Long-Term Grow-Out Affects Colonization Fitness in Coincidence With Altered Microbiota and Lipid Composition in the Cecum of Laying Hens

is one of the leading causes of gastrointestinal illness worldwide and is mainly transmitted from chicken through the food chain. Previous studies have provided increasing evidence that this pathogen can colonize and replicate in broiler chicken during its breeding; however, its temporal kinetics in laying hen are poorly understood. Considering the possible interaction between and gut microbiota, the current study was conducted to address the temporal dynamics of in the cecum of laying hen over 40 weeks, with possible alteration of the gut microbiota and fatty acid (FA) components. Following oral infection with 81-176, inocula were stably recovered from ceca for up to 8 weeks post-infection (.). From 16 weeks ., most birds became negative for and remained negative up to 40 weeks . 16S rRNA gene sequencing analyses revealed that most of the altered relative rRNA gene abundances occurred in the order , in which increased relative rRNA gene abundances were observed at >16 weeks . in the families , and . Lipidome analyses revealed increased levels of sterols associated with bile acid metabolisms in the cecum at 16 and/or 24 weeks . compared with those detected at 8 weeks ., suggesting that altered microbiota and bile acid metabolism might underlie the decreased colonization fitness of in the gut of laying hens.