A probiotic is a type of helpful bacteria or yeast that's good for your body, especially your digestive system. While we often think of bacteria as germs that make us sick, trillions of bacteria naturally live in our bodies and actually keep us healthy. Probiotics are the beneficial ones.

Your intestines contain a complex ecosystem of bacteria that help break down food, absorb nutrients, and fight off harmful germs. Sometimes this balance gets disrupted, like when you take antibiotics for an infection. Antibiotics kill both bad and good bacteria, which is why doctors sometimes recommend eating yogurt with “live active cultures” during treatment. Those cultures are probiotics that help restore your gut's healthy bacteria.

You'll find probiotics in fermented foods like yogurt, kefir, sauerkraut, and kimchi. Some people also take probiotic supplements in pill or powder form. Scientists are still learning exactly how different probiotics work, but many people find them helpful for digestive issues.

Think of probiotics as the good neighbors in your gut's bustling microscopic city, working alongside your body to keep everything running smoothly.