A cross-sectional study of compositional and functional profiles of gut microbiota in Sardinian centenarians

Abstract Sardinia, Italy, has a high prevalence of residents who live over 100 years. The reasons for longevity in this isolated region is currently unknown. Gut microbiota may hold a clue. To explore the role gut microbiota may play in healthy aging and longevity, we used metagenomic sequencing to determine the compositional and functional differences in gut microbiota associated with populations of different ages in Sardinia. Our data revealed that the gut microbiota of both young and elderly Sardinians shared similar taxonomic and functional profiles. A different pattern was found in centenarians. Within the centenarian group, the gut microbiota was correlated with the Functional Independence Measurement of the host. Centenarians had a higher diversity of core microbiota species and microbial genes compared with that in the young and elderly. We found that the gut microbiota in Sardinian centenarians displayed a rearranged taxonomic pattern when compared with these of the young and elderly, featured by depletion of Faecalibacterium prausnitzii and Eubacterium rectale, and enriched for Methanobrevibacter smithii and Bifidobacterium adolescentis. Moreover, functional analysis revealed the microbiota in centenarians had high capacity for central metabolism, especially glycolysis and fermentation to Short-Chain Fatty Acids (SCFAs), although the gut microbiota in centenarians was low in degradation of carbohydrates including fibers and galactose. The gut microbiota has been proposed as a promising determinant for human health. Centenarians as a model for extreme aging may help to understand the correlation of gut microbiota with healthy aging and longevity. Here we confirmed that centenarians had microbiota elements usually associated with benefits to health. Our finding of a high capacity of glycolysis and related SCFAs production represented a healthy microbiome and environment that is regarded as beneficial for host gut epithelium. The low abundance of pathways involved in carbohydrate degradation was also found in the gut microbiota of Sardinian centenarians and is often associated with poor gut health. Overall, our study here represents an expansion of previous research investigating the age-related changes in gut microbiota. Furthermore, our study provides a new prospective for potential targets for gut microbiota intervention directed at limiting gut inflammation and pathology and enhancing a healthy gut barrier.