Promoting Gastrointestinal Health and Reducing Subclinical Inflammation in Obese Individuals

Not Applicable

Completed

Conditions: Obesity
Overweight

Interventions: Other: Control
Other: Whole Grain
Other: Fruits and Vegetables

Registration Number: NCT02602496

Lead Sponsor: University of Nebraska Lincoln

Brief Summary: This study evaluates the impact of increased intake of fruits and vegetables and whole grains on markers of inflammation and gut microbial composition. The treatment groups are 3 servings of whole grain per day; 5 servings of fruits and vegetables per day; and a control (3 servings of refined grains per day provided).

Detailed Description: Literature data suggests that fruits and vegetables and whole grains containing dietary fiber and other nutrients are important for maintaining beneficial microbes in the gut. The presence of beneficial microbes in the gut may mediate the subclinical inflammation experienced in metabolic disease. In this project, overweight or obese participants with low intakes of fruits and vegetables or whole grains will increase their intake of these foods to recommended levels. Changes in markers of inflammation and gut microbiota composition will be determined to assess and compare the potential impact of these foods on metabolic disease.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 52

Inclusion Criteria

Obese or overweight men or women (body mass index, BMI, ≥25 kg/m2)
Free of known gastrointestinal disease
No supplements use (excluding multivitamin)
Participate in less than 1 h of exercise per week
Have not taken antibiotics in the last six months

Exclusion Criteria

Men and women with fruits and vegetable intake exceeding 2 servings/day
Men and women with whole grain intakes exceeding 1 serving/day
Pregnant
Do not fit the inclusion criteria

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Control	Control	3 servings of refined grains per day.
Whole Grain	Whole Grain	3 servings of whole grains per day.
Fruits and Vegetables	Fruits and Vegetables	5 servings of fruits and vegetable per day.

Primary Outcome Measures

Name	Time	Method
Change in Tumor Necrosis Factor-α (Value at Week 8 Minus Value at Week 0)	8 weeks	Plasma samples collected from participants at the beginning (week 0) and end of the study (week 8) will be analyzed for tumor necrosis factor-α concentrations using an enzyme linked immunosorbent assay. Changes in the concentrations of these inflammatory markers will be determined from week 0 to week 8.
Change in High Sensitivity C-reactive Protein (Value at Week 8 Minus Value at Week 0)	8 weeks	Plasma samples collected from participants at the beginning (week 0) and end of the study (week 8) will be analyzed for high sensitivity C-reactive protein concentrations using an enzyme linked immunosorbent assay. Changes in the concentrations of these inflammatory markers will be determined from week 0 to week 8.
Change in Lipopolysaccharide Binding Protein (Value at Week 8 Minus Value at Week 0)	8 weeks	Plasma samples collected from participants at the beginning (week 0) and end of the study (week 8) will be analyzed for lipopolysaccharide binding protein concentrations using an enzyme linked immunosorbent assay. Changes in the concentrations of these inflammatory markers will be determined from week 0 to week 8.
Change in Interleukin-6 (Value at Week 8 Minus Value at Week 0)	8 weeks	Plasma samples collected from participants at the beginning (week 0) and end of the study (week 8) will be analyzed for interleukin-6 concentrations using an enzyme linked immunosorbent assay. Changes in the concentrations of these inflammatory markers will be determined from week 0 to week 8.

Secondary Outcome Measures

Name	Time	Method
Change in Gut Microbiota Shannon's Alpha Diversity (Value at Week 8 Minus Value at Week 0)	8 weeks	The Shannon Diversity Index is a quantitative measure that reflects how many different bacterial species there are in a sample. The greater the index, the more diverse the gut microbiota. A negative change indicates a decrease in diversity and a positive change indicates an increase in diversity.
Change in Branched Chain Fatty Acids (Value at Week 8 Minus Value at Week 0)	8 weeks	Branched chain fatty acids (BCFA) are mostly saturated fatty acids (SFA) with one or more methyl branches on the carbon chain. BCFAs were extracted from stool samples and measured using gas chromatography.
Change in Fecal Short Chain Fatty Acids (Value at Week 8 Minus Value at Week 0)	8 weeks	Short-chain fatty acids (SCFAs) are the end products of fermentation of dietary fibers by the anaerobic intestinal microbiota. SCFAs have been shown to exert multiple beneficial effects on mammalian energy metabolism.