Intestinal Mucosa Reconstitution and Protection: Impact of Luminal Factors

Sammanfattning: The gastrointestinal mucosa is one of the most rapidly proliferating tissues in the body, and serves as a barrier to luminal bacteria and toxins. Enteral nutrition, luminal fiber and probiotics are of crucial importance for the integrity of this barrier. We examined the potential beneficial effects of lactobacilli and fiber on methotrexate-induced enterocolitis and radiation-induced intestinal injury in this study. Results indicate that pectin and oatbase significantly enhance the mucosal nutritional status and intestinal barrier function in the enterocolitis rats. The effects of fiber are greater in colon than in small bowel. Administration of lactobacilli to the enterocolitis rats decreases the inflammatory response, improves the mucosal architecture, mucosal mass, and intestinal barrier function by restoring the intestinal permeability and microecology, reducing bacterial translocation and endotoxemia. Among five tested Lactobacillus strains, Lactobacillus plantarum (both DSM 9843 and DSM 6595) show the best effects. Lactobacilli with fermentation have greater effects than those without fermentation, and lactobacilli both with and without fermentation have bigger impact than oat fiber alone. Supplementation of Lactobacillus plantarum DSM 9843 and Lactobacillus reuteri R2LC, but not fiber, improves the intestinal mucosal immunity by increasing sIgA level and T-helper/T-suppressor lymphocyte populations. Administration of lactobacilli and oatbase to the rats following radiation and colon resection significantly improves the host general conditions, decreases the intestinal inflammatory response, and accelerate the colonic anastomotic healing. Enteric administration of lactobacilli and fiber, as a "biological approach", is of value to rats under different stress conditions. They can be used in future bacteriotherapy for various human diseases.