Clinical trial NCT06925451: Effects of Natural Sourdough Fermentation Duration and Acid Development on Postprandial Blood Glucose in Prediabetic Adults
Official title: Effects of Natural Sourdough Fermentation Duration and Acid Development on Postprandial Blood Glucose in Prediabetic Adults
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Insulin Resistance
Keywords: fermentation
pre-diabetes
sourdough bread
post-prandial glycemia
Lead sponsor: Arizona State University
Sponsor class: OTHER
First posted: 2025-04-13
Enrollment: 15
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: The day prior to testing is standardized: no vigorous activity or alcohol consumption, and two bagels are to be consumed between 3 pm and 8 pm. Participants will begin an overnight fast starting around 10 pm (only water is to be consumed). The bagels will be provided at no charge. For each of the 4 test visits, participants arrive in a fasted state and a blood drop will be collected via finger prick to measure glucose. The 'test meal' will be consumed under observation within 8 minutes. The three fermented versions on the sourdough bread and the control bread will be fed using a four-block randomization process. Finger pricks will take place at 30, 60, 90, and 120 minutes post meal. The participant will be asked to complete hunger measures and report on the acceptability of the bread at the completion of testing.
Primary purpose: OTHER

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.

Eligibility criteria: 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

Primary outcomes:
measure: blood glucose
timeFrame: conducted at fasting and 30, 60, 90, and 120 minutes post-meal
Secondary outcomes:
measure: hunger rating
timeFrame: conducted at 120 minutes post-meal
measure: bread palatability
timeFrame: conducted at 120 minutes post-meal
Other outcomes:
Locations:
city: Phoenix
country: United States
facility: 850 PBC
state: Arizona
Study officials:
References: