Role of Colonic Short Chain Fatty Acids in Obesity

Study Overview
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Brief Summary
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The excess production of colonic short-chain-fatty-acids (SCFA) has been implicated in the promotion of obesity, but colonic fermentation of dietary-fiber to SCFA may also play a role in preventing diabetes. The investigators aimed to compare the effects of two fermentable fibers (inulin and resistant-starch) on postprandial SCFA, glucose, insulin, free-fatty acids (FFA) and gut hormone responses and to compare the responses in healthy overweight and obese (OWO) vs lean (LN) participants. Methods: Using a randomized, single blind, crossover design, 13 OWO and 12 LN overnight fasted participants were studied on 3 separate occasions. On each day they consumed a 300 mL drink containing 75g glucose (Control) or 75g glucose plus 24g inulin (IN), or 28.2g resistant-starch (RS). A standard lunch was served 4 h after the test drink.

Official Title
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Effect of Inulin and Resistant Starch on Postprandial Short Chain Fatty Acid, Glucose, Insulin and Gut Hormone Responses in Lean and Overweight Subjects.

Conditions
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Obesity

Intervention / Treatment
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* Other: Glucose
* Other: Inulin
* Other: Resistant Starch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: non-pregnant body mass index >=20 and <=35 Exclusion Criteria: history of diabetes mellitus history of cardiovascular disease history of bowel disease history of kidney disease history of liver disease use of antibiotics within 3 months of enrolment unusual dietary habits fasting glucose >6.9mmol/L hematocrit below normal range for age and sex

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Lean<br>Participants with body mass index <=25 | Other: Glucose<br>* 75g glucose<br>Other: Inulin<br>* 75g glucose plus 24g inulin<br>Other: Resistant Starch<br>* 75g glucose plus 28.2g resistant starch<br>|
| Other: Overweight<br>Participants with body mass index >25 | Other: Glucose<br>* 75g glucose<br>Other: Inulin<br>* 75g glucose plus 24g inulin<br>Other: Resistant Starch<br>* 75g glucose plus 28.2g resistant starch<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incremental area under the serum acetate response curve |  | For 6 hours after consuming the test meal | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incremental area under the serum propionate response curve |  | For 6 hours after consuming the test meal | 
| Incremental area under the serum butyrate response curve |  | For 6 hours after consuming the test meal | 
| Incremental area under the breath hydrogen response curve |  | For 6 hours after consuming the test meal | 
| Incremental area under the breath methane response curve |  | For 6 hours after consuming the test meal | 
| Incremental area under the serum glucose response curve |  | For 4 hours after consuming the test meal | 
| Incremental area under the serum glucose response curve |  | For 2 hours after consuming the standard lunch | 
| Incremental area under the serum insulin response curve |  | For 4 hours after consuming the test meal | 
| Incremental area under the serum insulin response curve |  | For 2 hours after consuming the standard lunch | 
| Incremental area under the serum c-peptide response curve |  | For 4 hours after consuming the test meal | 
| Incremental area under the serum c-peptide response curve |  | For 2 hours after consuming the standard lunch | 
| Total area under the serum free-fatty acid response curve |  | For 4 hours after consuming the test meal | 
| Total area under the serum free-fatty acid response curve |  | For 2 hours after consuming the standard lunch |