Mucilages

Fermentable fibers

Gels of soluble fibers that swell on contact with water and coat the intestinal wall.

They are only released with water: a dry flaxseed passes through intact, a soaked seed makes its gel.

Effects and benefits

Fibers that swell into a gel: flax, chia, psyllium, okra. This gel regulates transit in both directions, softening what is hard and firming what is too loose. With psyllium, trials also show lower LDL cholesterol and calmer blood sugar.

A spoonful of chia seeds in a glass of water turns into a jelly in ten minutes: that is mucilage. In the gut, this gel holds water. Hard stools soften, loose stools firm up: the same mechanism works both ways, which makes psyllium a fiber apart (McRorie, 2015).

Meta-analyses of trials are clear for psyllium: about ten grams a day lower LDL cholesterol by about 0.3 mmol/L (Jovanovski et al., 2018) and, taken with meals, reduce the rise in blood sugar (Gibb et al., 2015).

Flax and chia mucilages are fermented more than psyllium, which bacteria barely touch: they feed the microbiota more, while psyllium acts mainly through its gel. A large amount of dry seeds swallowed without drinking can hinder passage: a gel needs water.

Sources: McRorie, Nutr Today, 2015 · Jovanovski et al., AJCN, 2018 · Gibb et al., AJCN, 2015

Where to find it (48)

Also, in smaller amounts (33)

Its category: Soluble fibers & mucilages