Acidophilus helps with a number of health issues. Acidophilus, also known as Lactobacillus acidophilus, is the most well-known of the many species of friendly bacteria, also known as probiotics. Probiotic bacteria are important residents of your digestive and respiratory tracts, and as many as 3.3 pounds of bacteria are present in your large intestine. Acidophilus is present in a variety of fermented foods including; sauerkraut miso kimchi kefir yogurt