Plenty of people sing the praises of probiotics. These cultures of live bacteria can come in an array of products, from foods like yogurts to dietary supplements and even skin creams. Generally, these products tend to claim they’ll boost health by tweaking your microbiome, the collection of bacteria and other microorganisms that live in and on your body. And sometimes, doctors even encourage people to take probiotics after they’ve been on antibiotics, to help get things back to normal. But a new pair of studies claim that probiotics may not actually do that much good.