This document provides an overview of probiotics. It begins by defining probiotics as live microorganisms that provide health benefits when consumed. Probiotics are important for human health as they help maintain a balanced gut microbiome and support digestion. Common probiotic strains include lactobacilli and bifidobacteria. The document then discusses the history of probiotics, their modes of action, characteristics, uses for various clinical conditions, advantages, and disadvantages. It concludes that probiotics are a useful therapeutic tool for supporting immune function and maintaining a balanced microbiome without side effects.