Plant-Derived Polysaccharides Benefit Weaned Piglets by Regulating Intestinal Microbiota: A Review

The intestine harbors a community of bacteria that is intestinal microbiota, which is a complex and highly diverse community. This review discusses the gut microbiota in piglets, including the role of intestinal homeostasis in maintaining piglet health and the various factors that influence gut microbiota. Nutritional interventions, particularly the supplementation of plant-derived polysaccharides, including dietary fiber, for weaned piglets have been shown to enhance the abundance and colonization of beneficial intestinal microbes, reduce the incidence of gastrointestinal infections, and decrease the frequency of diarrhea, thereby improving gut health and growth performance. In this context, various polysaccharides, such as those derived from Medicago sativa L. (alfalfa), Glycyrrhiza uralensis Fisch. (licorice), and Lycium barbarum L. (wolfberry), Panax ginseng C.A. Mey. (ginseng), and Astragalus membranaceus (Fisch.) Bunge (astragalus) has demonstrated significant success. Additionally, dietary fibers such as inulin, pectin, beta-glucans, gums, cellulose, resistant starch, and starch derivatives have shown potential in regulating the gastrointestinal microbiota. Research has also explored the correlation between the structural characteristics of dietary polysaccharides and their biological activities. This review will pave the way for the development and utilization of plant-derived polysaccharides as effective non-antibiotic alternatives to restore gut microbial balance in weaning piglets.