Clinical Symptoms Do Not Distinguish Sucrose Malabsorption From SIBO.

BACKGROUND

Sucrose malabsorption and small intestinal bacterial overgrowth (SIBO) present with symptoms that overlap with those of disorders of gut-brain interaction (DGBI). Recent studies suggest that sucrose malabsorption is more prevalent than previously thought. This study aims to determine the prevalence of sucrose malabsorption based on 13C-sucrose breath test (SBT) in patients undergoing SIBO breath testing and assess whether symptoms distinguish sucrose malabsorption from SIBO.

METHODS

Three hundred patients referred for SIBO breath testing between August 2020 and March 2022 were recruited and asked to complete the Rome IV Questionnaire for bowel disorders, Irritable Bowel Syndrome Severity Score (IBS-SSS), and the Patient Assessment of Gastrointestinal Disorders Symptom Severity Index (PAGI-SYM). After in person SIBO breath testing, they were provided an at-home 13C-SBT.

RESULTS

One-hundred-and-forty patients returned the SBT. Of the SIBO negative patients, 22% (25/113) were SBT positive. No statistically significant differences were found in predominant symptoms or Rome IV diagnoses (IBS, functional constipation, or functional diarrhea), bloating frequency, IBS-SSS, or PAGI-SYM Scores between SBT positive and SBT negative patients. SBT positive only patients (n = 24) reported less abdominal pain (p = 0.04) than abnormal SIBO test only patients (n = 23).

CONCLUSION

Sucrose malabsorption was present in 22% of SIBO negative patients, indicating that it is a possible contributor to DGBI symptoms. Symptom profile alone did not predict sucrose malabsorption, nor distinguish between sucrose malabsorption and SIBO. This emphasizes the importance of considering carbohydrate malabsorption syndromes, such as sucrose malabsorption, when evaluating patients with symptoms consistent with functional gastrointestinal disorders (FGID).