Objective 1: Characterize indices of systemic inflammation and gut microbiota composition and function after chronic (12 weeks) intake of pulses compared to control diet in human OW/OB-IR participants. Objective 2: Characterize dietary- and microbial-derived metabolite pools after regular intake of pulses (12 weeks) in human participants with OW/OB-IR compared to control diet. Objective 3: Characterize cognitive functioning after chronic (12 weeks) intake of pulses compared to control diet in human OW/OB-IR participants.
The proposed study will be conducted in humans according to Good Clinical Practice (GCP) guidelines. All subjects will review and sign an Informed Consent Form approved by the Illinois Institute of Technology's Institutional Review Boards (IRB) prior to screening. The proposed study is a randomized, 3-arm, parallel, placebo-controlled design to investigate the effects of pulses consumption compared to non-pulse foods on indices of systemic inflammation and gut microbiota composition and function over a 12-week period. Potential changes in cognition will also be assessed. The study will test 3 treatment conditions in overweight (OW)/obese (OB) human subjects with insulin resistant (IR). Eighty-three men and women will be recruited, aiming for a completer set of Sixty-six subjects. Participants will be randomized into one of the three study food intervention groups: 1. Control group, (n=22): This group will receive a cup of white rice 7 days/week over a 12-week period. 2. Black bean group, (n=22): This group will receive a cup of black bean 7 days/week over a 12-week period. 3. Chickpea group, (n=22): This group will receive a cup of chickpea 7 days/week over a 12-week period. Each subject will be asked to come for 1 Screening Visit, 4 biweekly food pick-up/compliance visits and 3 Test Day Visits (two of which will also include cognitive testing). The initial screening visit will provide subjects with their site-specific, IRB-approved informed consent document prior to the start of any study-related procedures. Following 1-week diet stabilization and wash in from anthocyanins and ellagitannins, eligible subjects will be randomized to receive 1 of 3 test treatments based on a randomization schedule. The three main Test Day visits will occur at week 0 (day 1; baseline), end of week 6 (mid-point) and at the end of week 12 (end-point). Cognitive testing will occur during the baseline Test Day at week 0, and again at end-point Test Day at week 12. Subjects will be given a breakfast meal before cognitive testing. Pick-up Visits will occur at week 2, 4, 8, and 10. Subjects will pick-up study foods receive dietary counseling, confirm diet compliance and have anthropometrics checked during pick-up visits. Each of the 3 Test Day Visits will last about 2.5-3 h (not including cognitive testing) and involve blood pressure (BP) measurements, anthropometric (weight, waist circumference; body composition) assessment, and an oral glucose tolerance test (OGTT) will be performed. Urine and fecal samples will be collected to monitor modifications occurring in the metabolites during the supplementation. The two-Test Day Visits (baseline and end-point) will also include an additional 1-1.25 h of cognitive testing, for a total of 3.75-4.5 h of total subject time (as there will be a short break between OGTT and cognitive testing). Subjects will maintain daily food and GI-tract diary during the 12-week feeding trial. The diary will include questions about food intake and the condition of gastrointestinal tolerance and bowel function.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
103
This group will receive a cup of rice 7 days/week over a 12-week period
This group will receive a cup of black bean7 days/week over a 12-week period
This group will receive a cup of chick pea 7 days/week over a 12-week period
Clinical Nutrition Research Center
Chicago, Illinois, United States
Plasma biomarkers and measures of inflammation: Nrf2/ NF-κB
Investigate Nrf2/ NF-κB activation in PBMC
Time frame: Baseline to 12 weeks
Changes in plasma systemic and gut inflammatory markers
Collected plasma samples will be used to measure selected inflammatory markers (IL6, hs-CRP and TNF-α) using ELISA methods
Time frame: Baseline to 12 weeks
Determination of GLP-2 in plasma
Analysis of GLP-2 will be done in plasma samples before and after chronic exposure to the study foods using enzyme Immunoassay (EIA) kit as per manufacturer's instructions.
Time frame: Baseline to 12 weeks
Determination of TLR-2/4 gene expression in Human PBMC
Determination of TLR-2/4 gene expression in Human PBMC using RT-PCR method
Time frame: Baseline to 12 weeks
Gut inflammatory markers: Calprotectin, zonulin, and IgA in fecal samples
The concentration of calprotectin, zonulin, and IgA in fecal samples will be determined by enzyme-linked immunosorbent assay (ELISA) as per kit providers' instructions before and after chronic exposure to study foods.
Time frame: Baseline to 12 weeks
Describe functional metagenomics alterations in gut microbiome
Fecal samples will be collected with standard collection kits and stored at -80°C until analysis. Metagenomic and transcriptomic analyses will be performed
Time frame: Baseline to 12 weeks
Characterize metabolite profiles
Polyphenolic metabolites (phenolic acids and derivatives components) will be identified and quantified in urine and plasma.Metabolites in samples will be identified and quantified using an Agilent 6550 iFunnel UHPLC-QTOF-MS and 6460 UHPLC-QQQ-MS, respectively.
Time frame: Baseline to 12 weeks
Characterize bile acid metabolite pool
Bile acids in plasma and fecal samples will be determined using UHPLC-QQQ-MS.
Time frame: Baseline to 12 weeks
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