The Gut Microbiome, Aging, and Longevity: A Systematic Review

Abstract

Aging is determined by complex interactions among genetic and environmental factors. Increasing evidence suggests that the gut microbiome lies at the core of many age-associated changes, including immune system dysregulation and susceptibility to diseases. The gut microbiota undergoes extensive changes across the lifespan, and age-related processes may influence the gut microbiota and its related metabolic alterations. The aim of this systematic review was to summarize the current literature on aging-associated alterations in diversity, composition, and functional features of the gut microbiota. We identified 27 empirical human studies of normal and successful aging suitable for inclusion. Alpha diversity of microbial taxa, functional pathways, and metabolites was higher in older adults, particularly among the oldest-old adults, compared to younger individuals. Beta diversity distances significantly differed across various developmental stages and were different even between oldest-old and younger-old adults. Differences in taxonomic composition and functional potential varied across studies, but Akkermansia was most consistently reported to be relatively more abundant with aging, whereas Faecalibacterium, Bacteroidaceae, and Lachnospiraceae were relatively reduced. Older adults have reduced pathways related to carbohydrate metabolism and amino acid synthesis; however, oldest-old adults exhibited functional differences that distinguished their microbiota from that of young-old adults, such as greater potential for short-chain fatty acid production and increased butyrate derivatives. Although a definitive interpretation is limited by the cross-sectional design of published reports, we integrated findings of microbial composition and downstream functional pathways and metabolites, offering possible explanations regarding age-related processes.

Administration with Quinoa Protein Reduces the Blood Pressure in Spontaneously Hypertensive Rats and Modifies the Fecal Microbiota

“…On the other hand, similar to the findings of Hoffman et al [ 36 ], we reported a distinction between rats at different ages, i.e., the older rats (15-week-old) had higher alpha diversity than young rats (10-week-old). Aging has physiological effects on both the host and the microbiome, and age-related processes may influence the gut microbiota and its metabolites [ 37 ]. Therefore, age should be considered when comparing the results containing age-dependent changes.…”

Evidence for the Contribution of Gut Microbiota to Age-Related Anabolic Resistance

“…Nevertheless, recent interventional studies show probiotic administration of L. plantarum to fortify mucosal integrity [60] and improve exercise performance (i.e., grip strength and swim endurance) with age [61]. Moreover, a recent systematic review underscored the greater abundance of L. plantarum in healthy long-lived individuals [146], speculatively highlighting the importance of L. plantarum preservation throughout aging. In sum, these studies [54][55][56][57][58][59][60][61]146] provide compelling evidence in support of a role for the gut microbiome, and specifically L. plantarum, in influencing the somatotropic axis and thus, skeletal muscle responsiveness.…”

The Effects of Lifestyle and Diet on Gut Microbiota Composition, Inflammation and Muscle Performance in Our Aging Society

“…Inter-individual differences in gut microbiota composition also tend to be emphasized in the older age, as suggested by a recent systematic review and meta-analysis of 27 human studies [13]. Resilience to stressors remains an important characteristic of the gut microbiota even in the late life.…”