Key findings from detailed records
Population: 275 primary-care IBS patients aged 18–65 Findings: Responders were more common than with placebo: 57% versus 35% in month one, and 59% versus 41% in month two. Quality of life did not differ.
KNOWLEDGE RECORD
- Category
- Gut health and dietary fiber
- Last Reviewed
Names and related search termsPsyllium / Psyllium / Ispaghula / Ispaghula
Study type: human intervention study.
OUTCOME-SPECIFIC EVIDENCE
Scientific Evidence Profile
Assessment pending
An outcome-specific assessment has not yet been completed. This is not a finding that the ingredient is ineffective. The study records below remain available.
This profile concerns the stated outcome and population, not the ingredient as a whole. It is not a probability of benefit, a safety rating, a product efficacy rating or an indication of product adoption.
How we assess evidenceIngredient Profile
- What is it?
- Psyllium absorbs liquid and swells. This physical property explains why sufficient liquid and swallowing difficulties matter when considering its use. [1]
Sources for this profile
Compound properties and formulation properties are different. These sources do not establish the efficacy of a finished supplement.
- MedlinePlus — Psyllium Public health reference. U.S. National Institutes of Health. Not an individual clinical trial.
Profile sources checked:
Read the evidence in context
- Evidence: what was measured in the stated population or experimental model.
- Inference: an interpretation connecting findings; its applicability depends on the study conditions.
- Hypothesis: a proposed explanation or effect that remains to be tested.
Why It Matters #
Do soluble and insoluble fiber produce different IBS outcomes? Check the detailed records for study conditions and use the literature map to compare other populations and outcomes.
What Was Studied #
275 primary-care IBS patients aged 18–65 Randomized placebo-controlled trial. Outcomes: Proportion reporting adequate symptom relief for at least two weeks in the preceding month[1]
What Was Found #
Responders were more common than with placebo: 57% versus 35% in month one, and 59% versus 41% in month two. Quality of life did not differ.[1]
What the Evidence Means #
High attrition: around 56–64% in each group completed three months. Different fibers cannot be assessed as one intervention.[1]
Comparing similar populations, formulations, durations and outcomes helps identify where findings agree and where they differ.
What We Can Learn #
Consider fiber type and symptoms, not simply “more fiber.” Trial amounts are not individual instructions for use.
What Remains Unknown #
Further questions include reproducibility across populations and formulations, and the long-term balance of benefits and harms. Use the literature map as a starting point for these questions.
LITERATURE MAP / 10 PAPERS
Compare papers by conditions and findings.
A literature map covering different populations, outcomes and formulations. Read alongside detailed records to avoid treating one trial as the conclusion for an entire ingredient.
Selected: 2026-09-21. Bibliographic information checked against Europe PMC / PubMed. Editorial selection considered major papers and a range of populations and questions. This is not a systematic search covering all recent research.
10 RECORDS
A dash marks fields outside the bibliographic record. Use detailed records to compare findings and design records to connect mechanisms.
No papers match. Change the search conditions.
The literature map is an index of research questions and references. Individual assessment of results, doses, funding and COI is limited to the detailed study records. Related reports from the same trial may be included; paper counts are not counts of independent trials.
Explore the research Study Records
Listed doses describe study conditions, not recommended intake.
Soluble or insoluble fibre in irritable bowel syndrome in primary care? Randomised placebo controlled trial.
PubMed 19713235DOI: 10.1136/bmj.b3154
- Authors
- Bijkerk CJ, de Wit NJ, Muris JW, Whorwell PJ, Knottnerus JA, Hoes AW.
- Journal
- BMJ (Clinical research ed.)
- Publication year
- 2009
- Study design
- Randomized placebo-controlled trial
- Participants
- 275 primary-care IBS patients aged 18–65
- Dose and intervention
- Three groups: psyllium 10 g/day, bran 10 g/day or rice-flour placebo
- Duration
- 12 weeks
- Outcomes and their role in the study
- Proportion reporting adequate symptom relief for at least two weeks in the preceding month
- Findings
- Responders were more common than with placebo: 57% versus 35% in month one, and 59% versus 41% in month two. Quality of life did not differ.
- Limitations
- High attrition: around 56–64% in each group completed three months. Different fibers cannot be assessed as one intervention.
- Funding
- Supported by the Netherlands Organization for Health Research and Development. Pfizer BV supplied psyllium.
- Conflict of Interest
- The authors declared no competing interests.
- Scope of source review
- Primary-paper methods, relevant results, limitations and funding/COI checked on 2026-10-24. This record assesses the stated claims, not every analysis in the paper.
Cite this page
LÍFSVARÐA. Psyllium: Do soluble and insoluble fiber produce different IBS outcomes? Version 1.1 / Updated 2026-10-24
https://lifsvarda.com/knowledge/psyllium/Edited by LÍFSVARÐA (product brand).Editorial policy
Safety and use context
Psyllium swells with liquid. Follow the preparation label and take it with adequate fluid; do not swallow dry powder. Difficulty swallowing or a suspected intestinal blockage requires medical advice before use. Medicines may need to be separated in time: check with a pharmacist.
Sources and updates
- Bijkerk CJ, de Wit NJ, Muris JW, Whorwell PJ, Knottnerus JA, Hoes AW. (2009). Soluble or insoluble fibre in irritable bowel syndrome in primary care? Randomised placebo controlled trial.Primary-paper methods, relevant results, limitations and funding/COI checked on 2026-10-24. This record assesses the stated claims, not every analysis in the paper.
First published: 2026-09-21 / Version 1.1. Updated 2026-09-23: Added a research comparison table and links to design records. Source notes identify the scope of verification when the full paper has not been reviewed. Research summaries and LÍFSVARÐA’s interpretation are distinguished.