Microbiological Considerations in Selection and Preparation of Lactobacillus Strains for Use as Dietary Adjuncts

Abstract

Abstract A number of food, feed, and dairy products have been formulated to contain viable cells of Lactobacillus acidophilus (61, 62). The benefit offered during consumption of these dietary adjuncts is a continued supply of L. acidophilus to the gastrointestinal tract. This bacterium is a resident of the small intestine and is believed to help stabilize the gut microflora of both man and animals. Suggested roles of lactobacilli in the intestinal tract and potential benefits of supplying this organism through dietary adjuncts have been discussed (19, 48, 49, 53, 62) and, therefore, will not be dealt with extensively in this review. Since Metchni-koff's (39) original proposal on suppression of putrefying intestinal bacterial by acid-producing lactobacilli, evidence defining intestinal benefits of L. acidophilus has remained sporadic and often inconclusive. A major factor contributing to the difficulty in obtaining this information is the complexity of the gut ecosystem. Furthermore, early development of dietary adjuncts containing L. acidophilus preceded knowledge necessary to prepare the culture in a reliable form (61, 62).