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.

Seiya Makino,Jun Hemmi,Mari Kashiwagi,Yukio Asami,Kenichi Hojo,Hiroshi Kano

doi:10.3390/nu10070798

Abstract

Fatigue caused by summer heat is a typical indefinite complaint along with anorexia, loss of sleep, stress, lack of motivation and, in some cases, catching a cold. Yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 has been shown to stimulate the immune system and reduce the risk of catching colds. Here, we conducted a randomized, double-blinded, placebo-controlled trial to investigate whether ingesting this yogurt could ameliorate summer heat fatigue in 49 healthy males (median age 40.0 ± 6.0 years; 30–49 years) who felt fatigued every summer. Fatigue was evaluated by visual analogue scales (VAS) and the balance of sympathetic/parasympathetic nervous systems. After 12 weeks of ingestion in early autumn, the VAS fatigue scores in the yogurt group were lower than those of the placebo group. These results indicate that yogurt fermented with L. bulgaricus OLL1073R-1 can ameliorate summer heat fatigue lasting up to early autumn.

Highlights

Global warming is a world-wide problem that affects the health and productivity of working individuals [1]
We evaluated the effects of yogurt fermented with L. bulgaricus OLL1073R-1, which contains immunostimulatory EPS, on fatigue in the period between the summertime and early autumn
This study suggests that yogurt fermented with L. bulgaricus OLL1073R-1 ameliorates summer heat fatigue and has the potential to affect the autonomic nervous system

Summary

Introduction

Global warming is a world-wide problem that affects the health and productivity of working individuals [1]. High temperatures in the summer increase the incidence of death by heatstroke and are expected to increase summer heat fatigue, recognized as symptoms resulting mainly from the dysfunction of the autonomic nervous system, such as chronic fatigue, anorexia, loss of sleep, stress, lack of motivation and so on. Dysfunction of the immune system is expected to occur similar to that in patients with chronic fatigue syndrome [2] but it still remains unclear. Some of the active components were expected to be polysaccharides [9,10], and polysaccharides purified from fungi, marine algae, and green tea were shown to exhibit anti-fatigue effects in animal studies after physiological challenges such as swimming and running [11,12,13]

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Discussion

Conclusion