria such as Faecalibacterium prausnitzii and Roseburia have been consistently linked to favorable clinical outcomes, whereas pathogenic bacteria such as Escherichia coli and Clostridioides difficile are associated with worsening disease conditions. Although many studies have examined the role of gut microbiota in IBD, there is still a need for more targeted research on the connection between specific microbial communities and treatment outcomes. This study sought to address this gap by exploring the intricate relationship between the gut microbiota composition and the effectiveness of IBD medications.

The gut microbiota-brain axis in neurological disorders

Previous studies have shown a bidirectional communication between human gut microbiota and the brain, known as the microbiota-gut-brain axis (MGBA). The MGBA influences the host's nervous system development, emotional regulation, and cognitive function through neurotransmitters, immune modulation, and metabolic pathways. Factors like diet, lifestyle, genetics, and environment shape the gut microbiota composition together. Most research have explored how gut microbiota regulates host physiology and its potential in preventing and treating neurological disorders. However, the individual heterogeneity of gut microbiota, strains playing a dominant role in neurological diseases, and the interactions of these microbial metabolites with the central/peripheral nervous systems still need exploration. This review summarizes the potential role of gut microbiota in driving neurodevelopmental disorders (autism spectrum disorder and attention deficit/hyperactivity disorder), neurodegenerative diseases (Alzheimer's and Parkinson's disease), and mood disorders (anxiety and depression) in recent years and discusses the current clinical and preclinical gut microbe-based interventions, including dietary intervention, probiotics, prebiotics, and fecal microbiota transplantation. It also puts forward the current insufficient research on gut microbiota in neurological disorders and provides a framework for further research on neurological disorders.

Glaucoma and the Human Microbiome

PURPOSE OF REVIEW

To explore a view of the human microbiome as an interconnected, functional, dynamic system that may be linked to the pathogenesis and progression of glaucoma.

METHODS

A literature review was undertaken that included publications from 1966 to 2023.

RESULTS

Bacterial lipopolysaccharides (LPS) activate toll-like receptors (TLR) and mediate the human immune response. The LPS-TLR4 pathway is a potential avenue for the ocular, gut, and oral microbiomes to interface and/or influence ocular disease. Studies of gut dysbiosis have shown that alterations in the healthy microbiota can predispose the host to immune-mediated inflammatory and neurodegenerative conditions, while oral and ocular surface dysbiosis has been correlated with glaucoma. While developmental exposure to commensal microflora has shown to be necessary for the autoimmune and neurodegenerative responses to elevated intraocular pressure to take place, commensal bacterial products like short-chain fatty acids have regulatory effects protective against glaucoma.

SUMMARY

Alterations to human microbiotas have been associated with changes in intestinal permeability, gene regulation, immune cell differentiation, and neural functioning, which may predispose the host to glaucoma. Select microbes have been highlighted for their potential contributions to glaucoma disease progression or protection, raising the potential for microbiota-based treatment modalities. Current topical glaucoma treatments may disrupt the ocular surface microbiota, potentially having ramifications on host health. Further study of the relationships between human microbiome and glaucoma is needed.

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.

The association of dietary inflammatory index with sleep outcomes: A systematic review

Background

Sleep is a vital physiological process that plays a crucial role in various aspects of human health and well-being. Regarding the important role of diet on the sleep quality, the present study aimed to assess the association of dietary inflammatory index (DII) with the sleep outcomes and also to provide the potential mechanisms of action.

Methods

PubMed, Web of Science and Scopus databases and Google Scholar search engine were systematically searched for relevant studies related to DII and sleep outcomes using appropriate search terms until February 2024.

Results

From the initial systematic search of databases, 197 studies were retrieved. However, only 14 of them met the criteria for evaluation. Out of these, eleven studies indicated a significant correlation between higher DII scores and poor overall sleep quality and/or short/long sleep duration or its subscales. On the contrary, four studies did not find any proof of this association.

Conclusion

This systematic review indicated that following an anti-inflammatory diet could potentially lead to an improvement in the sleep outcomes. Well-designed clinical trials in the future will be necessary to provide a better understanding and quantification of this association.

Opioid Use and Gut Dysbiosis in Cancer Pain Patients

Opioids are commonly used for the management of severe chronic cancer pain. Their well-known pharmacological effects on the gastrointestinal system, particularly opioid-induced constipation (OIC), are the most common limiting factors in the optimization of analgesia, and have led to the wide use of laxatives and/or peripherally acting mu-opioid receptor antagonists (PAMORAs). A growing interest has been recently recorded in the possible effects of opioid treatment on the gut microbiota. Preclinical and clinical data, as presented in this review, showed that alterations of the gut microbiota play a role in modulating opioid-mediated analgesia and tolerability, including constipation. Moreover, due to the bidirectional crosstalk between gut bacteria and the central nervous system, gut dysbiosis may be crucial in modulating opioid reward and addictive behavior. The microbiota may also modulate pain regulation and tolerance, by activating microglial cells and inducing the release of inflammatory cytokines and chemokines, which sustain neuroinflammation. In the subset of cancer patients, the clinical meaning of opioid-induced gut dysbiosis, particularly its possible interference with the efficacy of chemotherapy and immunotherapy, is still unclear. Gut dysbiosis could be a new target for treatment in cancer patients. Restoring the physiological amount of specific gut bacteria may represent a promising therapeutic option for managing gastrointestinal symptoms and optimizing analgesia for cancer patients using opioids.

Effects of salidroside on atherosclerosis: potential contribution of gut microbiota

Much research describes gut microbiota in atherosclerotic cardiovascular diseases (ASCVD) for that the composition of the intestinal microbiome or its metabolites can directly participate in the development of endothelial dysfunction, atherosclerosis and its adverse complications. Salidroside, a natural phenylpropane glycoside, exhibits promising biological activity against the progression of ASCVD. Recent studies suggested that the gut microbiota played a crucial role in mediating the diverse beneficial effects of salidroside on health. Here, we describe the protective effects of salidroside against the progression of atherosclerosis. Salidroside regulates the abundance of gut microbiotas and gut microbe-dependent metabolites. Moreover, salidroside improves intestinal barrier function and maintains intestinal epithelial barrier function integrity. In addition, salidroside attenuates the inflammatory responses exacerbated by gut microbiota disturbance. This review delves into how salidroside functions to ameliorate atherosclerosis by focusing on its interaction with gut microbiota, uncovering the potential roles of gut microbiota in the diverse biological impacts of salidroside.

The Biomolecular Basis of Gut Microbiome on Neurological Diseases

The human gastrointestinal (GI) tract harbors many microorganisms, including viruses, protozoa, archaea, fungi, and bacteria. Altogether, these microbes constitute what we know as the gut microbiome (GM). These commensal communities have important implications for human health. They influence physiological processes through different mechanisms, including synthesizing neurotransmitters, regulating enzymatic pathways, and releasing molecules responsible for different signal pathways. The interaction between GM and brain function has been associated with the development and pathogenesis of neuropsychiatric diseases. This review discusses current studies targeting the regulation and modulation of GM in nerve, neuroendocrine, and immune pathways. Thus, we analyze current evidence on transcription, changes in composition, and specific interactions between the gut and brain from a biomolecular perspective. Special attention is paid to mood disorders and neurodegenerative diseases.

Berberine alleviates Alzheimer's disease by regulating the gut microenvironment, restoring the gut barrier and brain-gut axis balance

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease. Intestinal flora and its metabolism play a significant role in ameliorating central nervous system disorders, including AD, through bidirectional interactions between the gut-brain axis. A naturally occurring alkaloid compound called berberine (BBR) has neuroprotective properties and prevents Aβ-induced microglial activation. Additionally, BBR can suppress the synthesis of Aβ and decrease BACE1 expression. However, it is still unclear if BBR therapy can alleviate AD by changing the gut flora.

PURPOSE

In this study, we examined whether a partial alleviation of AD could be achieved with BBR treatment and the molecular mechanisms involved.

METHODS

We did this by analyzing alterations in Aβ plaques, neurons, and related neuroinflammation-related markers in the brain and the transcriptome of the mouse brain. The relationship between the intestinal flora of 5xFAD model mice and BBR treatment was investigated using high-throughput sequencing analysis of 16S rRNA from mouse feces.

RESULTS

The findings demonstrated that treatment with BBR cleared Aβ plaques, alleviated neuroinflammation, and ameliorated spatial memory dysfunction in AD. BBR significantly alleviated intestinal inflammation, decreased intestinal permeability, and could improve intestinal microbiota composition in 5xFAD mice.