A broad range of evidence points to the composition of the gut microbiome providing a similar degree of influence on long-term health as is the case for lifestyle choices in diet and degree of physical activity. The relative proportions of microbial species making up the gut microbiome change with age, and much of this change appears unfavorable. Microbes that manufacture beneficial metabolites necessary for tissue function throughout the body decline in number, while microbes that provoke chronic inflammation or manufacture harmful metabolites increase in number.
Studies involving the transfer of fecal material between young and old individuals, carried out in relatively short-lived species such as killifish and mice, give us some idea as to the importance of the gut microbiome. In killifish, old fish receiving a fecal microbiota transplant from young fish lived an average of ~40% longer than their untreated peers. Effect sizes in very short-lived species are typically much larger than is the case in mammals, but even in mice there are clear signs that transplantation of a young microbiome into an old animal produces a lasting rejuvenation of the gut microbiome and significant improvement in health.
These and other equally interesting results from animal studies in recent years have provoked a serious effort to produce a map of correlations in humans between clearly measurable health metrics and specific differences in composition in the gut microbiome. Even a partial map would pave the way for the development of therapies that use a much simpler composition of microbial species than is the case for a donor microbiome, making it possible to predict, understand, and assess the profile of possible side-effects. Transplanting a standard mix of three (or ten, or twenty) species is a much easier proposition to put in front of regulators than transplanting a varied mix of thousands of species taken from donors, if the goal is ultimately to treat large fractions of the population, a scenario in which a very high bar for safety will be set.
Healthy Ageing and Gut Microbiota: A Study on Longevity in Adults
Many studies have focused on ageing and gut microbiota, but the correlation between gut microbiota and physical function in older adults, especially those with longevity, remains obscure and deserves further exploration. In this study we investigated changes in the gut microbiota and the association between gut microbiota and physical function in adults with longevity. This is a prospective observational study. Fifty-one older adults aged ≥ 60 years (including 27 participants aged 90 years and above) were enrolled. Information on clinical data, physical function including intrinsic capacity by Integrated Care for Older People (ICOPE) tool, and dietary habits of participants was collected and analysed. Gut microbiota structure and functional pathways were analysed by Metagenomics.
Intrinsic capacity (measured as ICOPE scores) of adults' longevity (aged 90-98, LONGE group) was significantly lower than older adults aged 60-89 years (CON group) (5.44 ± 2.15 vs. 6.71 ± 1.46). Gut microbiota of the LONGE group is enriched in Akkermansia and Bifidobacterium, which may be beneficial to health. Gut microbiota was closely related to daily milk consumption, anxiety, and physical function including grip strength by the Short Physical Performance Battery (SPPB).
Bacteroides plebeius and Bacteroides eggerthii were increased in long-living adults with better physical function. Escherichia coli was more abundant in frail young-old adults. Grip strength is positively correlated with the abundance of Roseburia hominis, Eubacterium rectale, Eubacterium eligens, and Roseburia intestinalis. Pathways related to amino acid synthesis that include L-isoleucine, L-valine, and L-threonine were over-presented in long-living adults of better physical function. Adults with longevity showed comparable gut microbiota abundance to younger elderly individuals. The gut microbiota of long-living adults showed higher abundance of potentially beneficial bacteria, and the altered bacteria are closely associated with physical function.
Changes in the gut microbiota may precede clinical indicators during the process of ageing. Gut microbiota may be a potential biomarker for longevity and healthy ageing. Nutrition and emotional state can be important influencing factors.
View the full article at FightAging
