Studies of the intestinal microflora: A prerequisite for the development of probiotics

The intestinal microflora is composed of numerous bacterial species that inhabit the distal small bowel and the large bowel. This complex microbial collection weilds marked influences on the biochemistry, physiology, immunology and disease resistance of the host. The derivation of scientifically valid probiotic products should be based on knowledge of the intestinal microflora because, by definition, consumption of the probiotic impacts on the microbial community harboured in the digestive tract. Variation in the stability and complexity of bacterial populations harboured by different human subjects may influence the outcome of probiotic administration. An understanding of the colonisation attributes, biochemical activities, and immunostimulatory properties of lactobacilli and bifidobacteria is required so that rational choices can be made in the selection of strains for incorporation into probiotic products. (C) 1998 Elsevier Science Ltd. All rights reserved.