Boundaries and integration between microbiota, the nervous system, and immunity

Bidirectional regulation of the brain-gut-microbiota axis following traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202508000-00002/figure1/v/2024-09-30T120553Z/r/image-tiff Traumatic brain injury is a prevalent disorder of the central nervous system. In addition to primary brain parenchymal damage, the enduring biological consequences of traumatic brain injury pose long-term risks for patients with traumatic brain injury; however, the underlying pathogenesis remains unclear, and effective intervention methods are lacking. Intestinal dysfunction is a significant consequence of traumatic brain injury. Being the most densely innervated peripheral tissue in the body, the gut possesses multiple pathways for the establishment of a bidirectional "brain-gut axis" with the central nervous system. The gut harbors a vast microbial community, and alterations of the gut niche contribute to the progression of traumatic brain injury and its unfavorable prognosis through neuronal, hormonal, and immune pathways. A comprehensive understanding of microbiota-mediated peripheral neuroimmunomodulation mechanisms is needed to enhance treatment strategies for traumatic brain injury and its associated complications. We comprehensively reviewed alterations in the gut microecological environment following traumatic brain injury, with a specific focus on the complex biological processes of peripheral nerves, immunity, and microbes triggered by traumatic brain injury, encompassing autonomic dysfunction, neuroendocrine disturbances, peripheral immunosuppression, increased intestinal barrier permeability, compromised responses of sensory nerves to microorganisms, and potential effector nuclei in the central nervous system influenced by gut microbiota. Additionally, we reviewed the mechanisms underlying secondary biological injury and the dynamic pathological responses that occur following injury to enhance our current understanding of how peripheral pathways impact the outcome of patients with traumatic brain injury. This review aimed to propose a conceptual model for future risk assessment of central nervous system-related diseases while elucidating novel insights into the bidirectional effects of the "brain-gut-microbiota axis."

Short-chain fatty acids in Huntington's disease: Mechanisms of action and their therapeutic implications

Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor dysfunction, cognitive decline, and emotional instability, primarily resulting from the abnormal accumulation of mutant huntingtin protein. Growing research highlights the role of intestinal microbiota and their metabolites, particularly short-chain fatty acids (SCFAs), in modulating HD progression. SCFAs, including acetate, propionate, and butyrate, are produced by gut bacteria through dietary fiber fermentation and are recognized for their neuroprotective properties. Evidence suggests that SCFAs regulate neuroinflammation, neuronal communication, and metabolic functions within the central nervous system (CNS). In HD, these compounds may support neuronal health, reduce oxidative stress, and enhance blood-brain barrier (BBB) integrity. Their mechanisms of action involve binding to G-protein-coupled receptors (GPCRs) and modulating gene expression through epigenetic pathways, underscoring their therapeutic potential. This analysis examines the significance of SCFAs in HD, emphasizing the gut-brain axis and the benefits of dietary interventions aimed at modifying gut microbiota composition and promoting SCFA production. Further research into these pathways may pave the way for novel HD management strategies and improved therapeutic outcomes.

Investigating Causal Links Between Gut Microbiota and Neurological Disorders via Genome-Wide Association Studies

Many reports have highlighted the involvement of the gut microbiome in the occurrence, progression, and outcomes of neurological disorders. However, current reports are somewhat chaotic, especially concerning whether the gut microbiota has a causal effect on various neurological diseases. Furthermore, whether there is a common mechanism involving gut microbial communities in these neurological disorders has not to be revealed. In this study, we leveraged data from the largest-scale genome-wide association study (GWAS) by the MiBioGen consortium, which includes genetic and microbial composition data from 18,340 individuals spanning 24 cohorts. We utilized single-nucleotide polymorphisms (SNPs) associated with the gut microbiome as instrumental variables (IVs) in Mendelian randomization (MR) analyses. These IVs were rigorously selected based on their genome-wide and locus-wide significance to ensure robust causal inference. Our study established robust associations between specific gut microbiota and various neurological disorders using MR. We systematically depicted the bacteria with causal relationships in all diseases, covering the levels of phylum, class, order, family, and genus. We identified 34 bacterial species as significant risk or protective factors across disorders, including two main phylum levels such as Firmicutes (22 species) and Proteobacteria (8 species), as well as Bacteroidetes (2 species), Actinobacteria (1 species), and Verrucomicrobiota (1 species). At the family level of bacteria, we found that Lachnospiraceae and Ruminococcaceae are the most related to these 11 diseases and they may play different roles in the same disease.

Schisandrin B Improves Mitochondrial Function and Inhibits HT22 Cell Apoptosis by Regulating Sirt3 Protein

Neurological diseases refer to pathological changes that occur in the brain, spinal cord, and peripheral nerves. Their etiologies are complex, treatment outcomes are poor, and prognoses are unfavorable. Therefore, how to improve the treatment efficacy of neurological diseases is an urgent problem to be addressed in current clinical practice. Schisandrin B, a commonly used traditional Chinese medicine in clinical settings, has anti-tumor, anti-inflammatory, and wound-healing promoting effects. However, there are relatively few studies on its application in the treatment of neurological diseases. In this study, HT22 nerve cells were cultured, and an injury model was constructed by applying H2O2 stimulation to explore the protective effect of Schisandrin B on these cells. The research results showed that compared with the H2O2 group, Schisandrin B could significantly increase the viability (30.872%) and migration ability (42.756%) of HT22 cells, and inhibit the apoptosis of HT22 cells (22.817%). Further exploration of the mechanism revealed that Schisandrin B regulated the mitochondrial dynamic balance and membrane potential level of HT22 cells by upregulating the expression of Sirt3 protein, enhanced the mitochondrial energy metabolism (with an increase of 53.411% in ATP production), and maintained the integrity of the quantity and structure of mitochondria, ultimately exerting a protective effect on HT22 cells.

Gut microbiota and their metabolites in the immune response of rheumatoid arthritis: Therapeutic potential and future directions

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent joint inflammation, damage, and loss of function. In recent years, the role of gut microbiota and its metabolites in immune regulation has attracted increasing attention. The gut microbiota influences the host immune system's homeostasis through various mechanisms, regulating the differentiation, function, and immune tolerance of immune cells. Dysbiosis of the gut microbiota in RA patients is closely associated with abnormal activation of immune cells and excessive secretion of inflammatory cytokines. Metabolites produced by the gut microbiota, such as short-chain fatty acids (SCFAs), tryptophan metabolites, bile acids, and amino acid metabolites, play a critical role in immune responses, regulating the functions of immune cells like T cells, B cells, and macrophages, and inhibiting the release of pro-inflammatory cytokines. Restoring the balance of the gut microbiota and optimizing the production of metabolic products may become a new strategy for RA treatment. This review discusses the role of gut microbiota and its metabolites in the immune response of RA, exploring how they influence the immunopathological process of RA through the regulation of immune cells and key immune factors. It also provides a theoretical basis for future therapeutic strategies based on gut microbiota modulation.

Gut microbiota and atrial cardiomyopathy

Atrial cardiomyopathy is a multifaceted heart disease characterized by structural and functional abnormalities of the atria and is closely associated with atrial fibrillation and its complications. Its etiology involves a number of factors, including genetic, infectious, immunologic, and metabolic factors. Recent research has highlighted the critical role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, and this is consistent with the gut-heart axis having major implications for cardiac health. The aim of this work is to bridge the knowledge gap regarding the interactions between the gut microbiota and atrial cardiomyopathy, with a particular focus on elucidating the mechanisms by which gut dysbiosis may induce atrial remodeling and dysfunction. This article provides an overview of the role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, including changes in the composition of the gut microbiota and the effects of its metabolites. We also discuss how diet and exercise affect atrial cardiomyopathy by influencing the gut microbiota, as well as possible future therapeutic approaches targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but ecological dysbiosis can lead to a variety of symptoms, including the induction of heart disease. We focus on the pathophysiological aspects of atrial cardiomyopathy, the impact of gut microbiota dysbiosis on atrial structure and function, and therapeutic strategies exploring modulation of the microbiota for the treatment of atrial cardiomyopathy. Finally, we discuss the role of gut microbiota in the treatment of atrial cardiomyopathy, including fecal microbiota transplantation and oral probiotics or prebiotics. Our study highlights the importance of gut microbiota homeostasis for cardiovascular health and suggests that targeted interventions on the gut microbiota may pave the way for innovative preventive and therapeutic strategies targeting atrial cardiomyopathy.

[Functional disorders in chronic inflammatory bowel disease: the gut-brain axis]

BACKGROUND

In patients with inflammatory bowel diseases (IBD), functional complaints frequently persist after the clearing of inflammation and are clinically difficult to distinguish from symptoms of inflammation. In recent years, the influence of bidirectional communication between the gut and brain on gut physiology, emotions, and behavior has been demonstrated.

RESEARCH QUESTIONS

What mechanisms underlie the development of functional gastrointestinal complaints in patients with irritable bowel syndrome (IBS) and IBD? What therapeutic approaches arise from this?

MATERIALS AND METHODS

Narrative review.

RESULTS

The pathogenesis of IBS involves interactions between psychosocial factors, genetics, and microbiota as well as the central and peripheral nervous systems. The interplay between stress and visceral hypersensitivity is of central importance. Therapeutically, lifestyle changes with stress reduction and exercise alongside dietary, pharmacological, and psychotherapeutic options are useful.

DISCUSSION

The treatment of functional gastrointestinal disorders remains challenging, as pharmacological therapies are often ineffective and gut-directed psychotherapies are rarely available.

The microbiota-gut-brain axis: a potential target in the small-molecule compounds and gene therapeutic strategies for Parkinson's disease

BACKGROUNDS

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by motor symptoms and non-motor symptoms. It has been found that intestinal issues usually precede motor symptoms. Microorganisms in the gastrointestinal tract can affect central nervous system through the microbiota-gut-brain axis. Accumulating evidence has shown that disturbances in the microbiota-gut-brain axis are linked with PD. Thus, this pathway appears to be a promising therapeutic target for treatment of PD.

OBJECTIVES

In this review, we mainly described gut dysbiosis in PD and their underlying mechanisms for mediating neuroinflammation and peripheral immune response in PD pathology and futher discussed the potential small-molecule compounds and genic therapeutic strategies targeting the microbiota-gut-brain axis and their applications in PD.

CONCLUSIONS

Studies have found that some small molecule compounds and alterations of inflammation-related genes can improve the motor and non-motor symptoms of PD by improving the microbiota-gut-brain axis, which may provide potentially beneficial drugs and molecular targets for the therapies of PD.

Delving the depths of 'terra incognita' in the human intestine - the small intestinal microbiota

The small intestinal microbiota has a crucial role in gastrointestinal health, affecting digestion, immune function, bile acid homeostasis and nutrient metabolism. The challenges of accessibility at this site mean that our knowledge of the small intestinal microbiota is less developed than of the colonic or faecal microbiota. Here, we summarize the features and fluctuations of the microbiota along the small intestinal tract, focusing on humans, and discuss physicochemical factors and assessment methods, including the technical challenges of investigating the low microbial biomass of the proximal small bowel. We highlight the essential protective mechanisms of the small intestine, including motility, the paracellular barrier and mucus, and secretory immunity, to show their roles in limiting excessive exposure of host tissues to microbial metabolites. We address current knowledge gaps, particularly the variability among individuals, the effects of dysbiosis of the small intestinal microbiota on health and how different taxa in small intestinal microbiota could compensate for each other functionally.

Gut microbiota's role in high-altitude cognitive impairment: the therapeutic potential of Clostridium sp. supplementation

Prolonged exposure to high-altitude environments may increase the risk of cognitive decline in young migrants. Recent studies suggest that hypobaric hypoxia-induced alterations in gut microbial composition could partly contribute to this risk. However, the absence of direct evidence from cohort studies and an unclear mechanism hinder intervention development based on this hypothesis. This study recruited 109 young male migrants living in Xizang to investigate the microbial mechanisms underlying cognitive impairment associated with high-altitude migration. Multi-omic analysis revealed distinct microbiome and metabolome features in migrants with cognitive decline, notably a reduced abundance of Clostridium species and disrupted fecal absorption of L-valine. Mechanistic studies showed that hypobaric hypoxia significantly damaged the intestinal barrier, leading to lipopolysaccharide (LPS) leakage and an influx of inflammatory factors into the peripheral blood, which activated microglia and caused neuronal injury in the hippocampus of mice. Additionally, compromised L-valine absorption due to intestinal barrier damage correlated with lower hippocampal glutamate levels and neurotrophic factors. Intervention with Clostridium sp. effectively restored the intestinal barrier and enhanced L-valine absorption, which mitigated hypobaric hypoxia-induced inflammation and hippocampal neural damage in mice. In conclusion, cognitive impairment among young migrants at high altitude may be attributed to hypobaric hypoxia-induced gut microbiota disruption and subsequent intestinal barrier dysfunction. This study may provide a promising approach for preventing and treating high-altitude-associated cognitive impairment.

Diet shapes and maintains the personalized native gut microbiomes in mice

BACKGROUND

The gut microbiome plays a critical role in human health and disease. Different dietary backgrounds play an important role in the uniqueness and diversity of the gut microbiota in different individuals, which promotes heterogeneity in disease phenotypes and treatment responses. Here, we explored how diet affects the composition and function of the native gut microbiome of model mice, based on the shotgun metagenomic and metabolomic, by analyzing the gut microbiome of C57B/6J mice in different dietary backgrounds.

RESULTS

The gut microbiomes of mice receiving different diets consistently exhibit distinct compositions across bacterial species, strains, fungi and phages. This implies that native microbial communities cannot 'homogenize' rapidly becaise of priority effects and unchanging diets. Notably, hotspot bacteria such as Limosilactobacillus reuteri, Parabacteroides distasonis and Akkermansia muciniphila were significantly different among the groups. These species harbor diverse adaptive mutations, reflecting genomic evolutionary diversity. The functional profiles of the gut microbiota also exhibit selective differences, involving the capacity for carbohydrate, branched-chain amino acid and fatty acid synthesis, as well as virulence factors, carbohydrate-active enzymes and antibiotic resistance. Furthermore, the differences in the gut microbiota also propagate to the host's serum, where structural and specific metabolite differences were observed. Metabolites that directly impact host health, such as d-glucosamine 6-phosphate and testolic acid, also show significant differences between the different dietary groups.

CONCLUSION

Our findings underscore the profound influence of different dietary the composition and functionality of the gut microbiome, offering valuable insights into optimizing health outcomes through personalized nutritional interventions. © 2024 Society of Chemical Industry.

Plant-Based Diet and Sports Performance

Recently, interest in plant-based diets has grown significantly, driven by health and environmental concerns. Plant-based diets offer potential health benefits, including decreased risk of cardiovascular disease, weight management, and blood glucose regulation. This diet profile is rich in complex carbohydrates, antioxidants, dietary fiber, and phytochemicals. However, antinutrients in some plant foods can make nutrient absorption difficult, necessitating careful dietary planning. Plant-based diets can also improve sports performance; in addition, they can positively influence the intestinal microbial community, which can promote health and performance. The present study covered a review from 1986 to 2024 and involved an experimental design with human participants. The main objective was to evaluate the impact of plant-based diets on sports performance. Recent research suggests that plant-based diets do not harm athletic performance and may positively impact sports performance by improving blood flow and reducing oxidative stress. These findings have potential clinical significance, particularly for athletes seeking to optimize their physical capabilities through dietary interventions.

Protective effects of YCHD on the autoimmune hepatitis mice model induced by Ad-CYP2D6 through modulating the Th1/Treg ratio and intestinal flora

Background

Autoimmune hepatitis (AIH) is a chronic liver inflammatory disease mediated by autoimmune reactions, the pathogenesis of AIH is probably related to the imbalance of intestinal flora. Yinchenhao decoction (YCHD) has been used to relieve AIH. However, the mechanisms underpinning YCHD's hepatoprotective effects with the gut microbito have not been fully revealed.

Objective

To explore the potential mechanism of YCHD in treating AIH based on changes in the intestinal flora and Th1/Treg ratio in the spleen and hepatic hilar lymph nodes.

Methods

The AIH mice model induced by the adenovirus vectors that overexpress human cytochrome P450 family 2 subfamily D member 6 (Ad-CYP2D6) was established (untreated group). One week after the Ad-CYP2D6 injection, the AIH model mice were treated by administering YCHD by gavage for 14 days (YCHD-treated group). The therapeutic efficacy of YCHD on AIH was evaluated by detecting the histopathological changes of the liver, serum transaminases (ALT and AST), inflammatory factors (TNF-α,IL-17 and IFN-γ), and autoantibodies (including LKM-1 and LC-1). The ratio of Th1 to Treg within the spleen and hepatic hilar lymph nodes of the mice was detected by flow cytometry. The changes in the species and abundance of intestinal flora and intestinal flora metabolites were analyzed via 16S rRNA gene sequencing and gas chromatography-mass spectrometry (GC/MS) to reveal the protective mechanism of YCHD on liver injury.

Result

YCHD decreased the transaminase activity (AST and ALT), the content of autoantibodies (LC-1 and LKM-1), and the serum TNF-α, IL-12, and IL-17 levels in AIH mice. The degree of inflammatory infiltration in the YCHD-treated group was significantly less than that in the untreated group. YCHD can effectively reverse the abundance and diversity of intestinal flora in AIH mice and affect the release of short-chain fatty acids (SCFAs), especially butyric acid. Moreover, the flow cytometry results showed that YCHD could also decline the ratio of Th1/Treg, which probably be induced by SCFAs via the G protein-coupled receptor (GPR).

Conclusion

YCHD may affect the release of SCFAs by regulating the intestinal microbiota, thereby affecting the differentiation of Th1 and Treg, and achieving the effect of alleviating liver damage.

Fibre & fermented foods: differential effects on the microbiota-gut-brain axis

The ability to manipulate brain function through the communication between the microorganisms in the gastrointestinal tract and the brain along the gut-brain axis has emerged as a potential option to improve cognitive and emotional health. Dietary composition and patterns have demonstrated a robust capacity to modulate the microbiota-gut-brain axis. With their potential to possess pre-, pro-, post-, and synbiotic properties, dietary fibre and fermented foods stand out as potent shapers of the gut microbiota and subsequent signalling to the brain. Despite this potential, few studies have directly examined the mechanisms that might explain the beneficial action of dietary fibre and fermented foods on the microbiota-gut-brain axis, thus limiting insight and treatments for brain dysfunction. Herein, we evaluate the differential effects of dietary fibre and fermented foods from whole food sources on cognitive and emotional functioning. Potential mediating effects of dietary fibre and fermented foods on brain health via the microbiota-gut-brain axis are described. Although more multimodal research that combines psychological assessments and biological sampling to compare each food type is needed, the evidence accumulated to date suggests that dietary fibre, fermented foods, and/or their combination within a psychobiotic diet can be a cost-effective and convenient approach to improve cognitive and emotional functioning across the lifespan.

The Potential of Defatted Yellow Mealworm (Tenebrio molitor) Meal as an Alternative Protein Source for Juvenile Chinese Mitten Crab (Eriocheir sinensis)

This study was aimed to investigate the effects of replacing dietary fish meal (FM) with defatted yellow mealworm (Tenebrio molitor) meal (DYM) on growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile Chinese mitten crab (Eriocheir sinensis). Four hundred juvenile Chinese mitten crabs (4.94 ± 0.08 g) were randomly distributed into five groups in quadruplicate (20 crabs per tank), and each group was fed with diets that replaced FM with DYM at 0% (CON, containing 200 g/kg FM), 25% (DYM25), 50% (DYM50), 75% (DYM75), and 100% (DYM100) for 8 weeks, respectively. The results showed that the growth, serum immune and antioxidant indexes, digestive enzyme activities, intestinal histology, and microbiota composition of DYM25, DYM50, and DYM75 groups all reached the similar level as the CON group. While when 100% fishmeal was replaced, significantly decreased the final body weight (FBW), weight gain (WG), serum alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LZM), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) activities, hepatopancreas protease activity, mid-intestine folds height and number (P < 0.05), significantly increased the feed conversion ratio (FCR), serum malondialdehyde (MDA) content, and the abundance of intestinal harmful bacteria Shewanella (P < 0.05). Overall, these results suggest that 75% dietary FM (150 g/kg) can be effectively replaced by DYM without negative impact on the growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile E. sinensis.

Caveolin Regulates the Transport Mechanism of the Walnut-Derived Peptide EVSGPGYSPN to Penetrate the Blood-Brain Barrier

Bioactive peptides, derived from short protein fragments, are recognized for their neuroprotective properties and potential therapeutic applications in treating central nervous system (CNS) diseases. However, a significant challenge for these peptides is their ability to penetrate the blood-brain barrier (BBB). EVSGPGYSPN (EV-10) peptide, a walnut-derived peptide, has demonstrated promising neuroprotective effects in vivo. This study aimed to investigate the transportability of EV-10 across the BBB, explore its capacity to penetrate this barrier, and elucidate the regulatory mechanisms underlying peptide-induced cellular internalization and transport pathways within the BBB. The results indicated that at a concentration of 100 μM and osmotic time of 4 h, the apparent permeability coefficient of EV-10 was Papp = 8.52166 ± 0.58 × 10-6 cm/s. The penetration efficiency of EV-10 was influenced by time, concentration, and temperature. Utilizing Western blot analysis, immunofluorescence, and flow cytometry, in conjunction with the caveolin (Cav)-specific inhibitor M-β-CD, we confirmed that EV-10 undergoes transcellular transport through a Cav-dependent endocytosis pathway. Notably, the tight junction proteins ZO-1, occludin, and claudin-5 were not disrupted by EV-10. Throughout its transport, EV-10 was localized within the mitochondria, Golgi apparatus, endoplasmic reticulum, lysosomes, endosomes, and cell membranes. Moreover, Cav-1 overexpression facilitated the release of EV-10 from lysosomes. Evidence of EV-10 accumulation was observed in mouse brains using brain slice scans. This study is the first to demonstrate that Cav-1 can facilitate the targeted delivery of walnut-derived peptide to the brain, laying a foundation for the development of functional foods aimed at CNS disease intervention.

The communication mechanism of the gut-brain axis and its effect on central nervous system diseases: A systematic review

Gut microbiota is involved in intricate and active metabolic processes the host's brain function, especially its role in immune responses, secondary metabolism, and symbiotic connections with the host. Gut microbiota can promote the production of essential metabolites, neurotransmitters, and other neuroactive chemicals that affect the development and treatment of central nervous system diseases. This article introduces the relevant pathways and manners of the communication between the brain and gut, summarizes a comprehensive overview of the current research status of key gut microbiota metabolites that affect the functions of the nervous system, revealing those adverse factors that affect typical communication between the brain-gut axis, and outlining the efforts made by researchers to alleviate these neurological diseases through targeted microbial interventions. The relevant pathways and manners of communication between the brain and gut contribute to the experimental design of new treatment plans and drug development. The factors that may cause changes in gut microbiota and affect metabolites, as well as current intervention methods are summarized, which helps improve gut microbiota brain dialogue, prevent adverse triggering factors from interfering with the gut microbiota system, and minimize neuropathological changes.

A Mixture of Soybean Oil and Lard Alleviates Postpartum Cognitive Impairment via Regulating the Brain Fatty Acid Composition and SCFA/ERK(1/2)/CREB/BDNF Pathway

Lard is highly appreciated for its flavor. However, it has not been elucidated how to consume lard while at the same time eliminating its adverse effects on postpartum cognitive function. Female mice were divided into three groups (n = 10): soybean oil (SO), lard oil (LO), and a mixture of soybean oil and lard at a ratio of 1:1 (LS). No significant difference was observed between the SO and LS groups in behavioral testing of the maternal mice, but the LO group was significantly worse compared with these two groups. Moreover, the SO and LS supplementation increased docosahexaenoic acid (DHA) and total n-3 polyunsaturated fatty acid (PUFA) levels in the brain and short-chain fatty acid (SCFA)-producing bacteria in feces, thereby mitigating neuroinflammation and lowering the p-ERK(1/2)/ERK(1/2), p-CREB/CREB, and BDNF levels in the brain compared to the LO group. Collectively, the LS group inhibited postpartum cognitive impairment by regulating the brain fatty acid composition, neuroinflammation, gut microbiota, and the SCFA/ERK(1/2)/CREB/BDNF signaling pathway compared to lard.

Research progress on intestinal microbiota regulating cognitive function through the gut-brain axis

The intestinal microbiota community is a fundamental component of the human body and plays a significant regulatory role in maintaining overall health and in the management disease states.The intestinal microbiota-gut-brain axis represents a vital connection in the cognitive regulation of the central nervous system by the intestinal microbiota.The impact of intestinal microbiota on cognitive function is hypothesized to manifest through both the nervous system and circulatory system. Imbalances in intestinal microbiota during the perioperative period could potentially contribute to perioperative neurocognitive dysfunction. This article concentrates on a review of existing literature to explore the potential influence of intestinal microbiota on brain and cognitive functions via the nervous and circulatory systems.Additionally, it summarizes recent findings on the impact of perioperative intestinal dysbacteriosis on perioperative neurocognitive dysfunction and suggests novel approaches for prevention and treatment of this condition.

Prodromic Inflammatory-Oxidative Stress in Peritoneal Leukocytes of Triple-Transgenic Mice for Alzheimer's Disease

Inflammatory-oxidative stress is known to be pivotal in the pathobiology of Alzheimer's disease (AD), but the involvement of this stress at the peripheral level in the disease's onset has been scarcely studied. This study investigated the pro-inflammatory profile and oxidative stress parameters in peritoneal leukocytes from female triple-transgenic mice for AD (3xTgAD) and non-transgenic mice (NTg). Peritoneal leukocytes were obtained at 2, 4, 6, 12, and 15 months of age. The concentrations of TNFα, INFγ, IL-1β, IL-2, IL-6, IL-17, and IL-10 released in cultures without stimuli and mitogen concanavalin A and lipopolysaccharide presence were measured. The concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), lipid peroxidation, and Hsp70 were also analyzed in the peritoneal cells. Our results showed that although there was a lower release of pro-inflammatory cytokines by 3xTgAD mice, this response was uncontrolled and overstimulated, especially at a prodromal stage at 2 months of age. In addition, there were lower concentrations of GSH in leukocytes from 3xTgAD and higher amounts of lipid peroxides at 2 and 4 months, as well as, at 6 months, a lower concentration of Hsp70. In conclusion, 3xTgAD mice show a worse pro-inflammatory response and higher oxidative stress than NTg mice during the prodromal stages, potentially supporting the idea that Alzheimer's disease could be a consequence of peripheral alteration in the leukocyte inflammation-oxidation state.

Effects of exoskeleton-assisted walking on bowel function in motor-complete spinal cord injury patients: involvement of the brain-gut axis, a pilot study

Evidence has demonstrated that exoskeleton robots can improve intestinal function in patients with spinal cord injury (SCI). However, the underlying mechanisms remain unelucidated. This study investigated the effects of exoskeleton-assisted walking (EAW) on intestinal function and intestinal flora structure in T2-L1 motor complete paraplegia patients. The results showed that five participants in the EAW group and three in the conventional group reported improvements in at least one bowel management index, including an increased frequency of bowel evacuations, less time spent on bowel management per day, and less external assistance (manual digital stimulation, medication, and enema usage). After 8 weeks of training, the amount of glycerol used in the EAW group decreased significantly (p <0.05). The EAW group showed an increasing trend in the neurogenic bowel dysfunction (NBD) score after 8 weeks of training, while the conventional group showed a worsening trend. Patients who received the EAW intervention exhibited a decreased abundance of Bacteroidetes and Verrucomicrobia, while Firmicutes, Proteobacteria, and Actinobacteria were upregulated. In addition, there were decreases in the abundances of Bacteroides, Prevotella, Parabacteroides, Akkermansia, Blautia, Ruminococcus 2, and Megamonas. In contrast, Ruminococcus 1, Ruminococcaceae UCG002, Faecalibacterium, Dialister, Ralstonia, Escherichia-Shigella, and Bifidobacterium showed upregulation among the top 15 genera. The abundance of Ralstonia was significantly higher in the EAW group than in the conventional group, and Dialister increased significantly in EAW individuals at 8 weeks. This study suggests that EAW can improve intestinal function of SCI patients in a limited way, and may be associated with changes in the abundance of intestinal flora, especially an increase in beneficial bacteria. In the future, we need to further understand the changes in microbial groups caused by EAW training and all related impact mechanisms, especially intestinal flora metabolites. Clinical trial registration: https://www.chictr.org.cn/.

Fasting mimicking diet extends lifespan and improves intestinal and cognitive health

Caloric restriction is an effective means of extending a healthy lifespan. Fasting mimicking diet (FMD) is a growing pattern of caloric restriction. We found that FMD significantly prolonged the lifespan of prematurely aging mice. In naturally aging mice, FMD improved cognitive and intestinal health. Through a series of behavioral experiments, we found that FMD relieved anxiety and enhanced cognition in aged mice. In the intestine, the FMD cycles enhanced the barrier function, reduced senescence markers, and maintained T cell naïve-memory balance in the lamina propria mucosa. To further explore the causes of immune alterations, we examined changes in the stool microbiota using 16S rRNA sequencing. We found that FMD remodeled gut bacterial composition and significantly expanded the abundance of Lactobacillus johnsonii. Our research revealed that FMD has in-depth investigative value as an anti-aging intervention for extending longevity and improving cognition, intestinal function, and gut microbiota composition.

Regulatory effect of Ganoderma lucidum and its active components on gut flora in diseases

Driven by the good developmental potential and favorable environment at this stage, Ganoderma lucidum is recognized as a precious large fungus with medicinal and nutritional health care values. Among them, polysaccharides, triterpenoids, oligosaccharides, trace elements, etc. are important bioactive components in G. lucidum. These bioactive components will have an impact on gut flora, thus alleviating diseases such as hyperglycemia, hyperlipidemia and obesity caused by gut flora disorder. While numerous studies have demonstrated the ability of G. lucidum and its active components to regulate gut flora, a systematic review of this mechanism is currently lacking. The purpose of this paper is to summarize the regulatory effects of G. lucidum and its active components on gut flora in cardiovascular, gastrointestinal and renal metabolic diseases, and summarize the research progress of G. lucidum active components in improving related diseases by regulating gut flora. Additionally, review delves into the principle by which G. lucidum and its active components can treat or assist treat diseases by regulating gut flora. The research progress of G. lucidum in intestinal tract and its potential in medicine, health food and clinical application were fully explored for researchers.

Gut microbiota composition is altered in postural orthostatic tachycardia syndrome and post-acute COVID-19 syndrome

Postural Orthostatic Tachycardia Syndrome (POTS) reflects an autonomic dysfunction, which can occur as a complication to COVID-19. Our aim was to examine gastrointestinal symptoms and gut microbiota composition in patients with POTS and post-acute COVID-19 syndrome (PACS), compared with controls. POTS patients (n = 27), PACS patients (n = 32) and controls (n = 39) delivered fecal samples and completed a 4-day food diary, irritable bowel syndrome-severity scoring system (IBS-SSS), and visual analog scale for IBS (VAS-IBS). A total of 98 DNA aliquots were sequenced to an average depth of 28.3 million (M) read pairs (Illumina 2 × 150 PE) per sample. Diversity and taxonomic levels of the microbiome, as well as functional abundances were calculated for POTS and PACS groups, then compared with controls. There were several differences in taxonomic composition between POTS and controls, whereas only the abundance of Ascomycota and Firmicutes differed between PACS and controls. The clinical variables total IBS-SSS, fatigue, and bloating and flatulence significantly correlated with multiple individual taxa abundances, alpha diversity, and functional abundances. We conclude that POTS, and to a less extent PACS, are associated with differences in gut microbiota composition in diversity and at several taxonomic levels. Clinical symptoms are correlated with both alpha diversity and taxonomic and functional abundances.

Treatment of preterm brain injury via gut-microbiota-metabolite-brain axis

BACKGROUND

Brain injury in preterm infants potentially disrupts critical structural and functional connective networks in the brain. It is a major cause of neurological sequelae and developmental deficits in preterm infants. Interesting findings suggest that the gut microbiota (GM) and their metabolites contribute to the programming of the central nervous system (CNS) during developmental stages and may exert structural and functional effects throughout the lifespan.

AIM

To summarize the existing knowledge of the potential mechanisms related to immune, endocrine, neural, and blood-brain barrier (BBB) mediated by GM and its metabolites in neural development and function.

METHODS

We review the recent literature and included 150 articles to summarize the mechanisms through which GM and their metabolites work on the nervous system. Potential health benefits and challenges of relevant treatments are also discussed.

RESULTS

This review discusses the direct and indirect ways through which the GM may act on the nervous system. Treatment of preterm brain injury with GM or related derivatives, including probiotics, prebiotics, synbiotics, dietary interventions, and fecal transplants are also included.

CONCLUSION

This review summarizes mechanisms underlying microbiota-gut-brain axis and novel therapeutic opportunities for neurological sequelae in preterm infants. Optimizing the initial colonization and microbiota development in preterm infants may represent a novel therapy to promote brain development and reduce long-term sequelae.

Gut Microbiota as a Modifier of Huntington's Disease Pathogenesis

Huntingtin (HTT) protein is expressed in most cell lineages, and the toxicity of mutant HTT in multiple organs may contribute to the neurological and psychiatric symptoms observed in Huntington's disease (HD). The proteostasis and neurotoxicity of mutant HTT are influenced by the intracellular milieu and responses to environmental signals. Recent research has highlighted a prominent role of gut microbiota in brain and immune system development, aging, and the progression of neurological disorders. Several studies suggest that mutant HTT might disrupt the homeostasis of gut microbiota (known as dysbiosis) and impact the pathogenesis of HD. Dysbiosis has been observed in HD patients, and in animal models of the disease it coincides with mutant HTT aggregation, abnormal behaviors, and reduced lifespan. This review article aims to highlight the potential toxicity of mutant HTT in organs and pathways within the microbiota-gut-immune-central nervous system (CNS) axis. Understanding the functions of Wild-Type (WT) HTT and the toxicity of mutant HTT in these organs and the associated networks may elucidate novel pathogenic pathways, identify biomarkers and peripheral therapeutic targets for HD.