Table 1.
Characteristics of the included randomized controlled trials investigating the efficacy of low FODMAP diets in patients with IBD and FGS.
| First Author: | Bodini [26] | Cox [24,25] | Halmos [23] | Pedersen [27,28,29] |
|---|---|---|---|---|
| Publication: | Nutrition 2019 |
Gastroenterology 2020; J. Crohns Colitis 2018 |
Clin. Transl. Gastroenterol. 2017 | World J. Gastroenterol. 2017; Dan. Med. J. 2015; J. Crohns Colitis 2014 |
| Publication type: | Full-text (n = 1) | Full-text (n = 1) and poster abstract (n = 1) | Full-text (n = 1) | Full-text (n = 2) and poster abstract (n = 1) |
| Study duration: | NR | 2016–2017 | 2009–2011 | 2012–2013 |
| Origin: | Italy | UK | Australia | Denmark |
| Registry: | - | ISRCTN17061468 | ACTRN12612001185853 | - |
| Funding: | NR | Kenneth Rainin Fndn | National Health and Medical Research Council of Australia, Eva and Les Erdi Fndn, Monash University | NR |
| Ethical permission: | NR | London Dulwich | Eastern Health and Monash University Human Research and Ethics Committees | Ethics Committee of Science, Denmark |
| RCT Design: | Parallel | Parallel | Cross-over | Parallel |
| Randomization: | PC-generated sequence | Block, with a 1:1 ratio, stratified by diagnosis (CD/UC) and fCAL at screening | PC-generated order | A person not involved in the study generated the random sequence and numbered the envelopes |
| Masking: | Single-blind (clinician) | Single-blind (patients). The terms “fermentable carbohydrates”, “low FODMAP diet”, or the diet’s mechanisms were not mentioned to participants | Double-blind (?) § | Open-label |
| Multicenter: | - | √ | - | - |
| Recruitment site: | Ospedale Policlinico San Martino—IRCCS per l’Oncologia, Genoa | Two large gastroenterology clinics in London | Gastroenterology clinics and the internet | Tertiary hospital in Copenhagen |
| Participants: | N = 55 IBD-IBS patients on remission or with mild disease activity (PMS < 6 or HBi < 8) | N = 52 quiescent * IBD patients with FGD (IBS-D, IBS-M, IBS-U, FB, or FD), LFD naïve | N = 9 quiescent œ CD patients with FGS | N = 89 IBD patients with FGS in remission, or mild-to-moderate disease |
| Ethnicity: | NR | √ | NR | NR |
| CD/UC (n): | 35/20 | 26/26 | 9/0 | 28/61 |
| Criteria for IBS: | Rome IV [31] | Rome III [32] | Rome III [32] š | Rome III [32] |
| IBD Diagnostic criteria: | endoscopic, radiologic, and histologic evaluation | NR | NR | NR |
| Participant age: | 45 (20–75) † years | ≥18 years | 35 (29–41) ƒ years | 40 (20–70) † years |
| Intervention arm: | n = 26 | n = 27 | n = 9 | n = 44 |
| Control arm: | n = 29 | n = 25 | n = 9 | n = 45 |
| Inclusion criteria: | √ | √ | √ | √ |
| Exclusion criteria: | √ | √ | √ | √ |
| HLA-DQ2/DQ8: | NR | NR | All patients were negative | NR |
CD, Crohn’s disease; CRP, C-reactive protein; fCAL, fecal calprotectin; FB, functional bloating; FD, functional diarrhea; FGD, functional gastrointestinal disorders; FGS, functional gastrointestinal symptoms; Fndn, Foundation; FODMAP, Fermentable Oligo-, Di-, Monosaccharides, and Polyols; GI, gastrointestinal; HBi, Harvey Bradshaw Index for CD [33]; IBD, inflammatory bowel diseases; IBD-Q, inflammatory bowel disease—Quality of Life [34,35]; IBS, irritable bowel syndrome; IBS-D, diarrhea-predominant IBS; IBS-M, mixed IBS subtype; IBS-U, unsubtyped IBS; IRCCS, Institute for Research, Hospitalization and Health Care; LFD, Low FODMAP diet; NR, not reported; PC, personal computer; PGA, Physician Global Assessment; PMS, Partial Mayo Score for UC [36]; UC, ulcerative colitis. √ included in the study; * Defined by PGA, stable medications, no IBD flare in the previous 6 months, fCAL < 250 µg/g, and serum CRP < 10 mg/L; œ Defined by HBi < 5; † Median, range; ƒ Median, interquartile range; § Masking was reported as double-blind through a reference to a previous protocol [30], however (a) participants did not match between the two publications [23,30], and (b) in the latter publication [23], blinding of investigators was not reported in the manuscript text; š No information on IBS/FGS was provided in the manuscript presenting the RCT’s results [23]. A reference to a previous publication [30] is provided for more information concerning the sample; however, a mismatch in the sample is evident, as in the first reference, participants included IBS patients only [30], excluding all with diagnosed IBD, whereas in the latter publication [23], IBD was the primary inclusion criterion.