Intestinal Microflora and Clinical Medicine

Germ-free animals retards in wound healing to their counterparts with normal intestinal flora. Intestinal microflora modify the wound healing process via activating cellular immune reactions of the host. Gnotobiota with either Lactobacilli or Bifidobacteria could restore the healing potential of germ-free animals to the control levels. Supportive effects of probiotics on wound healing may be modified by their nutritional actions as well. Intestinal flora are also implicated in carcinogenesis of various organs. Their effects on colorectal carcinogenesis has attracted deep interests naturally. In spite of some promizing findings, no definite bacterial metabolites surely capable of inducing human colorectal cancer have not been demonstrated yet. Many studies have confirmed promoting effects of intestinal microflora on developing cancer of the large intestine. Normal intestinal microflora modify mammary carcinogenesis via the route of metabolizing phytoestrogens or manipulating the enterohepatic circulation of estrogen. Heated debates on Helicobacter pylori and gastric cancer problem have not been settled down yet, although the agreement that this microorganism can induce gastritis has been obtained. Cancer of the urinary bladder, bile ducts, etc., induced by parasitic infection can be explained by the deconjugating action of contaminating bacteria to liberate masked carcinogens. Intestinal microflora are also implicated in miscellaneous metabolic fields which are intimately related with clinical medicine offering endless interests.