Effects of Amazake and Raw-SHIOKOJI Containing Aspergillus oryzae on the Number of Fecal Bacteria and Defecation in Humans

Abstract

Recently, the role of the intestinal environment in complaints such as constipation and diarrhea has attracted attention. To improve the intestinal environment, various fermented foods and probiotic drinks are routinely marketed as probiotics in Japan. In particular, “Aspergillus oryzae” has been used for fermentation to make sake, miso and soy sauce for more than a thousand years in Japan. Although numerous studies on the improvement of food by fermentation have been performed, fewer studies on the improvement of the human intestine have been reported. Therefore, we evaluated the effects of foods containing Aspergillus oryzae on the number of intestinal bacteria and the defecation status. The subjects were 3 healthy adults from 30’s to 50’s. The subjects were asked to ingest amazake (125mL) or Raw-SHIOKOJI (7.5g) for 14 days. The feces of the subjects were collected on days 0, 7, 14 and 35. The number of the total bacteria and the number of Bifidobacterium (beneficial bacteria), Enterobacteriaceae (opportunistic bacteria) and Clostridium perfringens (harmful bacteria) in the feces were counted. A questionnaire on defecation was also completed. The subjects were also questioned regarding defecation frequency and composition. No significant change in the number of bacteria in the feces was seen according to the intake of foods containing Aspergillus oryzae during the study period. However, the defecation frequency of the subjects increased after the intake of foods containing Aspergillus oryzae. Some subjects stated that defecation became easier and that the form of their stools improved. The present study suggests that foods containing Aspergillus oryzae improve defecation and have beneficial effects on the intestinal environment in humans.