In 400 B.C., Hippocrates stated that “bad digestion is the root of all evil” and “death sits in the bowels”.
Despite an explosion of studies linking the gut microbiota to health and diseases, its application in clinical settings remains poorly understood and somehow confusing due to the huge interindividual variability.
What happens in aging?
In studies of genetically homogeneous rodents, such as mice aged in the same environment, it came out that natural aging decreases gut microbiota diversity and bacterial biosynthesis of some vitamins (B12 and B7), impairs gene expression associated with DNA repair, and enhances creatine degradation, associated with muscle catabolism.
The composition of the gut microbiota changes progressively as people age, despite significant interindividual variability and the influence of external factors such as diet, medications, type of exercise or mobility, and the geographical origin of the host. Gut dysbiosis and loss of beneficial commensals appear to facilitate premature death of elderly frail people, while higher microbial biodiversity and abundance of A. muciniphila are features of human centenarians.
Call it “longevity adaptation” or “microbial trajectories in aging”, an enrichment in health-associated gut bacteria is evident in our longest-lived communities. 💫 🥇
An Italian and Chinese study of centenarians found increased microbial community richness and abundance of health-related bacterial genera and families, such as Oscillospira, Christensenellaceae, Akkermansia, and Bifidobacterium, suggesting that healthy aging can be shaped by specific commensal microbes in the gut [1-2].
How?
Oscillospira and Christensenellaceae control leanness and decrease certain inflammatory markers
A. muciniphila protects the gut barrier integrity, supports SCFA-producing bacteria and dampens inflammation and metabolic impairments (such as insulin resistance)
Bifidobacterium generates lactate and acetate and counteracts pro-inflammatory bacteria (like Proteobacteria)
Moreover, a recent study on Nature proved how the pronounced virome in the centenarian microbiome increased the bacterial conversion of methionine to homocysteine, sulphate to sulphide and taurine to sulphide.
The intense metabolic output of microbial hydrogen sulphide in centenarians could in turn support the gut mucosal integrity and resistance to pathobionts [3].
As centenarians represent a unique and surprisingly vigorous population with a decreased susceptibility to age-related diseases, metabolic impairments and infections compared with frail elderly people, the key to their longevity deserves our mellowest attention. 🎯
Link to the paper: https://lnkd.in/dRhReb2Y
[1] Kong, F., Hua, Y., Zeng, B., Ning, R., Li, Y., & Zhao, J. (2016). Gut microbiota signatures of longevity. Current Biology, 26(18), R832-R833. https://lnkd.in/dvtw_rCz
[2] Biagi, E., Franceschi, C., Rampelli, S., Severgnini, M., Ostan, R., Turroni, S., ... & Candela, M. (2016). Gut microbiota and extreme longevity. Current Biology, 26(11), 1480-1485. https://lnkd.in/dJUKH8ms
[3] Johansen, J., Atarashi, K., Arai, Y., Hirose, N., Sørensen, S. J., Vatanen, T., ... & Plichta, D. R. (2023). Centenarians have a diverse gut virome with the potential to modulate metabolism and promote healthy lifespan. Nature microbiology, 8(6), 1064-1078. https://lnkd.in/dy-Yz5t8
[4] Ragonnaud, E., & Biragyn, A. (2021). Gut microbiota as the key controllers of “healthy” aging of elderly people. Immunity & Ageing, 18, 1-11. https://lnkd.in/dRhReb2Y
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