Effect of the Bacillus subtilis BS20 on physiological and immune parameters in mutant mice Muc2–/–

Introduction. Inflammatory bowel disease (IBD) is a common pathology that cannot be completely cured and requires lifelong therapy. One of the promising and sparing therapeutic strategies is the use of probiotics. Unlike Lactobacillus and Bifidobacterium, which represent the basis of most classical probiotics, Bacillus spp. are spore-forming bacteria that contributes to their resistance to the acidic environment of the stomach. It has been shown that the bacteria Bacillus spp. is an effective therapeutic drug for the relief of intestinal diseases with signs of inflammation and bacterial origin. Since the main factors causing IBD are dysbiosis and inflammation, and strains of Bacillus spp. as probiotics can be potential modulators of immunity and influence the intestinal microbiome, it is necessary to search for new strains of probiotic bacteria, including representatives of Bacillus spp., which have an effect on immunity and physiological indicators in experimental models of IBD. The aim of the scientific research — to study the effect of Bacillus subtilis BS20 spores on the physiological and immune parameters of the mutant mouse line Muc2–/–. Research objectives: Investigate survival of Muc2–/– mice, weight, immune parameters (cytokines and immune cells) and amino acid composition of muscles. Materials and methods. Muc2–/– females were fed spores of Bacillus subtilis BS20 in the amount of 109 CFU for 2 months. Analysis of the amino acid composition of the femoral muscle was performed by capillary electrophoresis. The concentration of cytokines in the supernatant was measured using the Magnetic Luminex assay kit. Determination of the number of lymphocytes was performed by flow cytometry. Results. The addition of Bacillus subtilis BS20 to the diet of mice reduced mortality and body weight loss in Muc2–/– females. We found a decrease in interleukin-6 and an increase in interleukin-17 in the descending colon and an increase in B and T helper lymphocytes in the spleen. Conclusion. B. subtilis BS20 improves the general condition of Muc2–/– mutant mice, has an anti-inflammatory and immunostimulating effect, reducing the level of the cytokine interleukin-6 and increasing the percentage of B cells and T helper cells in the spleen.