Characterisation And Analysis Of The Gut Microbial Community Of Chinese Rhesus Macaques In High-altitude And Low-altitude Environments

The mammal gut microbiota is involved in various physiological processes and plays a key role in host environment adaption.However,for non-human primates(NHPs),little is known about their gut microbial community in high-altitude environments and even less about their adaption to such habitats.Here we collected faecal samples of rhesus macaques from five high-altitude populations(above 3,000 m)and three low-altitude populations(below 500 m).We characterised the gut microbial community of rhesus macaques from multiple high-altitude environments and compared it to those of low-altitude populations:1.By calculating the alpha diversity index,we found that high-altitude populations exhibited a higher diversity.Statistical analysis of beta diversity indicated significant differences between high-and low-altitude populations.2.Significant differences were also detected at the phylum and family levels.At the phylum level,the high-altitude gut microbial community was dominated by Firmicutes(63.42%),while at low altitudes,it was dominated by Bacteroidetes(47.4%).At the family level,the high-altitude population was dominated by Ruminococcaceae(36.2%),while the low-altitude one was dominated by Prevotellaceae(39.6%).Some families,such as Christensenellaceae and Rikenellaceae,were consistently higher abundant in all high-altitude populations.3.We analysed the overlap of operational taxonomic units(OTUs)in high-altitude populations and determined their core OTUs(shared by all four high-altitude populations).However,when compared with the low-altitude core OTUs,only 65% were shared,suggesting a divergence in core OTUs.4.Function prediction indicated a significant difference in gene copy number of 35level-2 pathways between high-and low-altitude populations;29 of them were higher in high altitudes,especially in membrane transport and carbohydrate metabolism.Thus we draw our conclusion that the gut microbial community of high-altitude rhesus macaques was significantly distinct from that of low-altitude populations in terms of diversity,composition and function.The difference in gut microbiota between these two populations may be caused by differences in host diet,environmental temperature and oxygen pressure.These differentiated gut microbial microorganisms may play a critical role in the adaptive evolution of rhesus macaques to high-altitude environments.