Comprehensive analysis of the gut microbial diversity and metabolic profiles of brown bears and black bears from the Qinghai-Xizang Plateau

Abstract

Brown bears (Ursus arctos) and black bears (Ursus thibetanus) are important species on the Qinghai-Xizang Plateau. However, limited studies have been conducted on these species due to sampling constraints. This study, using 16S rRNA amplicon sequencing and untargeted metabolomics, analyzed fecal samples from six wild brown bears and six wild black bears. The results revealed distinct gut microbiota profiles, with brown bears showing higher microbial richness, particularly in Proteobacteria, Bacteroidota, and Actinobacteriota, while black bears were mainly enriched in Firmicutes. Lipid metabolism emerged as the primary metabolic pathway for both species, probably aiding adaptation to the plateau environment. Notably, we found positive correlations between differential metabolites and specific microbiota; in addition, traces of pesticides suggested contamination in the region. Our study provides valuable insights into the gut microbial diversity and metabolomic features of wild brown bears and black bears from the Qinghai-Xizang Plateau, contributing to our understanding of wildlife ecology in this unique environment.