Effects of heat-killed <i>Enterococcus faecalis</i> T-110 supplementation on gut immunity, gut flora, and intestinal infection in normal aged hamsters

Abstract Infectious diseases are a threat to elderly people, whose immune systems become depressed with age. Among the various infectious diseases, Clostridium difficile infections in particular lead to significant mortality in elderly humans and are a serious problem worldwide, especially because of the increasing infection rates. Probiotics have been proposed as an effective countermeasure against C. difficile infection. The aim of this study was to evaluate the effects of heat-killed Enterococcus faecalis T-110 on intestinal immunity, intestinal flora, and intestinal infections, especially C. difficile infections, in naturally ageing animals, for extrapolation to elderly human subjects. Twenty female hamsters were randomly distributed into two groups. Group 1 was fed a basal diet, and group 2 was fed a basal diet supplemented with heat-killed E. faecalis for 7 days. Heat-killed E. faecalis T-110 improved gut immunity and microflora, especially Clostridium perfringens and C. difficile , of the normal aged hamsters. Heat-killed E. faecalis T-110 may, therefore, be a countermeasure against age-related immune dysfunction and intestinal infections, especially C. difficile infection, in elderly humans. However, further investigation in humans is needed.