Beth Israel Deaconess Medical Center and Harvard Medical School Boston, Massachusetts
Introduction: Studies indicate that diet modification can improve symptoms in patients with IBS. Food intolerances/sensitivities are common in patients with IBS but outcomes following self-directed elimination diets are poor. The role of IgG antibodies in identifying patients with food sensitivities is controversial. This study was designed to evaluate the utility of a novel, proprietary IgG-based elimination diet to improve symptoms in IBS patients.
Methods: Adults with IBS (Rome IV), all subtypes, were enrolled from 6 centers into a 2-week baseline period. Patients who tested positive ≥ 1 food in an IgG panel (InFoods®, Biomerica, Irvine, CA) and who reported an average daily IBS abdominal pain intensity(API) score (0-10) between ≥3 - ≤7.5 were randomized to either a treatment diet arm or a sham(placebo) diet arm for 8 weeks. Patients in the treatment diet arm were instructed to eliminate foods to which they tested positive. Patients in the sham diet arm were instructed to eliminate foods to which they tested negative. The sham diet arm was balanced to the active diet arm with respect to the number of foods eliminated and self-reported frequency of consuming a particular food. Daily assessments included bowel habits, bloating, and API, as well as weekly assessments for IBS Adequate Relief(AR), Subject Global Assessment of Relief(SGA), and Global Improvement Scale(GIS). Linear mixed and logistic regression modeling of endpoints in the intent-to-treat (ITT) population is presented for all IBS patients and for non-IBS-D patients.
Results: 556 patients with IBS(all subtypes) entered the screening phase, 223 met eligibility criteria and entered the double-blind placebo-controlled diet treatment phase. IBS patients in the treatment diet arm showed a greater decrease in IBS-API and IBS-Bloating scores from baseline compared to patients in the sham diet arm (IBS-API p=0.0718; IBS-Bloating p=0.0827, these p-values did not reach the threshold of p< 0.05). However, GIS and SGA did show significant improvement (GIS p=0.0302; SGA p=0.0093). Non-IBS-D patients (n=149) showed the greatest decrease from baseline (IBS-API p=0.0139; IBS-Bloating p=0.0214) as well as for global measures (GIS p=0.0020; SGA p=0.0010). No significant adverse events were noted during the study.
Discussion: These results suggest that IgG-based elimination diets using a novel, proprietary diagnostic to guide therapy may offer benefit to patients with IBS. Results of this study should help guide other studies.
