Written by Babatunde Carew
Spoon Feed
An irritable bowel syndrome-specific IgG-based elimination diet significantly reduced abdominal pain in IBS patients.
Can IgG testing take a bite out of IBS?
IBS, the most common disorder of gut-brain interaction (DGBI), significantly impacts quality of life. The AGA notes that most IBS medications benefit less than half of patients, with only a 7%–15% advantage over placebo. There is increasing evidence supporting dietary modification as a primary treatment option. This randomized, double-blind, sham-controlled trial assessed the efficacy of an IBS-specific IgG-based elimination diet. Of 238 randomized participants, 170 completed the study. A greater proportion in the experimental diet group achieved the primary endpoint of ≥ 30% reduction in abdominal pain intensity compared to the sham diet group (59.6% vs. 42.1%, p=0.02). Subgroup analysis showed that there may be greater benefit in IBS with constipation (IBS-C) and mixed bowel habits (IBS-M). Limitations include small sample size, poor measure of dietary compliance, and some overlap between elimination diet items and common high FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) foods. In the intervention group, the most commonly eliminated foods were egg, cow’s milk, and wheat.
How does this change my practice?
The low-FODMAP diet remains the most studied and only guideline recommended dietary intervention for IBS, but is incredibly restrictive. An IgG based elimination diet could improve dietary compliance if proven effective, but larger studies with direct comparison to the low-FODMAP diet are needed before changing practice. Practicality is also a concern, as a global food based IgG panel would likely be expensive once commercially available.
Source
A Novel, IBS-Specific IgG ELISA-Based Elimination Diet in Irritable Bowel Syndrome: A Randomized, Sham-Controlled Trial. Gastroenterology. 2025 Jan 31:S0016-5085(25)00328-2. doi: 10.1053/j.gastro.2025.01.223. Epub ahead of print. PMID: 39894284
