Acidophilus milk as originally devised by Rettger and Cheplin in 19221 was the culmination of a series of efforts to establish a culture medium for the growth and study of Bacillus acidophilus which would preserve a high degree of viability of the organism and serve to meet various experimental and practical needs. Intensive search during the past ten years by various laboratories for a substitute possessing the merits of acidophilus milk in a form that would be more readily portable and with a potency relatively permanent has not attained any degree of success, so far as we are aware.
The principle of acidophilus therapy is based on the following well known observations: 1. B. acidophilus, or a closely related aciduric organism, constitutes the bulk of the intestinal flora of breast-fed infants. 2. The oral administration of lactose or dextrin to man and lower animals stimulates the development of B.