Gut-bone axis perturbation: Mechanisms and interventions via gut microbiota as a primary driver of osteoporosis

A growing number of studies have highlighted the significance of human gut microbiota (GM) as a potential target for osteoporosis. In this review, we discuss the effect of GM to bone metabolism focusing on two aspects: the local alterations of the human gut permeability that modify how the GM interact with the gut-bone axis (e.g., intestinal leakage, nutrient absorption), and the alterations of the GM itself (e.g., changes in microbiota metabolites, immune secretion, hormones) that modify the events of the gut-bone axis. We then classify these changes as possible therapeutic targets of bone metabolism and highlight some associated promising microbiome-based therapies. We also extend our discussions into combinatorial treatments that incorporate conservative treatments, such as exercise. We anticipate our review can provide an overview of the current pathophysiological and therapeutic paradigms of the gut-bone axis, as well as the prospects of ongoing clinical trials for readers to gain further insights into better microbiome-based treatments to osteoporosis and other bone- degenerative diseases. The translational potential of this article: This paper reviewed the potential links between gut microbiota and osteoporosis, as well as the prospective therapeutic avenues targeting gut microbiota for osteoporosis management, presenting a thorough and comprehensive literature review.