Resistant Starch Produces Short-Chain Fatty Acids Which Benefits the Large Intestine

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Resistant starch is a form of starch that is not digested and absorbed in the stomach and small intestine.  Instead it passes to the large intestine where it is fermented by the microbiota which confer numerous health benefits.  1

Resistant starch acts in similar ways to dietary fiber, yet it is not considered a dietary fiber.  It is considered more of a prebiotic substance since it serves as food for the large intestines microbiota.  Higher doses of resistant starch can cause flatulence.   2

There are five different types of resistant starch and can be viewed in the following Table.

There are a number of foods that naturally contain resistant starch.  Raw bananas and especially raw banana flour has the highest content of resistant starch.  The Table below lists those foods that contain resistant starch:

Resistant Starch in Various Foods

FoodServing sizeResistant starch (grams)
Banana flour, from green bananas1/4 cup, uncooked10.5-13.2
Banana, raw, slightly green1 medium, peeled4.7
Cold pasta1 cup1.9
Cold potato1/2" diameter0.6 - 0.8
Green peas, frozen1 cup, cooked4
High amylose RS2 corn resistant starch1 tablespoon (9.5 g)4.5
Lentils1/2 cup cooked2.5
Oatmeal1 cup cooked0.5
Oats, rolled1/4 cup, uncooked4.4
Pearl barley1/2 cup cooked1.6
White beans1/2 cup, cooked3.7
(Source: Resistant Starch Intakes in the United States)

When the three types of resistant starch, RSI, RSII and RSIII, are fermented by the large intestinal microbiota, short-chain fatty acids are produced.  There are seven short-chain fatty acids that are produced by the large intestine when it ferments dietary fiber and resistant starch.  Of these seven short-chain fatty acids, three of them are the most common:

  • acetate
  • propionate
  • butyrate

The most important short-chain fatty acid is butyrate.

Butyrate is a primary energy source for colonic cells.  3  4   Butyrate also has demonstrated anti-inflammatory properties.  5  Butyrate may also have a role in preventing certain types of colitis. A diet low in resistant starch and fiber, which will result in a low production of short-chain fatty acids in the colon, may explain the high occurrence of colonic disorders seen in the Western civilization.  6

Studies have demonstrated that butyrate has anti-carcinogenic properties:

  • It inhibits the growth and proliferation of tumor cell lines in vitro.  7
  • It induces differentiation of tumor cells, producing a phenotype similar to that of the normal mature cell.  8
  • It induces apoptosis or programmed cell death of human colorectal cancer cells.  9  10
  • It inhibits angiogenesis by inactivating Sp1 transcription factor activity and downregulating VEGF gene expression.  11

Resistant starch consistently produces more butyrate than other types of dietary fiber.   12  


Resources:

Wedo Banana Flour, 1 Pound

Bob’s Red Mill – Potato Starch, Gluten Free and Unmodified, 24 Ounces


Cover Photo by mauren veras