Sourdough Bread for Prediabetes

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Arizona State University

Must not be taking: Metformin

Disqualifiers: Carb-restricted diet, Smoker, Pregnant, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 4 weeks

15 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how different fermentation times of sourdough bread affect blood sugar levels after eating in people with prediabetes. Researchers are testing sourdough bread fermented for 24, 48, and 72 hours against a control bread fermented for 12 hours. The goal is to determine if longer fermentation better manages blood sugar. The trial seeks participants with prediabetes who are not taking the diabetes medication metformin and have no food allergies or specific dietary restrictions. As an unphased trial, this study offers a unique opportunity to contribute to understanding dietary impacts on prediabetes management.

Do I need to stop my current medications for the trial?

The trial does not specify if you need to stop your current medications, but you cannot participate if you are using medications that affect blood glucose.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that sourdough bread is generally safe to eat and may offer health benefits. Studies have found that it can improve blood sugar and insulin levels due to its lower glycemic index, meaning it doesn't cause blood sugar to rise as quickly.

For some, sourdough bread is also easier to digest. It reduces certain carbohydrates called FODMAPs, which can cause stomach problems, making it more tolerable for those with sensitive stomachs. Thus, sourdough bread appears to be a good choice for most people in terms of safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike standard treatments for prediabetes, which often include lifestyle changes like diet and exercise or medications like metformin, these investigational options focus on something as simple and enjoyable as bread. Researchers are excited about sourdough bread because it relies on natural fermentation, which might improve blood sugar control differently. The unique feature here is the extended fermentation times—24, 48, and 72 hours—which could enhance the bread's impact on blood sugar levels, potentially offering a tasty and accessible way to manage prediabetes.

What evidence suggests that this trial's treatments could be effective for prediabetes?

Studies have shown that sourdough bread can help lower blood sugar and insulin levels after meals in people with impaired glucose tolerance. Research indicates that the fermentation process in sourdough, lasting from 24 to 72 hours, reduces the glycemic index, which measures how quickly foods cause blood sugar levels to rise. This trial will compare different fermentation times of sourdough bread—specifically 24, 48, and 72 hours—to assess their impact on blood sugar control. Longer fermentation times, such as 48 or 72 hours, have been linked to better blood sugar control because the acids produced during fermentation may slow the release of sugar into the bloodstream. Overall, the unique fermentation process of sourdough appears promising for managing blood sugar levels in individuals with prediabetes. ^{1 2 6 7 8}

Are You a Good Fit for This Trial?

This trial is for adults with prediabetes who aren't on metformin, have no food allergies or sensitivities, and aren't taking pre/postbiotic supplements. It's not for those on low-carb diets, using meds that affect blood sugar, currently ill, smoking, pregnant or lactating women, anyone with GI tract surgery history, or unwilling to follow the study protocol.

Inclusion Criteria

No known food allergies or sensitivities

Not supplementing pre/post biotics

I have prediabetes and am not taking metformin.

Exclusion Criteria

Lactation

Following a diet that restricts carbohydrates

Acute illness

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants consume sourdough bread with varying fermentation times to assess postprandial glycemic response

4 weeks

Multiple visits for each bread type

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Sourdough Bread

Trial Overview

The trial is testing how different durations of sourdough bread fermentation (24h, 48h & 72h) affect blood sugar levels after eating in prediabetic adults. Participants will try various types of sourdough to see if longer fermentation improves glycemic response compared to regular yeast bread.

How Is the Trial Designed?

Group I: sourdough bread 72 Experimental Treatment 1 Intervention

72 hours fermentation

Group II: sourdough bread 48 Experimental Treatment 1 Intervention

48 hours fermentation

Group III: sourdough bread 24 Experimental Treatment 1 Intervention

24 hours fermentation

Group IV: Control bread Active Control 1 Intervention

12 hours fermentation

Who Is Running the Clinical Trial?

Arizona State University

Lead Sponsor

Trials

311

Recruited

109,000+

Citations

1.

bmcnutr.biomedcentral.com

bmcnutr.biomedcentral.com/articles/10.1186/s40795-024-00861-x

Sourdough bread as nutritional intervention tool for ...

Feeding rats on diet containing sourdough bread I or II showed significant elevation of insulin and reduction of glucose, which proven the anti- ...

2.

clinicaltrials.gov

clinicaltrials.gov/study/NCT06925451

Effects of Sourdough Fermentation Duration and Acid ...

Sourdough bread products also have a lower glycemic index value, meaning they do not cause the blood sugar to rise as quickly, thus slowing the release of ...

3.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC8000543/

Effect of Different Fermentation Condition on Estimated ...

Consumption of sourdough bread reduces postprandial blood glucose and insulin response. This mechanism could explain why organic acids, such as ...

4.

withpower.com

withpower.com/trial/phase-insulin-resistance-3-2025-22d55

Sourdough Bread for Prediabetes

Research shows that sourdough bread can help lower blood sugar and insulin levels after meals in people with impaired glucose tolerance, which is a condition ...

5.

sciencedirect.com

sciencedirect.com/science/article/pii/S2161831322013023

Nutritional benefits of sourdoughs: A systematic review

A Canadian study highlighted a significantly lower glucose iAUC (180 min) after the intake of sourdough whole-grain wheat bread than after the intake of refined ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10103004/

Nutritional benefits of sourdoughs: A systematic review - PMC

Regarding gastrointestinal outcomes, sourdough fermentation was shown to reduce FODMAP content in bread, making it more acceptable for patients with IBS ...

7.

mdpi.com

mdpi.com/2072-6643/16/15/2380

Sourdough Bread with Different Fermentation Times

The present study aimed to evaluate the effects of two sourdough breads, one with long (48 h) and one with short (2 h) fermentation, on clinical ...

8.

centerwatch.com

centerwatch.com/clinical-trials/listings/NCT06925451/effects-of-natural-sourdough-fermentation-duration-and-acid-development-on-postprandial-blood-glucose-in-prediabetic-adults

Effects of Natural Sourdough Fermentation Duration and ...

Sourdough bread products also have a lower glycemic index value, meaning they do not cause the blood sugar to rise as quickly, thus slowing the ...