Contributions of the intestinal microbiota to bone

Abstract

Introduction: Overall bone metabolism is highly regulated by the intestine, mainly mediated by parathyroid hormone (PTH) and vitamin D. However, emerging pieces of evidence have shown this regulation is also strongly associated with intestinal microbiota by releasing metabolites, which affects directly or indirectly the bone. Objective: To review the contributions of the intestinal microbiota to bone. Methods: Thus, a narrative review from articles on contributions of intestinal microbiota to bone was conducted using database PubMed covering a period from 1997 until July 2023. Articles published in the form of original articles, systematic review or meta-analysis using the descriptors: bone and microbiota, bone and bacteria, gut microbiota and bone and probiotics were read and summarized throughout text. Results: Initially, we searched for understanding, which bacteria are resident or transitory and which are the factors released that either indirectly or directly act on bone, thus modifying its quantity or quality. Therein, we briefly explored how intestine, and bone are interconnected and finally about how the type of intestinal microbiota is associated with bone metabolism, quality and quantity. In particular, we reported some main studies on probiotics and bone health. Conclusion: This review brought together information from the literature on the role of intestinal bacteria in bone, revealing possibilities for directing the microbiota to maintain or gain bone in quantity and quality and thus prevent bone fractures in a close future, especially for osteoporotic individuals.