NIA Symposium on Microbiome and Aging
NIH Roadmap funded the Human Microbiome Project in 2008. Since then, the reference genomes from over 5000 bacterial and viral strains collected from human airways, blood, eye, GI tract, heart, lymph node, oral, cavity, skin, urogenital tract, and other parts of body have now been sequenced and made available to researchers in the field. In addition to the sequencing of many microbiomes and tool development, fifteen demonstration projects have been funded to test hypothesized correlations between the microbiome and human health and disease. Although none of the funded demonstration projects funded from the Human Microbiome Project had focused on age -related changes in the microbiome, there are now multiple reports that changes in the composition of the microbiome, also known as dysbiosis, happen with aging and that alterations in diet, different classes of medications and the living environment are important drivers of these observed changes. Links are emerging between the microbiota and a variety of clinical problems plaguing older adults, including physical frailty, Clostridium difficile colitis, vulvovaginal atrophy, colorectal carcinoma, atherosclerotic and neurodegenerative diseases. Many of the mechanisms behind these links are largely unknown. However, the role of the metabolites produced by different bacterial species in health and disease is beginning to be appreciated. For example, the effects of one class of products that is referred to as short chain fatty acids (SCFAs), including butyric acid is beginning to be studied more extensively. Butyrate and other fermentation-derived SCFAs are produced in the mammalian gut by the fermentation of dietary fiber by several different bacterial species. The effects of butyrate and related compounds on various age-related diseases that have an inflammatory basis such as colon cancer, diabetes and neurological disorders are areas of active research. The alteration of bacterial composition can affect the levels of various metabolites which in turn can affect energy metabolism, immune function and epigenetic alterations in tissues including the aging brain. Manipulation of the microbiota and microbiome of older adults therefore holds promise as an innovative strategy to influence the development of comorbidities associated with aging.
A workshop will be held in Bethesda on Nov 29-30 to discuss the status of the field and research opportunities on studies of the microbiome and aging. It is hoped that the workshop may identify effective strategies to stimulate research on changes of microbiomes during aging and the effects of these changes on aging-related conditions and diseases.