Impact of Okara and Bio-okara Food Product on Gut and Glycaemic Health in Middle-aged and Older Adults in Singapore

Study Overview
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Brief Summary
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This research project aims to provide the scientific findings about the beneficial effects of okara (soybean pulp) consumption on gut and glycaemic health in middle-aged and older individuals in Singapore. In addition, it aims to examine the health promoting impact of bio-transformed okara in this population. We hypothesise that consuming a habitual diet with an okara (untreated or bio-transformed) incorporated food product will improve the gut microbiome composition and will increase the production of short chain fatty acids when compared to a same diet with no okara. Okara-based food product can also improve the glycaemic response in individuals compared to a product without okara in meal tolerance test (acute).

Detailed Description
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For this double-blind, randomized, crossover experiment, the participants will complete a 16-week study period. Following a 1-wk pre-intervention baseline period, each participant will be randomly assigned to consume their habitual diet that either contains or do not contain okara food product (untreated and bio-transformed okara) for 3 weeks. The food product will be equivalent to a consumption of 20 g of okara (dried) per day. Following a 3-week dietary 'washout' period, the participants will be assigned to consume the other diets for another 3 weeks. This process will be repeated until each participant have completed all three interventions. Fecal and fasting-state blood samples will be obtained at study weeks 1, 4, 7, 10, 13, and 16, which correspond to before and end of the three 3-week intervention periods. Additionally, during Weeks 1, 7 and 13, fasted participants will also be required to undergo a meal tolerance test. A cannula will first be inserted into the participant's forearm for blood sampling by a trained phlebotomist. One of three meals prepared by designated study personnel will then be randomly assigned during each visit, namely, control biscuit, untreated okara biscuit and bio-transformed okara biscuit. During each test, the participants will eat the prepared meal within 10 minutes and have blood samples drawn by intravenous cannulation at time = 0, 15, 30, 45, 60, 90, 120, 180 and 240 min, with time 0 being the time the participants first start eating the biscuits. The blood samples will analyzed for the postprandial blood glucose, insulin responses and lipid levels.

Official Title
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Impact of Okara and Bio-okara Food Product on Gut and Glycaemic Health in Middle-aged and Older Adults in Singapore

Conditions
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Microbiota, Gastrointestinal Microbiome, Blood Glucose, Aging

Intervention / Treatment
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* Dietary Supplement: Okara biscuits
* Dietary Supplement: Bio-okara biscuits
* Dietary Supplement: Control biscuits


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ability to give an informed consent Age 50 to 75 years Willing to follow the study procedures Exclusion Criteria: All subjects meeting any of the exclusion criteria at baseline will be excluded from participation Significant change in weight (≥ 3 kg body weight) during the past 3 months Allergy to soy-based products Acute illness at the study baseline Exercising vigorously over the past 3 months Following any restricted diet (e.g. vegetarian) Smoking Have a daily intake of more than 2 alcoholic drinks per day Prescribed and taking antihypertensive/cholesterol-lowering/ type-2 diabetic medication which started less than 5 years prior to the intervention participation Taking dietary supplements which may impact the outcome of interests (e.g. vitamin supplements, probiotic supplement etc.) Pregnant, lactating, or planning pregnancy in the next 6 months Insufficient venous access to allow the blood collection Very high intake of fibre/ vegetables on a daily basis

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 75 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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Okara biscuits<br>Subjects will consume their habitual diet with daily okara biscuit consumption accounting to 20 grams/ day of dry okara powder for 21 days. | Dietary Supplement: Okara biscuits<br>* Consumption of okara-enriched biscuits together with habitual diet.<br>|
| Experimental: Bio-okara biscuits<br>Subjects will consume their habitual diet with daily bio-okara biscuit consumption accounting to 20 grams/ day of dry bio-okara powder for 21 days. | Dietary Supplement: Bio-okara biscuits<br>* Consumption of bio-okara-enriched biscuits together with habitual diet. Bio-okara is a form of fermented okara.<br>* Other names: Fermented okara biscuits;|
| Experimental: Control biscuits<br>Subjects will consume their habitual diet with daily control biscuit consumption for 21 days. | Dietary Supplement: Control biscuits<br>* Consumption of control biscuits together with habitual diet.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in gut microbiome composition before and after a 3 week intervention. | Gut microbiome composition will be determined via fecal samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in fecal short chain fatty acids (SCFA) before and after a 3 week intervention. | SCFA will be determined via fecal samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in serum short chain fatty acids (SCFA) before and after a 3 week intervention. | SCFA will be determined via serum samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in fecal bile acids before and after a 3 week intervention. | Bile acids will be determined via serum samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in serum zonulin before and after a 3 week intervention. | Serum zonulin will be determined via serum samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood glucose levels before and after a 3 week intervention. | Glucose levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood insulin levels before and after a 3 week intervention. | Insulin levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood triglyceride levels before and after a 3 week intervention. | Total triglyceride levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood cholesterol levels before and after a 3 week intervention. | Total cholesterol levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood low-density lipoprotein-cholesterol levels before and after a 3 week intervention. | Low-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood high-density lipoprotein-cholesterol levels before and after a 3 week intervention. | High-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects at baseline and after each intervention period. | Baseline and post-intervention (at 3 weeks) | 
| Change in blood glucose levels over acute trial period | Glucose levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood insulin levels over acute trial period | Insulin levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood short-chain fatty acids levels over acute trial period | Short-chain fatty acids levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood amino acid levels over acute trial period | Amino acid levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in blood pressure | Blood pressure | Baseline and post-intervention (at 3 weeks) | 
| Change in anthropometric measurements | Waist circumference | Baseline and post-intervention (at 3 weeks) | 
| Change in anthropometric measurements | Weight | Baseline and post-intervention (at 3 weeks) | 
| Change in anthropometric measurements | Height | Baseline | 
| Dietary assessment | Dietary questionnaires (3-day food record) | Baseline and post-intervention (at 3 weeks) | 
| Stool assessment | Stool sampling questionnaire will be completed by subjects, which notes down food or alcohol consumed over the past 24 hours prior to collection, any discomfort, pain or bloating, flatulence, noticable changes in stool frequency or consistency, any blood in stool and any type of medication consumed over the past 3 months. | Baseline and post-intervention (at 3 weeks) | 
| Stool assessment | Bristol stool chart (Ranging from Type 1 to Type 7, with Type 3 or 4 being ideal. | Baseline and post-intervention (at 3 weeks) | 
| Sleep quality assessment | Pittsburgh sleep quality index questionnaire, with 7 different components assessing sleep and each component making up a minimum or 0 and maximum of 3 points. The full scale ranges from 0 to 21, with a lower score indicative of a better quality of sleep. | Baseline and post-intervention (at 3 weeks) | 
| Sleep quality assessment | Sleep evaluation questionnaire (survey) to assess eligibility for studies with sleep involved | Baseline and post-intervention (at 3 weeks) | 
| Cognitive assessment | Montreal cognitive assessment | Baseline and post-intervention (at 3 weeks) | 
| Appetite assessment | Visual analogue scale, with unit of measure being units on a scale | Baseline and post-intervention (at 3 weeks) | 
| Change in blood amino acids levels over acute trial period | Amino acid levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood triglyceride levels over acute trial period | Total triglyceride levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood cholesterol levels over acute trial period | Total cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood low-density lipoprotein-cholesterol levels over acute trial period | Low-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 
| Change in blood high-density lipoprotein-cholesterol levels over acute trial period | High-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention | Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Okara, Soybean pulp, Soybean, Fibre, Gut microbiome, Microbiota, Gastrointestinal microbiome, Glycemic, Glycaemic, Middle-aged and older adults, Singapore