Optimizing fullness by adding different dietary fibers to a scone

Characterization of the Impact of Dietary Fibre Interactions in Food Products on Postprandial Glycaemic Response, Satiety, and Microbiome Composition and Function

This trial will test whether adding different isolated dietary fibers to a scone changes blood sugar, gut microbes, and feelings of fullness in overweight adults.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 24 (estimated)
• Ages: 18 Years to 45 Years
• Sex: All
• Sponsor: University College Cork (Academic / other)
• Drugs / interventions: chemotherapy
• Locations: 1 site (Cork)
• Trial ID: NCT07420023 on ClinicalTrials.gov

What this trial studies

This randomized, single-blinded, placebo-controlled crossover trial enrolls overweight but otherwise healthy adults who will consume seven different fiber-enriched scone formulations over a 28-day period. Participants rotate through seven two-day intervention phases with a washout day after each phase while wearing continuous glucose monitors and receiving standardized, calorie-controlled meals and provided snacks. The study compares postprandial glycaemic responses, subjective satiety, and gut microbial fermentation to see how isolated fibers alone and in combination alter metabolic and microbial responses within a commonly consumed cereal-based food. Weekend days are left free to preserve ecological validity and two 14-day CGM sensors ensure continuous interstitial glucose measurement throughout the protocol.

Who should consider this trial

Good fit: Adults aged 18–45 with BMI 25–<30 kg/m2 and increased waist circumference, generally healthy and willing to follow dietary restrictions and wear continuous glucose monitors, are ideal candidates.

Not a fit: People with diagnosed type 2 diabetes, a BMI outside the 25–<30 range, significant medical conditions, or those unwilling to follow the diet or wear monitoring devices may not gain benefit or may be excluded.

Why it matters

Potential benefit: If successful, this could offer a practical food-based way to lower post-meal blood sugar and increase fullness, helping reduce metabolic risk.

How similar studies have performed: Previous studies show that replacing digestible carbohydrates with dietary fiber can reduce postprandial glucose and enhance satiety, but the effects of specific combinations of isolated fibers within processed foods are less well tested.

Eligibility criteria

Inclusion Criteria:

* Be willing and able to give written informed consent.
* Be between 18 and 45 years of age.
* Have a BMI of =25\<30kg/m2(overweight).
* Have a waist circumference of \>94cm for a male, \>80cm for a female (increased risk of metabolic syndrome).
* Have had a stable body weight (\<5% change over the past three months).
* Be in general good health as determined by the investigator through interview and vital signs (blood pressure, pulse, temperature). Systolic blood pressure less than 160mm Hg and diastolic blood pressure less than 100 mm Hg (defined as Hypertension stage 2).
* Be willing to avoid consuming dietary supplements (at the discretion of the investigator), prebiotics, probiotics, or fibre-rich supplements within four weeks before the baseline visit, and until the end of the study.
* Be willing to avoid vigorous physical activities on the interventional days (defined as any physical activity that is planned to achieve a fitness goal).
* Be willing to consume the investigational food products and menu plan daily for the duration of the study.

Exclusion Criteria:

* Pregnant, lactating, or post-menopausal women, or women who are planning to become pregnant over the study period.
* Have had antibiotic treatment within three months before baseline.
* Are taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk, or confound the interpretation of study results; to include anti-inflammatory drugs, H2 blockers, antacids, proton pump inhibitors, anti-hypertensive medications, corticosteroids, laxatives, enemas, antibiotics, anti-coagulants, and immunosuppressant medication. Participants should have a wash-out period of at least two weeks for each of these medications except for antibiotics, which should not have been taken in the previous three months. Participants taking proton pump inhibitors and medications for chronic conditions (e.g., anti-hypertensive medication) will be allowed into the study if the dose has been stable for at least two months before the study baseline visit.
* Have a history or indication of drug and/or alcohol abuse at the time of enrolment.
* Have a habitual alcohol consumption of \>2 alcoholic beverages/day (\>28g ethanol daily).
* Follow a vegetarian or vegan diet.
* Have a typical fibre intake of \>30g per day.
* Have experienced major dietary changes within three months before the study baseline.
* Plan major lifestyle changes (diet, physical activity, or travel) during the study period.
* Have a clinically diagnosed eating disorder.
* Have a food allergy or intolerance that would preclude study product intake (for example, eggs, gluten, nuts, milk, or any other food allergy or intolerance).
* Have an active gastrointestinal disorder or previous gastrointestinal surgery.
* Have a significant active and medically-diagnosed acute or chronic co-existing illness including: metabolic, psychiatric, cardiovascular, endocrinological, immunological condition, gastrointestinal disease or any other condition which contraindicates, in the investigator's judgement, entry to the study (such as, diarrhoea, Crohn's disease, ulcerative colitis, IBS, diverticulosis, stomach or duodenal ulcers, hepatitis A/B/C, HIV, cancer, diabetes etc) or a significant history of such diseases.
* Are severely immunocompromised (e.g., HIV positive, transplant patient, on anti-rejection medications, on a steroid for \>30 days, or chemotherapy or radiotherapy within the last 12 months).
* Have a malignant disease or concomitant end-stage organ disease.
* Have symptomatic respiratory or cardiac illness.
* Experience alarm features such as sudden weight loss, rectal bleeding, a recent change in bowel habits, or significant abdominal pain within three months before baseline.
* Individuals who, in the opinion of the investigator, are poor attendees or unlikely for any reason to be able to comply with the study protocol.
* Are receiving treatment involving experimental drugs.
* If the participant has been in a recent experimental trial, these must have been completed not less than 30 days before this study.
* Individuals who regularly undertake rigorous exercise.
* Individuals who smoke or vape.

Where this trial is running

Cork

• University College Cork — Cork, Ireland (Recruiting)

Study contacts

• Principal investigator: Jens Walter, PhD — University College Cork; University of Alberta
• Study coordinator: Manon Oliero, PhD

Conditions Metabolic Diseases, Type 2 Diabetes, Cardiovascular Disease; Dietary fibers; metabolic diseases; blood glucose; satiety; fermentation; food matrix