1.
Yeast Beta-Glucan Supplementation Downregulates Markers of Systemic Inflammation after Heated Treadmill Exercise.
Zabriskie, HA, Blumkaitis, JC, Moon, JM, Currier, BS, Stefan, R, Ratliff, K, Harty, PS, Stecker, RA, Rudnicka, K, Jäger, R, et al
Nutrients. 2020;(4)
Abstract
Aerobic exercise and thermal stress instigate robust challenges to the immune system. Various attempts to modify or supplement the diet have been proposed to bolster the immune system responses. The purpose of this study was to identify the impact of yeast beta-glucan (Saccharomyces cerevisiae) supplementation on exercise-induced muscle damage and inflammation. Healthy, active men (29.6 ± 6.7 years, 178.1 ± 7.2 cm, 83.2 ± 11.2 kg, 49.6 ± 5.1 mL/kg/min, n = 16) and women (30.1 ± 8.9 years, 165.6 ± 4.1 cm, 66.7 ± 10.0 kg, 38.7 ± 5.8 mL/kg/min, n = 15) were randomly assigned in a double-blind and cross-over fashion to supplement for 13 days with either 250 mg/day of yeast beta-glucan (YBG) or a maltodextrin placebo (PLA). Participants arrived fasted and completed a bout of treadmill exercise at 55% peak aerobic capacity (VO2Peak) in a hot (37.2 ± 1.8 °C) and humid (45.2 ± 8.8%) environment. Prior to and 0, 2, and 72 h after completing exercise, changes in white blood cell counts, pro- and anti-inflammatory cytokines, markers of muscle damage, markers of muscle function, soreness, and profile of mood states (POMS) were assessed. In response to exercise and heat, both groups experienced significant increases in white blood cell counts, plasma creatine kinase and myoglobin, and soreness along with reductions in peak torque and total work with no between-group differences. Concentrations of serum pro-inflammatory cytokines in YBG were lower than PLA for macrophage inflammatory protein 1β (MIP-1β) (p = 0.044) and tended to be lower for interleukin 8 (IL-8) (p = 0.079), monocyte chemoattractment protein 1 (MCP-1) (p = 0.095), and tumor necrosis factor α (TNF-α) (p = 0.085). Paired samples t-tests using delta values between baseline and 72 h post-exercise revealed significant differences between groups for IL-8 (p = 0.044, 95% Confidence Interval (CI): (0.013, 0.938, d = -0.34), MCP-1 (p = 0.038, 95% CI: 0.087, 2.942, d = -0.33), and MIP-1β (p = 0.010, 95% CI: 0.13, 0.85, d = -0.33). POMS outcomes changed across time with anger scores in PLA exhibiting a sharper decline than YBG (p = 0.04). Vigor scores (p = 0.04) in YBG remained stable while scores in PLA were significantly reduced 72 h after exercise. In conclusion, a 13-day prophylactic period of supplementation with 250 mg of yeast-derived beta-glucans invoked favorable changes in cytokine markers of inflammation after completing a prolonged bout of heated treadmill exercise.
2.
Effects of Yeast Mannan Which Promotes Beneficial Bacteroides on the Intestinal Environment and Skin Condition: A Randomized, Double-Blind, Placebo-Controlled Study.
Tanihiro, R, Sakano, K, Oba, S, Nakamura, C, Ohki, K, Hirota, T, Sugiyama, H, Ebihara, S, Nakamura, Y
Nutrients. 2020;(12)
Abstract
Yeast mannan (YM) is an indigestible water-soluble polysaccharide of the yeast cell wall. In vitro fecal fermentation studies showed that YM could exhibit a notable prebiotic effect. The aim of this randomized, double-blind, placebo-controlled study was to assess the efficacy of YM intake on the intestinal environment and skin condition. One hundred and ten healthy female subjects aged 30-49 years were supplemented with YM or placebo for eight weeks. Skin dryness was set as the primary endpoint. No side effects were observed during the study. Microbiota analyses revealed that YM intake selectively increased the relative abundance of Bacteroides thetaiotaomicron and Bacteroides ovatus compared to that by placebo. Feces and urine analyses showed that YM intake lowered the concentration of fecal p-cresol, indole, and skatole, and elevated urinal equol levels compared to those in placebo. Furthermore, YM supplementation ameliorated subjective skin dryness. This study suggests that YM intake could promote beneficial Bacteroides and improve the intestinal environment and skin condition.
3.
Soluble and Insoluble Yeast β-Glucan Differentially Affect Upper Respiratory Tract Infection in Marathon Runners: A Double-Blind, Randomized Placebo-Controlled Trial.
Mah, E, Kaden, VN, Kelley, KM, Liska, DJ
Journal of medicinal food. 2020;(4):416-419
Abstract
In a previous study, consumption of a dairy beverage incorporating insoluble β-glucan decreased upper respiratory tract infection (URTI) symptomatic days and severity in marathon runners. In this report, we extended our previous findings by presenting data on a dairy beverage containing soluble β-glucan and URTI in marathon runners. Healthy adults running in the 2017 Austin Marathon consumed dairy beverages (250 mL/day) containing 250 mg of insoluble (n = 69) or soluble (n = 76) baker's yeast β-glucan (Wellmune®) or placebo (n = 133) for the 45 days before, day of, and 45 days after the marathon (91 days total). Participants completed a daily online survey assessing compliance and URTI symptoms, which were evaluated using the Jackson Index and confirmed by the study physician. Total severity of URTI was significantly lower in the insoluble yeast β-glucan group compared to the placebo group, but was not different between the soluble yeast β-glucan group and placebo group. Severity ratings for nasal discharge were significantly lower in both the insoluble and soluble yeast β-glucan groups compared to the placebo group. Additionally, severity rating for sore throat was lower in the insoluble, but not the soluble yeast β-glucan group compared to the placebo group. The insoluble yeast β-glucan group, but not the soluble yeast β-glucan group also reported fewer URTI symptomatic days compared to the placebo group. The results suggest that soluble and insoluble yeast β-glucan, incorporated into a food matrix, differentially affected exercise-induced URTI in marathon runners.