Background: The dietary proteins are one of the most important factors determining health conditions in humans. The sufficient digestion and absorption of dietary proteins in the digestive tract has positive effects on performance and recovery in sportspeople and athletes. Improving protein digestibility is a strategy for maintaining health status and optimal performance in sport and exercise activities. Objectives: The aim of the present study is to verify whether Weizmannia coagulans BC 99 (BC99) can increase muscle mass and strength. Methods: This randomized double-blind, controlled trial assigned 72 male college students to receive probiotics (n = 36, 20.25 ± 1.03 years; 179.00 ± 5.94 cm; 73.55 ± 8.73 kg, protein powder with BC99) or the placebo (n = 36, 20.19 ± 0.79 years; 179.25 ± 5.16 cm; 73.61 ± 8.24 kg, protein powder) for 12 weeks. At the baseline and final stages of the study, strength tests and body composition assessment were performed. Blood and stool samples were taken at the end of the 12-week intervention, and digestive enzymatic activity of stool samples, biochemical parameters, amino acids and hormone level of plasma were analyzed. Results: BC99 administration significantly improved strength performance, skeletal muscle mass, activity of pepsin and trypsin, the concentrations of branched chain amino acids and essential amino acids, reduced activities of creatine kinase and lactic dehydrogenase and urea nitrogen (BUN) level and increased testosterone and glucagon-like peptide-1 level in male college students. Conclusions: Therefore, BC99 supplementation can be an important nutritional strategy to improve strength performance, body composition, protein digestion and body metabolism in healthy young males.

The increased emission and accumulation of microplastics pose a severe threat to humans and the environment. As effective biological agents for alleviating the effects of microplastics, the mechanism of action of probiotics remains unclear. In this study, based on the successful establishment of a reproductive virulence model of Caenorhabditis elegans (C. elegans), we explored the effect and mechanism of Weizmannia coagulans CGMCC 9951 (W. coagulans CGMCC 9951) on the reproductive toxicity of C. elegans. Our results showed that the gonad area and the number of offspring increased but the number of germ cells undergoing apoptosis decreased by 14% and 24% in C. elegans, after CGMCC 9951 treatments. Antioxidant test results showed that CGMCC 9951 increased the activity of Superoxide Dismutase (SOD), Catalase (CAT), and the content of Glutathione (GSH) in C. elegans. In addition, it was found by qPCR and mutagenesis experiments verified that CGMCC 9951 alleviated reproductive toxicity through the DNA checkpoint signaling pathway. Our findings suggested that CGMCC 9951 could alleviate the reproductive toxicity of polystyrene microplastics in C. elegans by enhancing antioxidant capacity and inhibiting DNA damage checkpoint signaling pathway. The above results suggest that probiotics can be used as a potential approach to alleviate the reproductive toxicity induced by polystyrene microplastics in humans.

The dietary proteins are one of the most important factors determining health conditions in human. The sufficient digestion and absorption of dietary proteins in the digestive tract have positive effects on performance and recovery in sportspeople or athletes. Improving of protein digestibility is a strategy for maintaining health status and optimal performance in sport or exercise activities. The hypothesis of the present study is that Weizmannia coagulans BC 99 (BC99) can increase muscle mass and strength. This randomized double-blind, controlled trial assigned 72 male college students to receive probiotics (n = 36, 20.25±1.03 years; 1.79±5.94 cm; 73.55±8.73 kg, protein powder with BC99) or placebo (n = 36, 20.19±0.79 years; 179.25±5.16 cm; 73.61±8.24 kg, protein powder) for 12-week. At the baseline and final stages of the study, strength tests and body composition assessment were performed; Blood and stool samples were taken at the end of the 12-week intervention, digestive enzymatic activity of stool samples, biochemical parameters, amino acids and hormone level of plasma were analyzed. BC99 administration significantly improved strength performance, skeletal muscle mass, activity of pepsin and trypsin, the concentrations of branched chain amino acids and essential amino acids, reduced activities of creatine kinase and lactic dehydrogenase and urea nitrogen (BUN) level, and increased testosterone and glucagon-like peptide-1 level in male college students. Therefore, BC99 supplementation can be an important nutritional strategy to improve strength performance, body composition, protein digestion and body metabolism in various groups of individuals.