Resistant starch

[3] Some types of resistant starch (RS1, RS2 and RS3) are fermented by the large intestinal microbiota, conferring benefits to human health through the production of short-chain fatty acids, increased bacterial mass, and promotion of butyrate-producing bacteria.

[4][5] Resistant starch has similar physiological effects as dietary fiber,[6] behaving as a mild laxative and possibly causing flatulence.

This includes resistant starch, non-starch polysaccharide fibers, oligosaccharides, and simple sugars which have significance in colon health.

[11][13] The fermentation of resistant starch produces short-chain fatty acids, including acetate, propionate, and butyrate and increased bacterial cell mass.

[17] Modest amounts of gases such as carbon dioxide, methane, and hydrogen are also produced in intestinal fermentation.

[30] There is limited evidence that resistant starch might improve inflammatory biomarkers, including interleukin-6, tumor necrosis factor alpha, and C-reactive protein.

[31][32][33][34][35] Plants store starch in tightly packed granules, consisting of layers of amylose and amylopectin.

RS has been categorized into five types:[9] Processing may affect the natural resistant starch content of foods.

[47][48] Cooling boiled potatoes overnight at 4 °C (39 °F) was found to increase the amount of resistant starch by a factor of 2.8.

[49] High amylose varieties of corn, wheat, barley, potato and rice have been naturally bred to increase the resistant starch content that will survive baking and mild extrusion processing, which enables the delivery of resistant starch in processed foods.

[58] The average resistant starch intake in developed countries ranges from 3–6 grams/day for Northern Europeans, Australians and Americans,[8][47][59][60][61] 8.5 grams/day for Italians[62] and 10–15 grams/day in Indian and Chinese diets.

[13] Rural black South Africans consume an average of 38 grams of resistant starch per day by having cooked and cooled corn porridge and beans in their diets.

[9] Resistant starch has a small particle size, white appearance, bland flavor and low water-holding capacity.