Effects of Malted Rice Amazake Consumption on Nutritional Status and Gut Microbiome in Older Patients and Residents of an Integrated Facility for Medical and Long-Term Care

Malnutrition is observed in approximately 20-50% of hospitals and long-term care facilities. We examined the effects of malted rice amazake beverage on the nutritional status and gut microbiome of older patients and residents in an integrated long-term care facility; 13 older patients and residents (84.6 ± 9.3 years) were prescribed 35 g of malted rice amazake daily for six weeks. Gut microbiome analysis, body composition and blood biochemistry test results, defecation surveys, dietary intake, and medications were recorded before and after the intervention. After the intervention, the Geriatric Nutritional Risk Index (GNRI) increased from 83.6 ± 9.1 points to 86.0 ± 9.8 points, and serum albumin increased from 3.3 ± 0.5 g/dL to 3.4 ± 0.5 g/dL. The α-diversity of gut bacteria increased from 390.1 ± 89.4 before to 447.2 ± 108.1, and the abundance of Desulfovibrio decreased from 0.76 ± 0.47% to 0.56 ± 0.60%. ΔGNRI showed a positive correlation with ΔBifidobacterium and ΔBarnesiella, but a negative correlation with ΔKlebsiella. Consumption of malted rice amazake for six weeks improved the GNRI and altered the gut microbiome of older patients and residents at moderate risk of nutritional disorders. Malted rice amazake may be a new way to improve nutrition because it has a high nutritional value, mainly in terms of carbohydrates, and improves the gut microbiome.