The Influence of Diet Composition on the Intestinal Synthesis of Riboflavin and Intestinal Microflora (Report I)

Abstract

It has been previously observed by Nagase and Fujita that riboflavin synthesis by intestinal bacteria was markedly promoted when the diet was supplemented with cellulose. It is very interesting, therefore, to research what changes would occur on the bacteria in the intestine by cellulose supplementation. It was experimented under the next conditions.The experimental subject was a 20-year old, healthy male, weight in 62kg and 173cm in height. The three kinds of experimental diets as shown in Table I were used, i. e., ordinary, meat and vegetable diets.As source of cellulose, cellulose powder and Toyo filter paper No. 7 were used. Each diet was supplied for 7 days by the next order, ordinary diet, vegetable diet, vegetable diet supplemented with cellulose powder, ordinary diet, meat diet, meat diet supplemented with filter paper and finally ordinary diet. The filter paper was ground in a mortar until it became mushy and was added to polished rice at a concentration of 2 per cent of the total diet and cooked.The measurements of various bacterial counts was published in the previous report.1. The amount of fecal riboflavin had a tendency to rise in case of the vegetable diet, but when the vegetable diet was supplemented with cellulose powder fecal riboflavin content was not increased, from which it is supposed that the effect of cellulose powder as cellulose was questionable. However, the amount of riboflavin in feces was found to decrease as changed to meat diet, and to rise by addition of mushy filter paper to this diet.2. Total bacterial count and coli form count hardly changed. Clostridium welchii count had a tendency to decrease by addition of cellulose. A switch of an ordinary to a vegetable diet resulted in small increase in Lactobacilli, and also when the mushed filter paper was added to the meat diet, the increase of Lactobacilli was observed.But in both Aerobacter and anaerobic bacilli the results were not so clearly.