Lactobacillus reuteri Stimulates Intestinal Epithelial Proliferation and Induces Differentiation into Goblet Cells in Young Chickens

Probiotics, such as Lactobacillus, have been proven to be effective in maintaining intestinal homeostasis. The modulatory effect of Lactobacillus on intestinal epithelial development in early life is still unclear. In this study, Lactobacillus isolates with good probiotic abilities were screened and orally administered to detect their regulatory effect on intestinal development in chickens. L. reuteri 22 was isolated from chickens and chosen for subsequent chicken experiments due to its strong acid and bile salt resistance and ability to adhere to epithelial cells. The 3-day-old chickens were orally administrated with 108 CFU L. reuteri 22 for consecutive 7 days. L. reuteri 22 increased Lgr5 mRNA expression (3.23 ± 0.40, P = 0.001) and activated the Wnt/β-catenin signaling pathway, with increasing expression of proliferating cell nuclear antigen (PCNA) (49.27 ± 9.81, P = 0.021) to support the proliferation of chicken intestinal epithelial cells. Moreover, L. reuteri 22 also inhibited the Notch signaling pathway to induce intestinal stem cell differentiation into goblet cells with increased mucin 2 (Muc-2) expression (1.72 ± 0.34, P = 0.047). L. reuteri 22 significantly enhanced lysozyme mRNA expression (2.32 ± 0.55, P = 0.019) to improve intestinal innate mucosal immunity. This study demonstrated that L. reuteri administration could regulate chicken intestinal epithelium development to ensure the function of the intestinal mucosal barrier, which is beneficial for newborn animals.