Shepherd et al. [18] | Patients with IBS | n = 25 | Low-FODMAP diet followed by DBPC crossover challenge with fructose and fructane | 2 weeks | 70% of patients receiving fructose, 77% receiving fructans, and 79% receiving a mixture reported symptoms were not adequately controlled, compared with 14% receiving glucose | Only some FODMAPs were tested in this study |
Staudacher et al. [19] | Consecutive patients with IBS | I = 43 C = 39 | Low FODMAP vs. standard IBS diet | 9 months | Improved satisfaction and IBS score in I group | Lack of randomization |
Staudacher et al. [20] | Patients with IBS | I = 19 C = 22 | RCT, Low FODMAPs vs. habitual diet | 1 weeks | More patients in the intervention group reported adequate control of symptoms (68%) compared with controls (23%) | Lack of blinding |
Biesiekierski et al. [3] | Patients with NCGS and IBS | n = 37 | Low-FODMAP diet followed by DBPC crossover challenge with gluten | 3 weeks | Improvement with low FODMAP diet, no change between gluten and placebo challenge | Lack of control and no blinding during the low FODMAP diet |
De Roest et al. [21] | consecutive patients with IBS | n = 90 | Open, low FODMAP diet | 16 months | Improvement of pre-study symptom | Lack of control group |
Halmos et al. [22] | Patients with IBS and controls | I = 30 C = 8 | Randomized, crossover, low-FODMAP diet vs. typical Australian diet | 3 weeks | Lower overall gastrointestinal symptom scores while on a diet low in FODMAPs | Lack of blinding |
Pedersen et al. [23] | Patients with IBS | I1 = 42 I2 = 41 C = 40 | Randomized, controlled trial comparing the low FODMAP diet, treatment with Lactobacillus GG or a control diet | 6 weeks | Both the low FODMAP diet and treatment with Lactobacillus GG were similarly effective | Lack of blinding |
Chumpitazi et al. [24] | Children with IBS | n = 33 | Randomized, double-blind, crossover trial, children with Rome III IBS completed a one-week baseline period. They then were randomised to a low FODMAP diet or typical American childhood diet | 2 days | Less abdominal pain occurred during the low FODMAP diet vs. typical diet | Complete blinding unlikely. Short duration of challenge (two days) |
Whigham et al. [25] | Patients with IBS | n = 365 | Evaluation of low FODMAP diet administered in a dietitian-led group education or traditional one-to-one education | 6 weeks | Significant decrease in symptom severity from baseline to follow-up for both groups but no difference in symptom response between group and one-to-one education | Lack of a control group; no randomization |
Böhn et al. [26] | Patients with IBS | I = 33 C = 34 | Multi-center, parallel, single-blind study. Subjects were randomly assigned to for four weeks to a low-FODMAP or standard IBS diet | 4 weeks | The severity of IBS symptoms was reduced in both groups during the intervention in both groups before vs. at the end of the four-week diet, without a significant difference between the groups | Single blinding |
McIntosh K et al. [27] | Patients with IBS | I = 19 C = 18 | Controlled, single blind study with randomization to a low or high-FODMAP diet for three weeks | 3 weeks | The IBS severity symptom score (SSS) was reduced in the low-FODMAP diet group but not the high-FODMAP group | Single blinding |
Peters et al. [28] | Patients with IBS | I1 = 25 I2 = 24 I3 = 25 | Consecutive patients were randomised to receive hypnotherapy, low-FODMAP diet or a combination | 6 weeks | Improvements in overall symptoms were observed from baseline to week six for hypnotherapy, diet and combination with no difference across groups | No control group, no blinding |
Laatikainen et al. [29] | Patients with IBS | n = 87 | randomised double blind controlled cross-over study. Participants were supplied with both regular rye bread and low-FODMAP rye bread for four weeks | 4 weeks | Many signs of IBS were milder on the low-FODMAP rye bread but no differences were detected in IBS-SSS or quality of life | Well-designed study; only rye FODMAPs were tested |
Valeur et al. [30] | Patients with IBS | n = 63 | Consecutive patients participating in a four-week FODMAP-restricted diet | 4 weeks | Following the dietary intervention, IBS-SSS scores improved significantly | Lack of control group, and lack of blinding |
Eswaran et al. [31] | Patients with IBS-D | I1 = 45 I2 = 39 | Single-center, randomized-controlled trial comparing a low-FODMAP with the mNICE diet for four weeks. | 4 weeks | 40%–50% of patients reported adequate relief of their IBS-D symptoms with the low-FODMAP diet or a diet based on modified NICE guidelines. The low-FODMAP diet led to significantly greater improvement in individual IBS symptoms, particularly pain and bloating | Lack of blinding |
Major et al. [32] | Patients with IBS | n = 58 | Three-period, cross-over study with a single dose of high- or low-FODMAP drink | 1 day | More patients reached the predefined symptom threshold after intake of inulin or fructose than glucose. Controls had lower symptom scores during the period after drink consumption, despite similar MRI parameters and breath hydrogen responses | Lack of blinding |
Hustoft et al. [33] | Patients with IBS | n = 20 | After three weeks of low-FODMAP patients were randomized and double-blindly assigned to receive a supplement of either FOS (FODMAP) or maltodextrin (placebo) for the next 10 days, followed by a three-week washout period before crossover | 10 days | Irritable bowel syndrome symptoms consistently improved after three weeks of low FOMAP, and significantly more participants reported symptom relief in response to placebo than FOS | Only one type of FODMAP was investigated in this study |