What Are Probiotics? Probiotics are live microorganisms that may help support the balance of beneficial bacteria within the gut microbiome. The gut microbiome contains trillions of microorganisms that influence digestion, immune function, metabolism, and overall health. Different probiotic strains serve different functions, which is why not all probiotics are the same. Trusted Probiotic Brands These are brands known for strain transparency, quality testing, and research-backe