RS has been noted to increase the production of short chain fatty acids (SCFAs) in the gut, and to modulate the composition of gut microbiota, the review in the British Nutrition Foundation’s Nutrition Bulletin found.
However, report authors Dr Stacey Lockyer and Dr Anne Nugent cautioned that there appeared to be “significant inter-individual variation” in responses, and the health implications of these changes were yet to be explained.
Approved EU health claim
There is already an approved EU health claim that states baked products containing at least 14% RS in place of digestible starch reduces post-meal blood-sugar levels.
RS and other fibre types may also work in conjunction in reducing glycaemic responses, the review said.
RS cannot be digested in the small intestine, meaning that it can be classified as a type of fibre. It passes through the small intestine intact and is then fermented in the large intestine, producing short chain fatty acids, which serve as an energy source for colonic cells.
SCFAs in the colon
Foods that increase the amount of SCFAs in the colon are thought help to prevent the development of abnormal cells in the gut.
RS is naturally present in some foods, such as bananas, potatoes, grains, pulses and seeds, and is also produced or modified commercially and incorporated into some food products.
There is some evidence that RS can also decrease appetite and short-term food intake, according to the review.
“Potential mechanisms include an increase in the release of gut hormones, which promote feelings of satiety, stimulated by SCFA,” it said.