“Lactic acid bacterium B240” is a plant-derived lactic acid bacterium isolated from fermented “Miang” tea in northern Thailand. B240 is taken up from Peyer's patches in the small intestine and exerts a sIgA production-enhancing effect on both live and heat-killed bacteria. In a basic study, oral administration of B240 protected against infection with seasonal and pandemic influenza viruses, Streptococcus pneumoniae and Salmonella. In addition, a human study has shown that B240 promotes the secretion of salivary sIgA and suppresses the incidence of common cold in a dose-dependent manner. On the other hand, we have obtained evidence that intake of branched chain amino acids (BCAA) reduces fatigue, muscle pain and muscle weakness after exercise. In addition, ingestion of whey protein immediately after exercise was effective for increasing skeletal muscle mass and strength. Therefore, it is expected that a combination of B240, whey protein, and BCAA would be beneficial to many individuals wishing to manage their physical condition during critical periods as a conditioning food for not only athletes but also elderly with a high risk of infection, students taking entrance exams, and also businesspersons.

A total of 100 taxi drivers under job stress were randomly assigned to either an experimental group who consumed yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1, or a control group who did not consume yogurt (n＝50/50). Each of the consumers was given 112 mL yogurt per day for 12 weeks between July 11 and October 5, 2016. Stress was evaluated in terms of the total score for a stress check list (SCL) and the major symptoms of stress were estimated separately using a visual analogue scale (VAS). The subjects also completed a questionnaire about bowel movements based on the Japanese version of the constipation assessment scale (J-CAS). After 12 weeks, in comparison with the control group (n＝47) , the yogurt consumers (n＝39) showed significant reductions in 1) the total SCL scores, 2) the degree of “dizziness or lightheadedness” and “fatigue” on the VAS, and 3) the degree of “less frequent bowel movements” and “diarrhea or liquid bowel movements” on the J-CAS. They also showed a significant improvement of “clear-headedness” and “sleep quality” on the VAS. These results suggest that the health and wellness of taxi drivers under job stress during the summer could be improved by consumption of yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1.