Intestinal microbiota shapes gut physiology and regulates enteric neurons and glia

T cells regulate intestinal motility and shape enteric neuronal responses to intestinal microbiota

How the gut microbiota and immune system maintain intestinal homeostasis in concert with the enteric nervous system (ENS) remains incompletely understood. To address this gap, we assessed small intestinal transit, enteric neuronal density, enteric neurogenesis, intestinal microbiota, immune cell populations and cytokines in wildtype and T-cell deficient germ-free mice colonized with specific pathogen-free (SPF) microbiota, conventionally raised SPF and segmented filamentous bacteria (SFB)-monocolonized mice. SPF microbiota increased small intestinal transit in a T cell-dependent manner. SPF microbiota increased neuronal density in the myenteric and submucosal plexuses of the ileum and colon, similar to conventionally raised SPF mice, independently of T cells. SFB increased neuronal density in the ileum in a T cell-dependent manner, but independently of T cells in the colon. SPF microbiota stimulated enteric neurogenesis (Sox2 expression in enteric neurons) in the ileum in a T cell-dependent manner, but in the colon this effect was T cell-independent. T cells regulated nestin expression in the ENS. SPF colonization increased Th17 cells, RORγT+ Treg cells, and IL-1β and IL-17A levels in the ileum and colon. By neutralizing IL-1β and IL-17A, we observed that they control microbiota-mediated enteric neurogenesis but were not involved in the regulation of motility. Together, these findings provide new insights into the microbiota-neuroimmune dialog that regulates intestinal physiology.

Gut microbial dysbiosis exacerbates long-term cognitive impairments by promoting intestinal dysfunction and neuroinflammation following neonatal hypoxia-ischemia

Neonatal hypoxic-ischemic brain damage (HIBD) is considered as a major cause of long-term cognitive impairments in newborns. It has been demonstrated that gut microbiota is closely associated with the prognosis of various neurological disorders. However, the role of microbiota-gut-brain axis on cognitive function following neonatal HIBD remains elusive. In this experiment, the correlation analysis supported the involvement of gut microbial changes following hypoxic-ischemic (HI) insult in the development of long-term cognitive impairments. Subsequent experiment revealed the involvement of the intestinal dysfunction in the hippocampal neuroinflammation and synaptic injury. In causal relationship validation experiments, fecal microbiota transplantation (FMT) from cognitively normal rats could restore gut microbial composition, improve intestinal dysfunction, reduce the serum levels of lipopolysaccharides (LPS) and inflammatory mediators, and alleviate neuroinflammation, synaptic damage and cognitive impairments in neonatal HIBD recipient rats. Conversely, the FMT from neonatal HIBD rats could induce above adverse pathological changes in the normal recipient rats. Moreover, oral administration of anti-inflammatory agent dexamethasone (DEX) exhibited the potential to alleviate these detrimental effects in neonatal HIBD rats, with the efficacy being partly reliant on gut microbiota. Further experiment on the potential molecular mechanisms using RNA sequencing indicated a significant increase in the toll-like receptor 4 (TLR4) gene in the intestinal tissues of neonatal HIBD rats. Additionally, the interventions such as TLR4 inhibitor TLR4-IN-C34 administration, FMT, and oral DEX were demonstrated to modulate intestinal function by inhibiting the LPS/TLR4 signaling pathway, thereby exerting neuroprotective effects. Collectively, these findings underscore the contribution of gut microbial dysbiosis post HI insult in activating the LPS/TLR4 signaling pathway, triggering intestinal inflammation and dysfunction, exacerbating systemic inflammation, and consequently worsening synaptic and cognitive impairments in neonatal HIBD rats. Hence, rectifying gut microbial dysbiosis or regulating intestinal function may represent a promising strategy for alleviating long-term cognitive impairments in neonates affected by HIBD.

Linking depression and neuroinflammation: Crosstalk between glial cells

The inflammatory hypothesis is one of the more widely accepted pathogenesis of depression. Glia plays an important immunomodulatory role in neuroinflammation, mediating interactions between the immune system and the central nervous system (CNS). Glial cell-driven neuroinflammation is not only an important pathological change in depression, but also a potential therapeutic target. This review discusses the association between depression and glial cell-induced neuroinflammation and elucidates the role of glial cell crosstalk in neuroinflammation. Firstly, we focus on the role of glial cells in neuroinflammation in depression and glial cell interactions; secondly, we categorize changes in different glial cells in animal models of depression and depressed patients, focusing on how glial cells mediate inflammatory responses and exacerbate depressive symptoms; Thirdly, we review how conventional and novel antidepressants affect the phenotype and function of glial cells, thereby exerting anti-inflammatory activity; finally, we discuss the role of the gut-brain axis in glial cell function and depression, and objectively analyze the problems that remain in current antidepressant therapy. This review aims to provide an objective analysis of how glial cell cross-talk may mediate neuroinflammation and thereby influence pathologic progression of depression. It is concluded that a novel therapeutic strategy may be to ameliorate glial cell-mediated inflammatory responses.

Interaction between nutritional factors and the enteric nervous system in inflammatory bowel diseases

The enteric nervous system (ENS) is a highly conserved, yet complicated network of neurons and glial cells located throughout the gut wall that controls digestive processes and gastrointestinal (GI) homeostasis. The intestinal epithelium, the immune system, and the gut microbiota are just a few examples of the cellular networks that the ENS interacts with on a variety of levels to maintain GI function. The presence or absence of nutrients in the intestinal lumen may cause short- and/or long-term changes in neurotransmitter expression, excitability, and neuronal survival, which ultimately affect gut motility, secretion, and permeability. Hence, the ENS should be identified as a key factor in initiating coordinated responses to nutrients. In this review we summarize current knowledge on nutrient-dependent ENS activity and how ENS secondary to nutrition may affect likelihood of developing inflammatory bowel disease. Our findings highlight that nutrients interact with enteroendocrine cells in the gut, triggering hormone secretion that plays a crucial role in signaling food-related information to the brain and regulating metabolic processes such as feeding behavior, insulin secretion, and energy balance; however, the complex interactions between nutrients, the ENS, and the immune system require further research to understand their contributions to GI disorders and potential therapeutic applications in treating obesity and metabolic diseases. Lay Summary: The enteric nervous system (ENS) controls digestion and interacts with nutrients in the gut to regulate processes like gut movement and hormone release, affecting metabolism and overall gut health. This review highlights the need for further research on how nutrient-ENS interactions contribute to conditions like inflammatory bowel disease, obesity, and metabolic disorders.

An inulin-type fructan CP-A from Codonopsis pilosula combined with 5-Fluorouracil alleviates colitis-associated tumorigenesis via inhibition of EGFR/AKT/ERK signaling pathway and regulation of intestinal flora

Inulin-type fructan CP-A, the main component of Codonopsis pilosula polysaccharides, has been found to have therapeutic effects on ulcerative colitis (UC). Herein, we established a colitis-associated cancer (CAC) mouse model by azomethane (AOM) and dextran sulfate sodium (DSS) and selected mouse colon cancer cells CT-26 to explore the therapeutic effects of the combined administration of CP-A and 5-fluorouracil (5-FU) in vivo and in vitro. High-throughput transcriptomics sequencing technology was used to identify differentially expressed genes (DEGs) in the mouse colon and enrich related pathways. 16S rRNA gene sequencing technology was used for gut microbiota research to identify microbial changes in mouse feces. Short-chain fatty acid (SCFA) content was identified in the mouse colon using gas chromatography-mass spectroscopy (GC-MS). In vivo experiments showed that compared with untreated CAC mice, those treated with the combined administration of CP-A and 5-FU had significantly restored body weight, fewer tumors, smaller tumor volume, and reduced disease activity index (DAI) and histopathological scores. The combination of CP-A and 5-FU increased the anti-inflammatory cytokine interleukin 10 (IL-10) and inhibited the expression of pro-inflammatory cytokines interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ). In vitro experiments indicated that a combination of CP-A and 5-FU promoted the apoptosis of CT-26 cells. The results of transcriptomics studies suggested that the therapeutic effect of the combined administration of CP-A and 5-FU on CAC may be related to the EGFR/AKT/ERK pathway. Both in vivo and in vitro experiments verified the regulatory effect of the combined administration of CP-A and 5-FU on the EGFR/AKT/ERK pathway. Moreover, the intestinal flora experiment manifested that compared with untreated CAC mice, the combined CP-A and 5-FU group had a more stable intestinal microbiota composition, and the combined administration of CP-A and 5-FU increased the abundance of SCFAs. Our experimental findings have demonstrated that the combination of CP-A and 5-FU exhibits promising efficacy in the treatment of CAC, warranting further clinical investigation in the future.

Intestinal-region-specific functions of AHR in intrinsic enteric neurons during infections

Intrinsic enteric neurons (iENs) form a crucial neuronal network within the myenteric and submucosal plexus of the gastrointestinal tract, primarily responsible for regulating gut peristalsis. The mechanisms by which iENs sense and integrate dietary and microbial signals to regulate intestinal homeostasis and inflammation remain unclear. Here, we showed that environmental sensor aryl hydrocarbon receptor (AHR) was expressed in different iEN subsets in the ileum and colon and that AHR ligands differentially modulated iEN activity in these regions. Genetic perturbation of Ahr in neurons increased iEN activation in the ileum but, conversely, decreased it in the colon in response to different intestinal pathogens. Furthermore, neuronal AHR deficiency enhanced the clearance of bacterial pathogens, which was associated with increased proliferation and abundance of group 3 innate lymphoid cells in the ileum. Together, our findings demonstrate the region-specific functions of AHR in neurons in response to infections.

The Impact of Antibiotic Therapy on Intestinal Microbiota: Dysbiosis, Antibiotic Resistance, and Restoration Strategies

The human gut microbiota-an intricate and dynamic ecosystem-plays a pivotal role in metabolic regulation, immune modulation, and the maintenance of intestinal barrier integrity. Although antibiotic therapy is indispensable for managing bacterial infections, it profoundly disrupts gut microbial communities. Such dysbiosis is typified by diminished diversity and shifts in community structure, especially among beneficial bacterial genera (e.g., Bifidobacterium and Eubacterium), and fosters antibiotic-resistant strains and the horizontal transfer of resistance genes. These alterations compromise colonization resistance, increase intestinal permeability, and amplify susceptibility to opportunistic pathogens like Clostridioides difficile. Beyond gastrointestinal disorders, emerging evidence associates dysbiosis with systemic conditions, including chronic inflammation, metabolic syndrome, and neurodegenerative diseases, underscoring the relevance of the microbiota-gut-brain axis. The recovery of pre-existing gut communities post-antibiotic therapy is highly variable, influenced by drug spectrum, dosage, and treatment duration. Innovative interventions-such as fecal microbiota transplantation (FMT), probiotics, synbiotics, and precision microbiome therapeutics-have shown promise in counteracting dysbiosis and mitigating its adverse effects. These therapies align closely with antibiotic stewardship programs aimed at minimizing unnecessary antibiotic use to preserve microbial diversity and curtail the spread of multidrug-resistant organisms. This review emphasizes the pressing need for microbiota-centered strategies to optimize antibiotic administration, promote long-term health resilience, and alleviate the disease burden associated with antibiotic-induced dysbiosis.

Prolonged postweaning protein restriction induces gut dysbiosis and colonic dysfunction in male mice

Insufficient or imbalanced protein can disrupt gut microbiota, potentially compromising gut barrier function and increasing health risks. Herein, we investigated the effects of protein restriction on cecal microbiota and colon morphofunction in male mice. From 30 to 120 days of age, C57Bl/6 mice were fed a control protein diet [14% protein, control (C) group] or a low-protein diet [6% protein, protein-restricted (R) group]. At the end of the experimental period, R mice exhibited typical features of undernutrition, such as reduced body weight, hypoalbuminemia, and hypoproteinemia. In addition, despite the hyperphagia displayed in the R group, these mice presented a decreased amount of excreted feces and less energy content in feces. Cecal microbiota analysis demonstrated that protein restriction led to reductions in Shannon and Simpson indices and, therefore, dysbiosis. This effect was accompanied by morphological modifications in the proximal colon of R mice, such as 1) reduction in the total area of neurons of myenteric plexus; 2) increased number of goblet cells, with mucin droplets less developed; 3) reductions in crypt depth and diameter; 4) decreases in gene expressions for mucins and in the tight junction proteins expression; 5) enhanced paracellular permeability and expression of pro-inflammatory cytokines (tumor necrosis factor α, toll-like receptor 4, interferon γ, interleukin 1β, and interleukin 6), decreased anti-inflammatory cytokines (interleukins 4 and 10) in the colon, and increased plasma LPS binding protein concentrations. Therefore, protein restriction induced gut dysbiosis and may result in structural and functional negative impacts on the proximal colon barrier against luminal bacteria.NEW & NOTEWORTHY Prolonged postweaning protein restriction induced gut dysbiosis and led to a reduced neuron area in the myenteric plexus, with increased but underdeveloped goblet cells. Protein restriction decreased colonic crypt depth and diameter, and increased paracellular permeability due to lower expression of mucin-related genes and tight junction proteins. The diminished barrier function resulted in systemic inflammation, evidenced by elevated plasma LPS-binding protein and pro-inflammatory markers in the colon.

Enteric Glia

Enteric glia are a unique type of peripheral neuroglia that accompany neurons in the enteric nervous system (ENS) of the digestive tract. The ENS displays integrative neural circuits that are capable of governing moment-to-moment gut functions independent of input from the central nervous system. Enteric glia are interspersed with neurons throughout these intrinsic gut neural circuits and are thought to fulfill complex roles directed at maintaining homeostasis in the neuronal microenvironment and at neuroeffector junctions in the gut. Changes to glial functions contribute to a wide range of gastrointestinal diseases, but the precise roles of enteric glia in gut physiology and pathophysiology are still under examination. This review summarizes current concepts regarding enteric glial development, diversity, and functions in health and disease.

Evaluation of the therapeutic effect of pomegranate peel ginger ultrafine powder on chronic enteritis in mice by regulating intestinal microbiota

To explore the efficacy and mechanism of Pomegranate peel Ginger ultrafine powder (PG) in treating chronic enteritis in mice. Sixty SPF-grade mice were randomly divided into a blank group, a model group, loperamide hydrochloride group (5 mg/kg), a high-dose PG group (100 mg/kg), a medium-dose group (50 mg/kg), and a low-dose group (25 mg/kg), with 10 mice in each group and an equal number of males and females. A chronic enteritis mouse model was established using a multifactorial method of low temperature + ice water + castor oil. The blank group was given an equal amount of physiological saline intragastrically, while the other groups were intervened with corresponding drugs for 7 consecutive days. After 7 days, samples were collected, and Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of interleuckin 1β (IL-1β), IL-6, and Tumor necrosis factorα(TNF-α) in mouse serum. HE staining was used to examine the pathological changes in the small intestine. oxidative reagent kits were used to detect the content of total superoxide dismutase(T-SOD) and Malondialdehyde (MDA) in the small intestine. Western blot was used to detect the expression of Aquaporin 8(AQP8) proteins in the small intestine. Real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to detect the expression of AQP3, AQP4, AQP8, and Sodium/hydrogen exchanger 8 (NHE8) genes in the small intestine. metagenomics was used to detect the gut microbiota in mouse feces. Compared with the model group, all doses of PG groups reduced the levels of IL-1β, IL-6, and TNF-α in mouse serum (P<0.05), improved pathological changes in the small intestine, increased the content of T-SOD in the small intestine tissue, reduced the content of MDA, increased the expression of AQP4 and AQP8 mRNA, and decreased the expression of AQP3 and NHE8 mRNA (P<0.05), increased the expression of AQP8 protein. PG could improve the pathological changes of chronic enteritis in mice, enhance antioxidant capacity, and alleviate diarrhea caused by chronic enteritis by downregulating the expression of intestinal epithelial transport proteins and acute-phase proteins, and altering gut microbiota.

Intervention and research progress of gut microbiota-immune-nervous system in autism spectrum disorders among students

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by difficulties in social interaction and communication, repetitive and stereotyped behaviors, restricted interests, and sensory abnormalities. Its etiology is influenced by both genetic and environmental factors, with no definitive cause identified and no specific pharmacological treatments available, posing a significant burden on patients' families and society. In recent years, research has discovered that gut microbiota dysbiosis plays a crucial role in the pathogenesis of ASD. The gut microbiota can influence brain function and behavior through the gut-brain axis via the nervous system, immune system, and metabolic pathways. On the one hand, specific gut microbes such as Clostridium and Prevotella species are found to be abnormal in ASD patients, and their metabolic products, like short-chain fatty acids, serotonin, and GABA, are also involved in the pathological process of ASD. On the other hand, ASD patients exhibit immune system dysfunction, with gut immune cells and related cytokines affecting neural activities in the brain. Currently, intervention methods targeting the gut microbiota, such as probiotics, prebiotics, and fecal microbiota transplantation, have shown some potential in improving ASD symptoms. However, more studies are needed to explore their long-term effects and optimal treatment protocols. This paper reviews the mechanisms and interrelationships among gut microbiota, immune system, and nervous system in ASD and discusses the challenges and future directions of existing research, aiming to provide new insights for the prevention and treatment of ASD.

Supplementary Hesperidin Alleviated CPT-11-Induced Diarrhea by Modulating Gut Microbiota and Inhibiting the IL-17 Signaling Pathway

Irinotecan (CPT-11) is a chemotherapy agent commonly used for the treatment of gastrointestinal tumors, with diarrhea being a frequent adverse effect. Hesperidin is a flavonoid abundant in citrus fruits and has shown potential in managing CPT-11-induced diarrhea (CID). However, the mechanisms underlying its effects remain unclear. This study established a mouse model of CID using CPT-11 administration to evaluate the effects of hesperidin on diarrhea severity, intestinal pathology, gut microbiota composition, and metabolite profiles by conducting biochemical analysis, histopathology, immunohistochemistry, 16S rRNA sequencing, and untargeted metabolomics. In addition, transcriptomic analysis, molecular docking, and molecular dynamics simulations were conducted to investigate potential mechanisms of action. Hesperidin supplementation was found to significantly alleviate CID in mice. Analysis of gut microbiota using 16S rRNA sequencing revealed that hesperidin improved microbial composition, with key taxa such as Alistipes, Limosilactobacillus, Rikenella, and Mucispirillum playing a central role in ameliorating CID. Furthermore, hesperidin enhanced intestinal barrier function by upregulating tight junction proteins, mitigating epithelial damage, and reducing the expression of IL-17A, TARF6, p38, phosphorylated-p38 (P-p38), and AP-1 proteins in the colon. These findings suggest that hesperidin supplementation mitigates CID by modulating gut microbiota and inhibiting the IL-17 signaling pathway, thereby improving intestinal barrier integrity.

Bifidobacterium bifidum CCFM1163 alleviates cathartic colon by activating the BDNF-TrkB-PLC/IP3 pathway to reconstruct the intestinal nerve and barrier

Introduction: Cathartic colon (CC) is a type of slow-transit constipation caused by a patient's long-term use of irritating laxatives. Probiotics play a crucial role in managing constipation. Objectives: This study aims to identify probiotics that can alleviate CC and explore their specific mechanisms of action. Methods: The CC-model was constructed using senna leaf extract. Bifidobacterium bifidum was applied to the mice for intervention. Relevant marker changes were then examined using ELISA and RT-qPCR. Furthermore, 16S rDNA sequencing was utilized for functional prediction of intestinal microorganisms, while GC-MS analysis was performed to determine the content of short-chain fatty acids (SCFAs) in feces. Results: Senna damages the intestinal nerve and the intestinal barrier while inducing CC. In contrast, Bifidobacterium bifidum CCFM1163 may enhance the brain-derived neurotrophic factor (BDNF) expression in the colon by altering the intestinal microbiota composition (e.g., increasing Lactobacillus and Bacteroides, and decreasing Faecalibaculum) and by elevating SCFA levels (e.g., acetic and isobutyric acid). Subsequently, elevated BDNF expression activates the BDNF-tyrosine kinase receptor B-phospholipase C/inositol trisphosphate (BDNF-TrkB-PLC/IP3) pathway, which upregulates the gene expression of Uchl1, S100β, and Acta2; repairs the enteric nervous system-interstitial cells of Cajal-smooth muscle cells (ENS-ICC-SMC) network; upregulates the gene expression of Ocln and Tjp1; improves intestinal permeability in CC mice; and modulates the immune response by upregulating Tlr4, downregulating Il1b, and upregulating Il10, ultimately alleviating CC. Conclusion: Bifidobacterium bifidum CCFM1163 was identified as a probiotic that can promote BDNF expression in the colon, activate the BDNF-TrkB-PLC/IP3 signaling pathway, and effectively alleviate CC.

The microbiome's influence on obesity: mechanisms and therapeutic potential

In 2023, the World Obesity Atlas Federation concluded that more than 50% of the world's population would be overweight or obese within the next 12 years. At the heart of this epidemic lies the gut microbiota, a complex ecosystem that profoundly influences obesity-related metabolic health. Its multifaced role encompasses energy harvesting, inflammation, satiety signaling, gut barrier function, gut-brain communication, and adipose tissue homeostasis. Recognizing the complexities of the cross-talk between host physiology and gut microbiota is crucial for developing cutting-edge, microbiome-targeted therapies to address the global obesity crisis and its alarming health and economic repercussions. This narrative review analyzed the current state of knowledge, illuminating emerging research areas and their implications for leveraging gut microbial manipulations as therapeutic strategies to prevent and treat obesity and related disorders in humans. By elucidating the complex relationship between gut microflora and obesity, we aim to contribute to the growing body of knowledge underpinning this critical field, potentially paving the way for novel interventions to combat the worldwide obesity epidemic.

Assessing the impact of moxibustion on colonic mucosal integrity and gut microbiota in a rat model of cerebral ischemic stroke: insights from the "brain-gut axis" theory

Objective

The aim of this study is to assess the impact of moxibustion on the colonic mucosal barrier and gut microbiota in a rat model of cerebral ischemic stroke (CIS).

Method

The CIS rat model was established using the modified Zea Longa suture method. Successfully modeled rats were randomly allocated into a model group and a moxibustion group, with a sham surgery group serving as the control. The moxibustion group received suspended moxibustion at Dazhui (GV 14), Baihui (GV 20), Fengfu (GV 16), and bilateral Tianshu (ST 25) and Shangjuxu (ST 37) acupoints. Neurological function was assessed using the Longa score, and brain infarct size was assessed through 2,3,5-triphenyl tetrazolium chloride staining. Gut microbiota composition was analyzed using 16S rDNA amplification sequencing. Intestinal mucosal permeability was evaluated using the FITC-Dextran tracer method. The serum ET-1 levels and the expression of Occludin and ZO-1 proteins in colonic tissues were also measured.

Result

The model group exhibited significantly higher Longa scores, larger brain infarct size, and higher serum FITC-Dextran levels and ET-1 levels when compared with the sham surgery group (p < 0.01). The model group demonstrated decreased expression of Occludin and ZO-1 in colonic tissues (p < 0.01) and changes in gut microbiota structure. When compared to the model group, the moxibustion group demonstrated significantly lower Longa scores, smaller brain infarct size, and lower serum FITC-Dextran levels and ET-1 levels (p < 0.05). Furthermore, the moxibustion group demonstrated decreased inflammatory cell infiltration in colonic tissues, increased expression of Occludin and ZO-1 proteins in colonic tissues (p < 0.05), enhanced gut microbiota structure, and a decreased Simpson index (p < 0.05).

Conclusion

Moxibustion can improve the neurological dysfunction in CIS model rats. The mechanism may be associated with the improvement in gut microbiota dysbiosis, reduction in colonic mucosal permeability, and restoration of intestinal mucosal barrier damage.

Acetate and propionate vs. iTBS as a novel method for cognitive dysfunction and anxiety symptoms in delayed encephalopathy after acute carbon monoxide poisoning rat

Background

The optimal treatment methods for delayed encephalopathy after acute carbon monoxide (CO) poisoning (DEACMP) were not identified. Thus, this study was conducted to compare the efficacies of intermittent theta burst stimulation (iTBS) and short-chain fatty acids (SCFAs) in treating cognitive dysfunction and anxiety symptoms of DEACMP rat.

Methods

In phase I, a DEACMP rat model was built to assess the inflammation levels in the hippocampus and levels of SCFAs in the serum of DEACMP rats. In phase II, DEACMP rats were randomly assigned into four groups: DEACMP + placebo, DEACMP + SCFAs, DEACMP + sham iTBS, and DEACMP + iTBS. The intervention was continued for 2 weeks. A Morris water maze and open field tests were used to assess cognitive function and anxiety symptoms, respectively.

Results

The levels of three inflammatory factors (IL-1β, IL-6, and TNF-α) and two SCFAs (acetate and propionate) were significantly increased and decreased, respectively, in DEACMP rats. After treatment, cognitive dysfunction and anxiety symptoms were significantly improved in the DEACMP + iTBS group and the DEACMP + SCFAs (consisting of acetate and propionate) group. Both SCFAs and iTBS could significantly improve the increased levels of IL-1β, IL-6, and TNF-α in the hippocampus, and SCFAs could also improve the decreased levels of GPR41, GPR43, dopamine, and norepinephrine in the hippocampus of DEACMP rats.

Conclusion

These results indicate that both iTBS and SCFA solutions consisting of acetate and propionate produced good effects on DEACMP rats by regulating inflammation levels in the hippocampus, and acetate/propionate-GPR41/GPR43-IL-1β/IL-6/TNF-α-dopamine/norepinephrine may be a potential pathway in SCFAs for the treatment of DEACMP.

Gut microbiota: A new window for the prevention and treatment of neuropsychiatric disease

Under normal physiological conditions, gut microbiota and host mutually coexist. They play key roles in maintaining intestinal barrier integrity, absorption, and metabolism, as well as promoting the development of the central nervous system (CNS) and emotional regulation. The dysregulation of gut microbiota homeostasis has attracted significant research interest, specifically in its impact on neurological and psychiatric disorders. Recent studies have highlighted the important role of the gut- brain axis in conditions including Alzheimer's Disease (AD), Parkinson's Disease (PD), and depression. This review aims to elucidate the regulatory mechanisms by which gut microbiota affect the progression of CNS disorders via the gut-brain axis. Additionally, we discuss the current research landscape, identify gaps, and propose future directions for microbial interventions against these diseases. Finally, we provide a theoretical reference for clinical treatment strategies and drug development for AD, PD, and depression.

[Thesium chinense Turcz. alleviates antibiotic-associated diarrhea in mice by modulating gut microbiota structure and regulating the EGFR/PI3K/Akt signaling pathway]

OBJECTIVES

To investigate the therapeutic mechanism of Thesium chinense Turcz. (TCT) for antibiotic-associated diarrhea (AAD).

METHODS

Network pharmacology, KEGG pathway enrichment analysis and molecular docking were used to identify the shared targets and genes of TCT and AAD, the key signaling pathways and the binding between the active components in TCT and the core protein targets. In a Kunming mouse model of AAD established by intragastric administration of lincomycin hydrochloride, the effects of daily gavage of 1% carboxymethyl cellulose sodium or TCT gel solutions at 1.5 g/kg and 3 g/kg (n=10) on body weight and diarrhea were observed. HE staining, ELISA, 16S rRNA sequencing, and Western blotting were used to examine pathologies, expression levels of IL-6 and TNF-α, changes in gut microbiota, and protein expressions of EGFR, p-EGFR, PI3K, p-PI3K, Akt, and p-Akt in the colon tissues of the mice.

RESULTS

We identified a total of 66 active components of TCT and 68 core targets including EGFR, STAT3 and PIK3CA. KEGG pathway enrichment analysis suggested that the therapeutic effects of TCT was mediated primarily through the PI3K/Akt signaling pathway. Molecular docking showed that EGFR had the highest binding affinity with coniferin, and the EGFR-coniferin complex maintained a stable conformation at 10 ns, whose stability was also confirmed by Gibbs free energy analysis. In the mouse models of AAD, treatment with TCT significantly improved colonic tissue morphology, decreased colonic levels of TNF-α and IL-6, increased gut microbiota diversity, and modulated the relative abundances of the key genera including Lactobacillus and Bacteroides. TCT treatment also markedly reduced protein expressions of p-EGFR, p-PI3K and p-Akt in the colon tissues of the mice.

CONCLUSIONS

TCT can alleviate AAD in mice by modulating gut microbiota composition, regulating the EGFR/PI3K/Akt signaling pathway, and reducing TNF‑α and IL-6 expressions.

Synergistic interactions between gut microbiota and short chain fatty acids: Pioneering therapeutic frontiers in chronic disease management

Microorganisms in the gut play a pivotal role in human health, influencing various pathophysiological processes. Certain microorganisms are particularly essential for maintaining intestinal homeostasis, reducing inflammation, supporting nervous system function, and regulating metabolic processes. Short-chain fatty acids (SCFAs) are a subset of fatty acids produced by the gut microbiota (GM) during the fermentation of indigestible polysaccharides. The interaction between GM and SCFAs is inherently bidirectional: the GM not only shapes SCFAs composition and metabolism but SCFAs also modulate microbiota's diversity, stability, growth, proliferation, and metabolism. Recent research has shown that GM and SCFAs communicate through various pathways, mainly involving mechanisms related to inflammation and immune responses, intestinal barrier function, the gut-brain axis, and metabolic regulation. An imbalance in GM and SCFA homeostasis can lead to the development of several chronic diseases, including inflammatory bowel disease, colorectal cancer, systemic lupus erythematosus, Alzheimer's disease, and type 2 diabetes mellitus. This review explores the synergistic interactions between GM and SCFAs, and how these interactions directly or indirectly influence the onset and progression of various diseases through the regulation of the mechanisms mentioned above.

Treating chronic stress and chronic pain by manipulating gut microbiota with diet: can we kill two birds with one stone?

Background: Chronic stress and chronic pain are closely linked by the capacity to exacerbate each other, sharing common roots in the brain and in the gut. The strict intersection between these two neurological diseases makes important to have a therapeutic strategy aimed at preventing both to maintain mental health in patients. Diet is an modifiable lifestyle factor associated with gut-brain axis diseases and there is growing interest in its use as adjuvant to main therapies. Several evidence attest the impact of specific diets or nutrients on chronic stress-related disorders and pain with a good degree of certainty. A daily adequate intake of foods containing micronutrients such as amino acids, minerals and vitamins, as well as the reduction in the consumption of processed food products can have a positive impact on microbiota and gut health. Many nutrients are endowed of prebiotic, anti-inflammatory, immunomodulatory and neuroprotective potential which make them useful tools helping the management of chronic stress and pain in patients. Dietary regimes, as intermittent fasting or caloric restriction, are promising, although further studies are needed to optimize protocols according to patient's medical history, age and sex. Moreover, by supporting gut microbiota health with diet is possible to attenuate comorbidities such as obesity, gastrointestinal dysfunction and mood disorders, thus reducing healthcare costs related to chronic stress or pain.Objective: This review summarize the most recent evidence on the microbiota-mediated beneficial effects of macro- and micronutrients, dietary-related factors, specific nutritional regimens and dietary intervention on these pathological conditions.

Aromatic Amino Acid Metabolites: Molecular Messengers Bridging Immune-Microbiota Communication

Aromatic amino acid (AAA) metabolites, derived from tryptophan, phenylalanine, and tyrosine through coordinated host and microbial metabolism, have emerged as critical modulators of immune function. We examine the complex journey of AAAs from dietary intake through intestinal absorption and metabolic transformation, highlighting the crucial role of host-microbe metabolic networks in generating diverse immunomodulatory compounds. This review provides a unique integrative perspective by mapping the molecular mechanisms through which these metabolites orchestrate immune responses. Through detailed analysis of metabolite-receptor and metabolite-transporter interactions, we reveal how specific molecular recognition drives cell type-specific immune responses. Our comprehensive examination of signaling networks-from membrane receptor engagement to nuclear receptor activation to post-translational modifications- demonstrates how the same metabolite can elicit distinct functional outcomes in different immune cell populations. The context-dependent nature of these molecular interactions presents both challenges and opportunities for therapeutic development, particularly in inflammatory conditions where metabolite signaling pathways are dysregulated. Understanding the complexity of these regulatory networks and remaining knowledge gaps is fundamental for advancing metabolite-based therapeutic strategies in immune-mediated disorders.

Harnessing Gut Microbiota for Biomimetic Innovations in Health and Biotechnology

The gut microbiota is a complex and dynamic ecosystem that plays a fundamental role in human health by regulating immunity, metabolism, and the gut-brain axis. Beyond its critical physiological functions, it has emerged as a rich source of inspiration for biomimetic innovations in healthcare and biotechnology. This review explores the transformative potential of microbiota-based biomimetics, focusing on key biological mechanisms such as resilience, self-regulation, and quorum sensing. These mechanisms have inspired the development of innovative applications, including personalized probiotics, synbiotics, artificial microbiomes, bioinspired biosensors, and bioremediation systems. Such technologies aim to emulate and optimize the intricate functions of microbial ecosystems, addressing challenges in healthcare and environmental sustainability. The integration of advanced technologies, such as artificial intelligence, bioengineering, and multi-omics approaches, has further accelerated the potential of microbiota biomimetics. These tools enable the development of precision therapies tailored to individual microbiota profiles, enhance the efficacy of diagnostic systems, and facilitate the design of environmentally sustainable solutions, such as waste-to-energy systems and bioremediation platforms. Emerging areas of innovation, including gut-on-chip models and synthetic biology, offer unprecedented opportunities for studying and applying microbiota principles in controlled environments. Despite these advancements, challenges remain. The replication of microbial complexity in artificial environments, ethical concerns regarding genetically engineered microorganisms, and equitable access to advanced therapies are critical hurdles that must be addressed. This review underscores the importance of interdisciplinary collaboration and public awareness in overcoming these barriers and ensuring the responsible development of microbiota-based solutions. By leveraging the principles of microbial ecosystems, microbiota biomimetics represents a promising frontier in healthcare and sustainability. This approach has the potential to revolutionize therapeutic strategies, redefine diagnostic tools, and address global challenges, paving the way for a more personalized, efficient, and sustainable future in medicine and biotechnology.

Quinazolinone Derivative MR2938 Protects DSS-Induced Barrier Dysfunction in Mice Through Regulating Gut Microbiota

Background/Objectives: Ulcerative colitis (UC), a chronic inflammatory bowel disease (IBD), is characterized by colorectal immune infiltration and significant microbiota compositional changes. Gut microbiota homeostasis is necessary to maintain the healthy state of humans. MR2938, a quinazolin-4(3H)-one derivative derived from the marine natural product penipanoid C, alleviated DSS-induced colitis in a dose-dependent manner. Herein, we aimed to investigate the impact of MR2938 on the gut microbiota in dextran sodium sulfate (DSS)-induced colitis in mice and to elucidate the role of the gut microbiota in the therapeutic mechanism of MR2938 for alleviating colitis. Methods: Acute colitis was induced with DSS in mice. Mice were administered with 100 mg/kg or 50 mg/kg of MR2938. Cecal content was also preserved in liquid nitrogen and subsequently analyzed following 16S RNA sequencing. Antibiotic cocktail-induced microbiome depletion was performed to further investigate the relationship between MR2938 and gut microbiota. The inflammatory factor levels were performed by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Alcian blue staining and immunofluorescence were used to estimate the intestinal barrier. Results: The 16S rRNA sequencing revealed microbiota modulation by MR2938. Compared with the model group, the 100 mg/kg MR2938 group was associated with higher abundances of Entercoccus and a lower abundance of Staphylococcus, while the 50 mg/kg MR2938 group was associated with higher abundances of Lactobacillus and a lower abundance of Staphylococcus. The antibiotic-mediated microbiota depletion experiments demonstrated that the gut microbiota primarily contributed to barrier function protection, with little impact on inflammatory factor levels during the MR2938 treatment. Conclusions: These findings suggest that intestinal flora play a crucial role in MR2938's therapeutic mechanism for alleviating colitis.

Synergistic defecation effects of Bifidobacterium animalis subsp. lactis BL-99 and fructooligosaccharide by modulating gut microbiota

Introduction

Synbiotics have revealed the possibility of improving constipation through gut microbiota. The synergistic efficacy of Bifidobacterium animalis subsp. lactis BL-99 (BL-99) and fructooligosaccharide (FOS) on constipation have not been investigated.

Methods

Loperamide-induced constipated mice model was established to explore the effect of BL-99, FOS, and BL-99+FOS on changes of defecation-related parameters, gut microbiota and metabolites.

Results and discussion

The results showed that BL-99, FOS, and BL-99+FOS each alleviated constipation, with the synbiotic showing significant efficacy in the first black stool defecation time, fecal number, fecal weight, and the gastrointestinal transit rate (P < 0.05). Additionally, significant increased in serum 5-HT and IL-10 were observed in the BL-99+FOS group, alongside an increased relative abundance of Lachnospiraceae_NK4A136_group, Blautia, and Clostridium sensu stricto 1, while significantly reducing the relative abundance of Alistipes and Bacteroides. These changes facilitated alterations in short-chain fatty acids (SCFAs) metabolism, and were closely associated with the expression of genes related to the 5-HT pathway and the modulation of serum inflammatory factors. This study provides a theoretical basis for BL-99 and FOS synbiotics to improve constipation by regulating the gut microbiota and metabolites.

Therapeutic potential of short-chain fatty acids for acute lung injury: a systematic review and meta-analysis of preclinical animal studies

Background

Short-chain fatty acids (SCFAs), derived from the fermentation of dietary fiber by intestinal commensal bacteria, have demonstrated protective effects against acute lung injury (ALI) in animal models. However, the findings have shown variability across different studies. It is necessary to conduct a comprehensive evaluation of the efficacy of these treatments and their consistency.

Objective

This systematic review and meta-analysis aimed to explore the effects of SCFAs on ALI based on preclinical research evidence, in order to provide new treatment strategies for ALI.

Methods

We included studies that tested the effects of SCFAs on ALI in animal models. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search for relevant studies was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases up to February 2024. The data were extracted in accordance with the established selection criteria, and the risk of bias was evaluated for each study.

Results

A total of 16 articles were finally included in the meta-analysis. The results indicated that the SCFAs significantly reduced lung wet-to-dry weight (SMD = -2.75, 95% CI = -3.46 to -2.03, p < 0.00001), lung injury scores (SMD = -5.07, 95% CI = -6.25 to -3.89, p < 0.00001), myeloperoxidase (SMD = -3.37, 95% CI = -4.05 to -2.70, p < 0.00001), tumor necrosis factor-alpha (SMD = -3.31, 95% CI = -4.45 to -2.16, p < 0.00001) and malondialdehyde (SMD = -3.91, 95% CI = -5.37 to -2.44, p < 0.00001) levels in animal models of ALI. The results of the subgroup analysis indicated that the efficacy of SCFAs varies significantly with dosage and duration of treatment.

Conclusion

SCFAs can reduce inflammation and oxidative stress in animal models of ALI. The clinical efficacy of SCFAs for ALI deserves further in-depth research.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=584008, CRD42024584008.

Neuro-immune cell interactions in the regulation of intestinal immune homeostasis

PURPOSE OF REVIEW

Bidirectional regulation between neurons and immune cells in the intestine governs essential physiological processes, including digestion, metabolism and motility, while also controlling intestinal inflammation and maintaining tissue homeostasis. This review covers recent advances and future research challenges focused on the regulatory molecules and potential therapeutic targets in neuron-immune interactions within the intestine.

RECENT FINDINGS

Recently identified molecular and cellular pathways have been shown to regulate neuron-immune cell cross talk in the context of maintaining tissue homeostasis, modulating inflammation, and promoting intestinal repair. Additionally, behaviors governed by the central nervous system, including feeding and stress responses, can play key roles in regulating intestinal immunity and inflammation.

SUMMARY

This review emphasizes recent progress in understanding the complex interplay between the nervous system and intestinal immune system and outlines future research directions. These advances have the potential to lead to innovative therapies targeting gastrointestinal disorders including inflammatory bowel diseases, allergic responses and cancer.

Neuroglia and the microbiota-gut-brain axis

Glial cells are key players in the regulation of nervous system functioning in both the central and enteric nervous systems. Glial cells are dynamic and respond to environmental cues to modulate their activity. Increasing evidence suggests that these signals include those originating from the gut microbiota, the community of microorganisms, including bacteria, viruses, archaea, and protozoa, that inhabit the gut. The gut microbiota and the brain communicate in a bidirectional manner across multiple signaling pathways and interfaces that together comprise the microbiota-gut-brain axis. Here, we detail the role of glial cells, including astrocytes, microglia, and oligodendrocytes in the central nervous system, and glial cells in the enteric nervous system along this gut-brain axis. We review what is known regarding the modulation of glia by microbial signals, in particular by microbial metabolites which signal to the brain through systemic circulation and via the vagus nerve. In addition, we highlight what is yet to be discovered regarding the role of other gut microbiota signaling pathways in glial cell modulation and the challenges of research in this area.

Nervous system in colorectal cancer

A malignant tumor is a complex systemic disease involving the nervous system, which regulates nerve signals. Cancer neuroscience is a field that explores the interactions between tumors and the nervous system. The gastrointestinal tract is a typical peripheral organ with abundant neuroregulation and is regulated by the peripheral, enteric, and central nervous systems (PNS, ENS, and CNS, respectively). The physiological functions of the gastrointestinal tract are maintained via complex neuromodulation. Neuroregulatory imbalance is the primary cause of gastrointestinal diseases, including colorectal cancer (CRC). In CRC, there is a direct interaction between the nervous system and tumor cells. Moreover, this tumor-nerve interaction can indirectly regulate the tumor microenvironment, including the microbiota, immunity, and metabolism. In addition to the lower nerve centers, the stress response, emotion, and cognition represented by the higher nerve centers also participate in the occurrence and progression of CRC. Herein, we review some basic knowledge regarding cancer neuroscience and elucidate the mechanism underlying tumor-nerve interactions in CRC.

Global research trajectories in gut microbiota and functional constipation: a bibliometric and visualization study

Background

Functional constipation (FC) negatively impacts quality of life and is associated with gut microbiota (GM) imbalances. Despite the growing interest in this area, a thorough analysis of research trends is missing. This study uses bibliometric methods to assess the global research on GM's role in FC, pinpointing key topics, impactful studies, and prominent researchers to guide future research and identify gaps.

Methods

In our study, we conducted a performance analysis and science mapping using bibliometric indicators such as publication trends, author and institutional contributions, productivity, impact, keyword analysis, and collaboration networks. We employed software tools like VOSviewer, Biblioshiny, CiteSpace, and SCImago Graphica to automate the assessment of metrics including country, institutional, and journal distribution, authorship, keyword frequency, and citation patterns.

Results

From 2013 to 2024, annual publications on GM and FC rose from 29 to 252, with a slight decrease to 192 in 2024. Average citations per publication peaked at 11.12 in 2021, declining to 6.43 by 2024. China led in research output (37.8%), followed by the United States (14.4%) and Japan (7.5%). Bibliometric analysis identified key authors like CHEN W and ZHANG H, with 30 and 27 articles, respectively. Jiangnan University and Harvard University were top contributors, with 131 and 81 articles. Keywords analysis revealed "constipation," "gut microbiota," and "probiotic" as central themes, with a shift toward "gut microbiota" and "intestinal flora" in recent years. This study provides a comprehensive overview of the research landscape, highlighting leading authors, institutions, and evolving research priorities in the field.

Conclusion

Our review synthesizes current GM and FC research, guiding future studies. It suggests exploring GM in various GI disorders, the impact of lifestyle and drugs on GM, advanced research techniques, and probiotics/prebiotics for FC. There's also a focus on therapies targeting GM's effect on the gut-brain axis, paving the way for improved FC management.

Exposure to greenspaces sourced soils improves mice gut microbiota

Greenspaces are important components of our living environment and have been linked to various human health. However, the mechanisms underlying the linkages remain unclear. Enriching microbiota has emerged as a novel mechanism, but the corresponding evidence is still limited. We collected soil samples from forest land, grassland, and barren land in Zunyi City, southwestern China and prepared soil solutions. A total of 40 BALB/c mice were evenly divided into normal control group, model control group, forest soil group, grassland soil group, and barren land soil group. After establishing the pseudo germ-free mouse model, different soil solutions were administered through gavage, lasting for seven weeks. Fecal samples were collected and a 16S rRNA high-throughput sequencing analysis was performed. Then, alpha- and beta-diversity were calculated and employed to estimate the effects of soil exposures on mice gut microbial diversity and composition. Further, Linear Discriminant Analysis Effect Size (LEfSe) analysis was carried out to evaluate the effects of soil exposures on gut microbiota specific genera abundances and functional pathways. Compared to mice exposed to barren land soils, those exposed to soils sourced from forest land showed an increase of 0.43 and 70.63 units in the Shannon index and the Observed ASVs, respectively. In addition, exposure to soils sourced from forest land and grassland resulted in healthier changes (i.e., more short-chain fatty acids (SCFAs)-producing bacteria) in gut microbiota than those from barren land. Furthermore, mice exposed to forest soil and grassland soil showed enrichment in 5 and 3 pathways (e.g., butanoate metabolism) compared to those exposed to barren land soil, respectively. In conclusion, exposure to various greenspaces soils may modify the gut microbial communities of mice, potentially fostering a more beneficial microbiota profile. Further better-designed studies are needed to validate the current findings and to explore the effects of greenspace related gut microbiota on human health.

Comprehensive insight into the alterations in the gut microbiome and the intestinal barrier as a consequence of iron deficiency anaemia

BACKGROUND

Iron deficiency is the top leading cause of anaemia, whose treatment has been shown to deteriorate gut health. However, a comprehensive analysis of the intestinal barrier and the gut microbiome during iron deficiency anemia (IDA) has not been performed to date. This study aims to delve further into the analysis of these two aspects, which will mean a step forward minimising the negative impact of iron supplements on intestinal health.

METHODS

IDA was experimentally induced in an animal model. Shotgun sequencing was used to analyse the gut microbiome in the colonic region, while the intestinal barrier was studied through histological analyses, mRNA sequencing (RNA-Seq), qPCR and immunofluorescence assays. Determinations of lipopolysaccharide (LPS) and bacteria-specific immunoglobulins were performed to assess microbial translocation.

RESULTS

Microbial metabolism in the colon shifted towards an increased production of certain amino acids, short chain fatty acids and nucleotides, with Clostridium species being enriched during IDA. Structural alterations of the colonic epithelium were shown by histological analysis. RNA-Seq revealed a downregulation of extracellular matrix-associated genes and proteins and an overall underdeveloped epithelium. Increased levels of serum LPS and an increased immune response against dysbiotic bacteria support an impairment in the integrity of the gut barrier during IDA.

CONCLUSIONS

IDA negatively impacts the gut microbiome and the intestinal barrier, triggering an increased microbial translocation. This study emphasizes the deterioration of gut health during IDA and the fact that it should be addressed when treating the disease.

Modification of gut and airway microbiota on ozone-induced airway inflammation

Ground-level ozone (O3) has been shown to induce airway inflammation, the underlying mechanisms remain unclear. The aim of this study was to determine whether gut and airway microbiota dysbiosis, and airway metabolic alterations were associated with O3-induced airway inflammation. Thirty-six 8-week-old male C57BL/6 N mice were divided into 2 groups: sterile water group and broad-spectrum antibiotics group (Abx). Each group was further divided into two subgroups, filtered air group (Air) and O3 group (O3), with 9 mice in each subgroup. Mice in the Air and O3 groups were exposed to filtered air or 1 ppm O3, 4 h/d for 5 consecutive days, respectively. Mice in Abx + Air and Abx + O3 groups were exposed to filtered air or O3, respectively, after drinking broad-spectrum Abx. 24 h after the final O3 exposure, mouse feces and bronchoalveolar lavage fluids (BALF) were collected and subjected to measurements of airway oxidative stress and inflammation biomarkers, 16S rRNA sequencing and metabolite profiling. Hematoxylin-eosin staining of lung tissues was applied to examine the pathological changes of lung tissue. The results showed that O3 exposure resulted in airway oxidative stress and inflammation, as well as gut and airway microbiota dysbiosis, and airway metabolism alteration. Abx pre-treatment markedly changed gut and airway microbiota and promoted O3-induced metabolic disorder and airway inflammation. Spearman correlation analyses indicated that inter-related gut and airway microbiota dysbiosis and airway metabolic disorder were associated with O3-induced airway inflammation. Together, inhaled O3 causes airway inflammation, which may implicate gut and airway microbiota dysbiosis and airway metabolic alterations.

Causal effects of gut microbiota on the risk of erectile dysfunction: a Mendelian randomization study

Erectile dysfunction ranks among the prevalent sexual disorders in men. Several studies have indicated a potential link between gut microbiota and erectile dysfunction. To validate this potential association, we were to screen statistical data from genome-wide association studies of gut microbiota and erectile dysfunction. p values of less than 1 × 10-5 were set as the threshold for screening instrumental variables that were strongly associated with gut microbiota. At the same time, in order to obtain more convincing findings, we further excluded instrumental variables with possible chain imbalance, instrumental variables with the presence of palindromes, instrumental variables with F-statistics less than 10, and instrumental variables associated with risk factors for erectile dysfunction. Five methods including inverse-variance weighted method, weighted median method, weighted mode, Mendelian randomization egger method and Mendelian randomization pleiotropy residual sum and outlier test were then used to analyse the 2591 instrumental variables obtained from the screening. We identified correlations between six gut microbiota and the risk of erectile dysfunction. The genus Ruminococcaceae UCG-013 exhibited an inverse association with the risk of developing erectile dysfunction (0.79 (0.65-0.97), P = 0.0214). Conversely, the genus Tyzzerella3 (1.13 (1.02-1.26), P = 0.0225), genus Erysipelotrichaceae UCG-003 (1.18 (1.01-1.38), P = 0.0412), genus LachnospiraceaeNC2004group (1.19 (1.03-1.37), P = 0.0191), genus Oscillibacter (1.23 (1.08-1.41), P = 0.0022), and family Lachnospiraceae (1.26 (1.05-1.52), P = 0.0123) demonstrated positive associations with an increased risk of erectile dysfunction. These sensitivity analyses of the gut microbiota were consistent. This study demonstrated a possible causal relationship between gut microbiota and erectile dysfunction risk through Mendelian randomization analysis, providing new potential possibilities for the prevention and treatment of erectile dysfunction.

Early-Life Stress Induced by Neonatal Maternal Separation Leads to Intestinal 5-HT Accumulation and Causes Intestinal Dysfunction

Background

The early childhood period is a critical development stage, and experiencing stress during this time may increase the risk of gastrointestinal disorders, including irritable bowel syndrome (IBS). Neonatal maternal separation (NMS) in rodent models has been shown to cause bowel dysfunctions similar to IBS, and 5-HT is considered to be a key regulator regulating intestinal function, but the precise underlying mechanisms remain unclear.

Results

We established a maternal separation stress mouse model to simulate early-life stress, exploring the expression patterns of 5-HT under chronic stress and its mechanisms affecting gut function. We observed a significant increase in 5-HT expression due to NMS, leading to disruptions in intestinal structure and function. However, inhibiting 5-HT reversed these effects, suggesting its potential as a therapeutic target. Furthermore, our research revealed that excess 5-HT in mice with early life stress increased intestinal neural network density and promoted excitatory motor neuron expression. Mechanistically, 5-HT activated the Wnt signaling pathway through the 5-HT4 receptor, promoting neurogenesis within the intestinal nervous system.

Conclusion

These findings shed light on the intricate changes induced by early life stress in the intestines, confirming the regulatory role of 5-HT in the enteric nervous system and providing potential insights for the development of novel therapies for gastrointestinal disorders.

The sports performance improving effects of konjac glucomannan with varying molecular weights in overtrained mice

Overtraining affects individuals engaged in high-volume training, potentially hindering athletic performance and revealing shortcomings in suggested solutions. This study evaluated the impact of konjac glucomannan (KGM) with varying molecular weights on the gut microbiome, endurance, and strength in mice subjected to excessive training. The native KGM (1.82 × 107 Da) was enzymatically degraded using endo-1,4-β-mannanase to generate moderate molecular weight KGM (KGM-EM, 1.89 × 105 Da) and low molecular weight KGM (KGM-EL, 1.34 × 104 Da). These fractions were characterized and compared with the native KGM regarding their effects on mice undergoing excessive training. The results demonstrated a positive correlation between KGM's molecular weight and its capacity to mitigate the adverse impacts of excessive training on strength or/and endurance (a significant increase of 55.57 % and 55.70 % by the native KGM compared with the excessive training group). In addition, the native KGM exhibited superior preservation of microbial diversity and composition in fecal samples against excessive training-induced shifts, along with increased production of individual and total short-chain fatty acids in plasma compared with the two degraded products. Overall, these results highlight the potential benefits of high molecular weight KGM for preventing overtraining syndrome and enhancing athletic performance in animal models.

Essential Fatty Acids along the Women’s Life Cycle and Promotion of a Well-balanced Metabolism

Abstract:

Linoleic acid (ω-6 LA) and α-linolenic acid (ω-3 ALA) are essential fatty acids (EFA) for human beings. They must be consumed through diet and then extensively metabolized, a process that plays a fundamental role in health and eventually in disease prevention. Given the numerous changes depending on age and sex, EFA metabolic adaptations require further investigations along the women’s life cycle, from onset to decline of the reproductive age. Thus, this review explains women’s life cycle stages and their involvement in diet intake, digestion and absorption, the role of microbiota, metabolism, bioavailability, and EFA fate and major metabolites. This knowledge is crucial to promoting lipid homeostasis according to female physiology through well-directed health strategies. Concerning this, the promotion of breastfeeding, nutrition, and physical activity is cardinal to counteract ALA deficiency, LA/ALA imbalance, and the release of unhealthy derivatives. These perturbations arise after menopause that compromise both lipogenic and lipolytic pathways. The close interplay of diet, age, female organism, and microbiota also plays a central role in regulating lipid metabolism. Consequently, future studies are encouraged to propose efficient interventions for each stage of women's cycle. In this sense, plant-derived foods and products are promising to be included in women’s nutrition to improve EFA metabolism.

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.

Interaction between intestinal mycobiota and microbiota shapes lung inflammation

Gut microbiota is an intricate microbial community containing bacteria, fungi, viruses, archaea, and protozoa, and each of them contributes to diverse aspects of host health. Nevertheless, the influence of interaction among gut microbiota on host health remains uncovered. Here, we showed that the interaction between intestinal fungi and bacteria shaped lung inflammation during infection. Specifically, antifungal drug-induced dysbiosis of gut mycobiota enhanced lung inflammation during infection. Dysbiosis of gut mycobiota led to gut Escherichia coli (E. coli) overgrowth and translocation to the lung during infection, which induced lung accumulation of the CD45+F4/80+Ly6G-Ly6C-CD11b+CD11c+ macrophages. Clearance of macrophages or deletion of TLR4 (Toll-like receptor 4, recognition of LPS) rather than Dectin-1 (recognition of beta-1,3/1,6 glucans on fungi) blocked the antifungal drug-induced aggravation of lung inflammation during infection. These findings suggest that the interaction between intestinal mycobiota and commensal bacteria affects host health through the gut-lung axis, offering a potential therapeutic target for ameliorating lung inflammation during infection.

Activation of GABABR Attenuates Intestinal Inflammation by Reducing Oxidative Stress through Modulating the TLR4/MyD88/NLRP3 Pathway and Gut Microbiota Abundance

Oxidative stress emerges as a prominent factor in the onset and progression of intestinal inflammation, primarily due to its critical role in damaging cells and tissues. GABAergic signaling is important in the occurrence and development of various intestinal disorders, yet its effect on oxidative stress remains unclear. We attempted to assess whether GABAergic signaling participated in the regulation of oxidative stress during enteritis. The results showed that lipopolysaccharide (LPS) significantly decreased γ-aminobutyric acid (GABA) levels in the ileal tissues of mice. Interestingly, the application of GABA significantly repressed the shedding of intestinal mucosal epithelial cells and inflammatory cell infiltration, inhibited the expressions of proinflammatory factors, including granulocyte colony-stimulating factor and granulocyte-macrophage colony stimulating factor, and enhanced the levels of anti-inflammatory cytokines interleukin (IL)-4 and IL-10, indicating that GABA could alleviate enteritis in mice. This observation was further supported by transcriptome sequencing, revealing a total of 271 differentially expressed genes, which exhibited a marked enrichment of inflammatory and immune-related pathways, alongside a prominent enhancement of GABA B receptor (GABABR) signaling following GABA administration. Effectively, Baclofen pretreatment alleviated intestinal mucosal damage in LPS-induced mice, suppressed proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor alpha expressions, and boosted total antioxidant capacity, superoxide dismutase (SOD), and glutathione (GSH) levels. Moreover, Baclofen notably enhanced the viability of LPS-stimulated IPEC-J2 cells, contracted the proinflammatory secretion factors, and reinforced SOD, GSH, and catalase levels, emphasizing the anti-inflammatory and antioxidant effects associated with GABABR activation. Mechanistically, Baclofen restrained the mRNA and protein levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3), and inducible nitric oxide synthase, while elevating nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 in both mice and IPEC-J2 cells, indicating that activating GABABR strengthened antioxidant abilities by interrupting the TLR4/MyD88/NLRP3 pathway. Furthermore, 16S rDNA analysis demonstrated that Baclofen increased the relative abundance of probiotic, particularly Lactobacillus, renowned for its antioxidant properties, while reducing the relative richness of harmful bacteria, predominantly Enterobacteriaceae, suggesting that GABABR signaling may have contributed to reversing intestinal flora imbalances to relieve oxidative stress in LPS-induced mice. Our study identified previously unappreciated roles for GABABR signaling in constricting oxidative stress to attenuate enteritis, thus offering novel insights for the treatment of intestinal inflammation.

Traditional Chinese medicine for functional gastrointestinal disorders and inflammatory bowel disease: narrative review of the evidence and potential mechanisms involving the brain-gut axis

Functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) are common clinical disorders characterized by recurrent diarrhea and abdominal pain. Although their pathogenesis has not been fully clarified, disruptions in intestinal motility and immune function are widely accepted as contributing factors to both conditions, and the brain-gut axis plays a key role in these processes. Traditional Chinese Medicine (TCM) employs a holistic approach to treatment, considers spleen and stomach impairments and liver abnormality the main pathogenesis of these two diseases, and offers a unique therapeutic strategy that targets these interconnected pathways. Clinical evidence shows the great potential of TCM in treating FGIDs and IBD. This study presents a systematic description of the pathological mechanisms of FGIDs and IBD in the context of the brain-gut axis, discusses clinical and preclinical studies on TCM and acupuncture for the treatment of these diseases, and summarizes TCM targets and pathways for the treatment of FGIDs and IBD, integrating ancient wisdom with contemporary biomedical insights. The alleviating effects of TCM on FGID and IBD symptoms are mainly mediated through the modulation of intestinal immunity and inflammation, sensory transmission, neuroendocrine-immune network, and microbiota and their metabolism through brain-gut axis mechanisms. TCM may be a promising treatment option in controlling FGIDs and IBD; however, further high-quality research is required. This review provides a reference for an in-depth exploration of the interventional effects and mechanisms of TCM in FGIDs and IBD, underscoring TCM's potential to recalibrate the dysregulated brain-gut axis in FGIDs and IBD.

ELP1, the Gene Mutated in Familial Dysautonomia, Is Required for Normal Enteric Nervous System Development and Maintenance and for Gut Epithelium Homeostasis

Familial dysautonomia (FD) is a rare sensory and autonomic neuropathy that results from a mutation in the ELP1 gene. Virtually all patients report gastrointestinal (GI) dysfunction and we have recently shown that FD patients have a dysbiotic gut microbiome and altered metabolome. These findings were recapitulated in an FD mouse model and moreover, the FD mice had reduced intestinal motility, as did patients. To understand the cellular basis for impaired GI function in FD, the enteric nervous system (ENS; both female and male mice) from FD mouse models was analyzed during embryonic development and adulthood. We show here that not only is Elp1 required for the normal formation of the ENS, but it is also required in adulthood for the regulation of both neuronal and non-neuronal cells and for target innervation in both the mucosa and in intestinal smooth muscle. In particular, CGRP innervation was significantly reduced as was the number of dopaminergic neurons. Examination of an FD patient's gastric biopsy also revealed reduced and disoriented axons in the mucosa. Finally, using an FD mouse model in which Elp1 was deleted exclusively from neurons, we found significant changes to the colon epithelium including reduced E-cadherin expression, perturbed mucus layer organization, and infiltration of bacteria into the mucosa. The fact that deletion of Elp1 exclusively in neurons is sufficient to alter the intestinal epithelium and perturb the intestinal epithelial barrier highlights a critical role for neurons in regulating GI epithelium homeostasis.

Specific gut microbiome's role in skin pigmentation: insights from SCARB1 mutants in Oujiang colour common carp

AIMS

Beyond the pivotal roles of the gut microbiome in initiating physiological processes and modulating genetic factors, a query persists: Can a single gene mutation alter the abundance of the gut microbiome community? Not only this, but the intricate impact of gut microbiome composition on skin pigmentation has been largely unexplored.

METHODS AND RESULTS

Based on these premises, our study examines the abundance of lipase-producing gut microbes about differential gene expression associated with bile acid synthesis and lipid metabolism-related blood metabolites in red (whole wild) and white (whole white wild and SCARB1-/- mutant) Oujiang colour common carp. Following the disruption of the SCARB1 gene in the resulting mutant fish with white body colour (SCARB1-/-), there is a notable decrease in the abundance of gut microbiomes (Bacillus, Staphylococcus, Pseudomonas, and Serratia) associated with lipase production. This reduction parallels the downregulation seen in wild-type white body colour fish (WW), as contrasting to the wild-type red body colour fish (WR). Meanwhile, in SCARB1-/- fish, there was a downregulation noted not only at the genetic and metabolic levels but also a decrease in lipase-producing bacteria. This consistency with WW contrasts significantly with WR. Similarly, genes involved in the bile acid synthesis pathway, along with blood metabolites related to lipid metabolism, exhibited downregulation in SCARB1-/- fish.

CONCLUSIONS

The SCARB1 knockout gene blockage led to significant alterations in the gut microbiome, potentially influencing the observed reduction in carotenoid-associated skin pigmentation. Our study emphasizes that skin pigmentation is not only impacted by genetic factors but also by the gut microbiome. Meanwhile, the gut microbiome's adaptability can be rapidly shaped and may be driven by specific single-gene variations.

Bioengineering of Intestinal Grafts

Intestinal failure manifests as an impaired capacity of the intestine to sufficiently absorb vital nutrients and electrolytes essential for growth and well-being in pediatric and adult populations. Although parenteral nutrition remains the mainstay therapeutic approach, the pursuit of a definitive and curative strategy, such as regenerative medicine, is imperative. Substantial advancements in the field of engineered intestinal tissues present a promising avenue for addressing intestinal failure; nevertheless, extensive research is still necessary for effective translation from experimental benchwork to clinical bedside applications.

Schwann cells and enteric glial cells: Emerging stars in colorectal cancer

Cancer neuroscience, a promising field dedicated to exploring interactions between cancer and the nervous system, has attracted growing attention. The gastrointestinal tracts exhibit extensive innervation, notably characterized by intrinsic innervation. The gut harbors a substantial population of glial cells, including Schwann cells wrapping axons of neurons in the peripheral nervous system and enteric glial cells intricately associated with intrinsic innervation. Glial cells play a crucial role in maintaining the physiological functions of the intestine, encompassing nutrient absorption, barrier integrity, and immune modulation. Nevertheless, it has only been in recent times that the significance of glial cells within colorectal cancer (CRC) has begun to receive considerable attention. Emerging data suggests that glial cells in the gut contribute to the progression and metastasis of CRC, by interacting with cancer cells, influencing inflammation, and modulating the tumor microenvironment. Here, we summarize the significant roles of glial cells in the development and progression of CRC and discuss the latest technologies that can be integrated into this field for in-depth exploration, as well as potential specific targeted strategies for future exploration to benefit patients.

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.

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

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

Diet-microbiome interactions promote enteric nervous system resilience following spinal cord injury

Spinal cord injury (SCI) results in numerous systemic dysfunctions, including intestinal dysmotility and enteric nervous system (ENS) atrophy. The ENS has capacity to recover following perturbation, yet intestinal pathologies persist. With emerging evidence demonstrating SCI-induced alterations to gut microbiome composition, we hypothesized that microbiome modulation contributes to post-injury enteric recovery. Here, we show that intervention with the dietary fiber, inulin, prevents SCI-induced ENS atrophy and dysmotility in mice. While SCI-associated microbiomes and specific injury-sensitive gut microbes are not sufficient to modulate intestinal dysmotility after injury, intervention with microbially-derived short-chain fatty acid (SCFA) metabolites prevents ENS dysfunctions in injured mice. Notably, inulin-mediated resilience is dependent on IL-10 signaling, highlighting a critical diet-microbiome-immune axis that promotes ENS resilience post-injury. Overall, we demonstrate that diet and microbially-derived signals distinctly impact ENS survival after traumatic spinal injury and represent a foundation to uncover etiological mechanisms and future therapeutics for SCI-induced neurogenic bowel.

Global research landscape of Peutz-Jeghers syndrome and successful endoscopic management of intestinal intussusception in patients with recurrent laparotomies

BACKGROUND

Peutz-Jeghers syndrome (PJS) has brought significant physical, psychological and economic burdens on the patients and their families due to its early onset, diagnostic and therapeutic challenges and increased recurrence risk.

AIM

To explore the current research status and emerging hotspots of PJS.

METHODS

Studies on PJS published during 1994-2023 were gathered based on Web of Science Core Collection. Additionally, a case of PJS-induced intestinal intussusception, successfully treated with endoscopic methods despite three laparotomies, was highlighted. Comprehensive bibliometric and visual analysis were conducted with VOSviewer, R and CiteSpace.

RESULTS

Altogether 1760 studies were identified, indicating a steady increase in the publication number. The United States had the highest influence, whereas the University of Helsinki emerged as the leading institution, and Aaltonen LA from the University of Helsinki was the most prolific author. Cancer Research, Oncogene and Endoscopy were the top three journals based on H-index. Keyword burst direction analysis revealed that "cancer risk", "management", "surveillance" and "familial pancreatic cancer" were the potential hotspots for investigation. Additionally, "early detection", "capsule endoscopy", "clinical management", "double-balloon endoscopy", "familial pancreatic cancer" and "molecular genetic basis" were identified as the key clusters of co-cited references. Endoscopic polypectomy remained effective on resolving intestinal intussusception in patients who underwent three previous laparotomies.

CONCLUSION

In the last three decades, global publications related to PJS show a steadily increasing trend in number. Endoscopic management is currently a research hotspot.

Modulation of gut microbiota on intestinal permeability: A novel strategy for treating gastrointestinal related diseases

Accumulating evidence emphasizes the critical reciprocity between gut microbiota and intestinal barrier function in maintaining the gastrointestinal homeostasis. Given the fundamental role caused by intestinal permeability, which has been scrutinized as a measurable potential indicator of perturbed barrier function in clinical researches, it seems not surprising that recent decades have been marked by augmented efforts to determine the interaction between intestinal microbes and permeability of the individual. However, despite the significant progress in characterizing intestinal permeability and the commensal bacteria in the intestine, the mechanisms involved are still far from being thoroughly revealed. In the present review, based on multiomic methods, high-throughput sequencing and molecular biology techniques, the impacts of gut microbiota on intestinal permeability as well as their complex interaction networks are systematically summarized. Furthermore, the diseases related to intestinal permeability and main causes of changes in intestinal permeability are briefly introduced. The purpose of this review is to provide a novel prospection to elucidate the correlation between intestinal microbiota and permeability, and to explore a promising solution for diagnosis and treatment of gastrointestinal related diseases.

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

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