Gut and health benefits of dietary fibre


Dietary fibre of edible plants comprises insoluble and soluble carbohydrates including cellulose, lignin, and nonstarch polysaccharides. Other dietary fibre components include nondigestible oligosaccharides such as inulin and oligofructose, as well as resistant starch (RS). They demonstrate resistance to digestion in the stomach and small intestine, allowing passage largely intact into the large intestine where they increase thickness and bulking of our feces. Epidemiological evidence consistently shows that a higher intake of dietary fibre is associated with a reduced risk of chronic diseases, such as cardiovascular disease (CVD), type 2 diabetes, various cancers, other forms of chronic disease including kidney disease and inflammation largely through fibre’s positive impact on the gut microbiota. 

As we moved from the rainforest to the parched savanna-woodlands of subtropical Africa, subsurface tubers, rhizomes, corns, and perennial bulbs, many rich in fibre, would have been a ready and important source of energy. About 60% of the calorific intake came from such sources. This would equate to a total dietary fibre intake of between 250 and 400 grams every day, with between 50 and 100 grams of inulin every day. Following the Western style diet, consumers are likely to get less than 10% of this amount. 

The consumption of dietary fibre appears to be a critical determinant for gut bacterial ecology, diversity and function. Consumption of dietary fibre significantly alters the composition of the intestinal microbiota, and provides the main sources of energy for the microbial communities that inhabit the human large intestine.  Fibre has also been shown to protect against degradation of the gut mucus membrane.

Dietary fibre is fermented in the large intestine by the commensal bacteria into short-chain fatty acids (SCFAs), mainly acetate, butyrate, and propionate, which are essential for good intestinal health and a reduction of dietary fibre significantly lowers fecal SCFAs. SCFAs are important for so many aspects of our health but also play a critical role in our gut pH, which can then have dramatic effects on the composition of the microbiome. The reduced fibre intake in Western diets is associated with reduced bacterial diversity and richness and as a result, many metabolic disorders.

Dietary fibre and high consumption of plant-based foods appears to inhibit the bacteria from producing harmful metabolites from proteins, emphasizing the importance of eating adequate complex carbohydrates to maintain gut microbiome carbohydrate fermentation.

That is why we are constantly recommending Kfibre