Lancet Gastroenterol Hepatol

CARBIS trial compares dietary and pharmacological interventions for IBS

April 24, 2024

Two 4-week dietary interventions and optimized medical treatment reduced the severity of IBS symptoms, with a larger effect size seen in the diet groups. Thus dietary interventions might be considered as an initial treatment for patients with IBS.

This single-centre, single-blind CARBIS trial was conducted in a specialized outpatient clinic at the Sahlgrenska University Hospital, Gothenburg, Sweden. Participants ages 18 and older with moderate-to-severe IBS and no other serious diseases or food allergies were randomly assigned (1:1:1) to:

1) the LFTD diet - a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) plus traditional IBS dietary advice recommended by the UK National Institute for Health and Care Excellence

2) the low-carbohydrate diet - a fibre-optimized diet low in total carbohydrates and high in protein and fat

3) optimized medical treatment based on predominant IBS symptom.

Study results:

• 294 participants were included in the modified intention-to-treat population (96 assigned to the LFTD diet, 97 to the low-carbohydrate diet, and 101 to optimized medical treatment).
• 241 (82%) of 294 participants were women and 53 (18%) were men and the mean age was 38.
• After 4 weeks, 73 (76%) of 96 participants in the LFTD diet group, 69 (71%) of 97 participants in the low-carbohydrate diet group, and 59 (58%) of 101 participants in the optimized medical treatment group had a reduction of 50 or more in IBS Severity Scoring System (IBS-SSS) compared with baseline, with a significant difference between the groups (p=0.023).
• 91 (95%) of 96 participants completed 4 weeks in the LFTD group, 92 (95%) of 97 completed 4 weeks in the low-carbohydrate group, and 91 (90%) of 101 completed 4 weeks in the optimized medical treatment group.

Source:

Nybacka S, et al. (2024, April 18). Lancet Gastroenterol Hepatol. A low FODMAP diet plus traditional dietary advice versus a low-carbohydrate diet versus pharmacological treatment in irritable bowel syndrome (CARBIS): a single-centre, single-blind, randomised controlled trial. https://pubmed.ncbi.nlm.nih.gov/38643782/