Role of Microbiota-Gut-Brain Axis in Regulating Dopaminergic Signaling

The effect of supplementation with prebiotic fiber on the gut microbiota of a group of older people with Parkinson's disease from the city of Santiago de Chile. A pilot study

Introduction

Introduction: Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. It has been demonstrated that there is a correlation between the increase in bacterial abundance and the severity of certain symptoms associated with PD. Aim: the aim of this pilot study was to analyze the effect of supplementation with prebiotic fiber on the gut microbiota (GM) and nutritional status of elderly volunteers with Parkinson's disease. Methodology: this is a pilot study of pre and post intervention with prebiotic fiber. All subjects involved were volunteers with PD, who were given nutritional counseling and gut microbiota measured on time cero and after 30 days of prebiotic fiber intervention. Results: a statistically significant difference was found in calf circumference (p 0.0422) after the intervention with prebiotic fiber. GM analyses show an initial difference in gut bacterial abundance of older people with PD and people without PD. Furthermore, our results showed a difference in bacterial families and genera after the supplementation with prebiotic fiber. in addition, we found a statistically significant difference in the val-ue of circumference calf and a trend in the improvement of body weight, Body mass index (BMI), neck circumference, arm circumference, brachial area, and Diet Quality Questionnaire (DQQ) for older adults. Conclusion: supplementation with 20 g of prebiotic fiber for 30 days could modify the intestinal microbiota, reducing bacterial genera and phylum that are abundant in Park-inson's disease, such as Verrucomicrobia. Therefore, the use of prebiotic fiber could represent an alternative to improve intestinal health and nutritional status of people with Parkinson's disease.

Interplay of Neuroinflammation and Gut Microbiota Dysbiosis in Alzheimer's Disease Using Diffusion Kurtosis Imaging Biomarker in 3 × Tg-AD Mouse Models

The relationship between alterations in brain microstructure and dysbiosis of gut microbiota in Alzheimer's disease (AD) has garnered increasing attention, although the functional implications of these changes are not yet fully elucidated. This research examines how neuroinflammation, systemic inflammation, and gut microbiota interact in male 3 × Tg-AD and B6129SF1/J wild-type (WT) mice at 6 months-old (6-MO) and 12 months-old (12-MO). Employing a combination of behavioral assessments, diffusion kurtosis imaging (DKI), microbiota profiling, cytokine analysis, short-chain fatty acids (SCFAs), and immunohistochemistry, we explored the progression of AD-related pathology. Significant memory impairments in AD mice at both assessed ages were correlated with altered DKI parameters that suggest neuroinflammation and microstructural damage. We observed elevated levels of pro-inflammatory cytokines, such as IL-1β, IL-6, TNFα, and IFN-γ, in the serum, which were associated with increased activity of microglia and astrocytes in brain regions critical for memory. Although gut microbiota analysis did not reveal significant changes in alpha diversity, it did show notable differences in beta diversity and a diminished Firmicutes/Bacteroidetes (F/B) ratio in AD mice at 12-MO. Furthermore, a reduction in six kinds of SCFAs were identified at two time points of 6-MO and 12-MO, indicating widespread disruption in gut microbial metabolism. These findings underscore a complex bidirectional relationship between systemic inflammation and gut dysbiosis in AD, highlighting the gut-brain axis as a crucial factor in disease progression. This study emphasizes the potential of integrating DKI metrics, microbiota profiling, and SCFA analysis to enhance our understanding of AD pathology and to identify new therapeutic targets.

OAB-14 Attenuated Glymphatic System Disorder, Neuroinflammation and Dyskinesia in Parkinson's Disease Model Mice Induced by Rotenone

Parkinson's Disease (PD) is a neurodegenerative disorder characterized by the pathological accumulation of alpha-synuclein (α-syn) in the neuronal cell bodies of the substantia nigra. The glymphatic system within the Central Nervous System (CNS) is responsible for clearing metabolic waste and abnormal proteins and its dysfunction may significantly contribute to the pathogenesis of PD. Our previous study showed that OAB-14, the novel small molecular compound, showed a great potential effect in APP/PS1 transgenic mice. Given the similarities in the pathogenesis of PD and Alzheimer's disease (AD), it is pertinent to explore the therapeutic potential of OAB-14 in the context of PD. This study utilized a rotenone-induced PD mice model to evaluate the effects of oral administration of OAB-14, and its underlying mechanisms. Here we confirmed the neuroprotective effect and motor improvement of OAB-14 in rotenone-induced PD model mice. Our research has shown that OAB-14 is capable of enhancing the glymphatic system function by promoting the influx and efflux of the CSF tracers to the brain and deep cervical lymph nodes, respectively, to promote the clearance of α-syn. In addition, OAB-14 could down-regulate MyD88, NF-kB (Ser 536) phosphorylation, and TLR4 to reduce glial cell activation; and down-regulate cleaved-caspase1, NLRP3, ASC, IL-1β, IL-6, IL-18, TNF-α, and IL-10 to reduce the expression of inflammatory vesicles and pro-inflammatory factors, and to reduce neuronal oxidative stress. In summary, OAB-14 may promote the clearance of brain α-syn through the glial lymphatic system, inhibit the α-syn/TLR4/NF-κB/NLRP3 inflammatory pathway, and improve movement disorders.

Dopaminergic Pathways in Neuroplasticity After Stroke and Vagus Nerve Stimulation

Stroke remains a significant cause of disability worldwide. In addition to multidisciplinary rehabilitation approaches, various forms of technology, including vagus nerve stimulation, have emerged to facilitate neuroplasticity and, thereby, improve functional status after stroke. Vagus nerve stimulation was recently approved by the Food and Drug Administration, but questions remain regarding its mechanism of action. Here, a potential role for dopaminergic signaling is considered. This review first examines evidence that dopamine is important to neuroplasticity after stroke. Next, 2 different dopaminergic pathways are considered potential mechanisms underlying vagus nerve stimulation-related benefits after stroke, direct modulation of brain dopaminergic pathways, and engagement of systemic dopaminergic pathways such as those found in the gut-brain axis. A contribution of dopamine signaling to vagus nerve stimulation efficacy could have therapeutic implications that extend to a precision medicine approach to stroke rehabilitation.

Benefits of inulin and fructo-oligosaccharides on high fat diet-induced type 2 diabetes mellitus by regulating the gut microbiota in mice

Type 2 diabetes mellitus (T2DM) is pathologically associated with gut microbiota imbalance, which is implicated in disease progression through metabolic and inflammatory pathways. The therapeutic potential of inulin, a well-characterized prebiotic, has been explored to mitigate T2DM via microbiota modulation. However, the efficacy of this intervention, with its performance dependent on the degree of polymerization (DP), requires further investigation. This study assessed the therapeutic roles of inulin (DP3-60) and fructo-oligosaccharides (FOS, DP3-10) in T2DM management. Dietary administration of these prebiotic compounds demonstrated a significant capacity to alleviate multiple metabolic pathologies, including obesity, insulin resistance, systemic inflammation, oxidative stress, dyslipidemia and hepatic steatosis in high-fat diet (HFD)-fed induced T2DM mice. Significant superior efficacy was observed in FOS for ameliorating glucose metabolic dysregulation, adipocyte hypertrophy, liver weight, and histopathological alterations in colonic tissue, while inulin exhibited greater potency in alleviating oxidative stress. Both inulin and FOS enhanced gut microbiota diversity and richness in T2DM mice, accompanied by a significant reduction in Firmicutes/Bacteroidetes ratio. Notably, the S24-7 family emerged as a crucial microbial taxon modulated by both inulin and FOS. Furthermore, FOS demonstrated superior capacity to restore HFD-induced gut microbiota. Taxonomically significant amplicon sequence variants (ASVs), which were altered by HFD and modulated by inulin and FOS, exhibited distinct taxonomic profiles between the two compounds. This study provides preliminary evidence that the biological effects and beneficial properties of inulin-type fructans exhibit DP-dependent variations, which may enhance their efficient utilization in metabolic disorders.

Neurobiological Relationships Between Neurodevelopmental Disorders and Mood Disorders

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), neurodevelopmental disorders (NDDs) are a group of conditions that arise early in development and are characterized by deficits in personal, social, academic, or occupational functioning. These disorders frequently co-occur and include conditions such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Mood disorders (MDs), such as major depressive disorder and bipolar disorder, also pose significant global health challenges due to their high prevalence and substantial impact on quality of life. Emerging evidence highlights overlapping neurobiological mechanisms between NDDs and MDs, including shared genetic susceptibilities, neurotransmitter dysregulation (e.g., dopaminergic and serotonergic pathways), neuroinflammation, and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Environmental factors such as early-life adversity further exacerbate these vulnerabilities, contributing to the complexity of their clinical presentation and comorbidity. Functional neuroimaging studies reveal altered connectivity in brain regions critical for emotional regulation and executive function, such as the prefrontal cortex and amygdala, across these disorders. Despite these advances, integrative diagnostic frameworks and targeted therapeutic strategies remain underexplored, limiting effective intervention. This review synthesizes current knowledge on the shared neurobiological underpinnings of NDDs and MDs, emphasizing the need for multidisciplinary research, including genetic, pharmacological, and psychological approaches, for unified diagnosis and treatment. Addressing these intersections can improve clinical outcomes and enhance the quality of life for individuals affected by these disorders.

Gut Microbial Control of Neurotransmitters and Their Relation to Neurological Disorders: A Comprehensive Review

The study explores the vital role of gut microbiota in regulating neurotransmitters and its subsequent effects on brain function and mental health. It aims to unravel the mechanisms by which microbial metabolites influence neurotransmitter synthesis and signaling. The ultimate goal is to identify potential therapeutic strategies targeting gut microbiota for the management and treatment of neurological disorders, such as depression, autism spectrum disorder (ASD), anxiety, and Parkinson's disease. The review synthesizes current research on the gut-brain axis, focusing on the influence of gut microbial metabolites on key neurotransmitters, including dopamine, serotonin, and gamma-aminobutyric acid (GABA). It incorporates a multidisciplinary approach, linking microbiology, neurobiology, and clinical research. Each section presents an in-depth review of scientific studies, clinical trials, and emerging therapeutic strategies. The findings highlight the intricate interplay between gut microbiota and the central nervous system. Gut microbes significantly impact the synthesis and signaling of crucial neurotransmitters, which play a pivotal role in neurological health. Evidence supports the hypothesis that modulating gut microbiota can alter neurotransmitter output and alleviate symptoms associated with neurological disorders. Notable therapeutic potentials include microbiota-targeted interventions for managing depression, ASD, anxiety, and Parkinson's disease. This comprehensive analysis underscores the critical connection between gut microbiota and neurological health. By bridging gaps between microbiology, neurobiology, and clinical practice, the study opens avenues for innovative therapeutic approaches. It provides a valuable resource for researchers, clinicians, and students, emphasizing the need for continued investigation into gut microbiota's role in neurological disorders and its therapeutic potential.

Bibliometric analysis of the intestinal microbiota and demyelinating diseases, particularly multiple sclerosis, since 2014

Background

The gut-brain axis (GBA) represents a complex, bidirectional communication network that connects the central nervous system (CNS) and the gastrointestinal system. Our study aimed to explore the correlation between the intestinal microbiota and demyelinating diseases from a bibliometric perspective, focusing on research since 2014.

Methods

A comprehensive search was carried out on the Web of Science Core Collection (WoSCC) to locate studies on the intestinal microbiota and demyelinating diseases, with a focus on publications from 1 January 2014 to 29 March 2024. We visualized and analyzed the data using VOSviewer, CiteSpace, and Charticulator.

Results

We gathered 429 scholarly articles on the intestinal microbiota and demyelinating disorders published in the past 10 years. Research concerning the intestinal microbiota and demyelinating diseases has demonstrated a consistent increase in frequency over time. The USA has the highest number of publications, while Canada has the highest average number of citations, reaching as high as 3,429, which is greater than that of the USA. Moreover, the journal with the highest number of publications was Frontiers in Immunology, with 33 publications and 1,494 citations. The majority of the scholars focused on "multiple sclerosis" and "gut microbiota," which are the primary keywords in the field of the intestinal microbiota and demyelinating diseases.

Conclusion

This study conducted a comprehensive analysis of existing research investigating the correlation between the intestinal microbiota and demyelinating diseases. Using advanced bibliometric tools such as VOSviewer and CiteSpace, this study analyzed the intricate relationship between the intestinal microbiota and the pathogenesis of demyelinating conditions. In addition, the study used literature statistical analysis to identify research hotspots and future directions in the field.

Influence of menstrual cycle and oral contraception on taxonomic composition and gas production in the gut microbiome

Introduction. Oral contraceptives (OCs) are widely used for birth control and offer benefits such as menstrual cycle regulation and reduced menstrual pain. However, they have also been associated with an increased risk of cancer and reduced bone mass density.Gap Statement. While the gut microbiome is known to interact with endocrine factors, the impact of hormonal OCs on its composition and function remains underexplored. Additionally, we explore the relationship of OC use and the microbiome to gas production, which can cause symptoms and be indicative of poor health.Aim. This study investigates the effects of OCs on the diversity and composition of the gut microbiome and its association with breath hydrogen (H2) and methane (CH4) levels.Methodology. We utilized 16S rRNA gene sequencing to analyse faecal samples from 65 women, comparing OC users with non-users at two menstrual cycle time points. Breath tests measured hydrogen and CH4 production. Data were analysed for microbial diversity, community composition and correlation with gas production.Results. There were no differences in overall microbial diversity between OC users and non-users in samples collected on day 2 of the menstrual cycle. However, on day 21, we found a significant difference in microbial richness, suggesting a cycle-dependent effect of OCs on gut microbiota species richness but not composition. We found a strong correlation between H2 and CH4 concentrations and an interaction between OC use and the menstrual cycle on H2 and CH4 production. We also identified several taxa associated with both high levels of H2 and CH4 production and OC use.Conclusion. Our study highlights the intricate relationships among hormonal contraceptives, the gut microbiota and gas production and connects shifts in the microbiome composition to gastrointestinal symptoms (e.g. gas production) that can impact overall health. This underscores the need for further research on the long-term effects of OCs and for the development of precise therapeutic strategies to address potential adverse effects. Our findings offer new perspectives on the microbiome-hormone-gas production nexus, potentially broadening our understanding of the systemic implications of OCs.

Behavioral alterations in antibiotic-treated mice associated with gut microbiota dysbiosis: insights from 16S rRNA and metabolomics

The gut and brain interact through various metabolic and signaling pathways, each of which influences mental health. Gut dysbiosis caused by antibiotics is a well-known phenomenon that has serious implications for gut microbiota-brain interactions. Although antibiotics disrupt the gut microbiota's fundamental structure, the mechanisms that modulate the response and their impact on brain function are still unclear. It is imperative to comprehend and investigate crucial regulators and factors that play important roles. We aimed to study the effect of long-term antibiotic-induced disruption of gut microbiota, host metabolomes, and brain function and, particularly, to determine the basic interactions between them by treating the C57BL/6 mice with two different, most commonly used antibiotics, ciprofloxacin and amoxicillin. Anxiety-like behavior was confirmed by the elevated plus-maze test and open field test. Gut microbes and their metabolite profiles in fecal, serum, and brain samples were determined by 16S rRNA sequencing and untargeted metabolomics. In our study, long-term antibiotic treatment exerted anxiety-like effects. The fecal microbiota and metabolite status revealed that the top five genera found were Lactobacillus, Bacteroides, Akkermansia, Ruminococcus_gnavus_group, and unclassified norank_f_Muribaculaceae. The concentration of serotonin, L-Tyrosine, 5-Hydroxy-L-tryptophan, L-Glutamic acid, L-Glutamate, 5-Hydroxyindole acetic acid, and dopaminergic synapsis was comparatively low, while adenosine was high in antibiotic-treated mice. The KEGG enrichment analysis of serum and brain samples showed that amino acid metabolism pathways, such as tryptophan metabolism, threonine metabolism, serotonergic synapsis, methionine metabolism, and neuroactive ligand-receptor interaction, were significantly decreased in antibiotic-treated mice. Our study demonstrates that long-term antibiotic use induces gut dysbiosis and alters metabolic responses, leading to the dysregulation of brain signaling molecules and anxiety-like behavior. These findings highlight the complex interactions between gut microbiota and metabolic functions, providing new insights into the influence of microbial communities on gut-brain communication.

Genomic Scale Analysis Foresees Enteroprotective and Butyrogenic Properties in Brazilian Isolates of Lactiplantibacillus plantarum

Probiogenomics offers a rapid and comprehensive approach to characterizing the beneficial properties of microorganisms, allowing the identification and selection of specific strains for improving human health. The species Lactiplantibacillus plantarum is highly ubiquitous and presents great genetic diversity making it difficult to conduct massive screening of probiotic strains when using conventional methods. Hence, this work aimed to taxonomically and functionally characterize the complete genomes of six novel L. plantarum strains isolated in Brazil through high-standard NGS. The taxonomy of strains E6, E10, E14, E18, Lpl2, and Lpl4 was investigated through average nucleotide identity analysis using the genome of L. plantarum SK151 from the GENBANK database as a reference. Moreover, multilocus phylogenetic analyses were performed to investigate their genetic relatedness to probiotic L. plantarum strains using a total of 225 complete genomes from the same database. To investigate specific health-promoting and safety properties, the isolates from Brazil were analyzed using several bioinformatic tools to predict antimicrobials and anti-inflammatory biomolecules and potential risk factors including drug resistance, virulence genes, and genetic mobility elements. The results confirmed that all six isolates belong to the species L. plantarum and the phylogenetic analysis suggests high proximity to known probiotics and strains that have demonstrated protective effects against inflammation and pathogens. Several bacteriocin genes were identified in the Brazilian isolates, mostly plantaricins, suggesting antimicrobial properties, especially in the strain E14 that presented 9 bacteriocins genes. Furthermore, the study revealed the potential capacity of these strains to produce anti-inflammatory compounds including metabolites such as butyrate through the fermentation of fructan sugars, and IL-10 stimulation activity mediated by adhesin proteins from the bacterial cell wall. The lpl4 strain glutamate decarboxylase (GADB) gene showed a high degree of genetic and structural conservation prediction and increased stabilization of the predicted protein compared to a functional homologous GADB from L. plantarum Taj-Apis362, suggesting lpl4 potential for the modulation of the gut-brain axis functions by the production of GABA. Regarding the presence of virulence and resistance genes, only one resistance island was observed in strain E6 genome. In conclusion, it is possible to suggest that most of the evaluated strains are safe and we highlight the strains Lpl4 and E14 for presenting outstanding enteroprotective properties such as the potential production of GABA and several bacteriocins.

Beyond weight loss: exploring the neurological ramifications of altered gut microbiota post-bariatric surgery

This review discusses findings related to neurological disorders, gut microbiota, and bariatric surgery, focusing on neurotransmitters, neuroendocrine, the pathophysiology of bacteria contributing to disorders, and possible therapeutic interventions. Research on neurotransmitters suggests that their levels are heavily influenced by gut microbiota, which may link them to neurological disorders such as Alzheimer's disease, Parkinson's disease, Multiple sclerosis, Depression, and Autism spectrum disorder. The pathophysiology of bacteria that reach and influence the central nervous system has been documented. Trends in microbiota are often observed in specific neurological disorders, with a prominence of pro-inflammatory bacteria and a reduction in anti-inflammatory types. Furthermore, bariatric surgery has been shown to alter microbiota profiles similar to those observed in neurological disorders. Therapeutic interventions, including fecal microbiota transplants and probiotics, have shown potential to alleviate neurological symptoms. We suggest a framework for future studies that integrates knowledge from diverse research areas, employs rigorous methodologies, and includes long-trial clinical control groups.

Vinpocetine and Lactobacillus Attenuated Rotenone-Induced Parkinson's Disease and Restored Dopamine Synthesis in Rats through Modulation of Oxidative Stress, Neuroinflammation, and Lewy Bodies Inclusion

Parkinson's disease (PD) is the main neurodegenerative disorder affecting motor activity, there are different pathophysiological pathways contributing to its development including oxidative stress, neuroinflammation, Lewy's bodies accumulation, and impaired autophagy. Vinpocetine is an herbal extract with antioxidant and anti-inflammatory activities that may counteract pathophysiologic neurodegeneration pathways. Moreover, Lactobacillus is a probiotic that can modulate the gut-brain axis and provide the body with the needed precursors of antioxidants and anti-inflammatory mediators. In the current study PD was induced experimentally in Sprague Dawley rats with rotenone (2.5 mg/kg, i.p, daily) for 60 days, vinpocetine; Vinpo (20 mg/kg, orally, daily) and Lactobacillus; Lacto (2.7 × 108 CFU/ml, orally, daily) were applied as protective treatment. Vinpocetine and Lactobacillus treatment significantly ameliorated motor function by increasing distance traveled and rearing frequency in the open field test with a concomitant increase in falling time from both the accelerating rotarod and the wire screen test. Moreover, vinpocetine and Lactobacillus treatment upregulates tyrosine hydroxylase expression (the rate-limiting enzyme in dopamine synthesis), leading to enhanced dopamine synthesis and improved dopaminergic function with regression of histopathological hallmarks. Antioxidant GSH levels were significantly increased after vinpocetine and Lactobacillus treatment with a significant decrease in MDA content in brain homogenates. Furthermore, vinpocetine and Lactobacillus treatment significantly decreased striatal inflammatory markers; nitrite, IL-1β and TNF-α. Proteinopathies were regressed with a substantial decrease in striatal α-synuclein and tau content. In conclusion, vinpocetine and Lactobacillus treatment reduced rotenone neurotoxicity with improved dopamine release and motor activity with correction of oxidative burden, neuro-inflammation, and proteinopathy.

Hypothalamus-pituitary-adrenal and gut-brain axes in biological interaction pathway of the depression

The hypothalamus-pituitary-adrenal (HPA) and gut-brain axes are vital biological pathways in depression. The HPA axis regulates the body's stress response, and chronic stress can lead to overactivation of the HPA axis, resulting in elevated cortisol levels that contribute to neuronal damage, particularly in regions such as the hippocampus and prefrontal cortex, both of which are involved in mood regulation and mental disorders. In parallel, the gut-brain axis, a bidirectional communication network between the gut microbiota and the central nervous system, influences emotional and cognitive functions. Imbalances in gut microbiota can affect the HPA axis, promoting inflammation and increasing gut permeability. This allows endotoxins to enter the bloodstream, contributing to neuroinflammation and altering neurotransmitter production, including serotonin. Since the majority of serotonin is produced in the gut, disruptions in this pathway may be linked to depressive symptoms. This review explores the interplay between the HPA axis and the gut-brain axis in the context of depression.

Antibiotics/coccidiostat exposure induces gut-brain axis remodeling for Akt/mTOR activation and BDNF-mediated neuroprotection in APEC-infected turkeys

The poultry industry relies extensively on antibiotics and coccidiostats as essential tools for disease management and productivity enhancement. However, increasing concerns about antimicrobial resistance (AMR) and the toxicological safety of these substances have prompted a deeper examination of their broader impacts on animal and human health. This study investigates the toxicological effects of antibiotics and coccidiostats on the gut-brain axis and microbiota in turkeys, with a particular focus on molecular mechanisms that may influence neurochemical and inflammatory responses. Our findings reveal that enrofloxacin exposure leads to the upregulation of BDNF, suggesting a neuroprotective effect, while monensin treatment significantly increased eEF2 kinase expression, indicative enhanced neuronal activity. In turkeys infected with Avian Pathogenic Escherichia coli (APEC), early administration of doxycycline and monensin significantly upregulated the mTOR/BDNF and Akt/mTOR pathways, along with elevated histamine levels, underscoring their role in inflammatory responses modulation. However, treatments administered at 50 days post-hatch did not significantly alter protein levels, though both enrofloxacin and monensin increased serotonin and dopamine levels, suggesting potential neurotoxicological impacts on mood and cognitive functions. These results highlight the complex interactions between antibiotic use, gut microbiota alterations, and neurochemical pathways, with toxicological implications for environmental pollution and public health. This research provides critical insights into the potential toxic effects of prolonged antibiotic and coccidiostat exposure in poultry production, emphasizing the need for responsible use to mitigate risks to ecosystems and human health.

Effect of Probiotics on the Symptomatology of Autism Spectrum Disorder and/or Attention Deficit/Hyperactivity Disorder in Children and Adolescents: Pilot Study

The aim of this study is to investigate the impact of using probiotics with strains related to dopamine and gamma-aminobutyric acid production on clinical features of autism spectrum disorder (ASD) and/or attention deficit/hyperactivity disorder (ADHD). This randomized, controlled trial involved 38 children with ADHD and 42 children with ASD, aged 5-16 years, who received probiotics (Lactiplantibacillus plantarum and Levilactobacillus brevis 109/cfu/daily) or placebo for 12 weeks. Parent-reported symptoms were assessed using Conners' 3rd-Ed and the Social Responsiveness Scale Test, 2nd-Ed (SRS-2), and children completed the Conners Continuous Performance Test, 3rd-Ed (CPT 3) or Conners Kiddie CPT, 2nd-Ed (K-CPT 2). Executive functions, quality of life and sleep patterns were also parent-assessed. Intention-to-treat analyses, controlling for sociodemographic and nutritional covariates, revealed no significant inter-group differences in parent-reported or neuropsychological data after the probiotic intervention. However, age-stratified analyses showed improved hyperactivity-impulsivity symptoms in younger children with ASD (Cohen's d = 1.245) and ADHD (Cohen's d = 0.692). Intra-group analyses supported these findings in the aforementioned age and intervention group for both diagnoses. An improvement in impulsivity for children with ASD was also observed in the intra-group analysis of the CPT commissions scores (probiotic: p = 0.001, Cohen's d = -1.216; placebo: p = 0.013, Cohen's d = -0.721). A better comfort score (quality of life) was shown in children with ASD (probiotic: p = 0.010, Cohen's d = 0.722; placebo: p = 0.099, Cohen's d = 0.456). The probiotics used, may improve hyperactivity-impulsivity in children with ASD or/and ADHD and quality of life in children with ASD. Further research is warranted to explore probiotics as an adjunctive therapeutic intervention for NDs.Trial registration: clinicaltrials.gov Identifier: NCT05167110.

Should we consider microbiota-based interventions as a novel therapeutic strategy for schizophrenia? A systematic review and meta-analysis

Schizophrenia is a chronic psychiatric disorder characterized by a variety of symptoms broadly categorized into positive, negative, and cognitive domains. Its etiology is multifactorial, involving a complex interplay of genetic, neurobiological, and environmental factors, and its neurobiology is associated with abnormalities in different neurotransmitter systems. Due to this multifactorial etiology and neurobiology, leading to a wide heterogeneity of symptoms and clinical presentations, current antipsychotic treatments face challenges, underscoring the need for novel therapeutic approaches. Recent studies have revealed differences in the gut microbiome of individuals with schizophrenia compared to healthy controls, establishing an intricate link between this disorder and gastrointestinal health, and suggesting that microbiota-targeted interventions could help alleviate clinical symptoms. Therefore, this meta-analysis investigates whether gut microbiota manipulation can ameliorate psychotic outcomes in patients with schizophrenia receiving pharmacological treatment. Nine studies (n = 417 participants) were selected from 81 records, comprising seven randomized controlled trials and two open-label studies, all with a low risk of bias, included in this systematic review and meta-analysis. The overall combined effect size indicated significant symptom improvement following microbiota treatment (Hedges' g = 0.48, 95% CI = 0.09 to 0.88, p = 0.004, I2 = 62.35%). However, according to Hedges' g criteria, the effect size was small (approaching moderate), and study heterogeneity was moderate based on I2 criteria. This review also discusses clinical and preclinical studies to elucidate the neural, immune, and metabolic pathways by which microbiota manipulation, particularly with Lactobacillus and Bifidobacterium genera, may exert beneficial effects on schizophrenia symptoms via the gut-brain axis. Finally, we address the main confounding factors identified in our systematic review, highlight key limitations, and offer recommendations to guide future high-quality trials with larger participant cohorts to explore microbiome-based therapies as a primary or adjunctive treatment for schizophrenia.

Sleep deprivation-induced shifts in gut microbiota: Implications for neurological disorders

Sleep deprivation is a prevalent issue in contemporary society, with significant ramifications for both physical and mental well-being. Emerging scientific evidence illuminates its intricate interplay with the gut-brain axis, a vital determinant of neurological function. Disruptions in sleep patterns disturb the delicate equilibrium of the gut microbiota, resulting in dysbiosis characterized by alterations in microbial composition and function. This dysbiosis contributes to the exacerbation of neurological disorders such as depression, anxiety, and cognitive decline through multifaceted mechanisms, including heightened neuroinflammation, disturbances in neurotransmitter signalling, and compromised integrity of the gut barrier. In response to these challenges, there is a burgeoning interest in therapeutic interventions aimed at restoring gut microbial balance and alleviating neurological symptoms precipitated by sleep deprivation. Probiotics, dietary modifications, and behavioural strategies represent promising avenues for modulating the gut microbiota and mitigating the adverse effects of sleep disturbances on neurological health. Moreover, the advent of personalized interventions guided by advanced omics technologies holds considerable potential for tailoring treatments to individualized needs and optimizing therapeutic outcomes. Interdisciplinary collaboration and concerted research efforts are imperative for elucidating the underlying mechanisms linking sleep, gut microbiota, and neurological function. Longitudinal studies, translational research endeavours, and advancements in technology are pivotal for unravelling the complex interplay between these intricate systems.

Fusobacterium nucleatum determines the expression of amphetamine-induced behavioral responses through an epigenetic phenomenon

Amphetamines (AMPHs) are psychostimulants commonly used for the treatment of neuropsychiatric disorders. They are also misused (AMPH use disorder; AUD), with devastating outcomes. Recent studies have implicated dysbiosis in the pathogenesis of AUD. However, the mechanistic roles of microbes in AUD are unknown. Fusobacterium nucleatum (Fn) is a bacterium that increases in abundance in both rats and humans upon AMPH exposure. Fn releases short-chain fatty acids (SCFAs), bacterial byproducts thought to play a fundamental role in the gut-brain axis as well as the pathogenesis of AUD. We demonstrate that in gnotobiotic Drosophila melanogaster, colonization with Fn or dietary supplementation of the SCFA butyrate, a potent inhibitor of histone deacetylases (HDACs), enhances the psychomotor and rewarding properties of AMPH as well as its ability to promote male sexual motivation. Furthermore, solely HDAC1 RNAi targeted inhibition recapitulates these enhancements, pointing to a specific process underlying this Fn phenomenon. Of note is that the expression of these AMPH behaviors is determined by the increase in extracellular dopamine (DA) levels that result from AMPH-induced reversal of DA transporter (DAT) function, termed non-vesicular DA release (NVDR). The magnitude of AMPH-induced NVDR is dictated, at least in part, by DAT expression levels. Consistent with our behavioral data, we show that Fn, butyrate, and HDAC1 inhibition enhance NVDR by elevating DAT expression. Thus, the participation of Fn in AUD stems from its ability to release butyrate and inhibit HDAC1. These data offer a microbial target and probiotic interventions for AUD treatment.

Probiotics in the Management of Chronic Bacterial Prostatitis Patients: A Randomized, Double-Blind Trial to Evaluate a Possible Link Between Gut Microbiota Restoring and Symptom Relief

Several studies have suggested that probiotics could play a role in the management of patients with chronic bacterial prostatitis (CBP). In this randomized, placebo-controlled clinical study, we evaluated the efficacy and safety of consumption of probiotics containing human Lactobacillus casei DG® as an add-on treatment in patients with clinical recurrences of CBP, through gut microbiota modification analysis. Enrolled patients with CBP were randomized to receive for 3 months probiotics containing human Lactobacillus casei DG® or placebo following 1 month treatment with ciprofloxacin. During the enrollment and follow-ups, urological examinations analyzed symptoms and quality of life, while microbiological tests analyzed gut and seminal microbiota. During the study, the development of adverse drug reactions was evaluated through the Naranjo scale. Twenty-four patients with CBP were recruited and treated for 3 months with placebo (n. 12) or with Lactobacillus casei DG® (n. 12). Lactobacillus casei DG® induced a significantly (p < 0.01) faster recovery of symptoms than placebo (2 days vs. 8 days) and an increased time free from symptoms (86 days vs. 42 days) without the occurrence of adverse events. In the probiotic group, the appearance of Lactobacilli after 30 days (T1) was higher vs. the placebo group, and a significant reduction in Corynebacterium, Peptoniphilus, Pseudomonas, Veillonella, Staphylococcus, and Streptococcus was also observed. These preliminary data suggest that in patients with CBP, the use of Lactobacillus casei DG after an antimicrobial treatment improves the days free of symptoms and the quality of life, without the development of adverse drug reactions.

Avolition Characterizes the Chronic Fatigue Experienced in Quiescent Inflammatory Bowel Disease

Background and Aims: Avolition is a symptom responsible for a high burden in patients suffering from psychiatric diseases. It refers to a motivation loss for initiating and maintaining goal-directed activities, often called fatigue by patients. Fatigue is a widespread complaint of patients suffering from inflammatory bowel disease (IBD), significantly impacting patients' well-being, even during the quiescent stage of the disease. We here address the hypothesis that fatigue experienced by IBD patients is associated with motivational impairment. Methods: Patients presenting IBD (n = 110) in a quiescent stage of Crohn's disease (CD) (n = 60) and ulcerative colitis (UC) (n = 50) were enrolled and classified following their declared experience of fatigue (n = 58) or not (n = 52). Patients were phenotyped using self-administered scales for fatigue experience, bowel disease disability, quality of life and mental health symptoms. Results: The self-administered negative symptoms scale scores identified avolition as a specific feature of fatigue experience: fatigued vs. no-fatigue in the CD group (3.806 vs. 2.103; p = 0.003) and in the UC group (2.815 vs. 1.174; p = 0.003). This difference is independent of current depressive disorder and previous history of depressive disorder. Avolition associates and correlates with the experience of fatigue (r = 0.49) in multivariate analysis. Conclusions: To tackle the question of fatigue in IBD, research should consider investigating the biological mechanisms implicating intestinal physiopathology of IBD in the impairment of brain structure involved in motivation. This may open new fields for treatment in targeting structures of the brain reward system.

The Gut Microbiome Regulates the Psychomotor Effects and Context-Dependent Rewarding Responses to Cocaine in Germ-Free and Antibiotic-Treated Animal Models

Cocaine use disorder remains a major global health concern, with growing evidence that the gut microbiome modulates drug-related behaviors. This study examines the microbiome's role in cocaine-induced psychomotor activation and context-dependent reward responses using germ-free (GF) and antibiotic-treated (ABX) models. In GF mice, the absence of a microbiome blunted cocaine-induced psychomotor activation (p = 0.013), which was restored after conventionalization. GF mice also showed reduced cocaine-conditioned place preference (CPP) (p = 0.002), which normalized after conventionalization. Dopaminergic function, critical for psychomotor responses and reward, was microbiome-dependent, with increased dopamine levels (p = 0.009) and normalized turnover ratios after conventionalization. In the ABX model, microbiome depletion reduced both cocaine-induced locomotion and CPP responses (p ≤ 0.009), further supporting the role of gut microbes in modulating psychomotor and reward behaviors. ABX-treated mice also showed significant declines in microbial diversity, shifts in bacterial structure, and dysregulation in metabolic, immune, and neurotransmitter pathways (p ≤ 0.0001), including alterations in short-chain fatty acids and gamma-aminobutyric acid metabolism. These findings highlight the gut microbiome's critical role in regulating cocaine's psychomotor and rewarding effects, offering insights into potential therapeutic strategies for cocaine use disorder.

Circadian disruption of feeding-fasting rhythm and its consequences for metabolic, immune, cancer, and cognitive processes

The circadian system is composed by a central hypothalamic clock at the suprachiasmatic nuclei (SCN) that communicates with peripheral circadian oscillators for daily coordination of behavior and physiology. The SCN entrain to the environmental 24-h light-dark (LD) cycle and drive daily rhythms of internal synchronizers such as core body temperature, hypothalamic-hypophysary hormones, sympathetic/parasympathetic activity, as well as behavioral and feeding-fasting rhythms, which supply signals setting core molecular clocks at central and peripheral tissues. Steady phase relationships between the SCN and peripheral oscillators keep homeostatic processes such as microbiota/microbiome composition/activity, metabolic supply/demand, energy balance, immunoinflammatory process, sleep amount and quality, psychophysiological stress, etc. Indeed, the risk of health alterations increase when these phase relationships are chronically changed prompting circadian disruption (CD), as occurring after sudden LD cycle changes (so-called jet-lag), or due to changes of activity/feeding-rest/fasting rhythm with respect to LD cycles (as humans subjected to nightwork, or restricting food access at rest in mice). Typical pathologies observed in animal models of CD and epidemiological studies include metabolic syndrome, type-2 diabetes, obesity, chronic inflammation, cancer, sleep disruption, decrease in physical and cognitive performance, and mood, among others. The present review discusses different aspects of such physiological dysregulations observed in animal models of CD having altered feeding-fasting rhythms, with potential translation to human health.

Exploring Gut Microbiota Imbalance in Irritable Bowel Syndrome: Potential Therapeutic Effects of Probiotics and Their Metabolites

Irritable bowel syndrome is a common functional gastrointestinal disorder characterized by recurrent abdominal discomfort, bloating, cramping, flatulence, and changes in bowel movements. The pathophysiology of IBS involves a complex interaction between motor, sensory, microbiological, immunological, and psychological factors. Diversity, stability, and metabolic activity of the gut microbiota are frequently altered in IBS, thus leading to a situation of gut dysbiosis. Therefore, the use of probiotics and probiotic-derived metabolites may be helpful in balancing the gut microbiota and alleviating irritable bowel syndrome symptoms. This review aimed to report and consolidate recent progress in understanding the role of gut dysbiosis in the pathophysiology of IBS, as well as the current studies that have focused on the use of probiotics and their metabolites, providing a foundation for their potential beneficial effects as a complementary and alternative therapeutic strategy for this condition due to the current absence of effective and safe treatments.

Radiation-Induced Brain Injury: Mechanistic Insights and the Promise of Gut-Brain Axis Therapies

Radiation therapy is widely recognized as an efficacious modality for treating neoplasms located within the craniofacial region. Nevertheless, this approach is not devoid of risks, predominantly concerning potential harm to the neural structures. Adverse effects may encompass focal cerebral necrosis, cognitive function compromise, cerebrovascular pathology, spinal cord injury, and detriment to the neural fibers constituting the brachial plexus. With increasing survival rates among oncology patients, evaluating post-treatment quality of life has become crucial in assessing the benefits of radiation therapy. Consequently, it is imperative to investigate therapeutic strategies to mitigate cerebral complications from radiation exposure. Current management of radiation-induced cerebral damage involves corticosteroids and bevacizumab, with preclinical research on antioxidants and thalidomide. Despite these efforts, an optimal treatment remains elusive. Recent studies suggest the gut microbiota's involvement in neurologic pathologies. This review aims to discuss the causes and existing treatments for radiation-induced cerebral injury and explore gut microbiota modulation as a potential therapeutic strategy.

Using lifestyle interventions and the gut microbiota to improve PTSD symptoms

Posttraumatic stress disorder is part of a spectrum of psychological symptoms that are frequently linked with a single defining traumatic experience. Symptoms can vary over the lifespan in intensity based on additional life stressors, individual stability, and connectedness to purpose. Historically, treatment has centered on psychotropic agents and individual and group therapy to increase the individual's window of tolerance, improve emotional dysregulation, and strengthen relationships. Unfortunately, there is a growing segment of individuals with posttraumatic stress disorder who do not respond to these traditional treatments, perhaps because they do not address the multidirectional relationships between chronic cortisol, changes in the brain gut microbiota system, neuroinflammation, and posttraumatic symptoms. We will review the literature and explain how trauma impacts the neuroendocrine and neuroimmunology within the brain, how these processes influence the brain gut microbiota system, and provide a mechanism for the development of posttraumatic stress disorder symptoms. Finally, we will show how the lifestyle psychiatry model provides symptom amelioration.

Neuroprotective effect of Bacillus subtilis in haloperidol induced rat model, targeting the microbiota-gut-brain axis

Functional microbes regulate Parkinson's disease (PD), according to contemporary research. The mechanism by which probiotics (PBT) improve PD was not fully explored yet. We examined the antioxidant impact and mechanism of PBT (Bacillus subtilis) on PD using gut-brain axis regulation. To establish a model of PD, rats were given haloperidol (HAL) intraperitoneally (i.p.) in this study. The standard group received L-DOPA for 21 days. After that, the motor function was assessed using different neurobehavioral tests. Further estimation comprehends the build up of alpha-synuclein, the manifestation of monoamine oxidase-B (MAO-B) activity, the deterioration of dopaminergic neurons and the induction of an oxidative stress reaction. In addition, the concentration of intestinal microbes was measured. These findings demonstrated that the administration of PBT in combination with L-dopa could alleviate motor impairments caused by HAL, the deterioration of dopaminergic neurons, and the build up of α-synuclein. Furthermore, the levels of superoxide dismutase (SOD) and dopamine were considerably raised by co-administration of L-dopa and PBT in the case of HAL-treated rats, whereas the levels of alpha-synuclein, MAO-B, and malondialdehyde (MDA) were reduced. Particularly, PBT administration reduced the gut microbial dysbiosis, which in turn raised the concentration of good bacteria i.e., Bifidobacterium and reduced the concentration of E. coli in experimental animals. These findings indicated that PBT might represent a promising candidate to inhibit the progression of Parkinson's disease by targeting the gut-brain axis.

The Role of the Gut Microbiota in Individuals with Irritable Bowel Syndrome: A Scoping Review

Irritable bowel syndrome (IBS) represents the most prevalent disorder of brain-gut interaction, affecting approximately 10% of the global population. The objective of this study was to examine the mechanisms by which the gut microbiota contributes to the development of IBS. To this end, a review of articles that examined the gut microbiota of IBS patients was conducted. A search was conducted using PubMed and J-STAGE for articles published over the past five years that relate to the gut microbiota in patients with IBS. Individuals diagnosed with IBS display a reduction in alpha diversity and a decline in butyrate-producing bacteria, which collectively indicate a state of dysbiosis within their gut microbiota. Butyrate plays a dual role in the body, acting as a source of nutrition for the intestinal epithelium while also regulating the expression of dopamine transporters and D2 receptors in the central nervous system through epigenetic mechanisms. These characteristics may be linked to dysfunction of the central dopamine D2 pathway and play a role in the formation of various symptoms in IBS.

Microbiome-based therapies for Parkinson's disease

The human gut microbiome dysbiosis plays an important role in the pathogenesis of Parkinson's disease (PD). The bidirectional relationship between the enteric nervous system (ENS) and central nervous system (CNS) under the mediation of the gut-brain axis control the gastrointestinal functioning. This review article discusses key mechanisms by which modifications in the composition and function of the gut microbiota (GM) influence PD progression and motor control loss. Increased intestinal permeability, chronic inflammation, oxidative stress, α-synuclein aggregation, and neurotransmitter imbalances are some key factors that govern gastrointestinal pathology and PD progression. The bacterial taxa of the gut associated with PD development are discussed with emphasis on the enteric nervous system (ENS), as well as the impact of gut bacteria on dopamine production and levodopa metabolism. The pathophysiology and course of the disease are associated with several inflammatory markers, including TNF-α, IL-1β, and IL-6. Emerging therapeutic strategies targeting the gut microbiome include probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT). The article explored how dietary changes may affect the gut microbiota (GM) and the ways that can affect Parkinson's disease (PD), with a focus on nutrition-based, Mediterranean, and ketogenic diets. This comprehensive review synthesizes current evidence on the role of the gut microbiome in PD pathogenesis and explores its potential as a therapeutic target. Understanding these complex interactions may assist in the development of novel diagnostic tools and treatment options for this neurodegenerative disorder.

Gut Microbiome in Impulsively Violent Female Convicts

INTRODUCTION

Impulsivity and aggression are often interlinked behavioral traits that have major implications for our society. Therefore, the study of this phenomenon and derivative interventions that could lead to better control of impulsive aggression are of interest.

METHODS

We analyzed the composition and diversity of the gut bacterial microbiome of 33 impulsively violent female convicts with dissocial personality disorder and 20 non-impulsive age-matched women. Further, levels of assorted neurotransmitters and short-chain fatty acids (SCFAs) were analyzed in serum and stool samples. We also assessed all participants using a battery of psychological questionnaires and tested possible correlations between the collected clinical data and the composition and diversity of their microbiomes and metabolites.

RESULTS

We identified four bacterial amplicon sequencing variants that were differentially abundant in non-impulsive versus impulsive women - the genera Bacteroides, Barnesiella, and the order Rhodospirillales were more abundant in impulsive women. In contrast, the genus Catenisphaera was more abundant in non-impulsive women. Fecal tryptophan levels were significantly higher in impulsive women. Association analysis revealed a strong positive intercorrelation between most fecal SCFAs in the entire dataset.

CONCLUSIONS

Our study demonstrated possible associations between gut microbiomes and their metabolites and impulsive behavior in a unique cohort of prisoners convicted of violent assaults and a matched group of non-impulsive women from the same prison. Genus Bacteroides, which was differentially abundant in the two groups, encoded enzymes that affect serotonin pathways and could contribute to this maladaptive behavior. Similarly, increased fecal tryptophan levels in impulsive individuals could affect neuronal circuits in the brain.

INTRODUCTION

Impulsivity and aggression are often interlinked behavioral traits that have major implications for our society. Therefore, the study of this phenomenon and derivative interventions that could lead to better control of impulsive aggression are of interest.

METHODS

We analyzed the composition and diversity of the gut bacterial microbiome of 33 impulsively violent female convicts with dissocial personality disorder and 20 non-impulsive age-matched women. Further, levels of assorted neurotransmitters and short-chain fatty acids (SCFAs) were analyzed in serum and stool samples. We also assessed all participants using a battery of psychological questionnaires and tested possible correlations between the collected clinical data and the composition and diversity of their microbiomes and metabolites.

RESULTS

We identified four bacterial amplicon sequencing variants that were differentially abundant in non-impulsive versus impulsive women - the genera Bacteroides, Barnesiella, and the order Rhodospirillales were more abundant in impulsive women. In contrast, the genus Catenisphaera was more abundant in non-impulsive women. Fecal tryptophan levels were significantly higher in impulsive women. Association analysis revealed a strong positive intercorrelation between most fecal SCFAs in the entire dataset.

CONCLUSIONS

Our study demonstrated possible associations between gut microbiomes and their metabolites and impulsive behavior in a unique cohort of prisoners convicted of violent assaults and a matched group of non-impulsive women from the same prison. Genus Bacteroides, which was differentially abundant in the two groups, encoded enzymes that affect serotonin pathways and could contribute to this maladaptive behavior. Similarly, increased fecal tryptophan levels in impulsive individuals could affect neuronal circuits in the brain.

Christensenella minuta mitigates behavioral and cardiometabolic hallmarks of social defeat stress

Psychological stress during early development and adolescence may increase the risk of psychiatric and cardiometabolic comorbidities in adulthood. The gut microbiota has been associated with mental health problems such as depression and anxiety and with cardiometabolic disease, but the potential role of the gut microbiota in their comorbidity is not well understood. We investigated the effects and mode of action of the intestinal bacterium Christensenella minuta DSM 32891 on stress-induced mental health and cardiometabolic disturbances in a mouse model of social defeat stress. We demonstrate that administered C. minuta alleviates chronic stress-induced depressive, anxiogenic and antisocial behavior. These effects are attributed to the bacterium's ability to modulate the hypothalamic-pituitary-adrenal axis, which mediates the stress response. This included the oversecretion of corticosterone and the overexpression of its receptors, as well as the metabolism of dopamine (DA) and the expression of its receptors (D1, D2L and D2S). Additionally, C. minuta administration reduced chronically induced inflammation in plasma, spleen and some brain areas, which likely contribute to the recovery of physical and behavioral function. Furthermore, C. minuta administration prevented chronic stress-induced cardiovascular damage by regulating key enzymes mediating liver fibrosis and oxidative stress. Finally, C. minuta increased the abundance of bacteria associated with mental health. Overall, our study highlights the potential of microbiota-directed interventions to alleviate both the physical and mental effects of chronic stress.

Microbiota-gut-brain axis: Natural antidepressants molecular mechanism

BACKGROUND

Major depressive disorder (MDD) is a severe mental health condition characterized by persistent depression, impaired cognition, and reduced activity. Increasing evidence suggests that gut microbiota (GM) imbalance is closely linked to the emergence and advancement of MDD, highlighting the potential significance of regulating the "Microbiota-Gut-Brain" (MGB) axis to impact the development of MDD. Natural products (NPs), characterized by broad biological activities, low toxicity, and multi-target characteristics, offer unique advantages in antidepressant treatment by regulating MGB axis.

PURPOSE

This review was aimed to explore the intricate relationship between the GM and the brain, as well as host responses, and investigated the mechanisms underlying the MGB axis in MDD development. It also explored the pharmacological mechanisms by which NPs modulate MGB axis to exert antidepressant effects and addressed current research limitations. Additionally, it proposed new strategies for future preclinical and clinical applications in the MDD domain.

METHODS

To study the effects and mechanism by which NPs exert antidepressant effects through mediating the MGB axis, data were collected from Web of Science, PubMed, ScienceDirect from initial establishment to March 2024. NPs were classified and summarized by their mechanisms of action.

RESULTS

NPs, such as flavonoids,alkaloids,polysaccharides,saponins, terpenoids, can treat MDD by regulating the MGB axis. Its mechanism includes balancing GM, regulating metabolites and neurotransmitters such as SCAFs, 5-HT, BDNF, inhibiting neuroinflammation, improving neural plasticity, and increasing neurogenesis.

CONCLUSIONS

NPs display good antidepressant effects, and have potential value for clinical application in the prevention and treatment of MDD by regulating the MGB axis. However, in-depth study of the mechanisms by which antidepressant medications affect MGB axis will also require considerable effort in clinical and preclinical research, which is essential for the development of effective antidepressant treatments.

Gut microbiota causally impacts adrenal function: a two-sample mendelian randomization study

Some studies have reported that the gut microbiota can influence adrenal-related hormone levels. However, the causal effects of the gut microbiota on adrenal function remain unknown. Therefore, we employed a two-sample Mendelian randomization (MR) study to systematically investigate the impact of gut microbiota on the function of different regions of the adrenal gland. The summary statistics for gut microbiota and adrenal-related hormones used in the two-sample MR analysis were derived from publicly available genome-wide association studies (GWAS). In the MR analysis, inverse variance weighting (IVW) was used as the primary method, with MR-Egger, weighted median, and cML-MA serving as supplementary methods for causal inference. Sensitivity analyses such as the MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis were used to assess pleiotropy and heterogeneity. We identified 27 causal relationships between 23 gut microbiota and adrenal function using the IVW method. Among these, Sellimonas enhanced the function of the adrenal cortex reticularis zone (beta = 0.008, 95% CI: 0.002-0.013, P = 0.0057). The cML-MA method supported our estimate (beta = 0.009, 95% CI: 0.004-0.013, P = 2 × 10- 4). Parasutterella, Sutterella, and Anaerofilum affect the functioning of different regions of the adrenal gland. Notably, pleiotropy was not observed. Our findings revealed that the gut microbiota is causally associated with adrenal function. This enhances our understanding of the gut-microbiota-brain axis and provides assistance in the early diagnosis and treatment of adrenal-related diseases in clinical practice.

What We Know About the Actual Role of Traditional Probiotics in Health and Disease

The complex relationship between probiotics and human health goes beyond their traditional function in gut health, generating considerable interest for their broad potential in disease treatment. This review explores the various functions of probiotics, highlighting their impact on the immune system, their benefits for gut and oral health, their effects on metabolic and neurological disorders, and their emerging potential in cancer therapy. We give significant importance to studying the effects of probiotics on the gut-brain axis, revealing new and non-invasive therapeutic approaches for complex neurological disorders. In addition, we expand the discussion to encompass the impact of probiotics on the gut-liver and gut-lung axes, recognizing their systemic effects and potential in treating respiratory and hepatic conditions. The use of probiotic "cocktails" to improve cancer immunotherapy outcomes indicates a revolutionary approach to oncological treatments. The review explores the specific benefits associated with various strains and the genetic mechanisms that underlie them. This study sets the stage for precision medicine, where probiotic treatments can be tailored to meet the unique needs of each patient. Recent developments in delivery technologies, including microencapsulation and nanotechnology, hold great potential for enhancing the effectiveness and accuracy of probiotic applications in therapeutic settings. This study provides a strong basis for future scientific research and clinical use, promoting the incorporation of probiotics into treatment plans for a wide range of diseases. This expands our understanding of the potential benefits of probiotics in modern medicine.

Low-Molecular-Weight Compounds Produced by the Intestinal Microbiota and Cardiovascular Disease

Cardiovascular disease is the main cause of mortality in industrialized countries, with over 500 million people affected worldwide. In this work, the roles of low-molecular-weight metabolites originating from the gut microbiome, such as short-chain fatty acids, hydrogen sulfide, trimethylamine, phenylacetic acid, secondary bile acids, indoles, different gases, neurotransmitters, vitamins, and complex lipids, are discussed in relation to their CVD-promoting or preventing activities. Molecules of mixed microbial and human hepatic origin, such as trimethylamine N-oxide and phenylacetylglutamine, are also presented. Finally, dietary agents with cardioprotective effects, such as probiotics, prebiotics, mono- and poly-unsaturated fatty acids, carotenoids, and polyphenols, are also discussed. A special emphasis is given to their gut microbiota-modulating properties.

Synergistic Antidepressant-like Effects of Biotics and n-3 Polyunsaturated Fatty Acids on Dopaminergic Pathway through the Brain-Gut Axis in Rats Exposed to Chronic Mild Stress

Probiotics, postbiotics, and n-3 polyunsaturated fatty acids (PUFA) have antidepressant-like effects. However, the underlying mechanisms of the dopaminergic pathway are unclear. The present study investigated the hypothesis that probiotics and postbiotics combined with n-3 PUFA synergistically improve depression by modulating the dopaminergic pathway through the brain-gut axis. Rats were randomly divided into seven groups: non-chronic mild stress (CMS) with n-6 PUFA, and CMS with n-6 PUFA, n-3 PUFA, probiotics, postbiotics, probiotics combined with n-3 PUFA, and postbiotics combined with n-3 PUFA. Probiotics, postbiotics, and n-3 PUFA improved depressive behaviors, decreased blood concentrations of interferon-γ, and interleukin-1β, and increased the brain and gut concentrations of short chain fatty acids and dopamine. Moreover, probiotics, postbiotics, and n-3 PUFA increased the brain and gut expression of glucocorticoid receptor and tyrosine hydroxylase; brain expression of l-type amino acid transporter 1 and dopamine receptor (DR) D1; and gut expression of DRD2. The expression of phosphorylated protein kinase A/protein kinase A and phosphorylated cAMP response element-binding protein/cAMP response element-binding protein increased in the brain, however, decreased in the gut by the supplementation of probiotics, postbiotics, and n-3 PUFA. There was synergistic effect of probiotics and postbiotics combined with n-3 PUFA on the depressive behaviors and dopaminergic pathway in blood, brain, and gut. Moreover, no significant difference in the dopaminergic pathways between the probiotics and postbiotics was observed. In conclusion, probiotics and postbiotics, combined with n-3 PUFA have synergistic antidepressant-like effects on the dopaminergic pathway through the brain-gut axis in rats exposed to CMS.

Modifications in the Composition of the Gut Microbiota in Rats Induced by Chronic Sleep Deprivation: Potential Relation to Mental Disorders

Introduction

Sleep deprivation(SD) has numerous negative effects on mental health. A growing body of research has confirmed the implication of gut microbiota in mental disorders. However, the specific modifications in mammalian gut microbiota following SD exhibit variations across different studies.

Methods

Male specific-pathogen-free Wistar rats were given a modified multiple-platform exposure for 7 days of SD. Fecal samples were obtained from the control and SD groups both at baseline and after 7 days of SD. We utilized 16S rDNA gene sequencing to investigate the gut microbial composition and functional pathways in rats.

Results

Analysis of the microbiota composition revealed a significant change in gut microbial composition after chronic SD, especially at the phylum level. The relative abundances of p_Firmicutes, g_Romboutsia, and g_Enterococcus increased, whereas those of p_Bacteroidetes, p_Verrucomicrobia, p_Fusobacteria, g_Akkermansia, and g_Cetobacterium decreased in animals after chronic SD compared with controls or animals before SD. The ratio of Firmicutes to Bacteroidetes exhibited an increase following SD. The relative abundance of gut microbiota related to the functional pathways of GABAergic and glutamatergic synapses was observed to be diminished in rats following SD compared to pre-SD.

Conclusion

Collectively, these findings suggest that chronic SD causes significant alterations in both the structural composition and functional pathways of the gut microbiome. Further researches are necessary to investigate the chronological and causal connections among SD, the gut microbiota and mental disorders.

Cold-pressed perilla seed oil: Investigating its protective influence on the gut-brain axis in mice with rotenone-induced Parkinson's disease

Perilla seed oil, derived from a regional plant native to northern Thailand, undergoes cold-pressing to analyze its bioactive components, notably alpha-linolenic acid (ALA). ALA, constituting approximately 61% of the oil, serves as a precursor for therapeutic omega-3 fatty acids, EPA and DHA, with neurodegenerative disease benefits and anti-inflammatory responses. This study administered different concentrations of perilla seed oil to male C57BL/6 mice, categorized as low dose (LP 5% w/w), middle dose (MP 10% w/w), and high dose (HP 20% w/w), along with a fish oil (FP 10% w/w) diet. An experimental group received soybean oil (5% w/w). Over 42 days, these diets were administered while inducing Parkinson's disease (PD) with rotenone injections. Mice on a high perilla seed oil dose exhibited decreased Cox-2 expression in the colon, suppressed Iba-1 microglia activation, reduced alpha-synuclein accumulation in the colon and hippocampus, prevented dopaminergic cell death in the substantia nigra, and improved motor and non-motor symptoms. Mice on a middle dose showed maintenance of diverse gut microbiota, with an increased abundance of short-chain fatty acid (SCFA)-producing bacteria (Bifidobacteria, Lactobacillus, and Faecalibacteria). A reduction in bacteria correlated with PD (Turicibacter, Ruminococcus, and Akkermansia) was observed. Results suggest the potential therapeutic efficacy of high perilla seed oil doses in mitigating both intestinal and neurological aspects linked to the gut-brain axis in PD.

Advanced Bioinspired Multifunctional Platforms Focusing on Gut Microbiota Regulation

Gut microbiota plays a crucial role in maintaining host homeostasis, impacting the progression and therapeutic outcomes of diseases, including inflammatory bowel disease, cancer, hepatic conditions, obesity, cardiovascular pathologies, and neurologic disorders, via immune, neural, and metabolic mechanisms. Hence, the gut microbiota is a promising target for disease therapy. The safety and precision of traditional microbiota regulation methods remain a challenge, which limits their widespread clinical application. This limitation has catalyzed a shift toward the development of multifunctional delivery systems that are predicated on microbiota modulation. Guided by bioinspired strategies, an extensive variety of naturally occurring materials and mechanisms have been emulated and harnessed for the construction of platforms aimed at the monitoring and modulation of gut microbiota. This review outlines the strategies and advantages of utilizing bioinspired principles in the design of gut microbiota intervention systems based on traditional regulation methods. Representative studies on the development of bioinspired therapeutic platforms are summarized, which are based on gut microbiota modulation to confer multiple pharmacological benefits for the synergistic management of diseases. The prospective avenues and inherent challenges associated with the adoption of bioinspired strategies in the refinement of gut microbiota modulation platforms are proposed to augment the efficacy of disease treatment.

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.

ICAM-1 may promote the loss of dopaminergic neurons by regulating inflammation in MPTP-induced Parkinson's disease mouse models

Parkinson's disease (PD) is a chronic neurodegenerative disease with unclear pathogenesis that involves neuroinflammation and intestinal microbial dysbiosis. Intercellular adhesion molecule-1 (ICAM-1), an inflammatory marker, participates in neuroinflammation during dopaminergic neuronal damage. However, the explicit mechanisms of action of ICAM-1 in PD have not been elucidated. We established a subacute PD mouse model by the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and observed motor symptoms and gastrointestinal dysfunction in mice. Immunofluorescence was used to examine the survival of dopaminergic neurons, expression of microglial and astrocyte markers, and intestinal tight junction-associated proteins. Then, we use 16 S rRNA sequencing to identify alterations in the microbiota. Our findings revealed that ICAM-1-specific antibody (Ab) treatment relieved behavioural defects, gastrointestinal dysfunction, and dopaminergic neuronal death in MPTP-induced PD mice. Further mechanistic investigations indicated that ICAM-1Ab might suppress neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra and relieving colon barrier impairment and intestinal inflammation. Furthermore, 16 S rRNA sequencing revealed that the relative abundances of bacterial Firmicutes, Clostridia, and Lachnospiraceae were elevated in the PD mice. However, ICAM-1Ab treatment ameliorated the MPTP-induced disorders in the intestinal microbiota. Collectively, we concluded that the suppressing ICAM-1 might lead to the a significant decrease of inflammation and restore the gut microbial community, thus ameliorating the damage of DA neurons.

Association between environmental phthalates exposure and gut microbiota and metabolome in dementia with Lewy bodies

BACKGROUND

Emerging evidence has shown the potential involvement of phthalates (PAEs) exposure in the development of dementia with Lewy bodies (DLB). Metabolomics can reflect endogenous metabolites variation in the progress of disease after chemicals exposure. However, little is known about the association between PAEs, gut microbiota and metabolome in DLB.

OBJECTIVE

We aim to explore the intricate relationship among urinary PAEs metabolites (mPAEs), dysbiosis of gut bacteria, and metabolite profiles in DLB.

METHODS

A total of 43 DLB patients and 45 normal subjects were included in this study. Liquid chromatography was used to analyze the levels of mPAEs in the urine of the two populations. High-throughput sequencing and liquid chromatography-mass spectrometry were used to analyze gut microbiota and the profile of gut metabolome, respectively. The fecal microbiota transplantation (FMT) experiment was performed to verify the potential role of mPAEs on gut dysbiosis contribute to aggravating cognitive dysfunction in α-synuclein tg DLB/PD mice.

RESULTS

The DLB patients had higher DEHP metabolites (MEOHP, MEHHP and MEHP), MMP and MnBP, lower MBP and MBzP than the control group and different microbiota. A significantly higher abundance of Ruminococcus gnavus and lower Prevotella copri, Prevotella stercorea and Bifidobacterium were observed in DLB. Higher 3 DEHP metabolites, MMP, MnBP and lower MBP and MBzP were significantly negatively associated with Prevotella copri, Prevotella stercorea and Bifidobacterium. Additionally, using metabolomics, we found that altered bile acids, short-chain fatty acids and amino acids metabolism are linked to these mPAEs. We further found that FMT of fecal microbiota from highest DEHP metabolites donors significantly impaired cognitive function in the germ-free DLB/PD mice.

CONCLUSION

Our study suggested that PAEs exposure may alter the microbiota-gut-brain axis and providing novel insights into the interactions among environmental perturbations and microbiome-host in pathogenesis of DLB.

The Relationship between Canine Behavioral Disorders and Gut Microbiome and Future Therapeutic Perspectives

Canine behavioral disorders have become one of the most common concerns and challenging issues among dog owners. Thus, there is a great demand for knowledge about various factors affecting dogs' emotions and well-being. Among them, the gut-brain axis seems to be particularly interesting, especially since in many instances the standard treatment or behavioral therapies insufficiently improve animal behavior. Therefore, to face this challenge, the search for novel therapeutic methods is highly required. Existing data show that mammals' gut microbiome, immune system, and nervous system are in continuous communication and influence animal physiology and behavior. This review aimed to summarize and discuss the most important scientific evidence on the relationship between mental disorders and gut microbiota in dogs, simultaneously presenting comparable outcomes in humans and rodent models. A comprehensive overview of crucial mechanisms of the gut-brain axis is included. This refers especially to the neurotransmitters crucial for animal behavior, which are regulated by the gut microbiome, and to the main microbial metabolites-short-chain fatty acids (SCFAs). This review presents summarized data on gut dysbiosis in relation to the inflammation process within the organism, as well as the activation of the hypothalamic-pituitary-adrenal (HPA) axis. All of the above mechanisms are presented in this review in strict correlation with brain and/or behavioral changes in the animal. Additionally, according to human and laboratory animal studies, the gut microbiome appears to be altered in individuals with mental disorders; thus, various strategies to manipulate the gut microbiota are implemented. This refers also to the fecal microbiome transplantation (FMT) method, based on transferring the fecal matter from a donor into the gastrointestinal tract of a recipient in order to modulate the gut microbiota. In this review, the possible effects of the FMT procedure on animal behavioral disorders are discussed.

Maternal gestational diabetes mellitus associates with altered gut microbiome composition and head circumference abnormalities in male offspring

The impact of gestational diabetes mellitus (GDM) on maternal or infant microbiome trajectory remains poorly understood. Utilizing large-scale longitudinal fecal samples from 264 mother-baby dyads, we present the gut microbiome trajectory of the mothers throughout pregnancy and infants during the first year of life. GDM mothers had a distinct microbiome diversity and composition during the gestation period. GDM leaves fingerprints on the infant's gut microbiome, which are confounded by delivery mode. Further, Clostridium species positively correlate with a larger head circumference at month 12 in male offspring but not females. The gut microbiome of GDM mothers with male fetuses displays depleted gut-brain modules, including acetate synthesis I and degradation and glutamate synthesis II. The gut microbiome of female infants of GDM mothers has higher histamine degradation and dopamine degradation. Together, our integrative analysis indicates that GDM affects maternal and infant gut composition, which is associated with sexually dimorphic infant head growth.

The Microbiome in Child and Adolescent Psychiatry

Recent research has increasingly emphasized the function of the microbiome in human health. The gut microbiome is essential for digesting food and seems to play a vital role in mental health as well. This review briefly overviews the gut microbiome and its interplay with the central nervous system. We then summarize some of the latest findings on the possible role of the microbiome in psychiatric disorders in children and adolescents. In particular, we focus on autism spectrum disorder, attention-deficit/hyperactivity disorder, anorexia nervosa, bipolar disorder, and major depressive disorder. Although the role of microbiota in mental development and health still needs to be researched intensively, it has become increasingly apparent that the impact of microbiota must be considered to better understand psychiatric disorders.

Exploring the nigrostriatal and digestive interplays in Parkinson's disease using dynamic total-body [11C]CFT PET/CT

PURPOSE

Dynamic total-body imaging enables new perspectives to investigate the potential relationship between the central and peripheral regions. Employing uEXPLORER dynamic [11C]CFT PET/CT imaging with voxel-wise simplified reference tissue model (SRTM) kinetic modeling and semi-quantitative measures, we explored how the correlation pattern between nigrostriatal and digestive regions differed between the healthy participants as controls (HC) and patients with Parkinson's disease (PD).

METHODS

Eleven participants (six HCs and five PDs) underwent 75-min dynamic [11C]CFT scans on a total-body PET/CT scanner (uEXPLORER, United Imaging Healthcare) were retrospectively enrolled. Time activity curves for four nigrostriatal nuclei (caudate, putamen, pallidum, and substantia nigra) and three digestive organs (pancreas, stomach, and duodenum) were obtained. Total-body parametric images of relative transporter rate constant (R1) and distribution volume ratio (DVR) were generated using the SRTM with occipital lobe as the reference tissue and a linear regression with spatial-constraint algorithm. Standardized uptake value ratio (SUVR) at early (1-3 min, SUVREP) and late (60-75 min, SUVRLP) phases were calculated as the semi-quantitative substitutes for R1 and DVR, respectively.

RESULTS

Significant differences in estimates between the HC and PD groups were identified in DVR and SUVRLP of putamen (DVR: 4.82 ± 1.58 vs. 2.58 ± 0.53; SUVRLP: 4.65 ± 1.36 vs. 2.84 ± 0.67; for HC and PD, respectively, both p < 0.05) and SUVREP of stomach (1.12 ± 0.27 vs. 2.27 ± 0.65 for HC and PD, respectively; p < 0.01). In the HC group, negative correlations were observed between stomach and substantia nigra in both the R1 and SUVREP values (r=-0.83, p < 0.05 for R1; r=-0.94, p < 0.01 for SUVREP). Positive correlations were identified between pancreas and putamen in both DVR and SUVRLP values (r = 0.94, p < 0.01 for DVR; r = 1.00, p < 0.001 for SUVRLP). By contrast, in the PD group, no correlations were found between the aforementioned target nigrostriatal and digestive areas.

CONCLUSIONS

The parametric images of R1 and DVR generated from the SRTM model, along with SUVREP and SUVRLP, were proposed to quantify dynamic total-body [11C]CFT PET/CT in HC and PD groups. The distinction in correlation patterns of nigrostriatal and digestive regions between HC and PD groups identified by R1 and DVR, or SUVRs, may provide new insights into the disease mechanism.

The Role of Microbiota-Related Co-Metabolites in MASLD Progression: A Narrative Review

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a growing health concern due to its increasing prevalence worldwide. Metabolic homeostasis encompasses the stable internal conditions vital for efficient metabolism. This equilibrium extends to the intestinal microbiota, whose metabolic activities profoundly influence overall metabolic balance and organ health. The metabolites derived from the gut microbiota metabolism can be defined as microbiota-related co-metabolites. They serve as mediators between the gut microbiota and the host, influencing various physiological processes. The recent redefinition of the term MASLD has highlighted the metabolic dysfunction that characterize the disease. Metabolic dysfunction encompasses a spectrum of abnormalities, including impaired glucose regulation, dyslipidemia, mitochondrial dysfunction, inflammation, and accumulation of toxic byproducts. In addition, MASLD progression has been linked to dysregulation in the gut microbiota and associated co-metabolites. Short-chain fatty acids (SCFAs), hippurate, indole derivatives, branched-chain amino acids (BCAAs), and bile acids (BAs) are among the key co-metabolites implicated in MASLD progression. In this review, we will unravel the relationship between the microbiota-related metabolites which have been associated with MASLD and that could play an important role for developing effective therapeutic interventions for MASLD and related metabolic disorders.

Gut microbial β-glucuronidases influence endobiotic homeostasis and are modulated by diverse therapeutics

Hormones and neurotransmitters are essential to homeostasis, and their disruptions are connected to diseases ranging from cancer to anxiety. The differential reactivation of endobiotic glucuronides by gut microbial β-glucuronidase (GUS) enzymes may influence interindividual differences in the onset and treatment of disease. Using multi-omic, in vitro, and in vivo approaches, we show that germ-free mice have reduced levels of active endobiotics and that distinct gut microbial Loop 1 and FMN GUS enzymes drive hormone and neurotransmitter reactivation. We demonstrate that a range of FDA-approved drugs prevent this reactivation by intercepting the catalytic cycle of the enzymes in a conserved fashion. Finally, we find that inhibiting GUS in conventional mice reduces free serotonin and increases its inactive glucuronide in the serum and intestines. Our results illuminate the indispensability of gut microbial enzymes in sustaining endobiotic homeostasis and indicate that therapeutic disruptions of this metabolism promote interindividual response variabilities.

Impact of menopause-associated frailty on traumatic brain injury

Navigating menopause involves traversing a complex terrain of hormonal changes that extend far beyond reproductive consequences. Menopausal transition is characterized by a decrease in estradiol-17β (E2), and the impact of menopause resonates not only in the reproductive system but also through the central nervous system, musculoskeletal, and gastrointestinal domains. As women undergo menopausal transition, they become more susceptible to frailty, amplifying the risk and severity of injuries, including traumatic brain injury (TBI). Menopause triggers a cascade of changes leading to a decline in muscle mass, accompanied by diminished tone and excitability, thereby restricting the availability of irisin, a crucial hormone derived from muscles. Concurrently, bone mass undergoes reduction, culminating in the onset of osteoporosis and altering the dynamics of osteocalcin, a hormone originating from bones. The diminishing levels of E2 during menopause extend their influence on the gut microbiota, resulting in a reduction in the availability of tyrosine, tryptophan, and serotonin metabolites, affecting neurotransmitter synthesis and function. Understanding the interplay between menopause, frailty, E2 decline, and the intricate metabolisms of bone, gut, and muscle is imperative when unraveling the nuances of TBI after menopause. The current review underscores the significance of accounting for menopause-associated frailty in the incidence and consequences of TBI. The review also explores potential mechanisms to enhance gut, bone, and muscle health in menopausal women, aiming to mitigate frailty and improve TBI outcomes.