Psyllium vs inulin: which fibre for what?
Same label word, very different fibres
"Fibre" on a label tells you little. Psyllium and inulin are both soluble fibres, but they behave almost oppositely — which is exactly why they're often used together.
Psyllium: the viscous one
Psyllium husk (Plantago ovata) is viscous — it absorbs water and swells into a gel, and it's only minimally fermented, so it helps support stool consistency and produces little gas. It's also the most-studied fibre for cholesterol: US FDA regulations permit a heart-health label claim for foods providing ≥7 g/day of soluble fibre from psyllium (about 10.2 g of husk) as part of a diet low in saturated fat and cholesterol — this is ingredient/regulatory context, not a Buta-8 claim. A 2022 meta-analysis found psyllium lowered LDL cholesterol by around 6–7% at that kind of dose (American Journal of Clinical Nutrition, 2022).
Inulin: the fast-fermenting prebiotic
Inulin (from chicory root and many plants) is fast-fermenting and strongly prebiotic — it feeds Bifidobacteria. Human studies commonly use inulin in the 5–10 g/day range for prebiotic effects, though responses vary by inulin type, dose and person (prebiotic inulin review, Advances in Nutrition, 2022). The trade-off: because it ferments quickly, inulin is the more likely of the two to cause gas if ramped too fast.
Which for what
| Psyllium | Inulin | |
|---|---|---|
| Type | Viscous soluble | Fermentable soluble |
| Ferments | Barely | Fast |
| Studied for | Stool consistency, cholesterol, low gas | Prebiotic (feeds Bifidobacteria) |
| Gas risk | Low | Higher if ramped fast |
| Typical study dose | ≥7 g soluble fibre (FDA label context) | 5–10 g/day (prebiotic studies) |
Why blends use both
They're complementary in function: psyllium is viscous and minimally fermented, while inulin is fermentable. Pairing them can also change gas patterns — in one RCT, psyllium taken with inulin produced less gas than inulin alone (Gunn et al., Gut, 2022).
Buta-8 lists 3 g psyllium and 2 g inulin, alongside two other fibre classes. See the recipe →
References: FDA psyllium health claim (21 CFR 101.81, 1998); AJCN psyllium meta-analysis 2022; prebiotic inulin review 2022; Gunn et al., Gut 2022.