Orally delivered β-glucans aggravate dextran sulfate sodium (DSS)-induced intestinal inflammation

beta-Glucans have beneficial health effects due to their immune modulatory properties. Oral administration of beta-glucans affects tumour growth, microbial infection, sepsis, and wound healing. We hypothesized that pre-treatment with orally delivered soluble and particulate beta-glucans could ameliorate the development of aggravate dextran sulfate sodium (DSS) induced intestinal inflammation. To study this, mice were orally pre-treated with beta-glucans for 14 days. We tested curdlan (a particulate beta-(1,3)-glucan), glucan phosphate (a soluble beta-(1,3)-glucan), and zymosan (a particle made from Saccharomyces cerevisiae, which contains around 55% beta-glucans). Weight loss, colon weight, and feces score did not differ between beta-glucan and vehicle treated groups. However, histology scores indicated that beta-glucan treated mice had increased inflammation at a microscopic level suggesting that beta-glucan treatment worsened intestinal inflammation. Furthermore, curdlan and zymosan treatment led to increased colonic levels of inflammatory cytokines and chemokines, compared to vehicle. Glucan phosphate treatment did not significantly affect cytokine and chemokine levels. These data suggest that particulate and soluble beta-glucans differentially affect the intestinal immune responses. However, no significant differences in other clinical colitis scores between soluble and particulate beta-glucans were found in this study. In summary, beta-glucans aggravate the course of dextran sulfate sodium (DSS)-induced intestinal inflammation at the level of the mucosa. (C) 2015 The Authors. Published by Elsevier Inc.