Habitat

The habitat of L. acidophilus can be found in many places. This bacterium can be found in animal and human intestinal tracts (for humans it is found in the gastrointestinal tract), soil, water, milk and milk products, plants, silage, and manure. 

Lactobacillus acidophilus is part of a group of lactobacilli---bacteria that live in the small intestine, vagina and similar parts of the human body. This beneficial bacteria helps prevent infection by disease-producing organisms and produces beneficial substances such as vitamin K and lactase. This bacteria is found in yogurt and other fermented milk products and is partially responsible for their sour taste.