Resistant dextrin/xanthan gum gels protect probiotics for application to ionizing radiation shielding

Resistant dextrin (RD) and xanthan gum (XG) are common food additives, and their functions have not sufficiently been uncovered. The wide beneficial functions of probiotics were hindered by the harsh gastric environment and colonization resistance. Here, RD and XG together formed a dense gel for simultaneously loading Bacillus coagulans (Bc) and Lactobacillus reuteri (Lr) to form multi-strain probiotics (MSP)-loaded RD/XG gels (i.e., MRX). The MSP was selected because the intrinsic oxygen consumption of Bc improved the growth of Lr that increases the production of short-chain fatty acids (SCFAs) and mucin in the gut. MRX showed good acid resistance and adhesion to protect probiotics from low pH and improved their colonization in the gut by colonic long-term retention. The protection function of oral MRX was confirmed by the prevention and treatment of radiation enteritis (RE) and hematopoietic acute radiation syndromes (H-ARS). Oral MRX alleviated reactive oxygen species (ROS)-induced gut damage, impaired intestinal barrier, and inflammation induced by ionizing radiation; moreover, the gut microbiota homeostasis was basically remained, the production of SCFAs was improved, the mortality of the ionizing radiation-mice was reduced, and the hematopoietic system was protected. The composite food gel is a promising carrier to load probiotics, which is a promising strategy for shielding ionizing radiation and other bowel disorders.