Introduction
Non-absorbable fiber supplements are widely used as a first-line treatment for constipation despite lack of consistent evidence. Two reviews identified placebo-controlled randomized trials evaluating soluble fibers [psyllium (n=3) maltodextrin (N=1) and inulin (N=1)] providing moderate evidence favoring their use in constipated subjects.
Partially Hydrolyzed Guar Gum (PHGG) is water-soluble fiber derived from the endosperm of Cyamopsis tetragonolobus L seeds. There are series of small to medium studies assessing 1 to 4 week intervention with PHGG in various population with constipation. These data suggest a dose-effect, with an optimal dose of approximately 10gr. Furthermore, the PHGG benefit was observed as soon as 1 week. However, data suggest that longer duration of treatment may bring added benefit, with more subjects achieving response.
Aims & Methods
To evaluate safety and efficacy of 6 weeks of daily consumption of 10gr of PHGG (Sunfiber TM, Taiyo, Japan) as compared to placebo in adults with functional- or IBS-constipation. This was a double-blind, placebo-controlled, randomized, 2-arm, parallel design study. Constipation outcomes measures were collected through daily eDiary and included: 1) Bowel movement (BM) frequency and characteristics 2) Bristol stool scale (BSS) and 3) PAC-SYM questionnaire. The primary efficacy endpoint was change in weekly mean frequency of spontaneous BM (SBM). Response rate was assessed as exploratory endpoint; responder was defined as having ≥3SBM/ week and an increase of ≥1SBM from baseline for at least 4 of the 6 weeks of treatment. Treatment groups were compared using ANCOVA model, which included baseline, fiber intake and age as co-variates. Data reported are ITT mean and percentage (95% CI) unadjusted estimates. Adjusted ANCOVA model p values are reported for ITT and PP populations.
Results
Patients (N=160) were randomized to receive PHGG (N=80) or pbo (N=80). Both groups were comparable at baseline (Table 1) SBM was significantly increased after PHGG vs pbo; p=0.033 (ITT) & 0.029 (PP). As per entry criteria all subjects had <3 SBM/ week at baseline. After treatment 40/ 71 (50%) and 26/73 (32.5%) reached SBM ≥3 in the active and pbo group, respectively. Pre-defined responder definition, ≥3SBM/ week and an increase of ≥1SBM from baseline for at least 4 of the 6 weeks of treatment was achieved by 34.2% (27%; 48.5%) vs. 17.7% (12%; 30%); p= 0.018 (ITT) & 0.019 (PP). BSS increased on average 1 (0.8;1.2) and 0.8 (0.5;1.0) points from baseline to the end of treatment in active and pbo, respectively; p= 0.149 (ITT) & 0.057 (PP). PAC-SYM decreased 0.85 (0.70; 0.99) and 0.69 (0.54; 0.84) in the active and pbo groups, respectively; p=0.049 (ITT) & 0.0621 (PP). There were no SAEs and no discontinuations due to AEs. 30 (37.5%) and 34 (42.5%) patients reported some AEs in the pbo and PHGG groups, respectively. Overall, PHGG was well tolerated (Table 2).
Table 1. Demographic and baseline characteristics
Baseline mean ( 95% CI) | Placebo (N= 80) | PHGG ( N=80) |
| Female (n, %) | 70 (87.5%) | 66 (82.5%) |
| Age (years) | 34 ( 31.6; 36.5) | 36 (33.4; 38.8) |
| Fiber intake (g/day) | 15.50 (14.3, 16.7) | 14.63 (13.6; 15.6) |
| SBM | 1.52 (1.42; 1.62) | 1.45 (1.35; 1.55) |
| Bristol Stool Scale (BSS) | 2.10 (1.92; 2.29) | 2.05 (1.85; 2.26) |
| PAC-SYM total score | 1.85 (1.69; 2.01) | 1.85 ( 1.70; 1.99) |
| Table 2. Safety. N° Subjects ( %) |
|
|
| Abdominal pain / discomfort (mild) | 4 (5%) | 3 (4%) |
| Diarrhea | 3 (4%) | 2 (2.5%) |
Conclusion
PHGG is well tolerated and increases the frequency of spontaneous bowel movements without increasing GI symptoms in patients with chronic functional or IBS-constipation.
References
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