Obesity, Overweight
Conditions
Keywords
Diet, Whole grain, Fruits, Vegetables, Gut health, Anti-inflammatory
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.
Interventions
5 servings of fruits or vegetables
OTHERWhole Grain
3 servings of whole grain
OTHERControl
3 servings of refined grain
Sponsors
University of Nebraska Lincoln
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 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. |
| 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. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in Body Mass Index (Value at Week 8 Minus Value at Week 0) | 8 weeks | Body mass index will be measured on participants at the beginning (week 0) and end of the study (week 8). Changes in body mass index will be determined. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Control 3 servings of refined grains per day.
Control: 3 servings of refined grain | 15 |
| Fruits and Vegetables 5 servings of fruits and vegetable per day.
Fruits and Vegetables: 5 servings of fruits or vegetables | 20 |
| Whole Grain 3 servings of whole grains per day.
Whole Grain: 3 servings of whole grain | 17 |
| Total | 52 |
Baseline characteristics
| Characteristic | Control | Fruits and Vegetables | Whole Grain | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 1 Participants | 1 Participants | 0 Participants | 2 Participants |
| Age, Categorical Between 18 and 65 years | 13 Participants | 17 Participants | 17 Participants | 47 Participants |
| Age, Continuous | 27.6 years STANDARD_DEVIATION 5.9 | 29.4 years STANDARD_DEVIATION 12.8 | 39.2 years STANDARD_DEVIATION 13.5 | 32.3 years STANDARD_DEVIATION 12.4 |
| high sensitivity C-reactive protein | 0.65 mg/mL STANDARD_DEVIATION 0.4 | 0.69 mg/mL STANDARD_DEVIATION 0.39 | 0.79 mg/mL STANDARD_DEVIATION 0.56 | 0.71 mg/mL STANDARD_DEVIATION 0.45 |
| Interleukin-6 | 3.6 pg/mL STANDARD_DEVIATION 2 | 3.8 pg/mL STANDARD_DEVIATION 2.2 | 4.7 pg/mL STANDARD_DEVIATION 3.3 | 4.05 pg/mL STANDARD_DEVIATION 2.58 |
| lipopolysaccharide binding protein | 1.83 mg/L STANDARD_DEVIATION 0.27 | 1.77 mg/L STANDARD_DEVIATION 0.45 | 1.90 mg/L STANDARD_DEVIATION 0.38 | 1.83 mg/L STANDARD_DEVIATION 0.38 |
| Race and Ethnicity Not Collected | — | — | — | 0 Participants |
| Sex: Female, Male Female | 7 Participants | 12 Participants | 11 Participants | 30 Participants |
| Sex: Female, Male Male | 7 Participants | 6 Participants | 6 Participants | 19 Participants |
| TNF-alpha | 23.8 pg/mL STANDARD_DEVIATION 5.9 | 24.2 pg/mL STANDARD_DEVIATION 5.2 | 26.7 pg/mL STANDARD_DEVIATION 4.17 | 24.8 pg/mL STANDARD_DEVIATION 5.2 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 14 | 0 / 18 | 0 / 17 |
| other Total, other adverse events | 0 / 14 | 0 / 18 | 0 / 17 |
| serious Total, serious adverse events | 0 / 14 | 0 / 18 | 0 / 17 |
Outcome results
Primary
Change in High Sensitivity C-reactive Protein (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: C-reactive protein was analyzed using an ELISA kit. The mean outcome is the mean of difference between the end and beginning of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in High Sensitivity C-reactive Protein (Value at Week 8 Minus Value at Week 0) | 0.01 mg/mL | Standard Error 0.08 |
| Fruits and Vegetables | Change in High Sensitivity C-reactive Protein (Value at Week 8 Minus Value at Week 0) | -0.06 mg/mL | Standard Error 0.06 |
| Whole Grain | Change in High Sensitivity C-reactive Protein (Value at Week 8 Minus Value at Week 0) | 0.00 mg/mL | Standard Error 0.12 |
p-value: 0.9708ANOVA
p-value: 0.1642ANOVA
p-value: 0.6043ANOVA
Primary
Change in Interleukin-6 (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: IL-6 was analyzed using an ELISA kit. The mean outcome is the mean of difference between the end and beginning of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Interleukin-6 (Value at Week 8 Minus Value at Week 0) | 0.35 pg/mL | Standard Error 0.45 |
| Fruits and Vegetables | Change in Interleukin-6 (Value at Week 8 Minus Value at Week 0) | -1.08 pg/mL | Standard Error 0.52 |
| Whole Grain | Change in Interleukin-6 (Value at Week 8 Minus Value at Week 0) | 0.51 pg/mL | Standard Error 0.86 |
p-value: 0.9942ANOVA
p-value: 0.0062ANOVA
p-value: 0.6843ANOVA
Primary
Change in Lipopolysaccharide Binding Protein (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: Lipopolysaccharide binding protein was analyzed using an ELISA kit. The mean outcome is the mean of difference between the end and beginning of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Lipopolysaccharide Binding Protein (Value at Week 8 Minus Value at Week 0) | 0.14 mcg/mL | Standard Error 0.07 |
| Fruits and Vegetables | Change in Lipopolysaccharide Binding Protein (Value at Week 8 Minus Value at Week 0) | -0.21 mcg/mL | Standard Error 0.07 |
| Whole Grain | Change in Lipopolysaccharide Binding Protein (Value at Week 8 Minus Value at Week 0) | -0.21 mcg/mL | Standard Error 0.08 |
p-value: 0.0868ANOVA
p-value: 0.0083ANOVA
p-value: 0.0151ANOVA
Primary
Change in Tumor Necrosis Factor-α (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: TNF-α was analyzed using an ELISA kit. The mean outcome is the mean of difference between the end and beginning of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Tumor Necrosis Factor-α (Value at Week 8 Minus Value at Week 0) | -0.36 pg/mL | Standard Error 1.58 |
| Fruits and Vegetables | Change in Tumor Necrosis Factor-α (Value at Week 8 Minus Value at Week 0) | -1.11 pg/mL | Standard Error 1.13 |
| Whole Grain | Change in Tumor Necrosis Factor-α (Value at Week 8 Minus Value at Week 0) | -5.40 pg/mL | Standard Error 0.92 |
p-value: 0.5096ANOVA
p-value: 0.2276ANOVA
p-value: 0.0006ANOVA
Secondary
Change in Branched Chain Fatty Acids (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: The outcome mean is the mean difference between the beginning and the end of the study.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Branched Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | -0.20 mmol/g | Standard Error 0.6 |
| Fruits and Vegetables | Change in Branched Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | -2.41 mmol/g | Standard Error 2.79 |
| Whole Grain | Change in Branched Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | 0.16 mmol/g | Standard Error 0.4 |
p-value: 0.8323ANOVA
p-value: 0.8927ANOVA
p-value: 0.3173ANOVA
Secondary
Change in Fecal Short Chain Fatty Acids (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: Mean outcome is the mean difference between the beginning and end of the study. SCFAs were extracted from stool samples and measured using gas chromatography.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Fecal Short Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | -45.82 mmol/g | Standard Error 22.5 |
| Fruits and Vegetables | Change in Fecal Short Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | 10.72 mmol/g | Standard Error 13.5 |
| Whole Grain | Change in Fecal Short Chain Fatty Acids (Value at Week 8 Minus Value at Week 0) | 2.88 mmol/g | Standard Error 10.18 |
p-value: 0.2252ANOVA
p-value: 0.4715ANOVA
p-value: 0.7157ANOVA
Secondary
Change in Gut Microbiota Shannon's Alpha Diversity (Value at Week 8 Minus Value at Week 0)
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.
Time frame: 8 weeks
Population: Alpha diversity was analyzed through the Shannon's Index. The mean outcome is the mean difference between the end and beginning of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Gut Microbiota Shannon's Alpha Diversity (Value at Week 8 Minus Value at Week 0) | 0.05 Shannon's Index | Standard Error 0.15 |
| Fruits and Vegetables | Change in Gut Microbiota Shannon's Alpha Diversity (Value at Week 8 Minus Value at Week 0) | 0.12 Shannon's Index | Standard Error 0.09 |
| Whole Grain | Change in Gut Microbiota Shannon's Alpha Diversity (Value at Week 8 Minus Value at Week 0) | -0.15 Shannon's Index | Standard Error 0.12 |
p-value: 0.9255ANOVA
p-value: 0.0454ANOVA
p-value: 0.292ANOVA
Other Pre-specified
Change in Body Mass Index (Value at Week 8 Minus Value at Week 0)
Body mass index will be measured on participants at the beginning (week 0) and end of the study (week 8). Changes in body mass index will be determined.
Time frame: 8 weeks
Population: Weight and height were measured to calculate the BMI. The outcome mean is the mean difference between the beginning and end of the treatment period.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control | Change in Body Mass Index (Value at Week 8 Minus Value at Week 0) | -0.16 kg/m^2 | Standard Error 0.09 |
| Fruits and Vegetables | Change in Body Mass Index (Value at Week 8 Minus Value at Week 0) | -0.22 kg/m^2 | Standard Error 0.25 |
| Whole Grain | Change in Body Mass Index (Value at Week 8 Minus Value at Week 0) | -0.12 kg/m^2 | Standard Error 0.1 |
p-value: 0.27ANOVA