This is a randomized, double-blind, placebo controlled crossover study. After obtaining informed consent, healthy, middle-aged adults with a larger waist circumference (n=30/probiotic cross with n=90 total/study) will be randomized to one of four groups: Bacillus subtilis, Lactobacillus plantarum, Bifidobacterium animalis subsp. lactis, or placebo. Participants will consume 1 capsule per day of probiotic or placebo for 6 weeks. After a 4-week washout period, participants will be crossed to the other treatment (i.e., probiotic to placebo or placebo to probiotic).