Effect of dietary xylanase supplementation on gut barrier integrity and mucosal immunity in pigs

This study investigated the effect of xylanase supplementation on growth performance and intestinal barrier integrity in pigs fed low metabolizable energy (ME) diets. Eighteen growing pigs (41.2 ± 0.8 kg) were allocated to three diets in a complete randomized design, including: basal diet (3300 kcal ME/kg), low ME diet (3200 kcal/kg), and low ME supplemented with 0.01% xylanase enzyme. After 14 days, performance and intestinal mucosa parameters, including the expression of molecules related to physiology and mucosal immunity, were assessed using a one-way ANOVA, followed by Tukey's test. Pigs fed the xylanase-supplemented diet had higher (P < 0.05) final bodyweight (55.45 kg) than low ME (51.10 kg), and comparable to basal (55.24 kg). Feed conversion ratio and feed costs were also improved (P < 0.05) in the xylanase group (2.19; 43.6 baht/kg) compared with both low ME (2.69; 52.2 baht/kg) and basal diet (2.46; 46.3 baht/kg). Xylanase supplementation upregulated (P < 0.05) ileal glucose transporters (SGLT1 and GLUT2), colonic immune-related genes (TLR4, BD, BD3 and BD4), compared to the other groups. Tight junction genes (CLDN2, CLDN5, and ZO1) were upregulated (P < 0.05) in the colon of xylanase-fed pigs compared to the low ME. Xylanase also upregulated (P < 0.05) mucosal defense factors (sIgA components and mucin 2) compared with the control. In conclusion, xylanase supplementation restored growth performance to the basal level while enhancing feed efficiency and intestinal barrier integrity in pigs fed low-ME diets.