Taking probiotics for your gut health is one thing. (Who's gonna say no to fewer stomach issues and more bathroom regularity? No one—that's who.) But can these teeny-tiny bacteria —found in dietary supplements and fermented foods—help you lose weight, too? They do live in your stomach, after all. First: What the heck are probiotics anyway? Probiotics are live microorganisms that naturally live in your body already, according to the National Center for Complementary and Integrative Health . "Probiotics are substances that encourage the growth of bacteria, specifically beneficial bacteria, that help to keep intestinal health in balance,” says Frances Largeman-Roth, R.D.N., author of Eating in Color . “A healthy balance of good bacteria in the body may help regulate weight and ward off a range of health issues." So, can probiotics help with weight loss? Honestly, no one knows for sure—that's because most probiotic resear...