There are trillions of bacteria and other tiny organisms living inside your body and on top of your skin. Many of them—including more than 1,000 different types of bacteria—reside in your intestines. This collection of microorganisms is called your gut microbiome. Your microbiome plays a major role in your well-being. Research shows that it can influence everything from your immune system to your cardiovascular health. It helps your body digest food and unlock nutrients, and helps your immune system function properly. A healthy gut microbiome may help protect you from a variety of diseases. One sign of a flourishing gut microbiome is having a wide variety of microorganisms. In fact, a study of twins found that those who had a more diverse gut microbiome were less likely to gain weight over time those with a smaller range of bacteria. When it comes to different bacteria in your gut, the more, the merrier!