Impact of Slowly Digestible Carbohydrates on the Gut-brain Axis

Study Overview
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Brief Summary
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Our laboratory is investigating the physiological outcomes and health benefits of the consumption of high-quality carbohydrates. One important aspect of the high-quality carbohydrate characteristics is a slow and sustained digestion and glucose release to the blood. In the proposed study, the investigators will evaluate the consumption of different types of slowly digestible carbohydrates (SDCs) and their beneficial effects including moderation of the glycemic response profile (postprandial glycemic response, PPGR) and stimulation of the gut-brain axis, which controls appetite and food intake. This stimulation will be evaluated in terms of second-meal food intake and the circulatory level of appetite-suppressing gut hormones (such as glucagon-like peptide-1).

Official Title
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Impact of Slowly Digestible Carbohydrates on the Gut-brain Axis

Conditions
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Appetitive Behavior, Obesity, Diabetes Mellitus, Type 2

Intervention / Treatment
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* Other: Rice flour
* Other: Alternanoligosaccharide 15
* Other: Inulin
* Other: Waxy potato starch
* Other: Waxy potato starch + epigallocatechin gallate (EGCG)
* Other: Chickpea flour + epigallocatechin gallate (EGCG)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 18.5 - 25 kg/m2 Stable weight for the past 3 months (i.e. +/- 2..5 kg) Exclusion Criteria: Pregnant or nursing women Diabetic Individuals with history of gastrointestinal disease

Ages Eligible for Study
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Minimum Age: 22 Years
Maximum Age: 45 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Rice flour<br>Rapidly digestible control | Other: Rice flour<br>* Rice flour made into rice porridge will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|
| Experimental: Alternanoligosaccharide 15<br> | Other: Alternanoligosaccharide 15<br>* Alternanoligosaccharide 15 incorporated into rice porridge will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|
| Experimental: Waxy potato starch<br> | Other: Waxy potato starch<br>* Retrograded waxy potato starch made into porridge meal will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|
| Experimental: Combination of waxy potato starch and epigallocatechin gallate (EGCG)<br> | Other: Waxy potato starch + epigallocatechin gallate (EGCG)<br>* A combination of retrograded waxy potato starch and EGCG made into porridge meal will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|
| Experimental: Combination of chickpea flour and epigallocatechin gallate (EGCG)<br> | Other: Chickpea flour + epigallocatechin gallate (EGCG)<br>* A combination of chickpea flour and EGCG made into porridge meal will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|
| Experimental: Inulin<br> | Other: Inulin<br>* Inulin incorporated into rice porridge will be tested for postprandial glycemic response, gut hormone levels, gastric emptying rate, appetitive response, and fermentability.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial glycemic response | Blood plasma glucose will be measured, (AUC) | Acute study: [4 hours of measurement after consumption of test food] | 
| Postprandial glycemic response | Blood plasma glucose will be measured, (C max) | Acute study: [4 hours of measurement after consumption of test food] | 
| Postprandial glycemic response | Blood plasma glucose will be measured, (t max) | Acute study: [4 hours of measurement after consumption of test food] | 
| Postprandial plasma gut hormone response | Blood plasma glucagon-like peptide-1 and insulin will be measured, (AUC) | Acute study: [4 hours of measurement after consumption of test food] | 
| Postprandial plasma gut hormone response | Blood plasma glucagon-like peptide-1 and insulin will be measured, (C max) | Acute study: [4 hours of measurement after consumption of test food] | 
| Postprandial plasma gut hormone response | Blood plasma glucagon-like peptide-1 and insulin will be measured, (t max) | Acute study: [4 hours of measurement after consumption of test food] | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gastric emptying rate | Breath test will be performed using 13C-acetate mixed into test meals | Acute study: 4 hours of measurement after consumption of test food] | 
| Appetite ratings (Visual Analog Scale, VAS) | Hunger and fullness scores will be measured using a 10-cm scale (0 = weakest feeling of hunger or fullness and 10 = strongest feeling of hunger or fullness) after consumption of test food. Weaker feelings of hunger and stronger feelings of fullness indicate better outcomes. | Acute study: [4 hours of measurement after consumption of test food] | 
| Food Intake of the next meal | At the end of the 4 hour window, participants will be given a large second meal for consumption and the amount of consumed food (food intake) will be estimated. | Acute study: After the consumption a second meal [4 hours later after consuming the first meal] | 
| Breath hydrogen (fermentability) | Breath samples will be collected in 15-minute intervals for 4 hours after consumption of test food and analyzed for hydrogen levels using a breath analyzer. Breath hydrogen levels are indicative of a food's fermentability. | Acute study: [4 hours of measurement after consumption of test food] |