The Diversity Of Capative Giant Panda Gut Microbiome Viewed Across Age

The giant panda is one of the world most precious endangered animals which always attracted attentions The intestinal flora is closely related to the host’s nutritional metabolism and diseases,and intestinal diseases are one of the foremost factors that realted to the health of giant panda.Thus the gut microbiota of giant pandas is of important implication to their health.By using molecular techniques,such as Illumina Hiseq sequencing combined with bioinformatics analysis,Faces samples from 22 giant pandas in Chengdu Research Base of Giant Panda Breeding at different ages were collected to explorethe gut microbial community diversity of giant pandas viewed across the age.The main research and conclusions follow:（1）A total of 712 OTUs were obtained from all samples.The sequencies could be classified to 17 phyla,36 classed,66 orders,120 families,and 259 genera.（2）The diversity indexes data showed that the OUT number and Chao1 index of geriatrics group were the highest,while adults showed the lowest.There was a significant difference between these two groups.The Shannon index showed that: geriatrics>adults>cubs>juveniles.（3）High-throughput sequencing results showed that Firmicutes（64.41%）and Proteobacteria（34.46%）were the dominant intestinal bacterias of giant pandas,as well as a small amount of Bacteroidetes（0.77%）.At the genus level,the top 10 bacteria were 95.33% of the sequences,including Escherichia-Shigella（32.51%）and Streptococcus（30.94%）were the main bacterial components.Followed by Clostridium_sensu_stricto₁（19.55%）,Sarcina（3.22%）,Turicibacter（3.00%）,Lactobacillus（2.79%）.（4）In phylum level,the relative abundance of Proteobacteria was the highest in cubs（75.43%）and significantly higher than that in juveniles and geriatrics（P<0.01）.In juveniles,Firmicutes was the absolute dominant bacteria（87.17%）and obviously higher than that in others（P<0.05）.Firmicutes was the highest relative abundance in adults and geriatrics and was about 2 times than that of Proteobacteria.（5）In genus level,Escherichia-Shigella was the most dominant bacteria in cubs,and the relative abundance of Escherichia-Shigella was much higher than that in other ages（P<0.05）.Streptococcus was the dominant bacteria in juveniles.Clostridium_sensu_stricto₁ and Streptococcus were the dominant bacteria in adults.In geriatrics,the relative abundance of the above three were the dominant bacteria.（6）Correlation analysis between the gut bacteria and the different age,Psychrobacter showed the highest correlation coefficient and the significant positive correlative with age（r=0.84,P<0.001）,Sarcina showed an obvious correlation with age.While [Ruminococcus]_gnavus_group,Pediococcus,Sphingomonas,Bacteroides and Lachnoclostridium had significant negative correlations with age.（7）The results of PICRUSt function prediction analysis showed that the gut microbiota of juveniles had the highest carbohydrate metabolism capacity and highest lactose degradation ability,while adults and geriatrics had higher cellulose degradation ability than that of juveniles.The lowest of the relative abundance of antibiotic resistance genes was observed in cubs,whereas the highest was observed in juveniles.Taken together,gut microbiota of giant panda changed with the age.The PICRUSt function prediction also indicated that the functional characteristics of bacterial communities were also different among different ages.This study further explored the relationship between the age-appropriate and the composition of gut bacterial compositions of captive giant pandas.These results provided an important theoretical basis for the development of health protection strategies,treatment plans for intestinal diseases and adjustment of diet composition for captive giant pandas at different ages.