Bacterial Community Structure Specificity Analysis of Different Gland Areas in the Stomach of Bactrian Camels

Bactrian camels living in the desert and semi-desertification regions of China are ideal animal models for studying adaptation to the desert environment. Long-term evolution and natural selection make the gastrointestinal microbial community form its unique physiological functions and metabolic characteristics. In this study, the 16s rRNA was applied in order to explore distribution characteristics and differences of the bacterial community on mucosal surfaces of cranial glandular sac area (CRGSA), caudal glandular sac area (CAGSA), third glandular sac area (TGSA), cardiac gland region (CGR), fundus gland region (FGR) and pyloric gland region (PGR). We analyzed five peak adult healthy Bactrian camel from the level of phylum, class, order, family and genus. 1724 operational taxonomic units (OTU) were identified at a 97% species level sequence identify. 22 phylums, 38 classes, 65 orders, 85 families and 108 genera were identified from 30 samples. At the phylum level, Bacteroidetes (54.97%), Firmicutes (21.7%) and Proteobacteria (7.3%) were pre-dominant bacteria on mucous surface of stomach gland area of Bactrian camel. Bacteroidetes and Fibrobacteres bacteria respectively accounted for 59.54% and 3.22% of the mucosa on the glandular sac area and 52.37% and 1.49% of the mucosa in the three glandular regions of the abomasum. The glandular sac area was higher than the three glandular regions of the abomasum. Sample OTU PCA, Alpha diversity and Beta diversity analysis showed that the diversity and community structure of bacteria were similar in the glandular sac area and CGR, but the bacterial species and abundance of the glandular sac area and CGR were lower than in FGR and the PGR. Bacteroidetes bacteria had no significant difference among the four groups( P ＞0.05) in CGRSA, CAGSA, TGSA and CGR. The relative proportion of the 4 groups was significantly higher than in FGR and PGR. There was no significant difference between FGR and PGR ( P ＞0.05). This research found that Bacteroidetes and Fibrobacteres bacteria than can digest cellulose distributed on the mucous of glandular sac areas of Bactrian camel. This important reason may make Bactrian camel digestive capacity higher than other ruminants. The tissue structure and gland secretion components of the glandular sac area and CGR are similar, and the bacterial community structure is similar on the mucosa. The tissue structure and gland secretion components of FGR and PGR are similar, and the bacterial community structure is also similar on this mucosa. It is suggested that the glandular tissue structure and its secreted glandular components may have an important influence on the distribution of bacterial communities.