Butyrate resistant starch fermentation

Much of the resistant and slowly hydrolysed starch is fermented by bacteria in the colon, and a proportion of the products of bacterial metabolism, including short-chain fatty acids, may be absorbed and metabolized. As discussed in section 7.3.3.2, butyrate produced by bacterial fermentation of resistant starch and non-starch polysaccharides has an antiproliferative action against tumour cells in culture, and may provide protection against the development of colorectal cancer. 

The main products of bacterial fermentation of non-starch polysaccharides and resistant starch are short-chain fatty acids such as propionate and butyrate. In addition to being absorbed, and hence used as metabolic fuels, they have an antiproliferative effect on tumour cells in culture, and there is some evidence that they provide protection against the development of colorectal cancer. 

Highly-fermentable fiber residues, like resistant starch, oat bran, and pectin are transformed by colonic bacteria into short-chain fatty acids including butyrate. One study found that resistant starch consistently produces more butyrate than other types of dietary fiber. 

Resistant starch Defined as the sum of starch and products of starch degradation not absorbed in the small intestine by healthy individuals. Resistant starches not digested in the small intestine reach the colon, where they are readily fermented by naturally occurring microflora. One of the main acids produced by these microorganisms is butyric acid, which is believed to play a positive role in promoting colon health. Resistant starch is classified into four categories. 

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