Table 3.

A summary of clinical trials of low FODMAPs diet

Ref #	Design	Study population	Intervention	Time	Outcome measures	Symptom improvement	Compliance	Additional Outcomes
32	Non- randomized, retrospective observational	IBS patients; standard diet group=39, low FODMAP group=43	Low FODMAP or NICE dietary guidelines (fiber, probiotics, exclusion diets), breath tests.	2–6 m	Change in symptoms (7-point Likert scale) and diet satisfaction (5-point Likert scale).	Composite symptom score improved in 86% vs. 49% (low FODMAP vs. standard group) (P<0.001).	84% of low FODMAP group assessed; 64% adhered strictly, 30% ~ 50% of the time.	Satisfaction= 76% vs. 54% (low FODMAP vs. standard group, P=0.038).
27	Double blind, randomized placebo controlled quadruple-armed	IBS (12 IBS-D, 5 IBS-C and 8 IBS-M) with FM; responded to low FODMAP diet for 3 months	Patients received 3 doses of either fructans (7,14, or 19 g/3 days), fructose (14,28,50 g/3 days), fructans + fructose or glucose (7,14,20g/8 days)	22 w	Daily symptom assessments and adherence to diet through daily food diaries	70% on fructose, 77% on fructans and 79% on fructose + fructans had symptom relapse (gas, bloating, pain) compared to 14% on glucose (P<0.001)	Diet adherence was > 95%.	Higher doses of fructose and/or fructans associated with more severe symptoms (P<0.01) but not with glucose.
33	Non- randomized prospective observational	90 IBS patients referred for lactose and fructose breath testing	All received high and low FODMAPs lists, recipes, reintroduction of restricted foods guidelines and consultation with dietitian.	Mean total 15.7 m	GI symptom questionnaire (7 point Likert) at baseline and 6 weeks. Adherence and opinion of diet.	Improvement (P<0.05) in all symptoms except feeling full, burping and passage of mucus.	76% adherent 50% of the time or more.	Satisfied= 77%; easy to follow diet= 50%. Presence of FM strongly associated with efficacy.
34	Randomized controlled single-blind crossover	30 IBS patients (10 IBS-D, 13 IBC-C, 5 IBS-M and 2 IBS-U) vs. 8 healthy controls	Average of 3.05 g FODMAP/day. Control diet = average of 23.7 g FODMAP per day.	21 d per diet	Daily food records and symptoms; differences in individual & overall symptoms, King’s stool chart & fecal water content.	Improvement in 70% of patients, including 70% with FM, 60% without FM and 75% no prior breath test. Pain, bloating and dissatisfaction with stool consistency improved (P<0.001) especially IBS-D.	Adherent= at least 17/21 days (80%); control diet=100%; low FODMAP diet= 80%.	None.
35	Randomized single-blind crossover study	15 IBS patients (4 IBS-D, 8 IBS- C, 2 IBS-M, 2 IBS-U) vs. 15 healthy controls	Low (9 g) or high (50 g) FODMAP for 2 days. Breath samples collected on day 2 of study.	2 d per diet	Breath H2, CH4 and symptoms measured on a Likert 0 to 3 scale	Abdominal pain, bloating, gas, heartburn, nausea and lethargy reduced in IBS patients when on low FODMAP diet. Gas lower in healthy patients on the low FODMAP diet.	Not assessed.	AUC for H2 (not CH4) higher with high vs. low FODMAP diet in both normal and IBS.

Ref#; references, IBS-D, C, M; irritable bowel syndrome-diarrhea, constipation and mixed type, FM; fructose malabsorption, H₂; hydrogen, CH₄; methane, AUC; area under the curve