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PubMed2026

Rumen microbiota-associated stress alleviation by creatine pyruvate in newly received cattle: a multi-omics study.

BACKGROUND: Stress experienced by newly received cattle is a significant challenge in the beef industry, frequently resulting in weakened immune responses and impaired growth. The rumen microbiota is essential to host health, and its imbalance can exacerbate stress. This study investigates the mechanisms by which creatine pyruvate (CrPyr) mitigates stress in newly received cattle through multi-omics approaches, including metagenomics, metabolomics, in vitro and in vivo experiments, and rumen microbiota transplantation (RMT) in mice. RESULTS: Our results revealed that CrPyr significantly reduces stress-related hormones (cortisol and adrenocorticotropic hormone) and inflammatory markers (IL-6, IL-1β, and TNF-α), and enhanced antioxidant capacity (SOD: 57.38 versus 46.93 U/mL, P < 0.05; GSH-Px: 305.87 versus 217.07 U/mL, P < 0.05; T-AOC: 9.62 versus 7.66 U/mL, P < 0.05). Metagenomic analysis demonstrated that CrPyr increased Prevotella abundance, a key rumen bacterium involved in volatile fatty acid (VFA) production, and enriches metabolic pathways associated with energy metabolism (ATP synthesis, and pyruvate metabolism) and antioxidant defense (glutathione metabolism, FC = 1.08, P < 0.05). In vitro and in vivo experiments, as well as RMT studies in mice, further validate these findings, demonstrating that CrPyr promote VFA synthesis and increased ATP production through the electron transport phosphorylation pathway. CONCLUSIONS: CrPyr modulates the abundance of ruminal Prevotella in transport-stressed cattle to enhance glutathione and VFA metabolism and to accelerate ATP and nucleotide synthesis, thereby alleviating stress in newly received cattle. This multimodal approach established CrPyr as an effective nutritional intervention that improves rumen function and increases livestock productivity. Video Abstract.

Animals↗

PubMed2026

Characterization of the gut phageome and functional genes carried by phages in laying hens with fatty liver hemorrhagic syndrome.

BACKGROUND: The gut microbiota is closely associated with the development of fatty liver hemorrhagic syndrome (FLHS); however, the function of its viral component, particularly bacteriophages, remains poorly understood. This study compared clinical parameters and the cecal phageome between 30-week-old (W30) and 50-week-old (W50) laying hens to characterize gut phages in the context of this metabolic disorder. RESULTS: Clinical analysis revealed that the W50 group exhibited typical FLHS, accompanied by elevated serum liver function and lipid markers (P < 0.05). Functional prediction of the gut microbiota suggested a reduced lipid-metabolic capacity in W50 compared to the W30 group. A total of 20,274 phage genomes were identified from the two groups. These phages were primarily classified into 67 viral families, including Salasmaviridae, Herelleviridae, Suoliviridae, Peduoviridae, Crevaviridae, and Casjensviridae. The families Druskaviridae, Felixviridae, and Stanwilliamsviridae were uniquely detected in the W50 group. The phage community structure differed significantly between groups, with both phage diversity and richness markedly lower in W50 (P < 0.05). LEfSe analysis revealed that phage taxa such as Stegnyidae, Herpelidae, and Chasovidae were significantly enriched in the W50 group, whereas Crewdviridae, Salasmaviridae, and Castroviridae were predominantly enriched in the W30 group. Functional annotation showed that these phages encode numerous metabolism-related genes and carry antimicrobial resistance genes (ARGs) as well as virulence factor genes. Notably, the diversity of ARGs carried by W50 phages was significantly higher (P < 0.05), and ARG-rank analysis indicated a greater potential risk to human health. CONCLUSIONS: This study provides the first characterization of the gut phageome associated with FLHS in laying hens and confirms that gut phages constitute an important reservoir of ARGs. These findings offer a new perspective for understanding the pathogenesis of this disease and its associated public health risks. Video Abstract.

Animals↗

PubMed2026

Capsaicin ameliorates glycemic levels via gut microbiota-derived 5-aminolevulinic acid in mice.

BACKGROUND: Capsaicin, a natural alkaloid in chili peppers, regulates glycemic levels; however, its mechanisms and therapeutic potential remain unclear. This study aimed to elucidate the role of gut microbiota and their metabolites in mediating capsaicin's glycemic regulatory effects. We conducted experiments in specific pathogen-free (SPF) and germ-free (GF) mice, transient receptor potential vanilloid 1 (TRPV1) receptor ablation studies, and fecal microbiota transplantation (FMT) to demonstrate the involvement of gut microbiota in capsaicin-mediated glycemic control. Metagenomics and metabolomics analyses were employed to identify key microbial strains and metabolic pathways. Keystone strains and metabolites were supplemented in GF mice without capsaicin intervention to validate their effects on glycemic regulation. In vitro co-culture experiments were performed to investigate the mutualistic relationships among keystone strains under capsaicin treatment. RESULTS: Gut microbiota constitute an important component of capsaicin-mediated glycemic regulation, acting in concert with but not solely dependent on TRPV1 signaling. Gut microbiota altered by capsaicin promote the production of 5-aminolevulinic acid (5-ALA), which contributes to heme synthesis and enhances glycemic control. Supplementation with Akkermansia muciniphila, Ligilactobacillus murinus, or 5-ALA in GF mice recapitulates the glycemic benefits of capsaicin. Furthermore, capsaicin enriches Akkermansia muciniphila, which in turn supports the growth of Ligilactobacillus murinus. CONCLUSION: Capsaicin-induced changes in the gut microbiota promote 5-ALA synthesis, leading to improved glycemic control. These findings suggest that dietary or probiotic interventions targeting gut microbiota, particularly Akkermansia muciniphila and 5-ALA, may offer promising strategies for managing glycemic disorders, including type 2 diabetes (T2D). Video Abstract.

Animals↗

PubMed2026

Precisely designed keystone metabolites boost shrimp disease resistance by recruiting symbionts via the lipoxin A4-AP-1 pathway.

BACKGROUND: Gut metabolites and symbionts are indispensable for host health, yet the precise identification of keystone metabolites and construction of synthetic microbial communities (SynComs) to enhance disease resistance remains limited. RESULTS: Using Litopenaeus vannamei as a model, we identified pyruvic acid and DL-glutamine (1:2) as keystone metabolites by borrowing the microbial ecology principles of bio-indicators and driver taxa. Dietary supplementation with these metabolites sufficiently protected shrimp from white feces syndrome (WFS). Multi-omics analyses demonstrated that keystone metabolites exerted positive effects by enriching beneficial Ruegeria lacuscaerulensis, Bacillus subtilis and Nioella nitratireducens, strengthening the gut network stability, and enhancing shrimp immunity, which collectively potentiated WFS resistance. The recruited three strains were consumers and producers of the two keystone metabolites, and discriminative strains between healthy and diseased shrimp across global datasets. A SynCom constructed from the three strains (4:3:2) replicated the efficacy of keystone metabolites. Both keystone metabolites and SynCom elevated shrimp gut and hepatopancreas lipoxin A4 (LXA4) levels, which suppressed the pro-inflammatory transcription factor AP-1, as validated by in vivo inhibition assay. CONCLUSIONS: Our findings demonstrate that precisely designed keystone metabolites enhance shrimp disease resistance through the recruitment of key symbionts-LXA4-AP-1 axis. The rationally designed keystone metabolites and SynCom are compelling biocontrol solutions in improving host disease resistance. Video Abstract.

Animals↗

PubMed2026

Convergent evolution of intestinal lineages in the phylum Methanobacteriota.

BACKGROUND: Representatives of the phylum Methanobacteriota occur in various anoxic environments, but only members of the genera Methanosphaera and Methanobrevibacter exclusively colonize the digestive tract of animals. Recent phylogenomic analyses revealed that the genus Methanobrevibacter, which harbors the majority of the intestinal species, is severely underclassified and represents a family-level taxon, "Methanobrevibacteraceae", that evolved entirely in the digestive tract of animals. RESULTS: Comparative genome analysis of 158 species of Methanobacteriota, including uncultured representatives in the Genome Taxonomy Database (GTDB), demonstrated that the intestinal lineages are clearly separated from the remaining members of the phylum. They differ from the non-intestinal lineages in genome size, GC content, coding density, an increased number of pseudogenes and adhesin-like proteins, and show numerous adaptations to the copiotrophic gut environment. A decreased biosynthetic potential led to a dependence on other community members and limits the dispersal of intestinal species into other habitats, which is reflected in coevolutionary patterns with their major host groups among arthropods, ungulates, and primates. Certain lineages even engaged in symbiotic associations with intestinal protists, presumably benefiting from the H2 produced by the hydrogenosomes of their anaerobic hosts. CONCLUSIONS: Our results reveal that the transition of free-living Methanobacteriota to a host-associated lifestyle involves the same genomic changes that were previously recognized in gut bacteria and bacterial endosymbionts of protists, reflecting resemblances between the two prokaryotic domains that are caused by evolutionary convergence in similar environments.

Animals↗

PubMed2025

Gut fungi are associated with human genetic variation and disease risk.

Human genetic determinants of the gut mycobiome remain uninvestigated despite decades of research highlighting tripartite relationships between gut bacteria, genetic background, and disease. Here, we present the first genome-wide association study on the number and types of human genetic loci influencing gut fungi relative abundance. We detect 148 fungi-associated variants (FAVs) across 7 chromosomes that statistically associate with 9 fungal taxa. Of these FAVs, several occur in the protein-coding genes PTPRC, ANAPC10, NAV2, and CDH13. Additional FAVs link to tissue-specific gene expression as fungi-associated expression quantitative trait loci. Notably, the relative abundance of gut yeast Kazachstania associates with genetic variation in CDH13 encoding T-cadherin, a protein linked to cardiovascular disease. Kazachstania forms a causal relationship with cardiovascular disease risk in a mendelian two-sample randomization analysis. These findings establish previously unrecognized connections between human genetics, gut fungi, and chronic disease, broadening the paradigm of human-microbe interactions in the gut to the mycobiome.

Humans↗

PubMed2025

The Aggregated Gut Viral Catalogue (AVrC): A unified resource for exploring the viral diversity of the human gut.

The growing interest in the role of the gut virome in human health and disease, has led to several recent large-scale viral catalogue projects mining human gut metagenomes each using varied computational tools and quality control criteria. Importantly, there has been to date no consistent comparison of these catalogues' quality, diversity, and overlap. In this project, we therefore systematically surveyed nine previously published human gut viral catalogues. While these catalogues collectively screened >40,000 human fecal metagenomes, 82% of the recovered 345,613 viral sequences were unique to one catalogue, highlighting limited redundancy between the ressources and suggesting the need for an aggregated resource bringing these viral sequences together. We further expanded these viral catalogues by mining 7,867 infant gut metagenomes from 12 large-scale infant studies collected in 9 different countries. From these datasets, we constructed the Aggregated Gut Viral Catalogue (AVrC), a unified modular resource containing 1,018,941 dereplicated viral sequences (449,859 species-level vOTUs). Using computational inference tools, annotations were obtained for each vOTU representative sequence quality, viral taxonomy, predicted viral lifestyle, and putative host. This project aims to facilitate the reuse of previously published viral catalogues by the research community and follows a modular framework to enable future expansions as novel data becomes available.

Humans↗

PubMed2026

Impact of Tilapinevirus tilapiae (TiLV) infection on the composition and functional dynamics of gut microbiota in Nile Tilapia (Oreochromis niloticus) (Linnaeus, 1758).

Tilapinevirus tilapiae (TiLV) (formerly Tilapia Lake Virus) is a highly prevalent pathogen capable of inducing significant mortality rates in Nile tilapia (Oreochromis niloticus). The alterations induced by Tilapia Lake Virus (TiLV) in the gut microbiota composition, diversity and functional prediction of Nile tilapia have not been thoroughly investigated. This study investigated the gut microbiota of a healthy control group and a TiLV-infected group of Nile tilapia of size 30 ± 2.45g. The alpha diversity of microbiota was hardly affected by TiLV infection, whereas species richness and beta diversity patterns explained the significant differences between control and TiLV-infected groups. The study highlighted a decline in Cetobacterium and an increase in Mycobacterium in the TiLV-infected group. The phyla, including Firmicutes, Actinobacteriota and Proteobacteria, exhibited a significant increase in the TiLV-infected group, while Bacteroidota and Fusobacteriota decreased substantially. The PICRUSt-based functional gene prediction revealed that TiLV infection had considerably changed the KEGG (Kyoto Encyclopaedia of Genes and Genomes) pathways associated with membrane transport, amino acid metabolism, transcription, carbohydrate metabolism, cellular process and signalling in the gut microbiota of Nile tilapia. The results suggest that the infection by TiLV altered the composition and functional pathways in the gut microbiota of Nile tilapia.

Animals↗

PubMed2026

[Mechanism of Tianshu Capsules in treating migraine rats based on gut microbiota].

This study aims to investigate the therapeutic effect of Tianshu Capsules(TS) on migraine rat model and explore its potential mechanism of action from the perspectives of the structure of the gut microbiota and functional pathway regulation. A migraine rat model was established via subcutaneous injection of nitroglycerin. The Sprague-Dawley rats were randomly divided into a control group, a model group, a low-dose TS group, a medium-dose TS group, a high-dose TS group, and an ibuprofen group. The efficacy of TS in improving migraine was evaluated by general condition observation and measurement of the craniofacial pain threshold. The expression of the gene c-fos in the trigeminal ganglion was determined by quantitative real-time polymerase chain reaction(PCR). The contents of endothelin-1(ET-1), calcitonin gene-related peptide(CGRP), and 5-hydroxytryptamine(5-HT) in serum were measured by enzyme-linked immunosorbent assay(ELISA). Fecal samples were subjected to metagenomic sequencing for systematic analysis of gut microbial diversity, taxonomic composition difference, and functional pathway changes of Kyoto Encyclopedia of Genes and Genomes(KEGG), and their correlations with behavioral and biochemical indices were further evaluated. The results show that TS significantly improves the increased body temperature and decreased craniofacial pain threshold in migraine rats. It also markedly suppresses the elevated expression levels of the gene c-fos in the trigeminal ganglion and reduces the levels of ET-1, CGRP, and 5-HT in serum. Metagenomic beta diversity analysis and differential taxonomic abundance analysis reveal that the migraine model induces significant gut microbiota dysbiosis, characterized by enrichment of harmful genera, including Streptococcus and Enterococcus, as well as a decline in the abundance of beneficial bacteria such as Allobaculum, Eubacterium, and Muribaculum. Functional pathway analysis results of KEGG further reveal that the relative abundances of pathways associated with biosynthesis of phenylalanine, tyrosine, and tryptophan, bacterial secretion system, citrate cycle, and biosynthesis of secondary metabolites are significantly decreased in the model group. TS intervention increased the abundance of the genus, such as Parabacteroides, Eubacterium, Allobaculum, and Muribaculum, while decreasing levels of microbiota, including Staphylococcus. TS also significantly upregulated pathways associated with barrier function(tight junction), amino acid biosynthesis pathways, and biosynthesis pathways of neurotransmitter precursors such as cysteine and methionine metabolism. In addition, it downregulated inflammatory pathways(Toll and IMD signaling) and pathways related to Staphylococcus aureus infection, thereby restoring the structure and function of the microbiota to a state close to those of the normal group. Spearman correlation analysis reveals that partial gut microbiota are significantly associated with migraine-related behavioral and biochemical indices(c-fos, ET-1, CGRP, and 5-HT). In conclusion, TS can regulate the disrupted gut microbiota structure and microbial functions related to neurotransmitter metabolism, intestinal barrier function, and inflammatory regulation in migraine model rats, which may be one of the potential key ways through which TS exert its anti-migraine effect.

Animals↗

PubMed2026

The Mediating Role of Immune Cells in the Genetically Predicted Relationship between Gut Microbiota and Puerperal Sepsis: A Mendelian Randomization Study.

INTRODUCTION: The causal relationship between gut microbiota and puerperal sepsis (PS) remains unclear, and there is a lack of in-depth research regarding the potential mediating role of immune cells in this context. OBJECTIVE: This study aims to investigate the causal relationship between gut microbiota and PS using Mendelian randomization (MR) analysis and to assess the mediating effects of immune cells on the risk of PS onset through mediation analysis. MATERIALS AND METHODS: We selected data from large-scale genome-wide association studies (GWAS) involving 473 gut microbiota species, 731 immune cell phenotypes, and PS datasets. Univariate MR (UVMR) analysis was employed to explore the causal relationship between gut microbiota and PS, with the primary statistical method being inverse variance weighting (IVW). Multiple statistical models were applied for sensitivity analysis to minimize the confounding effects of horizontal pleiotropy and heterogeneity. Subsequently, a two-step mediation MR analysis was conducted to evaluate whether immune cells mediate the relationship between gut microbiota and PS. RESULTS AND DISCUSSION: Analysis using various statistical models indicated that 11 gut microbiota species (e.g., Azorhizobium, Bacillus velezensis, CAG-245 sp000435175, Lentimicrobiaceae, and Providencia) exhibited a causal relationship with PS. Further reverse causal analysis between PS and gut microbiota ruled out the possibility of reverse causality. The two-step mediation MR analysis demonstrated that the percentage of IgD-CD27- B cells (10.26%) and CD62L- monocytes (17.29%) partially mediated the effect of CAG-245 sp000435175 on PS risk. CONCLUSION: This study provides evidence of a causal relationship between the abundance of certain gut microbiota species and PS, while also revealing a potential mediating role of immune cells. These findings offer valuable theoretical insights into personalized treatment strategies and the development of novel diagnostic biomarkers for PS.

Humans↗

PubMed2026

Novel Insights into Immune Cell Function in Type 2 Diabetes Mediated by Gut Microbiota: A Two-Sample Mendelian Randomization Study.

INTRODUCTION: The role of immune cells in type 2 diabetes mellitus (T2DM) development is well-studied, but their interactions with the gut microbiota and the mediating role in this process remain unclear. METHODS: We analyzed 731 immune cell phenotypes (3,757 Europeans), 473 gut microbiota traits (5,959 Finns), and T2DM data (over 400,000 Finns). Mendelian randomization (MR) was based on three assumptions: the instrumental variable (IV) is associated with exposure, IV is not influenced by confounding, and IV affects the outcome only through exposure. We selected single-nucleotide polymorphisms (SNPs) from genome-wide association studies as instrumental variables (IVs) to infer causal effects in two-sample MR analysis. RESULTS: We identified 36 immune cell phenotypes associated with T2DM, including 29 protective factors and seven risk factors, as well as 10 gut microbiota significantly linked to T2DM, with eight protective factors and two risk factors. MR revealed that five gut microbiota mediated the relationship between immune cells and T2DM. For example, the effects of CD3 on resting Treg (OR: 1.0136), CD3 on CM CD4+ (OR: 1.0180), and CD3 on naive CD4+ cells (OR: 1.0150) in T2DM were found to be partially mediated by the species Bacillus. AYThe corresponding mediation effect proportions were 8.99%, 11.8%, and 11.4%. DISCUSSION: MR analysis identified multiple gut microbiota mediators in the relationship between immune cells and T2DM, addressing previous observational evidence. Limitations included the European ancestry bias, among others. CONCLUSION: This study has highlighted the gut microbiota as a mediator between immune cells and T2DM, offering new insights for its early prevention and intervention.

Diabetes Mellitus, Type 2↗

PubMed2026

Gut Microbiota, Lipidome, and Metabolites Mediate Immune Dysregulation in Diabetic Microvascular Disease: A Two-sample Mendelian Randomization and Mediation Analysis.

INTRODUCTION: Diabetic microvascular disease (DMiVD) involves dysregulated immune cell function, but the precise pathogenic mechanisms remain unclear. MATERIALS AND METHODS: We conducted a two-sample Mendelian randomization (MR) study using comprehensive GWAS and FinnGen summary statistics, encompassing 731 immune cell phenotypes, 473 gut microbial taxa, 91 inflammatory proteins, 179 lipid types, 1,400 plasma metabolites, 20 micronutrients, and DMiVD cases. The analysis aimed to evaluate causal associations between these variables and DMiVD. We further explored potential mediating roles of gut microbiota, plasma lipidome, and metabolites using mediation analysis, with multiple sensitivity tests confirming the robustness of our findings. RESULTS: We identified 20 immune cell phenotypes, 33 gut microbial taxa, 31 lipid types, and 83 plasma metabolites with significant causal associations with DMiVD. Mediation analysis revealed that the risk effect of CD3+ resting Tregs on diabetic nephropathy was partly mediated by phosphatidylcholine (16:0_18:2) (10.7%). Additionally, the protective effect of CX3CR1 on monocytes against DMiVD was partly mediated by Unclassified Bacilli A (35%), Species CAG-177 sp003538135 (22.6%), and triacylglycerol (52:6) (25.5%). DISCUSSION: These findings advance understanding of DMiVD pathogenesis, highlighting that modulation of key metabolic pathways and immune regulatory nodes may represent promising therapeutic strategies. Further experimental studies are needed to validate these potential causal relationships. CONCLUSION: Using causal inference approaches, this study identifies immune cell-mediated mechanisms underlying DMiVD, involving gut microbiota, plasma lipids, and metabolites. The results suggest potential intervention targets for mechanistic studies and therapeutic development.

Mendelian Randomization Analysis↗

PubMed2025

Characterization of gut microbiota signatures in Indian preterm infants with necrotizing enterocolitis: a shotgun metagenomic approach.

INTRODUCTION: Necrotizing enterocolitis (NEC) is an inflammatory bowel disease that primarily affects preterm infants. Predisposing risk factors for NEC include prematurity, formula feeding, anemia, and sepsis. To date, no studies have investigated the gut microbiota of preterm infants with NEC in India. METHOD: In the current study, shotgun metagenomic sequencing was performed on fecal samples from premature infants with NEC and healthy preterm infants (n = 24). Sequencing was conducted using the NovaSeq X Plus platform, generating 2 × 150 bp paired-end reads. The infants were matched based on gestational age and postnatal age. RESULT: The median time to NEC diagnosis was 9 days (range: 1-30 days). Taxonomic analysis revealed a high prevalence of Enterobacteriaceae at the family level, with the genera Klebsiella and Escherichia particularly prominent in neonates with NEC. No statistically significant differences in alpha or beta diversity were observed between stool samples from infants with and without NEC. Linear regression analysis demonstrated that Enterobacteriaceae were significantly more abundant in stool samples from infants with NEC than without NEC (q < 0.05). Differential abundance analysis using Linear Discriminant Analysis Effect Size (LEfSe) identified Klebsiella pneumoniae and Escherichia coli as enriched in the gut microbiota of preterm infants with NEC. Functional analysis revealed an increase in genes associated with lipopolysaccharide (LPS) O-antigen, the type IV secretion system (T4SS), the L-rhamnose pathway, quorum sensing, and iron transporters, including ABC transporters, in stool samples from infants with NEC. CONCLUSION: The high prevalence of Enterobacteriaceae and enrichment of LPS O-antigen and T4SS genes may be associated with NEC in Indian preterm infants.

Humans↗

PubMed2025

Evaluation of the gastric microbiota based on body mass index using 16S rRNA gene sequencing.

INTRODUCTION: Obesity is a multifactorial condition influenced by various factors, including the gut microbiota. However, the relationship between the gastric microbiota and obesity remains poorly understood. This study aimed to investigate the composition of gastric microbiota, excluding Helicobacter pylori, in relation to body mass index (BMI) and metabolic indicators. METHODS: Thirty participants undergoing health checkups were classified into three groups-normal weight (BMI 18.5-22.9), overweight (BMI 23.0-24.9), and obese (BMI ≥25.0)-with ten individuals per group. Those with H. pylori infection, atrophic gastritis, or intestinal metaplasia were excluded. Gastric microbiota from four antral biopsies per subject were analyzed using 16S rRNA sequencing and functional profiling by metagenomic prediction. RESULTS AND DISCUSSION: Alpha diversity (Gini-Simpson index) was significantly lower in the combined overweight/obese group than that in the normal group (P=0.049). Beta diversity analysis revealed clear group separation (Bray-Curtis, P=0.005; unweighted UniFrac, P=0.004). Significant species differences between the groups were observed; specifically, the abundances of Muribaculum gordoncarteri, Turicibacter bilis, and Duncaniella dubosii, were significantly reduced in the overweight/obese group. Functional predictions showed differential enrichment of pathways related to fatty acid, amino acid, vitamin, and carbohydrate metabolism across BMI categories. These findings suggest that alterations in the gastric microbiota may be linked to obesity and metabolic dysregulation.

Humans↗

PubMed2026

Gut microbiota-derived metabolites target C5AR1/KDM2A/HCAR3 axis in inflammatory bowel disease: a multi-machine learning algorithms and molecular docking study.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic recurrent disorder. Gut microbiota-derived metabolites regulate intestinal homeostasis, but their molecular mechanisms in IBD remain unclear. Current studies lack systematic "microbiota-metabolite-target" network mining with multi-method validation. This study integrates network pharmacology, three machine learning algorithms, and molecular docking to construct this regulatory network in IBD. METHODS: Transcriptome data were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using limma (p < 0.05, |log2FC| > 0.5). Weighted gene co-expression network analysis (WGCNA) with an optimal soft threshold of β = 7 was performed to identify key module genes. Candidate genes were obtained by intersecting DEGs, gut microbiota-associated genes from the gutMGene database, and WGCNA module genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to explore the functional roles of candidate genes. Core genes were identified using three machine learning algorithms (LASSO, Boruta, and SVM-RFE), followed by protein-protein interaction (PPI) network analysis. Molecular docking was performed to assess the binding affinities between hub proteins and gut microbiota-derived metabolites. RESULTS: A total of 885 DEGs were identified between the IBD and control groups, including 463 upregulated and 422 downregulated genes. WGCNA identified 280 key module genes from the purple and yellow modules. The intersection of DEGs, gut microbiota-associated genes, and WGCNA module genes yielded 19 core candidate genes. PPI network analysis combined with three machine learning algorithms jointly identified C5AR1, KDM2A, and HCAR3 as core hub genes. ROC curve analysis demonstrated that all three hub genes achieved AUC values greater than 0.7 in both the training and validation sets, indicating excellent diagnostic performance for IBD. Enrichment analysis revealed significant associations with the TNF, NF-κB, and IL-17 signaling pathways. Molecular docking confirmed stable binding of C5AR1 with 1,3-Diphenylpropan-2-Ol (-7.87 ± 0.83 kcal·mol-¹) and HCAR3 with 3-Indolepropionic Acid (-6.35 ± 0.70 kcal·mol-¹), both below -5.0 kcal·mol-¹. CONCLUSION: This study first constructs a "gut microbiota-metabolite-hub gene" axis in IBD, providing a computational framework for microbiota-targeted precision therapy, and identifying C5AR1/KDM2A/HCAR3 as computationally predicted diagnostic biomarkers and 1,3-Diphenylpropan-2-Ol/3-Indolepropionic Acid as candidate intervention molecules that warrant further experimental validation.

Molecular Docking Simulation↗

PubMed2026

Brucellar spondylitis is associated with disturbance in gut microbiota and histamine metabolism associated inflammation.

BACKGROUND: The pathogenesis of brucellar spondylitis (BLS) has traditionally been considered to be primarily limited to local osteoarticular lesions. With the proposal of the "gut-spine axis" concept, the role of intestinal microecological dysbiosis in inflammatory spinal diseases has attracted in an increase of attention. The overactivated inflammatory cytokine network not only mediates bone destruction and intervertebral disc damage, but also forms a bidirectional interaction with gut microbiota dysbiosis through the "gut-spine axis," collectively driving disease progression. However, the inflammatory mechanism by which gut microbiota participates in the pathological process of BLS remains largely unclear. METHODS: This study recruited 20 BLS patients and 20 healthy donors. Multi-omics analysis including metagenomics, untargeted metabolomics, and targeted short-chain fatty acids (SCFAs) analysis, were used to compare the structural differences in gut microbiota between the two groups and screen for signature differential bacterial species. Plasma levels of histamine and histidine decarboxylase were measured by ELISA to clarify the role of differential histidine metabolic pathway in the disease. Additionally, plasma levels of lipopolysaccharide (LPS) and inflammatory cytokines (IL-1β, IL-6, IL-10, IL-17A, TNF-α) were detected by ELISA. The correlation between gut microbiota and inflammatory indicators was further analyzed. RESULTS: Compared to the healthy control group, the α-diversity of the gut microbiota in BLS patients was significantly reduced, with the microbial community structure exhibiting increased homogeneity. Beta diversity analysis revealed significant differences, suggesting that disease progression is associated with an overall imbalance in the gut microbiota and the deterioration of its specific structural composition. At the phylum level, the abundances of Actinomycetota, unclassified_d_Viruses, and Fusobacteriota were significantly increased in the gut microbiota of BLS patients compared to the control group, while the abundances of Bacillota and Pseudomonadota were significantly decreased. Further analysis revealed that, compared to the control group, the generic abundance of Enterococcus was significantly increased, while the proportions of Blautia, Faecalibacterium, Ruminococcus, Agathobacter, Roseburia, Clostridium, Eubacterium, Alistipes and Anaerobutyricum were significantly decreased. At the species level, the abundances of Enterococcus sp and Enterococcus-faecium were increased, whereas Blautia sp, Ruminococcus sp, Faecalibacterium sp, Faecalibacterium prausnitzii, Agathobacter rectalis, Eubacterium sp, Agathobacter sp, and Roseburia sp were decreased. Furthermore, untargeted metabolomics revealed that metabolites were enriched in the histidine metabolic pathway, and the levels of SCFAs including butyrate, isobutyrate, valerate, and 4-methylvalerate in the intestinal contents were reduced in BLS. Functional KEGG profiling revealed that key KOs involved in butyrate synthesis (e.g., K00074, K00172, K01640) and transport were globally downregulated in the patient group, whereas histidine decarboxylase KOs (K01693, K11755, K19787) that convert histidine to pro-inflammatory histamine were significantly enriched. The loss of butyrate-producing symbionts led to SCFAs deficiency and mucosal barrier disruption, creating ecological niches for facultatively anaerobic Enterococcus, which further exacerbated local inflammation via proteolytic fermentation and histamine production. Compared with the control group, BLS patients showed decreased plasma levels of IL-10, while levels of IL-1β, IL-6, IL-17A, and TNF-α were increased, and LPS levels were elevated. In addition, significantly elevated plasma pro-inflammatory LPS levels in patients with BLS suggest disruption of intestinal integrity and permeability. Correlation analysis indicated a close relationship between gut microbiota and inflammation. CONCLUSION: BLS is associated with gut microbiota dysbiosis and alterations in microbial metabolites, which may be linked to inflammatory responses and histamine metabolism. The differential microbial taxa identified in this study could be developed into a stool-based non-invasive diagnostic panel to facilitate early differentiation of BLS from other spinal disorders. Furthermore, restoring gut microbial balance through probiotic supplementation or dietary modulation may represent a promising adjunctive strategy to enhance the efficacy of standard antibiotic therapy and reduce disease recurrence.

Humans↗

PubMed2026

Alleviation of allergic rhinitis symptoms in an animal model by Lactiplantibacillus plantarum BGI-N6.

Allergic rhinitis (AR) is a chronic inflammatory disease with rising global prevalence and a substantial public health burden. Current treatments have limited efficacy and tolerability, highlighting the need for new strategies. Probiotics represent a promising approach due to their ability to modulate gut microbiota and host immunity. Here, we investigated the preventive potential of Lactiplantibacillus plantarum BGI-N6 in an OVA/ALUM-induced AR rat model. BGI-N6 administration alleviated AR symptoms and nasal mucosal pathology, reduced key allergic mediators, shifted serum immunoglobulin and cytokine levels toward normal, and restored the Th1/Th2/Th17/Treg balance. Metagenomic sequencing of cecal contents showed that these effects were accompanied by expansion of Bacteroidota-affiliated SCFA-producing taxa, restoration of microbial functional capacity, and identification of 41 core functional genes (KEGG Orthologues) consistently shifted across all three dose groups, with Bacteroides showing the strongest enrichment. Correlation analyses further connected these microbial shifts with immune parameters. These findings support BGI-N6 as a probiotic intervention for AR and implicate gut microbiota remodeling as a central correlate of probiotic-induced immunomodulation.

Animals↗

PubMed2026

Probiotic Lacticaseibacillus casei 2S-1 Attenuates Escherichia coli-Induced Enteritis via Gut Microbiota Modulation and Host Gene Regulation.

Maintaining gut microbial homeostasis is crucial for host health, whereas infection with Escherichia coli (E. coli) is a major contributor to intestinal inflammation and microbial dysbiosis. Recent research has focused on probiotic strategies for managing enteric inflammatory disorders. Previous studies have shown that beneficial microorganisms show protection through modulating host immune responses, enhancing intestinal epithelial barrier integrity, and inhibiting pathogenic bacteria. To evaluate the prophylactic effectiveness of a recently isolated strain, Lacticaseibacillus casei 2S-1, in a murine model of E. coli-induced enteritis, this study focuses on interactions within the microbiota-intestinal-immune axis, together with host transcriptional responses and pathway enrichment associated with oxidative stress and mitochondrial function. In vitro analysis of probiotic features, including growth dynamics, acidogenic capacity, and tolerance to acidic and bile salt environments, as well as genetic safety profiling, followed the methodical isolation and taxonomic identification of L. casei 2S-1. A preventive intervention protocol was established, and a murine model of enteritis was induced by exposure to E. coli. Histopathological analyses were performed to observe in vivo safety and protective efficacy. Changes in gut microbial structure were characterized by 16S rRNA gene sequencing, while host responses were identified by intestinal immunohistochemistry and transcriptome profiling. L. casei 2S-1 showed probiotic properties. In vitro analyses showed that the strain exhibited tolerance to acidic and bile salt conditions, and its untreated culture supernatant showed antimicrobial activity against pathogenic bacteria. Its safety profile was supported by genomic analysis, which verified the lack of virulence-associated genes and antibiotic resistance factors. In vivo, L. casei 2S-1 pretreatment reduced mortality and intestinal inflammation, modulated gut microbial composition, and preserved intestinal barrier-associated protein expression in infected mice. This study provides experimental evidence supporting the prophylactic effects of L. casei 2S-1 and its associations with gut microbiota modulation and host transcriptional responses, providing a foundation for further investigation of probiotic-based preventive strategies against intestinal infections.

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