2025 Volume 39 Issue 4 Pages 213-226
With the arrival of a super-aging society, preventing diseases and extending the healthy life expectancy of the elderly are essential for reducing medical costs. For two decades, the Nakanojo Study has investigated the relationship between habitual physical activity and the physical and mental health of elderly populations; and since 2014, this research has expanded to examine the health effects of gut microbiota and the intake of lactic acid bacteria by the elderly. Recent research has indicated that gut bacteria have a major impact on host health, although the mechanisms are not fully understood. However, an increasing number of reports suggest that lactic acid bacteria have a beneficial impact on health. Clinical studies have shown that Lacticaseibacillus paracasei YIT 9029 (LcS; formerly known as Lactobacillus casei strain Shirota) provides health benefits, such as intestinal regulation, infection prevention, stress relief, and improved sleep quality. Despite the daily consumption of approximately 10 million bottles of dairy products containing LcS in Japan, its health effects among the general population had not been adequately investigated. Therefore, the Nakanojo Study conducted a fundamental investigation of the temporal variability of gut microbiota among the elderly and the relationships among diet, lactobacilli intake, physical activity, and gut microbiota. It also assessed the impact of lactobacilli on the health of the elderly, focusing on gut microbiota stability, hypertension incidence, defecation status, and physical fitness.
