Fibre

How to grade any fibre

Four questions that work on every product on the shelf, each mapped to a mechanism — applied to Buta-8 as well.

Who eats what

Bacteria can only ferment what they carry enzymes for, and most butyrate is made in two steps by two different groups.

Speed is a design variable

Rate decides where a fibre ferments and whether it feels like anything. Why gas is a rate problem, and why slow fibres are not weak ones.

No single fibre does every job

Solubility is one property out of four, and the only one on the label. Why two soluble fibres can behave in opposite ways.

When the fuel runs out

Bacteria that run out of fibre switch to protein. What that produces, where it happens, and what carbohydrate fermentation suppresses for as long as it lasts.

Your colon is not one place

Fermentation front-loads at the caecum and thins towards the sigmoid. Why the far end is the interesting end — and the popular claim that gets the gradient backwards.