Table 2.

Summary of findings for randomized controlled trials

Study details				Patient details				Intervention details				Outcomes
Reference, year, country	Type of fiber	Design	CCRBT	Number recruited and evaluated	Male:Female	Age	Disease type and status	Intervention	Duration	Concomitant medication	Compliance check	Clinical, microbiome, and immunological outcomes
James et al, 2014,37 Australia	WB-associated fiber and amylose-associated RS	Single-blinded, randomized, controlled cross-over	Red crossed circle symbol	Recruited: 25 UC 12 controls Evaluated: 19 UC 10 controls	UC group ratio 9:10 Controls group ratio 3:7	>18	Ulcerative colitis patients in remission and healthy controls	“Low RS/WB” = 2–5 g RS and 2–5 g WB fiber per day “High RS/WB” = 15 g RS and 12 g WB fiber per day G1: Low RS/WB + high RS/WB G2: High RS/WB + low RS/WB	48 days: 2 × 17 days; doses were increased incrementally over 3 days to increase tolerance, then full doses were given for 14 days, and 14-day wash-out period between periods	Only standard therapy with mesalazine was allowed	Yes, combination of returned foods, checklists and diary entries	Disease activity: no difference between groups Symptoms: no difference in symptoms reported between the two treatment groups Fecal mass and metabolites: starch (P = 0.002) and non-starch polysaccharides (P = 0.002) output more than doubled during the high RS/WB dietary intervention in the healthy controls, but no significant changes were found in the patients with UC.
Ejderhamn et al, 1991,34 Sweden	Wheat fiber and ispaghula	Double-blinded, randomized, placebo (wash-out) cross-over	Yellow crossed circle symbol	Recruited: NS Evaluated: G1: 5 G2: 5	NS	10–18	Ulcerative colitis patients in remission	G1: 16 g wheat fiber, placebo (molded crisps), 16.1 g ispaghula G2: 16.1 g ispaghula, placebo, 16 g wheat fiber	18 mo; 6 mo fiber 1, 6 mo placebo, 6 mo fiber 2	Standard therapy (sulfasalazine 2–3 g/d)	Yes, dietary records and unpredicted counts of sachets at irregular times during the course of the study	Fecal mass: did not change significantly after daily supplementation with either wheat fiber or ispaghula Microbiota: significant decreases are reported in some strains); Bacteroides (P < 0.05) and Enterococcus faecium (P < 0.05) after intake of wheat fiber, and Bacillus (P < 0.05) after intake of ispaghula.
Hallert et al, 1991,38 Sweden	Ispaghula husks	Double-blinded, randomized, placebo cross-over	Red crossed circle symbol	Recruited: 36 Evaluated: 29	14:22	20–75	Ulcerative colitis patients in remission	G1: Ispaghula husks, placebo G2: Placebo, ispaghula husks	4 mo: 2 mo ispaghula husk (or placebo), 2 mo placebo (or ispaghula husk) 2 wks placebo in both groups prior to intervention	Standard therapy: 25% were receiving medication regularly (70% sulfasalazine)	NS	Symptoms: during treatment, the intervention group reported generally less symptoms while taking ispaghula compared with patients taking placebo (P < 0.001). At baseline, patients reported 5.9 (SEM, 0.20) symptoms (out of a possible 8). Both treatments caused a reduction: 26% by ispaghula (4.3, SEM 0.39, P < 0.001), 16% by placebo (5.0, SEM 0.36, P < 0.05), with no significant difference between intervention and placebo.
Fernández-Bañares et al, 1999,35 Spain	PO seeds	Open-label, randomized, controlled (parallel group)	Red crossed circle symbol	Recruited: G1: 35 G2: 37 G3: 30 Evaluated: G1: 32 G2: 35 G3: 27	G1 ratio 16:19 G2 ratio 24:13 G3 ratio 15:15	18–70	Ulcerative colitis patients in remission	G1: 20 g/d PO G2: 1.5 g/d mesalazine G3: 20 g/d PO + 1.5 g/d mesalazine	12 mo	NA	Yes, unused sachet count at each study visit	Disease activity: there was no difference in the probability of maintaining remission over 1 year among the 3 intervention groups (Mantel–Cox test, P = 0.67, Breslow test, P = 0.58). SCFAs: butyrate concentrations were significantly increased, comparing baseline concentrations with postintervention concentrations.
Faghfoori et al, 2011,36 Iran	GBFs	Open-label, randomized, controlled (parallel group)	Red crossed circle symbol	Evaluated: G1: 20 G2: 21	26:25	>18	Ulcerative colitis patients in remission	G1: 30 g/d GBF + standard therapy G2: Standard therapy	2 mo	Standard therapy; not specified	NS	Immunological parameters: between the pretreatment serum values of TNF-α (P = 0.28), IL-6 (P = 0.19) and IL-8 (P = 0.6) there was no significant difference, when comparing patients in the treatment arm and the control arm. TNF-α: decreased after intervention in the treatment group (P = 0.18) and increased in the control group (P = 0.08). IL-6: a significant reduction was seen after the intervention in the treatment group (P = 0.034), but there was an increase in the control group (P = 0.46). IL-8: decreased in the treatment group (P = 0.013) after intervention, but there was an increase in the control group (P = 0.35).
Kanauchi et al, 2002,32 Japan	GBFs	Open-label, randomized, controlled (parallel group)	Green crossed circle symbol	Recruited: 18 Evaluated: G1: 11 G2: 7	NS	>18	Ulcerative colitis patients with mild to moderate active disease	G1: 20–30 g GBF and baseline treatment G2: Baseline anti-inflammatory therapy	4 wks	NS	NS	Disease activity: at baseline, there was no significant difference between the groups. After 4 wks of GBF, disease activity scores were significantly lower than in the control group. Endoscopy: after 4 wks of GBF, erythema, granularity and erosion were dramatically attenuated.
Benjamin et al, 2011,25 UK	FOSs	Double-blinded, randomized, placebo	Yellow crossed circle symbol	Recruited: 122 Evaluated: G1: 54 G2: 49	G1 ratio 18:36 G2 ratio 22:27	>18	Crohn’s disease patients with active disease	G1: 15 g/d FOSs G2: 15 g/d placebo (maltodextrin)	4 wks	The maximum permissible steroid dose was 20 mg/d.	Yes, sachet count at end of study period	Disease activity: there was no significant difference in CDAI between groups after the intervention (P = 0.112), and there was no difference in the intention-to-treat population in the number of patients achieving clinical response after the intervention between groups (P = 0.067). Quality of life: IBDQ scores between groups at baseline did not differ, whereas after 4 wks of intervention, the treatment group reported significantly lower scores than the placebo group (129.9 ± 36.3 vs 149.9 ± 24.5, P = 0.0004). Fecal calprotectin: There was no difference in concentrations between groups at baseline nor after treatment.
Casellas et al, 2007,33 Spain	Inulin	Double-blinded, randomized, placebo, pilot	Yellow crossed circle symbol	Recruited: G1: 10 G2: 9 Evaluated: G1: 7 G2: 8	G1 ratio 2:8 G2 ratio 4:5	18–75	Ulcerative colitis patients with mild to moderate active disease	G1: 12 g/d oligofructose-enriched inulin G2: 12 g/d maltodextrin	2 wks	Mesalazine (3 g/d)	Yes, bringing study medication to visits	Disease activity: Rachmilewitz score decreased in both groups after 14 days (P < 0.05). At the end of the study, almost all patients showed a decline in disease activity, and scores were lower than at baseline in both groups (P < 0.05). There was no difference between groups. Symptoms: dyspeptic symptoms scale decreased significantly with active treatment but not with placebo. Quality of life: IBD-related QOL increased in both groups but the change did not reach significance. Fecal calprotectin: at day 7, an early significant reduction in calprotectin was observed in the treatment group but not in the placebo group. Reductions in the fecal concentration of human DNA were not significant.

The Cochrane Risk-of-Bias Tool (CCRBT) was used to assess the risk of bias in studies – overall judgment for randomized trials (ROB2): green crossed circle symbol = low risk, orange crossed circle symbol = some concerns, red crossed circle symbol = high risk; see Figure S1 in the Supporting Information online for detailed quality assessment. FOSs, fructo-oligosaccharides; GBF, germinated barley foodstuff; G1, Group 1; G2, Group 2; G3, Group 3; NS, not specified; PO, Plantago ovata; RS, resistant starch; SCFAs, short-chain fatty acids; WB, wheat bran.