Xylo-oligosaccharides improve the adverse effects of plant-based proteins on weaned piglet health by maintaining the intestinal barrier and inhibiting harmful bacterial growth.

Introduction: Piglets are more susceptible to weaning stress syndrome when fed high levels of plant-based proteins that contain abundant food antigens and anti-nutritional factors. Xylo-oligosaccharides (XOS) are a potential prebiotic that may improve the tolerance of weaned piglets to plant-based proteins. The aim of this study was to investigate the effects of XOS supplementation in high and low plant-based protein diets on growth performance, gut morphology, short-chain fatty acid (SCFA) production, and gut microbiota of weaned piglets.

Methods: A total of 128 weanling piglets with an average body weight (BW) of 7.63 ± 0.45 kg were randomly allocated to one of the four dietary treatments in a 2 × 2 factorial arrangement, with two levels of plant-based proteins (d 1-14: 68.3 or 81.33%, d 15-28: 81.27 or 100%) and XOS complex (0 or 0.43%) over a 28-day trial.

Results: The growth performance of piglets did not differ significantly among groups ( > 0.05). However, the diarrhea index of weaned piglets fed a high plant-based protein diet (HP) was significantly higher than that of those fed a low plant-based protein diet (LP) at days 1-14 and throughout the experimental period ( < 0.05). XOS treatment tended to reduce the diarrhea index at days 1-14 ( = 0.062) and during the whole experiment period ( = 0.083). However, it significantly increased the digestibility of organic matter at days 15-28 ( < 0.05). Moreover, dietary XOS supplementation increased ileal mucosa mRNA expression of and ( < 0.05). Furthermore, the concentration of butyric acid (BA) in the cecal contents and in the concentrations of BA and valeric acid (VA) in colon contents were significantly elevated in the XOS groups ( < 0.05). Additionally, XOS optimized the gut flora by lowering the number of pathogenic bacteria such as , thereby stabilizing the gut ecosystem.

Discussion: In conclusion, the HP diet aggravated diarrhea in weaned piglets while the XOS diet alleviated it by improving nutrient digestibility, protecting intestinal morphology, and optimizing the gut flora.