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.

Yeast fermentate prebiotic improves intestinal barrier integrity during heat stress by modulation of the gut microbiota in rats.

AIMS: To evaluate efficacy of Saccharomyces cerevisiae fermentate prebiotic (EH) in protection of intestinal barrier integrity in rats during heat stress, to analyze the impact of heat stress and preventive treatment with EH on the structure of the gut microbiota. METHODS AND RESULTS: Two groups of rats were treated orally with EH or phosphate-buffered saline for 14 days. On day 15, half of the rats in each group were exposed to heat stress conditions, while control animals were kept at room temperature. Histological and Western blot analyses of the intestine, culture-based microbiological analysis and high-throughput 16S rRNA sequencing for the gut microbiota were performed for each rat. Exposure of animals to heat stress conditions resulted in inhibition of tight junction (TJ) proteins expression, decrease of Paneth and goblet cells, decrease of beneficial and increase of pathogenic bacteria. Oral treatment of rats with EH before stress significantly prevents these adverse effects by elevation of the gut beneficial bacteria, particularly butyrate-producing bacteria. CONCLUSIONS: Essential effect of EH in protection of intestinal barrier integrity during heat stress is connected with beneficial modulation of the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results will contribute to the development of new approaches to prevention of heat stress-related complications.

Oral administration of Bacillus subtilis strain BSB3 can prevent heat stress-related adverse effects in rats.

AIMS: To determine the efficacy of Bacillus subtilis strain in prevention of heat stress-related complications in rats. METHODS AND RESULTS: Male Sprague-Dawley rats weighing 250-300 g were treated by oral gavage with B. subtilis BSB3 strain or PBS twice a day for 2 days. Half of the rats of each group were exposed to heat stress (45°C, relative humidity 55% for 25 min), while the remaining rats were placed at identical conditions but at 25°C. Bacterial translocation, histological changes in the intestine, cytokines profile, serum lipopolysaccharide level (LPS), as well as vesiculation of erythrocytes were analysed and compared between groups. Adverse effects of heat stress (morphological changes in intestine, bacterial translocation, elevated levels of LPS and IL-10, increased vesiculation of erythrocytes) were observed only in rats not protected with B. subtilis strain and exposed to heat. All registered parameters in rats pretreated with bacilli and exposed to heat were similar to control groups. CONCLUSIONS: Bacillus subtilis BS3B strain was effective in the prevention of complications related to heat stress in rats. SIGNIFICANCE AND IMPACT OF THE STUDY: This work will contribute towards better understanding of probiotics' mechanisms of action and will bring new approaches to characterize and use of beneficial bacteria.