Heritable Gut Microbiome Associated with Serovar Pullorum Infection in Chickens.

Pullorum disease is one of the most common diarrhea-related diseases caused by subspecies serovar Gallinarum biovar Pullorum ( Pullorum); it negatively affects the poultry industry. However, limited studies have explored the association between the gut microbiota and Pullorum infection in chickens. In the present study, we performed a microbiome comparison and a microbiome genome-wide association study (mGWAS) to investigate the association among the host genetics, the gut microbiota, and pullorum disease in chickens. We found that Pullorum infection in chickens could alter the abundance of 39 bacterial genera (0.05). The altered structure and composition of the gut microbiota were also detected in the offspring. mGWAS results revealed host genetic variants to be prominently associated with gut microbial diversity and individual microbes. The pathogens and , which had a high abundance in positive parent chickens and their offspring, were significantly associated with several genetic mutations in immunity-related genes, such as , , and This finding explained why and were heritable in Pullorum-infected chickens. The heritable gut microbes and identified genetic variants could provide references for the selection of resistant chickens and the elimination of pullorum disease. The present study investigated the association among the host genome, the gut microbiome, and Pullorum infection in chickens. The results suggested that the gut microbial structure is altered in Pullorum-infected chickens. The diversity and abundance of the gut microbiota remarkably differed between the offspring coming from Pullorum-positive and Pullorum-negative chickens. Heritable gut microbiota were detected in the offspring. Moreover, host genetic variants were associated with microbial diversity and individual gut microbes. The pathogens and , which exhibited a high heritability in Pullorum-positive parents and their offspring, were associated with several genetic mutations in immunity-related genes.