Poncirus trifoliata peel extract supplementation elevates gut CD4+ T cells and microbial diversity in both laying hens and broilers.

Intestinal diseases have long plagued the chicken industry, leading to reduced egg production in laying hens and compromised growth performance in broilers, causing significant economic losses in the farming industry. For that reason, natural products have been widely used as dietary immunomodulators in the chicken industry to prevent infectious diseases while sustaining a healthy gut, regulating immune cells, maintaining the gut barrier, and balancing the microbiome. However, the impact of Poncirus trifoliata, a member of the citrus family, on the health, immunity, and productivity of laying hens and broilers has not yet been clearly elucidated. Therefore, we evaluated the effect of the Poncirus trifoliata peel extract (PE) on the growth performance of broilers and egg production in laying hens. Additionally, we analyzed gut immune-related parameters, including oxidative stress indices, gut barrier functions, and gut microbiome. Approximately 21-week-old laying hens and 1-day-old broilers were randomly divided into two groups: one group was fed a control (CON) diet and the other was fed a diet supplemented with PE. The PE group exhibited increased expression of glutathione peroxidase 2 (Gpx2; P < 0.01) in laying hens and occludin (Ocln; P < 0.01) in broilers. Furthermore, PE treatment increased the CD4+ T cell populations (P < 0.01) and the gut microbial diversity in the intestine of both laying hens and broilers. Our findings suggest that PE administration could be a promising strategy for improving intestinal health in laying hens and broilers by modulating tight junction expression, intestinal immune cells, and the microbial communities.