Strength Lies in Diversity: How Community Diversity Limits Abundance in the Chicken Intestine.

The transfer of the intestinal microbiota from adult to juvenile animals reduces prevalence and abundance. The mechanism behind this exclusion is unknown, however, certain member species may exclude or promote pathogen colonization and abundance in chickens correlates with intestinal community composition. In this study, newly hatched chicks were colonized with Typhimurium and 16S rRNA libraries were generated from the cecal bacterial community at 21, 28, 35, and 42 days of age. was quantified by real-time PCR. Operational taxonomic units (OTUs) were assigned, and taxonomic assignments were made, using the Ribosomal Database Project. Bacterial diversity was inversely proportional to the abundance in the chicken cecum ( < 0.01). In addition, cecal communities with no detectable (exclusive community) displayed an increase in the abundance of OTUs related to specific clostridial families (, , and ), genera ( and ) and member species (, , and ). For cecal communities with high abundance (permissive community), there was a positive correlation with the presence of unclassified , clostridial genera and clostridial species , , and . These findings strongly support the link between the intestinal bacterial species diversity and the presence of specific member species with abundance in the chicken ceca. Exclusive bacterial species could prove effective as direct-fed microbials for reducing in poultry while permissive species could be used to predict which birds will be super-shedders.