Gut microbiota composition and bone mineral lossepidemiologic evidence from individuals in Wuhan, China

The SummaryWe explored the association between gut microbiota composition and bone mineral loss in Chinese elderly people by high-throughput 16S ribosomal RNA (rRNA) gene sequencing. Compared with controls, a smaller number of operational taxonomic units (OTUs), several taxa with altered abundance, and specific functional pathways were found in individuals with low-bone mineral density (BMD).IntroductionGut microbiota plays important roles in human health and associates with a number of diseases. However, few studies explored its association with bone mineral loss in human.MethodsWe collected 102 fecal samples from each eligible individual belonging to low-BMD and control groups for high-throughput 16S rRNA gene sequencing.ResultsThe low-BMD individuals had a smaller number of OTUs and bacterial taxa at each level. At the phylum level, Bacteroidetes were more abundant in the low-BMD group; Firmicutes were enriched in the control group; Firmicutes and Actinobacteria positively correlated and Bacteroidetes negatively correlated with the BMD and T-score in all subjects. At the family level, the abundance of Lachnospiraceae in low-BMD individuals reduced and positively correlated with BMD and T-score; meanwhile, BMD increased with increasing Bifidobacteriaceae. At the genus level, low-BMD individuals had decreased proportions of Roseburia compared with control ones (P<0.05). Roseburia, Bifidobacterium, and Lactobacillus positively correlated with BMD and T-score. Furthermore, BMD increased with rising abundance of Bifidobacterium. Functional prediction revealed that 93 metabolic pathways significantly differed between the two groups (FDR-corrected P<0.05). Most pathways, especially pathways related to LPS biosynthesis, were more abundant in low-BMD individuals than in control ones.ConclusionsSeveral taxa with altered abundance and specific functional pathways were discovered in low-BMD individuals. Our findings provide novel epidemiologic evidence to elucidate the underlying microbiota-relevant mechanism in bone mineral loss and osteoporosis.