Fiber Supplement Types Explained
Fiber supplements are not all the same. Gel-forming fibers such as psyllium hold water, while highly fermentable fibers such as inulin are broken down by gut bacteria and produce gas in the process.[PubMed]
| Fiber | Score | Owner comments | Unwanted effects | Notes |
|---|---|---|---|---|
| Psyllium husk | 4.2 | 1064 | 9% | Gel-forming soluble fiber from Plantago ovata seed husks. |
| PHGG (Sunfiber) | 3.9 | 507 | 9% | Partially hydrolyzed guar gum, a low-viscosity soluble fiber sold under the Sunfiber name. |
| Inulin / FOS | 3.5 | 131 | 11% | A fermentable prebiotic fiber (fructan) usually made from chicory root. Fructans are high-FODMAP. |
| Acacia fiber | 3.8 | 106 | 11% | Soluble fiber from acacia tree gum (gum arabic). |
| Wheat dextrin (Benefiber) | 3.7 | 92 | 9% | A soluble fiber made from wheat starch, best known as Benefiber. |
Unwanted effects = share of rated owner comments that describe gas, bloating, cramping or a similar effect.
Gel-forming: psyllium
Psyllium is the most-discussed fiber in our data. It is sold both as a supplement and as an OTC bulk laxative, and MedlinePlus advises taking each dose with at least 8 ounces of liquid.[MedlinePlus] A 2016 review found that non-fermented, gel-forming fiber such as psyllium had a laxative effect while fermented fibers did not.[PubMed]
Partly fermentable: PHGG and acacia
PHGG (sold as Sunfiber) is guar gum cut into shorter chains, so it dissolves without thickening drinks.[PubMed] People in IBS communities often describe PHGG and acacia as gentler to start with than psyllium or inulin.
Highly fermentable: inulin
Inulin is a fructan, one of the FODMAP groups limited on a low-FODMAP diet.[PubMed] A 2019 meta-analysis found no overall improvement in IBS symptoms from prebiotics.[PubMed]
Head to head: psyllium vs PHGG (Sunfiber) and PHGG vs inulin.
You can also compare all rated IBS supplements on one page. Read which gut supplements need extra caution first. For quick shortlists by symptom, see which gut supplements IBS communities rate highest.