Lactobacillus casei is a species of genus Lactobacillus foun in the human intestine and mouth. As a lactic acid producer, it has been found to assist in the propagation of desirable bacteria. This particular species of lactobacillus is documented to have a wide pH and temperature range, and complements the growth of L. acidophilus, a producer of the enzyme amylase (a carbohydrate-digesting enzyme). It is known to improve digestion and reduce milk intolerance and constipation.