Influence of Lactobacillus reuteri on the colonic microbiota in health and DSS-induced colitis
(English)Manuscript (preprint) (Other academic)
Aim: To investigate the impact of Lactobacillus reuteri and Dextran Sulphate Sodium (DSS) on the colonic microbiota by investigating bacterial content and composition in the individual colonic mucus layers and mesenteric lymph nodes.
Methods: Rats were divided into 4 groups: control, L. reuteri, DSS and L. reuteri+DSS. L. reuteri was given as a cocktail containing 109 cfu of four different strains of L. reuteri by gavage daily for 16 days. Colitis was induced by 5% DSS in the drinking water for 9 days. The firmly and loosely mucus layers and mesenteric lymph nodes were collected, homogenized and its bacterial content was monitored using both culturing as well as the molecular method terminal restriction fragment length polymorphism (TRFLP).
Results: In controls, the number of bacteria was significantly lower in the inner firmly adherent mucus layer than the outer loosely adherent layer, indicating a barrier function of the inner mucus layer. The composition of the microbiota was also different between layers. L. reuteri prevented colitis but did not alter the microbiota. DSS obliterated the differences between mucus layers both in terms of number of bacteria, and bacterial composition, indicating that DSS destroys the mucus regardless of the addition of L. reuteri. L. reuteri did however significantly decrease bacterial translocation in the DSS-model.
Conclusion: The firmly adherent mucus layer serves as a barrier towards luminal bacteria. DSS alters the colonic microbiota and destroys the mucus barrier. L. reuteri ameliorates DSS-colitis by decreasing bacterial translocation.
Experimental colitis, DSS, probiotics, Lactobacillus reueteri, lactobacilli, colonic microbiota, colonic mucus, bacterial translocation, T-RFLP
Microbiology in the medical area
Research subject Physiology
IdentifiersURN: urn:nbn:se:uu:diva-112501OAI: oai:DiVA.org:uu-112501DiVA: diva2:287681