Dietary pulses, including beans, chickpeas, and lentils, are high in soluble fiber with potential benefits to human health: Pulses are moderate energy density foods, low in fat and high in dietary protein, fiber, vitamins and minerals. Moderate pulse consumption is associated with improvements in glycemic control and reduced risk of cardiovascular disease, obesity and type 2 diabetes. Measuring pulse consumption in humans is difficult, due to limitations in current methods for dietary assessment which are largely based on dietary recalls that are subject to reporting bias. Robust tools for pulse intake assessment are needed, and biomarkers of dietary pulse intake are one approach to solve this problem. The goal of this human feeding study is evaluate the presence of biomarkers of dietary pulses in human subjects.
Dietary pulses, including beans, chickpeas, and lentils, are high in soluble fiber with potential benefits to human health: Pulses are moderate energy density foods, low in fat and high in dietary protein, fiber, vitamins and minerals. Moderate pulse consumption is associated with improvements in glycemic control and reduced risk of cardiovascular disease, obesity and type 2 diabetes. However, only 5% of the U.S. population currently meet recommended fiber intakes. As pulses are an excellent source of fiber, increasing their levels in the American diet could lead to demonstrable health benefits in the population, including positive influences on glucose regulation. Additionally, pulse impacts on the gut microbiome may be responsible for reported health benefits. While diet has direct impacts on health, these effects can be mediated by the microbiome, and dietary fiber is a key determinant of this interaction. The fermentation of soluble fiber by specific microbial species lead to the production of short chain fatty acids (SCFAs) including propionate and butyrate which are positively associated with insulin sensitivity. In general, elevated colonic SCFA production is associated with improved glucose regulation, appetite modulation, and immune system modulation. The overall goal of this research is to evaluate how pulse digestion and microbial fermentation influence the circulating and excreted metabolome. To achieve this goal, a randomized controlled feeding study including one week of control, low pulse and high pulse diet will be provided to participants. Metabolomics will be used to identify biomarkers or signatures for pulse enriched diets in urine and plasma. In addition, researchers will investigate dietary pulse related changes in the microbiome community and short chain fatty acid production in fecal samples.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
20
The control Typical American Diet (TAD) diet pattern will mimic the level of intake of fruits, vegetables, whole grains, added sugars, saturated fats and sodium in the general U.S. population. This diet will feature no servings of pulses per day.
The Low Pulse diet will be designed based on the TAD with substitution of pulses for lean meat and grains. This diet will feature 0.2 cups of pulses per day at 2,000 kilocalories (kcals).
The High Pulse diet will be designed based on the TAD with substitution of pulses for lean meat and grains. This diet will feature 1.5 cups of pulses per day at 2,000 kilocalories (kcals).
USDA ARS Western Human Nutrition Research Center
Davis, California, United States
Change in urine metabolomics profile
Urine metabolites will be measured by gas chromatography mass spectrometry (GCMS) before and after consumption of control, low pulse or high pulse diets.
Time frame: Day 14, 28, and 42; fasting and post prandial 0.5hr, 2hr, 3hr, 6hr, 12hr and 24hr
Change in plasma metabolomics profile
Plasma metabolites will be measured by gas chromatography mass spectrometry (GCMS) before and after consumption of control, low pulse or high pulse diets.
Time frame: Day 14, 28, and 42; fasting and post prandial 0.5hr, 2hr, 3hr and 6hr
Change in fecal microbiome community
DNA of colonic microbiome will be measured before and after each diet exposure.
Time frame: Day 7, 14, 21, 28, 35, 42
Change in fecal short chain fatty acids
Acetate, propionate and butyrate will be measured by GCMS before and after each diet exposure.
Time frame: Day 7, 14, 21, 28, 35, 42
Change in fecal bile acids
Bile acids will be measured by GCMS before and after each diet exposure.
Time frame: Day 7, 14, 21, 28, 35, 42
Change in plasma short-chain fatty acids
Plasma acetate, propionate and butyrate will be measured by GCMS before and after consumption of control, low pulse or high pulse diets.
Time frame: Day 14, 28, and 42; fasting and post prandial 0.5hr, 2hr, 3hr and 6hr
Change in pro-inflammatory cytokines
Cytokines including tumor necrosis factor alpha (TNF-a), interleukin (IL)-1, IL-6 and interferon-gamma will be measured in plasma using multiplex assays.
Time frame: Day 14, 28, and 42; fasting and post prandial 0.5hr, 2hr, 3hr and 6hr
Change in anti-inflammatory cytokines
Cytokines including interleukin (IL)-1 receptor antagonist, IL-4, IL-10, IL-11, and IL-13 will be measured in plasma using multiplex assays.
Time frame: Day 14, 28, and 42; fasting and post prandial 0.5hr, 2hr, 3hr and 6hr
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.