IBS, functional bowel disorders: prebiotics don’t affect symptoms

  • Wilson B & al.
  • Am J Clin Nutr
  • 4 Apr 2019

  • International Clinical Digest
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • For patients with irritable bowel syndrome (IBS) and other functional bowel disorders (FBDs), evidence does not demonstrate the effect of prebiotics on most symptoms or QoL.
  • Studies were heterogeneous; evidence is of low quality.

Why this matters

  • Many IBS patients have fewer bifidobacteria, which have been linked to abdominal pain.
  • Prebiotics may nourish beneficial gut microbiota. 
  • Previous reviews did not include non-IBS FBDs.

Key results

  • Prebiotics vs placebo:
    • Overall symptom response (3 studies):
      • 54% (52/97) vs 63% (59/94);
      • OR, 0.62; 95% CI, 0.07-5.69;
      • P=.67. 
    • 2 studies of IBS alone, 2 of prebiotics >6 g/day, and 2 of duration ≥4 weeks: no difference.
    • Integrative symptom scores (7 studies): no difference.
    • Abdominal pain (9 studies), bloating (8 studies), incomplete evacuation (2 studies): no difference.
    • QoL (4 studies), anxiety (5 studies), depression (2 studies): no difference.
    • Flatulence severity varied with prebiotic type and dose, with inulin-type fructans worsening it.
  • Prebiotics increased abundance of bifidobacteria but not lactobacilli.

Study design

  • Systematic review, meta-analysis of 11 randomized controlled trials comparing prebiotics with placebo (n=729).
  • Participants were adults with FBDs, including IBS, but not functional constipation.
  • Outcomes: symptoms, QoL, bacterial abundance.
  • Funding: Clasado Biosciences Ltd.

Limitations

  • Much heterogeneity, bias risk.