Gut microb-aging and its relevance to frailty aging

Pathogenicity of commensal gut biofilm in prefrail aging

Pathophysiological mechanisms of unhealthy aging, particularly the transition from robustness to frailty, remain poorly understood. Despite extensive microbiome research on taxonomy, the behavior of early prefrail gut bacteria in their natural community-host mucosal tissue context remains unexplored. Using fecal samples from the INSPIRE-T aging human cohort, we characterized gut microbiota phenotype during prefrailty stages using a polymicrobial biofilm model. Results revealed that prefrail-derived biofilms exhibited distinct taxonomic and physical alterations, enhanced dispersal, and increased epithelial virulence compared to robust counterparts. Multiparametric analyses linked biofilm characteristics to clinical traits, suggesting their potential as aging status indicators. Polyphenol-rich grape pomace extract partially reversed prefrail biofilm alterations and reduced proinflammatory prefrail biofilm responses in vitro. Microbiota from prefrail-aged mice induced colon damage in antibiotic-treated recipients, establishing a prefrail microbiome-inflammation causality. Overall, the findings identified novel prefrail microbiome characteristics, established causal inflammatory links, and supported microbiota-targeted geroprotective interventions for the prefrail populations.

The Role of the Gut Microbiota in Female Reproductive and Gynecological Health: Insights into Endometrial Signaling Pathways

Fertility is a dynamic, multifactorial process governed by hormonal, immune, metabolic, and environmental factors. Recent evidence highlights the gut microbiota as a key systemic regulator of reproductive health, with notable impacts on endometrial function, implantation, pregnancy maintenance, and the timing of birth. This review examines the gut-endometrial axis, focusing on how gut microbial communities influence reproductive biology through molecular signaling pathways. We discuss the modulatory roles of microbial-derived metabolites-including short-chain fatty acids, bile acids, and tryptophan catabolites-in shaping immune tolerance, estrogen metabolism, and epithelial integrity at the uterine interface. Emphasis is placed on shared mechanisms such as β-glucuronidase-mediated estrogen recycling, Toll-like receptor (TLR)-driven inflammation, Th17/Treg cell imbalance, and microbial translocation, which collectively implicate dysbiosis in the etiology of gynecological disorders including endometriosis, polycystic ovary syndrome (PCOS), recurrent implantation failure (RIF), preeclampsia (PE), and preterm birth (PTB). Although most current evidence remains correlational, emerging insights from metagenomic and metabolomic profiling, along with microbiota-depletion models and Mendelian randomization studies, underscore the biological significance of gut-reproductive crosstalk. By integrating concepts from microbiology, immunology, and reproductive molecular biology, this review offers a systems-level perspective on host-microbiota interactions in female fertility.

Analysis of alterations in the composition of the intestinal microbiota in frail older individuals

BACKGROUND

Frailty is an ageing-associated geriatric syndrome that severely affects the functional status, quality of life and life expectancy of older adults. Immune dysfunction and chronic inflammation play crucial roles in frailty, and this study aimed to explore the correlation between the intestinal microbiota and frailty.

METHODS

A cross-sectional survey was conducted using a comprehensive geriatric assessment of older individuals who underwent medical checkups at the Health Management Center from April 2023 to May 2024. A total of 672 older individuals who met the inclusion criteria were included and divided into a healthy control group and a frail case group. Clinical data, as well as blood and stool samples, were collected. The data from the two groups were analysed with 16S rRNA sequencing in 20 and 30 cases, respectively. SPSS 25.0 was used for statistical analysis.

RESULTS

There were significant differences in income, smoking, and globulin levels between the two groups, while there were no differences in age or sex. There was no significant difference in the abundance or species evenness of intestinal bacteria between the two groups. However, the abundance of accessory bacteria, bifidobacteria, and Escherichia coli in the frail group was greater than that in the control group. Specifically, Escherichia-Shigella was significantly upregulated and fit well into the prediction model of frailty.

CONCLUSION

The gut microbiota of frail older individuals underwent significant changes in structural composition, and the presence of Escherichia-Shigella may be a diagnostic marker for debilitating diseases. These findings provide an essential clinical reference value for developing methods for preventing or alleviating frailty based on specific microbial communities.