Recently In Japan, many people are working on intestinal health for the sake of their health and beauty, and “fermentable fiber” has also been in the spotlight as a food ingredient that is key to intestinal health. In this article, we will explain what fermentable fiber is, its functions, and how to consume it properly.
What is fermentable fiber?
As a premise, dietary fiber is a food ingredient that cannot be digested by human digestive enzymes. The definition of dietary fiber has not yet been fully established, but the “Japanese Dietary Intake Guidelines” refer to indigestible carbohydrates as dietary fiber.
Carbohydrates such as sugars are nutrients that provide the energy we need to live, but dietary fiber is not digested, so it cannot be used as an energy source. However, dietary fiber has the effect of regulating the intestinal environment and suppressing the rise in blood sugar and cholesterol levels in the blood, making it an essential food ingredient for maintaining health.
Until now, the functionality of dietary fiber has been studied in terms of its classification into “soluble dietary fiber” that dissolves easily in water and “insoluble dietary fiber” that does not dissolve in water, but in recent years, a new concept of dietary fiber has been attracting attention. That is “fermentable fiber.”
Fermentation is the process by which bacteria and other microorganisms break down food ingredients to produce substances that are beneficial to humans. Among dietary fibers, those that are easily fermented by intestinal bacteria are called fermentable fibers, including soluble dietary fibers such as β-glucan and pectin, some insoluble dietary fibers such as hemicellulose, and resistant starch.
Why you should actively consume fermentable fiber
Fermentable fiber has a significant effect on the intestinal flora (intestinal flora) by serving as food for intestinal bacteria. The ideal intestinal flora is considered to be a diverse state in which various types of bacteria coexist in a balanced manner, but it has been confirmed that the diversity of the intestinal flora decreases when mice are continuously fed food with low fermentable fiber*1. In order to maintain the diversity of the intestinal flora, it is important to regularly consume a diet rich in fermentable fiber.
Beneficial bacteria such as lactic acid bacteria, bifidobacteria, and butyric acid bacteria produce acids called “short-chain fatty acids” when fermenting and decomposing fermentable fiber. Short-chain fatty acids have the effect of suppressing the growth of harmful bacteria, increasing beneficial bacteria, and enhancing the barrier function of the intestine, making them essential for intestinal health. In addition, short-chain fatty acids are known to regulate metabolism and control appetite*2, and may also play an important role in preventing obesity.
If you consume a low amount of fermentable fiber, the short-chain fatty acids produced by beneficial bacteria will decrease, so it is important to actively consume fermentable fiber in order to prevent a decrease in their production.
If you want to consume fermentable fiber, we recommend glutinous barley!
Fermentable fiber is found in many foods such as grains, fruits, beans, and potatoes. Among them, glutinous barley is the perfect food for consuming fermentable fiber.
Glutinous barley is rich in fermentable fiber such as β-glucan and arabinoxylan. According to a study using mice, consuming barley increased bifidobacteria and lactic acid bacteria, and also increased the production of short-chain fatty acids*3. Mice that consumed barley also showed a decrease in blood cholesterol and suppressed the rise in blood sugar after meals*3.
If you want to easily consume barley, we recommend “barley rice”, which can be easily made by simply mixing it with rice before cooking it. In addition to that, you can also enjoy to eat by boiling(about 20 minutes), so mixing with vegetables is standard and popular. The texture of barley and vegetables goes very well together, so this comvination is used well in restaurants and salad shops that pay attention to natural and health.
*1 Sonnenburg ED, et al.: Nature 2016; 529: 212–215.
*2 Morrison DJ, et al.: Gut Microbes 2016; 7: 189–200.
*3 Seiichiro Aoe: Research on Human Life and Culture 2017; 27: 343-348.
