Gut microbiota dysbiosis and its relation to osteoporosis and sarcopenia in older people

Purpose of review: Gut microbiome is increasingly recognized as a modulator of the biology of aging. Several preclinical studies suggest that dysbiosis, typically arising in the older age, is associated with osteoporosis and sarcopenia. This review examines the recent findings on the mechanistic aspects of the gut-bone and gut-muscle axes in aging and provides a critical overview on their translation to clinical practice. Recent findings: Gut microbiome can modulate the pathophysiology of osteoporosis and sarcopenia through multiple mechanisms, particularly involving the production of bioactive mediators such as short-chain fatty acids (SCFAs), bile acids and tryptophan metabolites. Dysbiosis increases the risk of osteoporosis, fragility fractures and muscle wasting, with possible sex-specific differences, but the definition of GM traits associated with each condition is inconsistent across studies. Short-term microbiome-modifying treatments, including probiotics and functional foods, slowed down the age-related decline in bone mineral density and improved muscle function in a handful of small-sized clinical studies. Summary: Gut microbiome remains a very promising therapeutic target against osteoporosis and sarcopenia, but no recommendations can be made for clinical practice at the current state-of-art. Microbiome-targeted strategies may soon emerge as valuable adjuvant therapies in the management of age-related musculoskeletal decline.