Malted rice amazake ingestion changes constipation and microbiota in independently living older adults

Abstract

【Background】 Constipation is a condition in which feces that should be discharged outside the body cannot be discharged in a sufficient amount and comfortably. The likelihood of constipation increases with aging. Laxatives and enemas are used to reduce constipation. However, the use of such medications can often cause continence, which leads to an increased burden on the elderly and caregivers, resulting in a decline in quality of life. Amazake, which is a fermented food, comes in two different types: malted rice amazake and Sake lees amazake. Although malted rice amazake has been reported to reduce constipation, the mechanism is unknown. In this study, we examine changes in the intestinal environment caused by the ingestion of malted rice amazake. It is expected that the ingestion of malted rice amazake will bring out an improvement in the intestinal environment in the elderly. 【Method】 The subjects were 32 elderly people who took 35 g/day of malted rice amazake for 6 weeks. Before and after the intervention, Bristol stool scale （BSS） and Constipation Assessment Scale （CAS）, collection of feces was conducted. DNA was extracted from the collected samples and relative values were calculated for gut microbiota by quantitative PCR using specific primers. 【Results】 Ingestion of malted rice amazake normalized stool in hard-stool and loose-stool subjects and significantly reduced constipation symptoms in the constipation group. Microbiota showed a significant decrease in the ratio of Firmicutes/Bacteroidetes, with significant decrease in Firmicutes on all subjects. In the constipation group, there was a significant increase in Bifidobacterium and Akkermansia. 【Conclusion】 It was suggested that the intake of malted rice amazake normalized stool and changed gut microbiota, which resulted in the reduction of constipation.