<i>Lactobacillus reuteri</i> Stimulates Intestinal Epithelial Proliferation and Induces Differentiation into Goblet Cells in Young Chickens

Abstract

Probiotics, such as <i>Lactobacillus</i>, have been proven to be effective in maintaining intestinal homeostasis. The modulatory effect of <i>Lactobacillus</i> on intestinal epithelial development in early life is still unclear. In this study, <i>Lactobacillus</i> isolates with good probiotic abilities were screened and orally administered to detect their regulatory effect on intestinal development in chickens. <i>L. reuteri</i> 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 <i>L. reuteri</i> 22 for consecutive 7 days. <i>L. reuteri</i> 22 increased Lgr5 mRNA expression (3.23 ± 0.40, <i>P</i> = 0.001) and activated the Wnt/β-catenin signaling pathway, with increasing expression of proliferating cell nuclear antigen (PCNA) (49.27 ± 9.81, <i>P</i> = 0.021) to support the proliferation of chicken intestinal epithelial cells. Moreover, <i>L. reuteri</i> 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, <i>P</i> = 0.047). <i>L. reuteri</i> 22 significantly enhanced lysozyme mRNA expression (2.32 ± 0.55, <i>P</i> = 0.019) to improve intestinal innate mucosal immunity. This study demonstrated that <i>L. reuteri</i> administration could regulate chicken intestinal epithelium development to ensure the function of the intestinal mucosal barrier, which is beneficial for newborn animals.