Bacillus subtilis TO-A suppresses the age-related decline in locomotion in Caenorhabditis elegans

Research on the role of probiotics in maintaining locomotor function in aged Caenorhabditis elegans is limited. Therefore, we investigated whether a probiotic strain, Bacillus subtilis TO-A (BSTOA), which extends the lifespan of worms can prevent age-related declines in the locomotor functions of aged worms. This study revealed that aged worms fed BSTOA (BSTOA_day13) maintained better locomotor function than those fed Escherichia coli OP50 (OP50_day13). BSTOA_day13 exhibited better activity than OP50_day13 in maintaining actin structure during age-related changes in body wall muscles. Notably, the expression levels of oxidative stress-related genes fluctuated in BSTOA_day13; these worms also displayed high survival rates based on the paraquat assay. An examination of the locomotor function of aged gpx-7 mutants revealed that even worms fed BSTOA had a reduced thrashing rate. Therefore, consuming BSTOA may prevent the decline in age-related locomotor functions, such as symptoms of sarcopenia in humans, by inhibiting the decrease in gpx-7 expression in aged worms.