Probiotics are live microorganisms that are intended to provide health benefits when consumed. Major probiotic organisms include Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus. Élie Metchnikoff is considered the father of probiotics for his work studying the long lives of Bulgarians who regularly consumed fermented milk products. Sources of probiotics include yogurt, kefir, miso soup, kombucha, cultured vegetables, probiotic supplements, and microalgae.