The Bacteriomes of Ileal Mucosa and Cecal Content of Broiler Chickens and Turkeys as Revealed by Metagenomic Analysis

The gastrointestinal (GI) bacteriome of poultry is important in host nutrition and health, but its diversity and composition remain poorly characterized. In this study we phylogenetically characterized the bacteriome in the cecal contents and ileal mucosa of chickens and turkeys using metagenomics empowered by pyrosequencing technique. >95% coverage of bacterial diversity was achieved except for the turkey ileal mucosa. Collectively, 3,401 and 125 operational taxonomy units (OTU, defined at a 0.03 phylogenetic distance) in chicken, and 1,687 and 16 OTUs in turkey were identified from the cecal content and the ileal mucosa, respectively. Besides those previously reported, 39 and 50 additional genera of bacteria were identified in the chicken and turkey cecal bacteriome, respectively. Although the GI bacteriomes of the same region in both species exhibited greater similarity than the bacteriomes of different regions within each species, broiler chickens and turkeys harbor a distinct intestinal bacteriome. Such difference may suggest different dietary interventions for bacteriome modulation for enhanced nutrient utilization and gut health. The results may also be useful in developing prebiotics, probiotics, and analytical tools (e.g., phylochips). We also determined the variation in the number of OTUs and variability between two independent pyrosequencing runs and two data processing pipelines.