Prevention of excessive exercise‐induced adverse effects in rats with Bacillus subtilis BSB3

AIMS: To characterize efficacy of the Bacillus subtilis BSB3 (BSB3) strain in the prevention of excessive exercise‐induced side effects and in maintaining stability of the gut microbiota. METHODS AND RESULTS: Rats were pretreated by oral gavage with B. subtilis BSB3 (BSB3) or with phosphate‐buffered saline (PBS) twice a day for 2 days, and were either exposed forced treadmill running or remained sedentary. Histological analysis of intestine, immunofluorescence staining of tight junction (TJ) proteins, serum lipopolysaccharide and intestinal fatty acid‐binding protein assay, culture‐based analysis and pyrosequencing for the gut microbiota were performed for each rat. Forced running resulted in a substantial decrease in intestinal villi height and total mucosa thickness, the depletion of Paneth cells, an inhibition of TJ proteins expression. Short‐term treatment of rats with BSB3 before running prevented these adverse effects. Culture‐based analysis of the gut microbiota revealed significant elevation of pathogenic microorganisms only in treadmill‐exercised rats pretreated with PBS. High‐throughput 16S rRNA gene sequencing also revealed an increase in pathobionts in this group. Preventive treatment of animals with BSB3 resulted in predominance of beneficial bacteria. CONCLUSIONS: BSB3 prevents excessive exercise‐associated complications by beneficial modulation of the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study shows a new application of beneficial bacteria for prevention the adverse effects of excessive exercise.