Ecological control of the gastrointestinal tract. The role of probiotic flora

Abstract

Ecological control of the gastrointestinal tract. The role of probiotic floraThe "new" lifestyle-a threat to health?It is increasingly evident that human diseases are most often related to lifestyle, and should in theory be preventable.The stress of modern life, our reduced physical activity, and our consumption of manipulated and processed foods, and of chemicals-including pharmaceuticals-all contribute to our decreasing resistance to disease.Much evidence supports the fact that our genes, adapted during millions of years to the lifestyle of our prehistoric ancestors, tolerate poorly the dramatic changes in lifestyle that have occurred, especially in food habits during the past 100 years. 1 Changes in food habits in Western countries that no doubt constitute stresses to the human body and that may predispose to inflammatory, infectious, ulcerative, degenerative, and neoplastic diseases include the following: the consumption of 100 lb refined sugar per individual per year; the 10-fold increase in sodium consumption; the fourfold increase in consumption of saturated fat; the doubled consumption of cholesterol; a much reduced consumption of vegetable fibres, and of minerals such as potassium, magnesium, calcium, and chromium; and a considerable reduction in consumption of n-3 fats, membrane lipids, vitamins, and antioxidants.In severe disease, important food ingredients, such as arginine, glutamine, taurine, nucleic acids, vitamins, and antioxidants, such as glutathione, are often not supplied in large enough quantities.Perhaps even more important than the decrease in these food ingredients, is the fact that prehistoric food contained several thousand times more bacteria, mainly the so called probiotic bacteria.Prehistoric methods of food preservation were either drying, or, more commonly, storing in holes dug into the ground, where the food became naturally fermented.This is how Stone Age man learned to produce most of our still common fermented foods, such as beer, wine, green olives, and sauerkraut.Our modern lifestyle has dramatically reduced the availability of foods produced by natural fermentation.After the early identification of microbes, bacteria were regarded mainly as a source of disease, and unwanted in commercially manufactured food.Furthermore, the desire of the food industry to prolong shelf life promoted alternative production methods such as the use of enzymes instead of live bacteria.Combined with extensive hygiene measures practised during delivery and in child care, children in Western societies may have diYculty developing a satisfactory protective indigenous gut flora.][4] Lindeberg 5 recently published a series of studies of an ethnic group in New Guinea with a dramatically diVerent diet to that of people in the Western world.This diet contained no processed foods like butter, margarine, lard, oils, refined sugar, or alcohol.Instead, the group's diet was rich in fibre, water, vitamins, minerals, and n-3 fats such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).Despite the fact that about 80% of the population smokes and has a heavy consumption of saturated fat from coconut, cerebrocardiovascular diseases are virtually absent and the incidence of diabetes and cancer is very low.