Location: Small Grain and Food Crops Quality Research
Project Number: 3060-21650-002-022-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2021
End Date: Dec 31, 2025
Objective:
(1) Determine the acute and chronic effects of pulse (common beans and lentils) consumption on satiety compared to a control, no pulse diet in humans; (2) Determine how changes in microbial composition and function influence the rate of production of the short chain fatty acids (acetate, propionate, and butyrate) from colonic fermentation of fibers in humans at baseline and after 4-wks of pulse consumption in comparison to a control no pulse diet; (3) Determine the impact of pulse consumption on cardiometabolic risk factors.
Approach:
Adult, overweight males and females (n=44 total, BMI 25-35 kg/m2) with at least one characteristic of the metabolic syndrome will be randomly assigned to either a pulse-rich diet or a no pulse diet in a 4-wk, parallel-arm, repeated-measures study. Before a baseline visit, food records will be collected and analyzed to tailor the 4-wk intervention diets as much as possible to each subject’s food preferences. Each subject will receive a one-week run-in diet mirroring the control diet. The protocol used for the meal test will include 2 cups of pulses for women and 3 cups of pulses for men in any given week. Fecal samples will be collected at baseline, day 14, and day 28. At baseline and at day 28, meal tests will be performed and at the same time, stable isotopes will be infused and venous blood samples will be taken in the fasting and postprandial states. Blood samples will be taken to measure appetite hormones (GLP-1, PYY, ghrelin with aprotinin added to plasma to block degradation, glucose, insulin, short-chain fatty acids, triglycerides, HDLc, and LDLc). Questionnaires and surveys will be administered to assess subjective appetite at different time points during the meal test, and other eating behaviors. Fecal samples will be collected for DNA extraction and high-throughput sequencing and bioinformatics using the QIIME 2 platform will be used. Microbial diversity (alpha- and beta diversity) will be assessed, as well as the Firmicutes to Bacteroidetes ratio. Plasma short-chain fatty acids also will be analyzed.
