Abstract 17335: Dietary Carbohydrate Quality Affects Plasma Lipid Profile and the Microbiome
Considerable data is available on the effect of carbohydrate (carb) quantity on CVD risk factors but data for carb quality is limited. Our objective was to determine the relative comparability for an isocaloric exchange of unrefined-carb (endosperm+germ+bran, e.g., whole wheat flour), refined-carb (endosperm only, e.g., white flour) and simple-carb (sucrose, e.g., high fructose corn syrup), on cardiometabolic risk factors and the gut microbiome. All foods/beverages (60%E total carb, 15%E protein, 27%E fat [7%E SFA, 10%E MUFA, 10%E PUFA], 80mg cholesterol/1000 kcal) were provided to study subjects (n=11 men and women, 65 years, BMI 27.5 kg/m2, LDL-C ≥100 mg/dL) for 5 weeks (randomized, single-blind, cross-over design). Body weight was maintained constant. At the end of each diet phase plasma lipid profile, inflammatory factors and glucose homeostasis were determined using standard methods. Fecal microbiota taxa was characterized by 16S rRNA sequencing and data analyzed using QIIME and PathoScope. Plasma LDL-C levels differed among diets (125 ± 29 mg/dLb, 129 ± 29 mg/dLa,b and 136 ± 24 mg/dLa, unrefined-, simple- and refined-carb , respectively). Carb quality had no significant effect on HDL-C, TG, FFA, glucose, insulin, CRP or IL-6 levels. There were 21 genera that had a mean relative abundance (RA) of ≥1% and 4 genera (Roseburia, Oscillospira, Ruminococcus and Coprococcus) varied significantly across diets but after multiple testing adjustment, only Roseburia RA variations remained significant ( 2.58%a, 0.99%b, and 0.81%b, unrefined-, simple- and refined-carb, respectively). Interesting trends were observed between the RA of the following genera and plasma lipids: Roseburia was negatively associated with LDL-C (r=0.28, p=0.097) and HDL-C (r=-0.39, p=0.022); Oscillospira was negatively associated with TG (r=-0.53, p=0.097), and Anaerostipes was positively associated with TG (r=0.40, p=0.0585) levels. These data suggest that carb quality alters the RA of butyrate-producing bacteria, presumably leading to higher short chain fatty acid production, with subsequent alterations in plasma lipids. This study provides novel information about the impact of carb quality on the phylogenetic structure and functional capacity of the fecal microbiome.
Author Disclosures: N.R. Matthan: None. A.V. Kane: None. W. Johnson: None. S. Manimaran: None. T. Faits: None. A.H. Lichtenstein: None.
- © 2015 by American Heart Association, Inc.