Key takeaways:
- Of 186 patients with IBS, 38.2% and 48.9% tested positive for fructose and fructan malabsorption, respectively.
- Of these, 22.6% tested positive for both.
Patients with irritable bowel syndrome who tested positive for fructan or fructose malabsorption via hydrogen breath testing had nearly two times higher odds of testing positive for the other carbohydrate, according to study results.
“Various factors contribute to the pathophysiology of IBS, including food sensitivities,” Twan Sia, a medical student at Stanford University, and colleagues wrote in BMC Gastroenterology. “Fructose and fructans are FODMAPs that have been of interest due to their prevalence in modern diets.”
Data derived from: Sia T, et al. BMC Gastroenterol. 2024;doi:10.1186/s12876-024-03230-x.
They continued: “While there are no standardized diagnostic tests for fructose or fructan malabsorption, the hydrogen breath test is the most accepted and well-studied. … Though fructose and fructan are structurally related carbohydrates, fructose and fructan malabsorption have never been described in the same patient cohort.”
In a retrospective chart review to evaluate the associate between fructose and fructan malabsorption in IBS, researchers used data from 186 patients (median age, 36.7 years; 37.6% men) with IBS who underwent fructose and fructan hydrogen breath testing between January 2017 and June 2022. After fasting for 12 hours, patients were given a fructose solution of 25 g fructose in 250 cc of water or a fructan solution of 10 inulin in 250 cc of water, followed by breath hydrogen readings every 30 minutes for 3 hours; hydrogen levels of at least 20 ppm were considered positive for malabsorption.
At baseline, 154 patients reported food-related complaints, including 16 related to fructose-containing foods and 33 with fructan-containing foods.
According to results, 71 patients (38.2%) tested positive for fructose malabsorption and 91 patients (48.9%) tested positive for fructan malabsorption. Of these, 42 patients (22.6%) tested positive for both. Researchers reported that positive results did not differ significantly when fructose or fructan testing was done first.
Further, results showed patients who tested positive for either malabsorption had 1.951-times (95% CI, 1.072-3.475) higher odds of testing positive for the other carbohydrate.
“Our study is the first to investigate the association between fructose malabsorption and fructan malabsorption in the same patients with IBS,” Sia and colleagues wrote. “Patients with either a positive fructan or fructose hydrogen breath test had higher odds of testing positive for the other carbohydrate. Therefore, fructan malabsorption should be suspected in a patient with fructose malabsorption, and vice versa.”
Sources/Disclosures
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Disclosures:
Sia reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.