Also called · partially hydrolysed guar gum · prebiotics · beta-glucan · inulin
What it is
Dietary fibre splits into soluble and insoluble.
Insoluble fibre bulks up stool and speeds transit through the gut. Whole grains, vegetables and fruit skins are full of it.
Soluble fibre meets water, forms a gel, and ferments in the colon into short-chain fatty acids (SCFAs). This is the half that changes the gut environment.
Not all soluble fibre is equal, though. It needs both viscosity and fermentability to blunt sugar and cholesterol absorption and improve the gut flora. Non-viscous fibres such as fructo-oligosaccharides and inulin cannot form a gel, so they cannot do that job.
What it does
It works on constipation and diarrhoea at the same time
Soluble fibre holds water in a hard stool to soften it, and absorbs water from a loose stool to firm it up. That is how one ingredient addresses two opposite problems.
Short-chain fatty acids — lowering gut pH
Fermentation in the colon produces propionate, butyrate and acetate. These lower the pH inside the gut, holding back harmful bacteria and helping beneficial ones grow. Insoluble fibre, which microbes struggle to use, produces none of this no matter how much you feed.
It is what the good bacteria eat
With nothing to eat, gut bacteria start grazing on the mucus coat lining the gut. A steady supply of soluble fibre lets that coat regenerate; without it the layer thins, eventually breaches, and harmful bacteria and food particles pass through. This is why raising probiotics alone is risky.
Satiety and weight
The stomach empties liquids into the small intestine first, and a gel does not read as liquid, so it stays in the stomach longer. Short-chain fatty acids also stimulate leptin, GLP-1 and PYY, which suppress appetite.
How to feed it
The same principle applies, but cats sit closer to obligate carnivory, so there is a hard limit to how much fibre you can feed at all.
Mixed into meals every day, consistently. Gut flora take time to respond — give it at least 2–4 weeks.
What to watch for
Drying removes water, so nutrients and calories concentrate into a smaller volume. The small size makes it easy to overfeed, and feeding it without water makes constipation worse, not better.
If you raise insoluble fibre to relieve constipation, water intake has to rise with it. Without enough water the constipation gets worse.
Common questions
Most whole foods are overwhelmingly insoluble. Trying to hit a useful soluble dose that way means massively overfeeding insoluble fibre.
Fructo-oligosaccharides and inulin are non-viscous fibres that cannot form a gel, so the viscosity-dependent roles — binding toxins in the colon, for instance — are out of reach.
Concerns this ingredient relates to
General nutrition information. It does not replace a diagnosis or a prescription. If your animal has a medical condition or is on medication, talk to your veterinarian first.