Abstract
Yogurt supplemented with brewer's yeast cell wall (BYC) was administered to 24 constipated female volunteers, and the effect on the stool frequencies, fecal quantities, fecal characteristics, and fecal microflora were examined. Yogurt contained 6 g of BYC per 200 ml, and the other batch without BYC served as control diet. The volunteers ingested BYC-yogurt (BYC-Y) or control yogurt (CONT) every day for one week in a crossover experiment. Stool frequencies and fecal quantities of the subjects during the entire period of BYC-Y intake were found to be significantly higher than those under the CONT diet. It was observed that the proportion of Bifidobacterium in the fecal microflora significantly increased (p<0.05), and those of Clostridium perfringens and Streptococcus significantly decreased (p<0.05) with the ingestion of BYC-Y. The fecal water content and levels of short-chain fatty acids (SCFAs) in feces were also higher in subjects with BYC-Y intake than in CONT diet. Furthermore, because of the fermentation of SCFAs, BYC-Y administration significantly lowered fecal pH. A similar effect was observed with CONT intake; however, it was less evident than in the BYC-Y intake. These results indicate that the BYC-Y intake is effective to prevent the constipation. Furthermore, these findings suggest that the synergistic effects of beneficial bacteria in yogurt and BYC in improving the intestinal environment and bowel movement. These effects of BYC are related to such properties as fermentation, water-holding capacity, and swelling force in the large intestine.
