Functional limitations decrease quality of life for older adults and are associated with myriad health risks. The gut microbiome is a potential therapeutic avenue for promoting functional independence among older adults, but a clearer understanding of mechanisms by which commensal gut bacteria may affect functional independence is needed.
To study the effects of microbes on independent functioning in older adults, I analyzed data from an ongoing cohort study, Integrative Longevity Omics (ILO), which so far has 220 shotgun metagenomics samples of the gut microbiome in centenarians and their offspring. By examining centenarians and their families, I am leveraging a population known to be enriched in protective factors for longevity and increased health span that have translational potential for mitigating age-related symptoms in older adults generally.
In this preliminary analysis, I tested for associations between microbial alpha/beta diversity and measures of functioning including activities of daily living (ADLs) and instrumental activities of daily living (IADLs). I also measured associations of taxonomic relative abundance with ADLs and IADLs. Species-level alpha diversity was not associated with ADLs or IADLs via linear regression adjusting for age, sex, and education. Beta diversity (Bray-Curtis dissimilarity) was associated with ADLs(p=0.03) and IADLs(p=0.004) adjusting for age, sex, and education using PERMANOVA analysis. Finally, we identified several taxa associated with ADLs, including families Coriobacteriaceae (β=-0.595; FDR q=0.008) and Desulfovibrionaceae (β=-0.386; FDR q=0.04), which have previously documented associations with diet, inflammation, and liver and cardiovascular disease. Future analyses will utilize an expanded dataset, include frailty outcomes, and integrate metabolomics data.