Clinical Trial: Effect of a 28-Day Low FODMAP Diet on Gastrointestinal Symptoms Associated With Endometriosis (EndoFOD)—A Randomised, Controlled Crossover Feeding Study

Background

Gastrointestinal symptoms affect most women with endometriosis, but therapeutic interventions are poorly defined.

Aims

To compare the effects of a 28-day low fermentable oligo-, di- and mono-saccharides and polyols (FODMAP) or control diet on gastrointestinal symptom severity in individuals with endometriosis and poorly controlled gastrointestinal symptoms.

Method

In this single-blinded randomised, controlled cross-over feeding trial, we randomised women aged ≥ 18 years to 28 days of either a low FODMAP (< 5 g/day FODMAPs) or control diet (20 g/day FODMAPs), both modelled on Australian Dietary Guidelines, before a ≥ 28-day washout and crossover to the alternate diet. The primary outcome was the proportion of responders defined according to the response in overall gastrointestinal symptoms on a 100-mm visual analogue scale. Secondary outcomes included gastrointestinal symptoms, quality of life and psychological status.

Results

Of 35 women randomised (mean age 31; 95% confidence interval 29, 33 years), 21 (60%) responded to the low FODMAP diet compared with 9 (26%) to the control diet (p = 0.008). In the 4th week of the dietary intervention, overall symptom scores were 35 (21, 42) mm on the low FODMAP diet and 58 (55, 65) mm on the control diet (p < 0.001). Abdominal pain, bloating, stool form and quality of life for both gastrointestinal and endometriosis-associated scales were significantly better for the low FODMAP diet compared with the control diet, but not overall for perceived stress, anxiety or depression.

Conclusions

The low FODMAP diet ameliorates gastrointestinal symptoms related to endometriosis and improves quality of life. Confirmation of these findings in a real-world setting is required.

Trial Registration

The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000153819).