Lactobacillus acidophilus is a friendly bacterium that lives in the human gut and vagina. People take it as a probiotic to help digestion and keep the gut microbiome in balance.
It supports immune function and can ease occasional diarrhea or the discomfort from lactose intolerance. Capsule, tablet, and powder forms are common, and taking it with a meal helps buffer stomach acid so more bacteria survive the trip through the digestive tract.
Mild gas or bloating can show up at first. Anyone with a weakened immune system, recent surgery, or a critical illness should skip probiotics unless a doctor says otherwise.