Comparative analysis of different Phyllostachys species on gut microbiome and fecal metabolome in giant pandas (Ailuropoda melanoleuca)

Abstract

The influences of different bamboo species on the microbiome and metabolome of giant pandas (Ailuropoda melanoleuca) remain understudied. The aim of this study was to investigate the effects of different Phyllostachys species on the gut microbial communities and fecal metabolite profiles in giant pandas. Metagenome and metabolome were performed on the feces of giant pandas fed with different Phyllostachys species (P. edulis, P. iridescens, P. glauca, and P. violascens). The results of metagenome showed that dietary with P. glauca could notably decrease the microbial Shannon index. The relative abundances of both Cellulosilyticum and Pseudomonas were enhanced after dietary with P. iridescens, suggesting P. iridescens could enhance the cellulose-degrading function in giant pandas. However, dietary with P. glauca or P. violascens could increase the relative abundances of certain pathogenic bacteria (Escherichia, Shigella, and Klebsiella). Metabolomics analysis further revealed that all experimental groups exhibited notably elevated levels of fecal flavonoids and fatty acids. In addition, the correlation analysis showed that certain nutrients of bamboo leaves (mainly crude protein and Cu) were significantly correlated with several differential gut bacteria and fecal metabolites. Based on the present results, P. iridescens might be a substitute for the routinely used Phyllostachys species (P. edulis) in the captive management of giant pandas. The results have revealed that bamboo species is an important factor affecting the gut microbiota and fecal metabolites in giant pandas. Our results could provide important information about bamboo species-induced alterations on the microbiome and metabolome in giant pandas.