Project description:Synbiotics are a combination of probiotics and prebiotics which can alter the composition of the gastrointestinal tract evoking beneficial effects throughout the body through the production of a battery of bioactive metabolites. In this study, a synbiotic was used to reduce the behavioral and biochemical symptoms of depression and this nanostring panel was used to decipher where along the gut-brain-axis the synbiotic-derived metabolites were invoking their beneficial effects on the immune system. The synbitoic was composed of two probiotic bacteria (Lactobacillus fermentum ATCC 793 and Bifidobacteria longum ATCC 15707 and a grape -derived prebiotic composed of grape seed polyphenol extract, resveratrol and a concord grape extract. Male mice (C57BL/6) were pretreatment with either nothing (control), BDPP, probiotic or synbiotic and underwent 28 days of chronic unpredicitable stress. After 28 days, animals' behavior reflected an increase in depressive- and anxiety-like behavior, rescued specifically by the synbiotic. This nanostring multiplex analysis reveals both tissue- and treatment-specific effects on immune modulators.
Project description:Background and Objectives: Antibiotic (ABx) therapy is associated with an increased risk for Crohn´s Disease but the underlying mechanisms are unknown. We observed high fecal serine protease activity (PA) to be a frequent side effect of ABx therapy in patients. The aim of the present study was to unravel whether this rise in PA may promote colitis development via detrimental effects on the large intestinal barrier. Design: Transwell experiments were used to assess the impact of high PA in ABx-treated patients or vancomycin/metronidazole (V/M)-treated mice on the epithelial barrier. Serine protease profiling was performed using LC-MS/MS analysis. The impact of high PA on the intestinal barrier in WT/IL10-/- mice and on colitis development in IL10-/- mice was investigated using V/M+/-oral serine protease inhibitor (AEBSF) treatment. Results: The ABx-induced high PA was found to be due to significantly increased levels of pancreatic proteases and to impair the epithelial barrier. In WT mice, the rise in PA caused a transient increase in intestinal permeability but did not affect susceptibility towards DSS-induced acute colitis. In IL10-/- mice, the rise in PA caused a lasting impairment of the intestinal barrier, which was associated with inflammatory activation of the large intestinal tissue. In the long term, the lasting increase in PA upon repeated V/M treatment aggravated colitis development in IL10-/-mice. Conclusion: High PA is a frequent adverse effect of ABx therapy which is detrimental to the large intestinal barrier and may contribute to the development of chronic inflammation in genetically susceptible individuals.