JMIR Publications

ABSTRACT

Background:

Excessive sugar consumption is a public health concern. Allulose, a low-calorie sugar with similar functional properties to sucrose, offers potential metabolic benefits. Animal and limited human studies suggest it may stimulate GLP-1 secretion, improve glucose regulation, and support weight management. However, evidence in humans remains scarce.

Objective:

This study aimed to assess the effects of a four-week allulose intervention on postprandial GLP-1 profile (primary outcome) compared with aspartame in healthy adults. Secondary outcomes included parameters of satiety, glucose metabolism, body weight and composition, and gastrointestinal tolerance as well as sugaromics and microbiome analysis.

Methods:

We conducted a randomized, double-blind, placebo-controlled, crossover trial in healthy adults. Subjects consumed either an allulose-sweetened or aspartame-sweetened beverage daily for four weeks, followed by a washout and crossover to the alternate intervention. Standardized inpatient procedures were conducted at baseline, at the beginning and the end of each intervention phase. Primary and secondary outcomes were assessed through fasting and postprandial blood and urine sampling, continuous glucose monitoring, indirect calorimetry, visual analog scales for satiety, and weekly gastrointestinal symptom questionnaires.

Results:

Ten participants (4 female and 6 male, mean age 31.2 ± 6.8 years, BMI 25.1 ± 2.6 kg/m²) completed the study. Participant compliance was high, with minimal missed consumptions and complete return of study materials. Weekly gastrointestinal symptom questionnaires showed good overall tolerance to both interventions, with most ratings indicating none to mild symptoms. Sample and data collection was generally feasible, though minor issues occurred with questionnaire completion, sensor adherence for glucose monitoring, and environmental influences during indirect calorimetry. These challenges led to isolated missing data, which were considered random. A systematic evaluation of indirect calorimetry data quality is warranted before analysis.

Conclusions:

The study protocol was feasible and the intervention beverages were well tolerated, with high participant compliance and minimal adverse effects. Allulose was generally well accepted and did not cause relevant gastrointestinal symptoms. While data collection was largely successful, minor procedural adjustments could improve data quality in future studies. The findings support the suitability of the study design for investigating metabolic effects of allulose, and contribute to the growing evidence for its potential role in dietary sugar reduction strategies. Clinical Trial: German Clinical Trials Register DRKS00028521; https://drks.de/search/en/trial/DRKS00028521