Preventive effects against infections by intake of yogurt fermented with Lactobacillus delbrueckii ssp.bulgaricus OLL1073R-1

摘要

Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (1073R-1) is an exopolysaccharide (EPS)-producing lactic acid bacterial strain, the EPS of which has been reported to stimulate immune cells in vitro. We confirmed that the oral administration of either EPS or yogurt fermented with this strain (1073R-1 yogurt) enhanced the activity of natural killer (NK) cells in mice. We also investigated whether the intake of 1073R-1 yogurt had an inhibitory effect on respiratory tract infections. In the animal study, survival periods were longer, the activity of NK cells was higher, and anti-influenza virus antibody titers were larger in the group administered 1073R-1 yogurt and EPS orally than in the water-treated groups. In the human study, the risk of catching common colds and the flu was significantly lower in the group given 1073R-1 yogurt than in the group given milk.NK cell activity also increased in subjects who had low NK cell activity prior to consuming 1073R-1 yogurt.