How flour milling methods affect blood sugar and gut feelings after eating bread
Official title: Effects of Wheat Flour Milling Method on Postprandial Glycemic Response and Gastrointestinal Symptoms: A Randomized Crossover Trial (STONEMILL)
Run by University of Bergen · NCT07858110 · Data updated 2026-11-12
In healthy adults who eat bread regularly, this study tests whether bread made from stone-milled flour leads to a smaller rise in blood sugar and fewer gut symptoms than bread made from roller-milled flour.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 20 Years to 40 Years |
| Sex | All |
| Enrollment | 26 (estimated) |
| Sponsor | University of Bergen Academic / other |
| Locations | 1 site (Bergen, Vestland) |
| Status | Recruiting |
| Started | October 14, 2026 |
| Main results expected | February 28, 2027 |
| Study ends | February 28, 2027 |
| Registry record updated | October 5, 2026 |
| Trial ID | NCT07858110 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Healthy adults aged 20–40 who eat bread most days and are willing to consume study breads and wear a CGM for 14 days.
✕Probably not a fit
Individuals with diagnosed diabetes, celiac disease, gluten sensitivity, or those unable to follow the meal pattern may not benefit from this study.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This randomized crossover study compares two breads made from the same wheat: stone-milled versus roller-milled. Participants will eat each type for 3 days at breakfast and lunch, with a switch to the other bread after a washout period, while wearing a continuous glucose monitor to track glucose levels. The goal is to see if milling method influences postprandial glycemia and gastrointestinal tolerance. The trial will control for bread preparation and wheat type to isolate the effect of milling technique. Healthy adults aged 20–40 with regular bread intake are eligible to participate.
Why it matters
Potential benefit: If successful, the findings could inform bread production choices and dietary recommendations to improve glycemic responses and gut comfort after bread consumption.
How similar studies have gone: Prior human data in type 2 diabetes suggested a lower postprandial glucose response with stone-ground flour, but this within-subject, repeated-measures design in healthy adults is novel.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * BMI 18.5-25 kg/m2 * Healthy, defined by reference to the exclusion criteria below * Habitual consumption of bread on most days, at more than one meal per day * Willing and able to consume the study breads, to follow the standardized meal pattern for 14 days, and to wear a CGM sensor continuously for 14 days Exclusion Criteria: * Smoking/tobacco use * Any disease or condition or use of drugs or other compounds or treatments that could have a clinically significant impact on energy metabolism and/or gastrointestinal health (Roma IV to rule out IBS) * Diagnosed diabetes mellitus of any type (no screening measure of glycemic status will be obtained because sample collection is minimized within the project resources) * Diagnosed celiac disease, or self-reported gluten or wheat sensitivity leading to habitual avoidance of wheat products * Pregnancy or lactation * Systemic antibiotic use within 4 weeks before the calibration visit * Night-shift or rotating-shift work during the study period * Skin condition at the sensor site precluding CGM wear * No allergies to wheat/grains
Where it's running
-
Research Unit for Health Surveys, University of Bergen
Bergen, Vestland, Norway Recruiting
Study contacts
- Principal investigator: Simon N Dankel, PhD — University of Bergen
- Study coordinator: Simon N Dankel, PhD
- Email: simon.dankel@uib.no
- Phone: +4794308637
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.