Positive glucose breath testing is more prevalent in patients with IBS-like symptoms

Positive glucose breath testing is more prevalent in patients with IBS-like symptoms compared with controls of similar age and gender distribution, finds the latest issue of Journal of Clinical Gastroenterology.

Small intestinal bacterial overgrowth  may mimic a functional disorder such as irritable bowel syndrome (IBS) or functional bloating.

Dr Andrea Parodi and colleagues assessed the utility of glucose breath test in patients with the above conditions.

Glucose breath test showed an increased methane excretion in 26% of patients

Journal of Clinical Gastroenterology

The team included 200 consecutive patients, and 70 controls with similar age and sex distribution.
 
Patients and controls underwent 50 g glucose breath test and a H2 peak of 12 ppm was considered diagnostic of small intestinal bacterial overgrowth.

Positive patients received rifaximin of 1200mg/day for 10 days and underwent a second glucose breath test 1 month after the end of treatment.

A symptom questionnaire was completed before and after therapy.

The researchers found that the glucose breath test resulted to be altered in 21 out of 130 irritable bowel syndrome patients and in 2 out of 70 functional bloating  patients with a significant difference of the former group compared with controls.

Most irritable bowel syndrome patients with a positive glucose breath test complained of diarrhea.

Glucose breath test showed an increased methane excretion in 26% of patients, who were equally distributed among different bowel pattern subgroups.

The research team noted that the previous abdominal surgery was more frequently seen in glucose breath test-positive patients.

After antibiotic treatment, eradication of small intestinal bacterial overgrowth was achieved in 70% of patients, with a significant improvement of symptoms in eradicated patients compared with the not eradicated ones.

Dr Parodi's team concluded, “Glucose breath test is useful to identify a subgroup of irritable bowel syndrome -like patients, whose symptoms are owing to small intestinal bacterial overgrowth.”

“Normalization of glucose breath test after antibiotic therapy is associated with a significant improvement of symptoms.”

“Glucose breath test does not offer any advantage in functional bloating patients.”