the.com/fibre

means The part of plant food — found in whole grains, fruits, vegetables, and legumes — that your body can't break down, but that keeps your digestive system moving and your blood sugar steadier anyway.

from From Latin 'fibra,' meaning a thread, filament, or fiber of a plant or tissue — likely related to the idea of something stringy and strand-like. The word sat quietly in English for centuries meaning literal threads (muscle fiber, wood fiber) before 20th-century nutrition science borrowed it for the indigestible plant matter that, ironically, became famous for doing its job precisely by refusing to be broken down.