Foundation for Integrated Medicine - Microbes

Foundation for Integrated Medicine - Microbes: "The Effect of Intestinal Microbes on Systemic Immunity
EXCERPTED FROM POWER HEALING (RANDOM HOUSE, 1998)
BY LEO GALLAND, M.D.
In keeping with its immense surface area and intense exposure to foreign antigens, the intestinal tract is the largest organ of immune surveillance and response in the human body (Targan et al., 1987). It should not be surprising that events occurring in its lumen or on the mucosal surface have systemic effects on immune function and disease resistance. This chapter examines the contribution made by luminal organisms commonly encountered in humans: bacteria, protozoa and yeasts. Particular attention win be given to data concerning a role for Giardia lamblia infestation and Candida albicans colonization in the pathogenesis of chronic fatigue and immune dysfunction.
BACTERIAL MICROFLORA
Over 500 species of bacteria live in the healthy human alimentary canal; in the average adult they weigh about one kilogram. The normal colonic microflora ferment soluble fibre to yield short-chain fatty acids which supply 5-10% of human energy requirements (McNeil, 1984). Endogenous flora synthesize at least seven essential nutrients, supplementing dietary intake: folic acid, biotin, pantothenic acid, riboflavin, pyridoxine, cobalamin and vitamin K (Mackowiak, 1982). They participate in the metabolism of drugs, hormones and carcinogens, including digoxin (Lindenbaum et al., 1981), sulphasalazine, and estrogens (Gorbach, 1982). By demethylating methylmercury, gut flora protect mice from mercury toxicity (Rowland et al., 1984). They prevent potential pathogens from establishing infection by numerous mechanisms, which include: production of short-chain fatty acids and bacteriocin, induction of a low oxidation-reduction potential, competition for nutrients, deconjugation o"