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

Not Applicable

• Conditions: Blood Glucose; Aging; Microbiota; Gastrointestinal Microbiome
• Interventions: Dietary Supplement: Okara biscuits; Dietary Supplement: Control biscuits; Dietary Supplement: Bio-okara biscuits

• Registration Number: NCT03978104
• Lead Sponsor: National University of Singapore

Brief Summary

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

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.

Study Timeline

• Study First Submitted: 2019-05-24
• Study First Submitted QC: 2019-06-05
• Study First Posted: 2019-06-06
• Study Start: 2019-11-01
• Primary Completion: 2020-09-28
• Status Verified: 2022-03
• Last Update Submitted: 2022-03-23
• Last Update Posted: 2022-03-24
• Study Completion: 2022-09

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

1. Ability to give an informed consent
2. Age 50 to 75 years
3. Willing to follow the study procedures

Exclusion Criteria

All subjects meeting any of the exclusion criteria at baseline will be excluded from participation

1. Significant change in weight (≥ 3 kg body weight) during the past 3 months
2. Allergy to soy-based products
3. Acute illness at the study baseline
4. Exercising vigorously over the past 3 months
5. Following any restricted diet (e.g. vegetarian)
6. Smoking
7. Have a daily intake of more than 2 alcoholic drinks per day
8. Prescribed and taking antihypertensive/cholesterol-lowering/ type-2 diabetic medication which started less than 5 years prior to the intervention participation
9. Taking dietary supplements which may impact the outcome of interests (e.g. vitamin supplements, probiotic supplement etc.)
10. Pregnant, lactating, or planning pregnancy in the next 6 months
11. Insufficient venous access to allow the blood collection
12. Very high intake of fibre/ vegetables on a daily basis

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Okara biscuits	Okara biscuits	Subjects will consume their habitual diet with daily okara biscuit consumption accounting to 20 grams/ day of dry okara powder for 21 days.
Control biscuits	Control biscuits	Subjects will consume their habitual diet with daily control biscuit consumption for 21 days.
Bio-okara biscuits	Bio-okara biscuits	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.

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
Appetite assessment	Baseline and post-intervention (at 3 weeks)	Visual analogue scale, with unit of measure being units on a scale
Change in blood pressure	Baseline and post-intervention (at 3 weeks)	Blood pressure
Change in anthropometric measurements	Baseline	Height
Cognitive assessment	Baseline and post-intervention (at 3 weeks)	Montreal cognitive assessment
Stool assessment	Baseline and post-intervention (at 3 weeks)	Bristol stool chart (Ranging from Type 1 to Type 7, with Type 3 or 4 being ideal.
Change in blood low-density lipoprotein-cholesterol levels over acute trial period	Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks).	Low-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention
Sleep quality assessment	Baseline and post-intervention (at 3 weeks)	Sleep evaluation questionnaire (survey) to assess eligibility for studies with sleep involved
Change in blood amino acids levels over acute trial period	Time 0, 15, 30, 45, 60, 90, 120 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks).	Amino acid levels will be determined via fasted blood samples of subjects and after consumption of intervention
Dietary assessment	Baseline and post-intervention (at 3 weeks)	Dietary questionnaires (3-day food record)
Change in blood triglyceride levels over acute trial period	Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks).	Total triglyceride levels will be determined via fasted blood samples of subjects and after consumption of intervention
Change in blood cholesterol levels over acute trial period	Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks).	Total cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention
Change in blood high-density lipoprotein-cholesterol levels over acute trial period	Time 0, 15, 30, 45, 60, 90, 120, 180, 240 minutes held on pre- intervention arm visit (Every 6 weeks, up to 12 weeks).	High-density lipoprotein-cholesterol levels will be determined via fasted blood samples of subjects and after consumption of intervention

Trial Locations

Locations (1)

Department of Food Science and Technology; National University of Singapore; 🇸🇬 Singapore, Singapore