Impacts of Age on the Gut Microbiota in Captive Giant Pandas

The gut microbiota is the most complex and most abundant symbiotic microbial ecosystem in animals. Aging is one of the main factors that cause gut microbiota structure changes, and the relationship between age and the gut microbiota in the giant panda has been a key focus of attention. The giant panda has a specialized diet of bamboo, and it relies on the microbiota that colonizes its gut to complete digestion. However, there is no in-depth understanding of the changes in the gut microbiota across the lifespan of giant pandas. Here, we identified the differences in the gut microbiota between four age groups (cubs, juveniles, adults, and geriatrics) using 16S rRNA gene high-throughput sequencing on an Illumina MiSeq platform. The results revealed that Firmicutes (mean{+/-}SD: 65.45{+/-}30.21%; range: 0.91-99.62%) and Proteobacteria (mean{+/-}SD: 31.49{+/-}27.99%; range: 0.26-85.35%) were the dominant phyla. The relative abundance of Escherichia-Shigella was high in both the cubs and juveniles. It is interesting to note that the adults had the highest richness and lowest diversity, while the cubs had the opposite. In summary, our study indicates that the gut microbial community composition, abundance, and functional pathways differ across four age groups of giant pandas. Exploring the influence of age, an endogenous influencing factor, on gut microbes provides basic scientific data for monitoring gut microbial dynamics and formulating gut microbial health management approaches, thereby improving the protection of giant pandas.