High Molecular Weight Barley β-Glucan Alters Gut Microbiota Toward Reduced Cardiovascular Disease Risk

Abstract

The physiological cholesterol-lowering benefits of β-glucan have been well documented, however, whether modulation of gut microbiota by β-glucan is associated with these physiological effects remains unknown. The objectives of this study were therefore to determine the impact of β-glucan on the composition of gut microbiota in mildly hypercholesterolemic individuals and to identify if the altered microbiota are associated with bioactivity of β-glucan in improving risk factors of cardiovascular disease (CVD). Using a randomized, controlled crossover study design, individuals received for 5-week either a treatment breakfast containing 3 g high molecular weight (HMW), 3 g low molecular weight (LMW), 5 g LMW barley β-glucan, or wheat and rice. The American Heart Association (AHA) diet served as the background diet for all treatment groups. Phases were separated by 4-week washout periods. Fecal samples were collected at the end of each intervention phase and subjected to Illumina sequencing of 16S rRNA genes. Results revealed that at the phylum level, supplementation of 3 g/d HMW β-glucan increased Bacteroidetes and decreased Firmicutes abundances compared to control (P < 0.001). At the genus level, consumption of 3 g/d HMW β-glucan increased Bacteroides (P < 0.003), tended to increase Prevotella (P < 0.1) but decreased Dorea (P < 0.1), whereas diets containing 5 g LMW β-glucan and 3 g LMW β-glucan failed to alter the gut microbiota composition. Bacteroides, Prevotella, and Dorea composition correlated (P < 0.05) with shifts of CVD risk factors, including body mass index, waist circumference, blood pressure, as well as triglyceride levels. Our data suggest that consumption of HMW β-glucan favorably alters the composition of gut microbiota and this altered microbiota profile associates with a reduction of CVD risk markers. Together, our study suggests that β-glucan induced shifts in gut microbiota in a MW-dependent manner and that might be one of the underlying mechanisms responsible for the physiological benefits of β-glucan.

Nutritional Models of Experimentally-Induced Subacute Ruminal Acidosis (SARA) Differ in Their Impact on Rumen and Hindgut Bacterial Communities in Dairy Cows

“…The PLS-regression coefficients were used to identify genera that were most characteristic of each treatment group. The significant shifts of taxa were determined when the error bars of each component was above or below x axis of coefficient plot (Wang et al, 2016). The results of PLS-DA were visualized by PLS-DA loading scatter plots (Supplementary Figures 1–3).…”

Human Oral Buccal Microbiomes Are Associated with Farmworker Status and Azinphos-Methyl Agricultural Pesticide Exposure

“…have not been investigated in this cohort to date. Hispanics have a disproportionate disease burden for many common diseases related to vasculature (i.e., diabetes and cardiovascular disease) (82)(83)(84)(85)(86)(87)(88)(89)(90) that have also been shown to have microbiome-related disease variables in many other experimental contexts (91)(92)(93)(94)(95)(96)(97)(98)(99)(100)(101)(102)(103)(104). Dental health, bacterial infection, and peripheral vascular disease have many independent associations (105), and some of the etiology could be affected by systemic loosening of tight junctions as induced by organophosphates (78).…”

Molecular Mechanism of Functional Ingredients in Barley to Combat Human Chronic Diseases

“…Barley β-glucan can reduce low-density lipoprotein cholesterol and non-highdensity lipoprotein cholesterol as well as alters the gut microbiota for preventing cardiovascular disease (see Table 2) [98]. Oxidative stress and inflammation are two important factors of atherosclerosis, and polysaccharide extracts with antioxidation and anti-inflammation of hulless barley prevent cardiovascular diseases [17].…”

“…Higher consumption of barley β-glucan is associated with lower systolic and diastolic blood pressure (see Table 2), i.e., diets rich in β-glucans reduce systolic blood pressure by 2.9 mmHg (95% CI 0.9 to 4.9 mmHg) and diastolic blood pressure by 1.5 mmHg (95% CI 0.2 to 2.7 mmHg) for a median difference in β-glucans of 4 g [121]. The consumption of high molecular weight barley β-glucan can reduce blood pressure [98].…”