Response of patients with irritable bowel syndrome and lactase deficiency using unfermented acidophilus milk.

Acidophilus milk has been reported to help patients with irritable bowel syndrome by correcting the "imbalance of flora" and to be tolerated better by lactase-deficient subjects by providing bacterial lactase in the small intestine. In a double-blind randomized study, 61 lactase-sufficient patients with irritable bowel syndrome each ingested 240 ml of milk three times a day for 2 wk and the same amount of acidophilus milk for an additional 2 wk. The degree of symptoms during the two milk-drinking periods was the same as during the control periods. Also, 18 lactase-deficient patients ingested unaltered milk for 1 wk and acidophilus milk for 1 additional wk. There was no difference in the degree of tolerance to the two varieties of milk. In summary, patients with irritable bowel syndrome were not helped by the ingestion of acidophilus milk, and lactase-deficient patients were as intolerant to acidophilus milk as to unaltered milk.