Fructose and Fructan Malabsorption Strongly Linked in IBS

TOPLINE:

A clinically significant association exists between fructose and fructan malabsorption in certain patients with irritable bowel syndrome (IBS), indicating that some may benefit from eliminating both carbohydrates.

METHODOLOGY:

• Previous research has focused on fructose or fructan malabsorption separately in patients with IBS, rather than together in the same cohort.
• Researchers conducted a retrospective review of electronic medical records obtained from January 2017 to June 2022 at a single US medical clinic from patients with IBS who had undergone fructose and fructan hydrogen breath tests (HBTs).
• Patients were advised to have a low-carbohydrate dinner the day before, and fast for at least 12 hours prior to the HBT.
• Separate fructose and fructan HBTs were performed at baseline and again on separate days (minimum 1 day between HBTs) by administering a 25-g fructose or 10-g insulin solution and noting the breath hydrogen readings every 30 minutes for 3 hours. Breath hydrogen levels ≥ 20 ppm indicated a positive malabsorption result for either of the carbohydrates.
• The HBT results were compared to study the association between fructose and fructan malabsorption.

TAKEAWAY:

• Among 186 patients (median age, 36.7 years; 37.6% men), 38.2% tested positive for fructose malabsorption, 48.9% for fructan malabsorption, and 22.6% for both.
• There was a significant association between positive fructose and positive fructan HBT readings (P = .0283).
• Patients who tested positive for fructose or fructan malabsorption had a 1.951 times higher likelihood of testing positive for the other carbohydrate (95% CI, 1.072-3.476).

IN PRACTICE:

“The positive association between fructose and fructan malabsorption in patients with IBS suggests that fructan malabsorption should be suspected in a patient who tests positive for fructose malabsorption, and vice versa,” the authors wrote.

SOURCE:

The study, led by Twan Sia, MD, Boston Specialists, Boston, was published online in BMC Gastroenterology.

LIMITATIONS:

The findings may have limited generalizability, as it included patients primarily from the northeastern region of the United States. The study limited HBT to 3 hours, beyond which rises in hydrogen gas might have been missed. Moreover, the use of an absolute hydrogen threshold of 20 ppm differs from that used in most other studies.

DISCLOSURES:

This study did not receive any specific grant from any funding agencies. One of the authors declared being a consultant for various pharmaceutical companies.
 

A version of this article appeared on Medscape.com.