| The human colonic microflora is a complex microbial ecosystem and the most heavily colonised region of the digestive tract (1012 bacteria/gram content). The colonic mucosa is unable to nourish itself from the blood (1), its nutritive demands must be met from the lumen, initially from breast milk (2). Different nutrients, e.g. short-chain fatty acids, amino acids, polyamines, growth factors, vitamins, and antioxidants are produced by non-pathogenic, commensal, protective probiotic flora (3,4). In the first weeks of life, these are originally derived from the birthcanal and bowels of the mother. The substrates for the production of nutrients are prebiotics, which consist mainly of ingested fibres and complex proteins (colon food), however it also includes necrotic mucosal cells, mucous, gastro-intestinal secretions including bile acids, bacteria and yeasts. |