The gut microbiota is today regarded as one of the main determinants of healthy aging. The most recent evidence shows how the composition of the microbiome influences longevity, immunity, and the risk of chronic diseases, opening up new prospects for personalized medicine. On the occasion of initiatives dedicated to learning about the microbiota, attention to the role of microorganisms in human health is growing.
Also for this reason, on the occasion of the World Microbiome Day on June 27, scientists, healthcare professionals, and citizens participate in events, conferences, and initiatives dedicated to understanding the microbiota, with the goal of raising awareness about the importance of microorganisms for the health of humans, animals, and the entire planet.
Gut Microbiota and Aging
The intestinal microbiota, a vast endogenous ecosystem, coevolves with the host from birth, establishing a mutually beneficial symbiotic relationship. In adults, the human gut microbiota typically comprises bacteria, fungi, viruses, and bacteriophages. The dominant bacterial phyla include Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Verrucomicrobia, with Firmicutes and Bacteroidetes representing the majority of the microbial population.
These intestinal commensals contribute critically to host metabolism, energy homeostasis, and immune stability, synthesizing key microbial metabolites, such as short-chain fatty acids (SCFAs), secondary bile acids (SBAs), essential vitamins (B vitamins, vitamin K2), and other fundamental nutrients.
The composition and diversity of the intestinal microbiota gradually change with age. Specifically, meta-analyses of global metagenomic sequencing data have consistently confirmed that older individuals harbor a greater abundance of pro-inflammatory pathobionts, including Enterococcus, Streptococcus, Actinomyces, and Ruminococcus, and a reduced abundance of beneficial SCFA-producing bacteria such as Faecalibacterium, Roseburia, and Coprococcus. These microbial signatures may be linked to aging phenotypes that are not healthy.
Profiling studies of the gut microbiome in centenarians in China and Italy have revealed greater alpha diversity than younger individuals, challenging the general trend of decreasing alpha diversity with age. In diverse populations, including those in China, Korea, Japan, and Italy, centenarians consistently show enrichment of Akkermansia and Christensenellaceae, suggesting that the bacterial taxa may serve as potential microbial biomarkers of healthy aging and longevity.
A Modulator and Mediator of Aging
A review, published in Biomedicines, synthesizes the current evidence on the role of the gut microbiota in aging, examining its role in modulating and mediating the effects of longevity interventions, as well as how microbiota-associated mechanisms intersect with emerging anti-aging therapies.
The gut microbiota is a key modulator of aging: it influences immune regulation, metabolic homeostasis, and neuroendocrine signaling. A diversified and balanced gut microbiota promotes healthy longevity by supporting intestinal barrier integrity, nutrient metabolism, and anti-inflammatory responses. Conversely, dysbiosis contributes to the onset and progression of age-related diseases, including neurodegeneration, cardiovascular diseases, cancer, and metabolic disorders.
Currently, targeted anti-aging interventions at the main biological mechanisms of aging, such as insulin/IGF-1 signaling, mTOR, AMPK, and sirtuins, represent a primary objective in the field of gerontology. Compounds such as metformin, rapamycin, anti-inflammatory agents, GLP-1 agonists, senolytics, spermidine, SGLT2 inhibitors, and sirtuin activators have demonstrated lifespan extension in animal models. In humans, some of these interventions are associated with improvements in metabolic, cardiovascular, musculoskeletal, respiratory, cognitive, and ocular functions.
Towards Personalized Strategies
Future research should prioritize:
- integration of multi-omics technologies (metagenomics, metabolomics, single-cell sequencing, and host transcriptomics) to identify predictive microbial biomarkers of aging and their dynamic regulatory networks;
- development of precision intervention strategies, such as AI-driven profiling of the gut microbiome to guide the design of personalized probiotic combinations;
- exploration of new delivery systems (e.g., encapsulation of SCFAs in nanoparticles or next-generation engineered probiotics) to enhance efficacy;
- conducting large-scale longitudinal cohort studies to determine the long-term impact of microbiota-targeted interventions on healthy lifespan and resilience in aging populations.
In conclusion, the gut microbiota acts as both a biosensor of aging physiology and a potentially modifiable therapeutic target. By integrating knowledge from centenarian biology, fecal microbiota transplant studies, and translational omics sciences, the field is poised to move beyond purely correlative studies to focus on causal relationships and clinical applications. The strategic integration of microbiota-based interventions into personalized geriatric care offers a promising systemic approach to delaying aging, reducing disease burden, and promoting healthy aging.
Sources
Gao W, Lee HY, Min KJ. Aging and the microbiome: implications for health and disease. BMB Rep. 2026 Jan;59(1):40-50. doi: 10.5483/BMBRep.2025-0152. PMID: 41276282; PMCID: PMC12867172;
Garzon-Escamilla N, Medina-Cardena M, Roy P et al. Mechanistic Links Between the Gut Microbiome and Longevity Therapeutics. Biomedicines. 2026; 14(2):316. https://doi.org/10.3390/biomedicines14020316.
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