Effect of Low Dose Galactose on Glycaemia and Glucose Kinetics

NCT07599683 | Recruiting

• 2 other identifiers: 5530-15133UKRI/BB/C001910/1
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

This project will establish the degree to which adding low-dose galactose to a meal can control blood sugar levels. People will consume standardised glucose drinks (75g glucose, as an oral glucose tolerance test). People will consume these with and without the addition of galactose, and with the addition of another sugar (fructose) for an extra comparison. We will use state-of-the-art labelling methods (dual stable isotope technology) to follow what happens to the glucose that is ingested and understand what happens to sugar being released by the liver and sugar being taken up by other tissues like the muscles. These methods can tell us how the addition of galactose can control blood sugar levels. For example, the galactose could slow down the appearance of glucose from the gut and/or liver released into the blood, or it could increase the disappearance of glucose from the blood into muscles. We will measure the appearance of our label on exhaled breath, which will establish whether ingested sugar is stored, or burned as fuel. We will also explore other potential ways in which galactose might control blood sugar levels by measuring key hormones and metabolites that contribute to blood sugar control (for example, insulin, fatty acids, and incretin hormones which potentiate insulin secretion). This additional evidence of how galactose can control blood sugar levels will provide the understanding required to best make use of this approach across a variety of settings.

Conditions

Glucose

Outcome Measures

Primary Outcomes (3)

• Glucose incremental area under the curve

  Difference in glucose concentration incremental area under the curve between treatments over a 180-minute postprandial period.

  180 minutes

• Plasma glucose kinetics

  Difference in plasma glucose kinetics (rate of total glucose appearance, rate of endogenous glucose appearance, rate of exogenous glucose appearance, rate of glucose disappearance and glucose metabolic clearance rate) between treatments over a 180-minute postprandial period.

  180 minutes

• Oxidative and non-oxidative fate of ingested glucose

  Difference in oxidative and non-oxidative fate of ingested glucose between treatments over a 180-minute postprandial period.

  180 minutes

Secondary Outcomes (2)

• Glucoregulatory and metabolite concentrations

  180 minutes

• Whole-body carbohydrate and fat oxidation

  180 minutes

Other Outcomes (1)

• Other analyte concentrations

  180 minutes

Study Arms (3)

CONTROL

SHAM COMPARATOR

75 g oral glucose tolerance test

Dietary Supplement: Glucose Powder

GALACTOSE

EXPERIMENTAL

75 g oral glucose tolerance test plus 7.5 g galactose

Dietary Supplement: galactose; Dietary Supplement: Glucose Powder

FRUCTOSE

ACTIVE COMPARATOR

75 g oral glucose tolerance test plus 7.5 g fructose

Dietary Supplement: fructose; Dietary Supplement: Glucose Powder

Interventions

galactose DIETARY_SUPPLEMENT

7.5 g galactose

GALACTOSE

fructose DIETARY_SUPPLEMENT

7.5 g fructose

FRUCTOSE

Glucose Powder DIETARY_SUPPLEMENT

75 g glucose

CONTROL; FRUCTOSE; GALACTOSE

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age: 18 years and above;
• Normoglycaemic (fasting glucose \<6.1 mmol/L)
• Body mass index: 18.5-30 kg/m2

You may not qualify if:

• weight instability (\>5% change within last 3 months);
• pregnant or lactating;
• following a very low-carbohydrate (ketogenic) diet;
• diagnosis of diabetes or prediabetes, or any other metabolic disease;
• dietary intolerances or allergies, or to any other study procedures;
• disorders in the ability to metabolise galactose or fructose (e.g., galactosemias);
• diagnosis of any gastrointestinal disorders;
• any other condition/medications that could introduce bias;
• unable to understand and follow study procedures

Sponsors & Collaborators

• University of Bath: lead
• University of Birmingham: collaborator
• Arla Foods: collaborator

Study Sites (1)

University of Bath

Bath, United Kingdom

RECRUITING

Related Publications (1)

• Watkins J, Simpson A, Betts JA, Thompson D, Holliday A, Deighton K, Gonzalez JT. Galactose Ingested with a High-Fat Beverage Increases Postprandial Lipemia Compared with Glucose but Not Fructose Ingestion in Healthy Men. J Nutr. 2020 Jul 1;150(7):1765-1772. doi: 10.1093/jn/nxaa105.

  PMID: 32297937 BACKGROUND

MeSH Terms

Interventions

Galactose; Fructose

Intervention Hierarchy (Ancestors)

Hexoses; Monosaccharides; Sugars; Carbohydrates; Ketoses

Central Study Contacts

Lucy Merrell, PhD

CONTACT

+441225385518; lhm31@bath.ac.uk

Javier T Gonzalez, PhD

CONTACT

+441225385518; j.t.gonzalez@bath.ac.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Nutrition and Metabolism

Study Record Dates

• First Submitted: May 14, 2026
• First Posted: May 20, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2029
• Last Updated: May 20, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE

Locations

GB (1)