"Probiotics are live bacteria and yeasts that are good for your health, especially your digestive system. We usually think of bacteria as something that causes diseases. But your body is full of bacteria, both good and bad.Probiotics are often called "good" or "helpful" bacteria because they help keep your gut healthy." I'm definetly not an expert and don't want to give non supported evidence. But I started to take them to have a healthy gut. Iv read there is a strong connection between the brain and stomach, including majority of serotonin is in the stomach. The guy at gnc said it helps prevent from getting sick. So I figured having a healthy balanced gut will improve my health in other areas.