Effect of Low Dose Galactose on Glycaemia and Glucose Kinetics

Overview

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. The investigators 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 the investigators 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. The investigators will measure the appearance of the label on exhaled breath, which will establish whether ingested sugar is stored, or burned as fuel. The investigators 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.

Interventions

• Dietary supplement galactose
  7.5 g galactose
• Dietary supplement fructose
  7.5 g fructose
• Dietary supplement Glucose Powder
  75 g glucose

Primary outcome measures

• Glucose incremental area under the curve [Time frame: 180 minutes]
• Plasma glucose kinetics [Time frame: 180 minutes]
• Oxidative and non-oxidative fate of ingested glucose [Time frame: 180 minutes]

Secondary outcome measures (2)

• Glucoregulatory and metabolite concentrations [Time frame: 180 minutes]
• Whole-body carbohydrate and fat oxidation [Time frame: 180 minutes]

Eligibility criteria

Inclusion criteria

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

Exclusion criteria

• 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Triple blind

Primary purpose

Basic science

Study locations

United Kingdom · 1 center

• University of Bath — Bath

Publications

• 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

Identifiers

NCT: NCT07599683 · 5530-15133 · UKRI/BB/C001910/1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗