Psyllium fiber impact on the microbiome

A reader asked me about psyllium fiber. I find that I always want to check “common medical beliefs” against — very often what was believed 10 years ago has been shown to be incorrect.

  • Psyllium Fiber Reduces Abdominal Pain in Children With Irritable Bowel Syndrome in a Randomized, Double-Blind Trial [2016]
  • Psyllium Fiber Does Not Alter Gut Microbiome Composition in Children With Irritable Bowel Syndrome (IBS) [2016]

  • “In general, high doses (≥7g) of wheat bran, inulin, and psyllium tend to delay gastric emptying, whereas lower doses do not show a significant effect…” [2013]
    • “treatment with dried plums (prunes, 6g/day fiber) compared with psyllium (6g/day fiber) in 40 patients (99). Dried plums not only contain fiber but also sorbitol and fructans, non-absorbable carbohydrates that, when fermented by colonic bacteria, create an osmotic load that can dramatically alter stool frequency and consistency (100). Treatment with dried plums resulted in a greater improvement in constipation symptoms as reflected by a significant increase in the number of complete spontaneous bowel movements and in stool consistency (softer stools) when compared to treatment with psyllium”
    • “The difference between psyllium and placebo, however, was no longer significant at 3 months. Bran provided benefits over placebo only at 3 months. Over 60% of subjects randomized to psyllium or bran reported moderate adverse events, the most common of which were constipation and diarrhea.”
    • “an often-cited patient survey of 100 IBS patients found that 55% felt worse and only 10% felt better on bran (105).”
  • “Less fermentable psyllium fiber was shown to shift the fermentation of high-amylase–resistant starch toward the distal colon in rats (22)….Psyllium fiber supplementation (7–14 g/d for 3 mo) to obese individuals led to no changes in the inflammatory markers (66)…a diet supplemented with psyllium to a final total fiber concentration of ∼27 g/d were found to similarly decrease the amount of C-reactive protein. The effect was greater in lean normotensive subjects than in obese hypertensive subjects (69).”. [2013]

We are talking about 1 ounce by weight. i.e. 3 bottles of below a month

    • Bottom Line

    • Taking psyllium has no documented benefit for IBS or CFS. It does not alter the microbiome and had a significant (60%) risk of moderate adverse effect.
    • Consider dry plums instead!! or any high fiber fruit!