Effects of Natural Sourdough Fermentation Duration and Acid Development on Postprandial Blood Glucose in Prediabetic Adults

Not Applicable

Recruiting

• Conditions: Insulin Resistance

• Registration Number: NCT06925451
• Lead Sponsor: Arizona State University

Brief Summary

The primary intervention for management of prediabetes is lifestyle changes. Eating healthier and increasing physical activity was found to slow the progression of prediabetes into diabetes, reduce the risk of other diseases like cardiovascular disease and hypertension, and have a lasting impact even after the intervention is discontinued. Studies found that increasing the intake of fiber, pre- and probiotics, and fermented foods have been linked to improved glycemic biomarkers. The goal of this crossover randomized trial is to assess the relationship between lengthened fermentation time of sourdough bread, e.g., an increased amount of lactic acid and acetic acid in the bread product, and postprandial glycemic response in healthy adults with prediabetes.

Detailed Description

Sourdough bread has been proven to have higher fiber content and contains beneficial microorganisms from the fermentation process and has been linked to reduced risk of various diseases like diabetes, cardiovascular disease, and dyslipidemia. The fermentation of sourdough bread products converts starch and sugar in the dough into resistant starches and other slower digesting compounds. 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 insulin in the body, leading to reduced risk of insulin resistance. However, very few studies exist studying the effects of naturally fermented sourdough products in individuals with prediabetes. It is worth exploring if increasing the fermentation time of naturally fermented sourdough bread increases the effects on relevant biomarkers relating to postprandial glycemia and insulinemia in prediabetic adults.

This study examined the acute effect of varying lengths of sourdough fermentation times on postprandial blood glucose levels over a 4-week period in adults with prediabetes (as evidenced by fasting glucose ≥100 or diagnosis by physician), but not taking diabetic medications. For each trial, the sourdough bread was ingested after an overnight fasting period in order to evaluate the effects of the bread when incorporated into the diet in place of breads made with baker's yeast. The goal of this crossover randomized trial was to assess the relationship between lengthened fermentation time, meaning an increased amount of lactic acid and acetic acid in the bread product, and glycemic and insulinemic response.

Study Timeline

• Status Verified: 2025-04
• Study Start: 2025-04-04
• Study First Submitted: 2025-04-06
• Study First Submitted QC: 2025-04-06
• Study First Posted: 2025-04-13
• Last Update Submitted: 2025-04-29
• Last Update Posted: 2025-05-01
• Primary Completion: 2025-08
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 15

Inclusion Criteria

• prediabetes; not on metformin; no known food allergies or sensitivities; not supplementing pre/post biotics

Exclusion Criteria

• following diet that restricts carbohydrates; medication use affecting blood glucose; acute illness; smoker; pregnant; lactating; GI tract surgery; not willing to follow protocol

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
blood glucose	conducted at fasting and 30, 60, 90, and 120 minutes post-meal	blood glucose will be measured using a glucometer and capillary blood from finger prick

Secondary Outcome Measures

Name	Time	Method
hunger rating	conducted at 120 minutes post-meal	Hunger rating will be determined using Likert scale. Anchors: not hungry at all and as hungry as I have ever felt. A higher score indicates greater hunger.
bread palatability	conducted at 120 minutes post-meal	bread palatability will be measured by Likert scale

Trial Locations

Locations (1)

850 PBC; 🇺🇸 Phoenix, Arizona, United States