Dietary patterns have been identified as one of the most important modifiable risk factors for several non-communicable diseases, inextricably linked to the health span of older people. Poor dietary choices may act as triggers for immune responses such as aggravated inflammatory reactions and oxidative stress contributing to the pathophysiology of several ageing hallmarks. Novel dietary interventions are being explored to restore gut microbiota balance and promote overall health in ageing populations. Probiotics and, most recently, postbiotics, which are products of probiotic fermentation, have been reported to modulate different signalling biomolecules involved in immunity, metabolism, inflammation, and oxidation pathways. This review presents evidence-based literature on the effects of postbiotics in promoting healthy ageing and mitigating various age-related diseases. The development of postbiotic-based therapeutics and diet-based interventions within a personalised microbiota-targeted approach is proposed as a possible direction for improving health in the elderly population. Despite growing evidence, the data regarding their exact mechanistic pathways for antioxidant and immunomodulating activities remain largely unexplored. Expanding our understanding of the mechanistic and chemical determinants of postbiotics could contribute to disease management approaches, as well as the development of and optimisation of biotherapeutics.

Aging is associated with alterations in gut microbiota, yet the combined effects of geography and diet remain underexplored in elderly populations. This study investigated the gut microbiota of 227 healthy Vietnamese individuals aged ≥60 years, stratified by select urban and rural residence in both Hanoi and Thanh Hoa provinces, and across three age groups (60–69, 70–79, ≥80 years). Dietary patterns were collected and recorded for each participant. 16S rRNA gene sequencing revealed significant differences in microbial diversity and composition associated with geographical location (urban, rural) and age. Urban participants in Hanoi exhibited higher richness and greater abundance of health-associated genera, including Bifidobacterium, Fusicatenibacter, and Blautia, likely reflecting more diverse plant-based diets. In contrast, rural participants in Thanh Hoa showed enrichment of beneficial butyrate-producing genera such as Fusicatenibacter, Roseburia, Lachnospira and Blautia, possibly linked to traditional diets rich in freshwater fish and fermented foods. Participants aged 70–79 years displayed reduced microbial richness compared to other age groups. Age-related reductions in Roseburia, Veillonella, and Prevotella were also observed. These findings highlight how geography, diet, and aging shape the gut microbiota and may guide microbiota-targeted dietary strategies to promote healthy aging.