The gut microbiota of centenarians: Signatures of longevity in the gut microbiota profile

The changing physiology and lifestyle of elderly people affect the gut microbiota composition, the changes of which can, in turn, affect the health maintenance of the ageing host. In a co-evolutionary vision of the relationship between gut microbiota and ageing as an adaptive process of the human superorganism, long-living individuals who get to "successfully" age might be the ones whose microbiota manages to continuously re-establish a mutualistic relationship with the host, adapting to the progressive endogenous and environmental changes. The study of the gut microbiota of long-living people might provide insights on whether and how the gut microbiota can contribute to health maintenance and survival. Here, we provide the state of the art on the study of the gut microbiota in ageing and longevity, with particular attention to the perspective and direction this peculiar field of the microbiota research should take, in order to be a starting point for future mechanistic, pharmacological and clinical studies in ageing research. In particular, longevous people having different genetic, environmental, and cultural background must be analyzed and compared in the attempt to describe "universal" longevity dynamics, useful to unravel how the gut microbial ecosystem can help in expanding human healthspan.