In June 2018 researchers from Japan published the results of their study to assess whether the consumption of yoghurt fermented with Lactobacillus bulgaricus reduced summer heat fatigue and associated symptoms (anorexia, loss of sleep, stress, lack of motivation and, in some cases, catching a cold). 49 healthy males (average age 40 years) who suffered from summer heat fatigue every summer were included in the study. The individuals were divided into two groups, with one group consuming yoghurt fermented with L. bulgaricus for 12 weeks in the early autumn. Fatigue levels were evaluated by visual analogue scales. Results showed that the VAS fatigue scores were lower in those who had consumed the yoghurt when compared to those who had not. The researchers therefore concluded that yoghurt fermented with L. bulgaricus can improve summer heat fatigue.
Makino S et al. Anti-Fatigue Effects of Yogurt Fermented with Lactobacillus delbureckii subsp. bulgaricus OLL1073R-1 in Healthy People Suffering from Summer Heat Fatigue: A Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. 2018 Jun 21;10(7)