AUTHOR=Niu Qing , Wang Xiaoxu , Qi Xinyong , Cao Changjian , Yang Kaixuan , Gu Caiju , Zhou Zhenxiang , Huang Qizhong TITLE=Identification of the gut microbiota affecting Salmonella pullorum and their relationship with reproductive performance in hens JOURNAL=Frontiers in Microbiology VOLUME=Volume 14 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1216542 DOI=10.3389/fmicb.2023.1216542 ISSN=1664-302X ABSTRACT=Pullorum disease is one of the common bacterial infectious diseases caused by Salmonella Pullorum (S. Pullorum), which can result in a decrease in the reproductive performance of laying hens thus causing considerable economic losses. However, researches about characteristics of intestinal microbiota with pullorum and their potential association with reproductive performance in hens are still limited. This study was to identify gut microbiota associated with S. Pullorum in poultry. A total of 30 hens with S. Pullorum-negative (PN) and 30 hens with S. Pullorum-positive (PP) were analyzed for hatchingeggs laid in 2 weeks (HEL), fertilization eggs (FE), chick number (CN) and microbial structure. There were significant differences in HEL (p<0.01), FE (p<0.01) and CN (p<0.01) between PP and PN.Histomorphological observations showed abnormal morphology of ovaries and fallopian tubes and low integrity of epithelial tissue in ileum and cecum in PP. 16S rRNA gene sequencing revealed that such beneficial cecal microbes as Bacteroides, Desulfovibrio, and Megamonas, were positively correlated with reproductive performance and had lower abundance in PP (p=0.001). Furthermore, reflecting in PP, phosphotransferase system (PTS), pentose phosphate pathway, butanoate metabolism and oxidative phosphorylation all diminished. Taken together, this study clarified the morphological characteristics of the reproductive tract and intestines of chickens infected with S. Pullorum and preliminarily explored the potential association between cecal microbiota and reproductive performance in hens. Our data may provide a reference for revealing the intestinal microbial characteristics of hens in resisting pullorum and exploring novel approaches to infection control in future studies.