Abstract
This review focuses on the specific effects of nutrients on the colonic microflora with special emphasis on how human milk and its components influence the intestinal microflora in early infancy compared with formula-fed infants. Some proteins such as lactoferrin and lysozyme and some casein and whey peptides, as well as non-protein nitrogen derivatives, particularly nucleotides, influence the growth of bifidobacteria. In addition, g -lactose and milk oligossaccharides, together with milk gangliosides, seem to affect the intestinal colonisation of the infant and the establishment of a particular microflora. Specific effects of protein and nitrogen derivatives, carbohydrates, lipids and some minerals on colonic microorganisms and how this affects health are also considered. There is an increasing interest in how non-absorbable carbohydrates affect the colonic microecology and how they may have a role in the maintenance of human health. However, there are only few data on how other nutrients, namely non-protein nitrogen derivatives, lipids, macrominerals, microminerals, and other non-nutrient components of foods may affect individual colonic microorganisms. Further research in these areas is highly recommended.