Gut microbes, ageing & organ function: a chameleon in modern biology?

Abstract

All species, including humans, are cohabited by a myriad of microbial species, which massively influences body function in a diet‐, exercise‐ and age‐dependent manner. The microbiome composition differs between individuals, partly due to the polymorphic immune system, as well as the environment, making the microbe–host interplay unique in each one of us. Ageing is a gradual loss of function in part due to reduced repair mechanisms and accumulation of tissue damage through mechanisms largely unknown. Accumulating evidence suggests that our indigenous microbes, a known major regulator of human physiology, are also connected to regulate the ageing process through signalling pathways and metabolites though the biological mechanisms are unknown. At an ageing meeting in Singapore in 2018, investigators discussed the current understanding of microbe regulation and its impact on healthy ageing. This review summarizes the highlights from the meeting and conveys some of the new ideas that emerged around gut microbes and the biology of ageing. While highly speculative, an idea emerged in which gut microbes constantly respond and evolve to environmental cues, as part of an ageing process, thus serving as a second messenger to support and attenuate organ decline in a diet‐, gender‐ and age‐dependent manner.

Differences in the gut Firmicutes to Bacteroidetes ratio across age groups in healthy Ukrainian population

“…The F/B ratio was also found to be lower in elderly subjects (65 y and older, n = 161) when compared to young adults (28-46 y, n = 9) in the study by Claesson et al [41]. It has been speculated that such changes in microbiome composition may reflect the gradual decline of organ function and ability to maintain barrier integrity in elderly [42,43]. In the study by Biagi et al [44], F/B ratios were estimated as 3.6, 5.1, and 3.9 in young adults (25-40 y, n = 20), elderly (63-76 y, n = 22) and centenarians (99-104 y, n = 21), respectively.…”

Gut Microbiome in Retina Health: The Crucial Role of the Gut-Retina Axis

“…These components are closely connected with the resident microbial community and suffer deterioration too, related to aging (Branca et al, 2019). With age, when all body functions also decline due to a gradual loss of stem cells and organ inefficiency increases due to the lower ability to repair cell damage, the composition of the microbiome also changes, reducing its diversity and richness (Reza et al, 2019). During aging we assist to a progressive modification of gut microbiota due to host factors as genetics, intestinal and immunological senescence, and due to environmental factors such as nutrition, biogeography, exposure to drugs, etc (García-Peña et al, 2017).…”

Advances of Mechanisms-Related Metabolomics in Parkinson’s Disease

“…As we all know, gastrointestinal microbes and host usually remain in a mutualistic relationship, in which the microbes keep its diversification and function via the gut to absorb nutrition. In turn, the parasitic microbiota parasitize in the digestive tract and produce a series of biochemical compounds to contribute physical and bioactive barriers or trigger protective immune responses to withstand the effect of exogenous factors ( Reza et al, 2019 ; Parker et al, 2020 ). Accumulating evidence suggests that many diseases have specific microbiome profiles and potentially communicate mechanisms between the gastrointestinal and the nervous systems, so alterations in gut microbiota have been linked to neurodegeneration, including AD, PD, and Multiple Sclerosis ( Sasmita, 2019 ).…”