We get it…it stinks. So, to help make sense of this potential, unexpected side effect, mbg dug into the research and chatted with functional medicine doctors. Here’s what they have to say. (Curious about other potential side effects of probiotics? Check out our guide.) According to integrative medicine doctor Bindiya Gandhi, M.D., “Everyone’s microbiome is always changing.” If you’re suddenly introducing a new bacteria to the environment—even if it’s a good bacteria—the microbiome will have to adjust. “This usually happens when someone has a gut imbalance of good and bad bacteria,” Gandhi adds. Additionally, it may be helpful to eat foods rich in prebiotics, which can help the probiotic bacteria flourish. “Prebiotics are largely nondigestible fibers that provide nourishment for beneficial bacteria,” Singh writes for mbg. “Think of prebiotics as fertilizer for the good guys.” If the side effects don’t subside after a few weeks of taking probiotics, visit a doctor or gastroenterologist. “Definitely talk to your functional or integrative doctor because that is a telltale sign something else is going on underneath,” Gandhi says. In the meantime, you may need to stop taking the probiotic you’re currently on and find one with targeted strains that meet your specific digestive needs.*