Lactobacillus species prevents colitis in interleukin 10 gene-deficient mice

Background & Aims: Intestinal luminal microflora, or their products, are li kely an important initiating factor in the pathogenesis of inflammatory bow el disease. The aim of this study was to determine the role of colonic aero bic luminal bacteria and Lactobacillus species in the development of coliti s in interleukin (IL)-10 gene-deficient mice, Methods: Intestine from 2-16- week-old mice was scored histologically and cultured for bacteria. Lactobac illus sp, repopulation of the colonic lumen was achieved via daily rectal d elivery of Lactobacillus reuteri or oral lactulose therapy. Results: At 2 w eeks of age, IL-10 gene-deficient mice showed no colonic injury Rut did dis play abnormal colonic bacterial colonization with increased colonic mucosal aerobic adherent and translocated bacteria in conjunction with reduced Lac tobacillus sp, levels, In association with the abnormal colonic bacterial c olonization, colitis developed by 4 weeks of age. Restoring Lactobacillus s p, to normal levels reduced levels of colonic mucosal adherent and transloc ated bacteria and attenuated the development of the colitis. Conclusions: I n the neonatal period, IL-10 gene-deficient mice have decreased levels of c olonic Lactobacillus sp, and an increase in colonic mucosal adherent and tr anslocated bacteria, Normalizing Lactobacillus sp, levels reduced colonic m ucosal adherent and translocated bacteria and prevented colitis.