Efficacy of heat-killed Lactococcus lactis JCM 5805 on immunity and fatigue during consecutive high intensity exercise in male athletes: a randomized, placebo-controlled, double-blinded trial. Issue 1 (2nd August 2018)

• Record Type: Journal Article
• Authors: Komano, Yuta; Shimada, Kazunori; Naito, Hisashi; Fukao, Kosuke; Ishihara, Yoshihiko; Fujii, Toshio; Kokubo, Takeshi; Daida, Hiroyuki
• Is Part Of: Journal of the International Society of Sports Nutrition. Volume 15:Issue 1(2018)
• Publication Date: 2018-08-02
• Subjects: Dendritic cells -- High intensity exercise -- LC-plasma -- Upper respiratory tract infections -- Fatigue; Athletes -- Nutrition -- Periodicals; Exercise -- Physiological aspects -- Periodicals; 613.2024796
• DOI: 10.1186/s12970-018-0244-9
• Languages: English
• ISSNs: 1550-2783

Abstract

Abstract: Background: Lactococcus lactis JCM 5805 (LC-Plasma) is a unique lactic acid bacteria (LAB) which activates plasmacytoid dendritic cells (pDC). We aimed to evaluate the effect of LC-Plasma on dendritic cell (DC) activity and subjective indices of upper respiratory tract infections (URTI) and fatigue in athletes under high intensity exercise. Methods: We conducted a randomized, placebo-controlled, double-blinded trial. Fifty-one male subjects belonging to a university sports club were randomized into placebo ( n = 25) and LC-Plasma ( n = 26) groups. Individuals ingested placebo capsules containing cornstarch or LC-Plasma capsules containing 100 billion cells of heat-killed LC-Plasma per day for 13 days. During the intervention period, subjects performed high intensity exercise according to their sports club training regime. Blood and saliva sampling were obtained at days 1 and 14, and physical conditions were recorded in a diary. We investigated expression of maturation markers on DCs, muscle damage and stress markers and used student's t test adjusted by Bonferoni's method for multiple comparison between groups. These data were presented as mean ± SD. We also investigated cumulative days of symptoms regarding infections and fatigue and used Chi-square test for comparison between groups. These data were presented as cumulative number. Results: CD86 as maturation marker on pDC was significantly increased in the LC-Plasma group at day 14 (Placebo: 296 ± 70 vs. LC-Plasma: 365 ± 115; Mean Fluorescent Intensity; p = 0.013). Cumulative days of URTI were significantly lower in the LC-Plasma group (Placebo: URTI positive 56, URTI negative 256 vs. LC-Plasma: URTI positive 39, URTI negative 299; days; p = 0.028) and symptoms like sneeze or running nose were significantly lower in the LC-Plasma group (Placebo: Symptom positive 52, Symptom negative 258, vs. LC-Plasma: Symptom positive 36, Symptom negative 301; days; p = 0.032). Moreover, the cumulative days of fatigue were significantly fewer in the LC-Plasma group (Placebo: Symptom positive 128, Symptom negative 182, vs. LC-Plasma: Symptom positive 110, Symptom negative 225; days; p = 0.032). Markers of muscle damage and stress markers were not significantly different between groups. Conclusion: We consider that heat-killed LC-Plasma supplementation relieves morbidity and symptoms of URTI via activation of pDC and decreases fatigue accumulation during consecutive high intensity exercise in athletes. However, LC-Plasma ingestion did not affect markers of muscle damage and stress. Trial registration: UMIN-CTR, UMIN000020372 . Registered 28 December 2015.