Can eating barley prevent obesity in children?

Last month, an article was published in which researchers described how in people who eat a relatively large amount of barley, the gut looks different than in people who eat relatively little barley. It was previously revealed that these people also had lower cholesterol levels and lower blood sugar than people who eat little barley. Is eating more barley a solution to the increase in health problems among children?

In the scientific paper, published March 14, Japanese researcher Tsubasa Matsuoka of Yamanashi University, along with colleagues at the National Institute of Health and Nutrition in Osaka, describes how they studied the effect of eating barley on health. They divided a group of 236 subjects into two groups based on the amount of barley they ate in their daily lives. Then they compared the composition of the bacteria in the gut of these two groups.

Microbiota of the gut
Intestinal bacteria, along with some fungi and viruses, make up the gut microbiota (sometimes called microflora or gut flora). It is estimated that there are as many as three times more microbiota cells in our bodies than human cells. The microbiota consists of a wide variety of types of bacteria. In Tsubasa’s study, it was found that the group of people who ate relatively more barley had a different composition of the microbiota than the group who ate little barley. So the variation of types of bacteria was different here. But what does this mean for health?

In recent years, the role of microbiota in health has become increasingly clear. Probably the most well-known is the breakdown of dietary fiber. The Nutrition Center explains on their website: “Healthy diets, rich in fiber from vegetables, fruits, whole grains, nuts and legumes, stimulate the growth of bacteria [in the gut]…” So, foods that we describe as healthy in this context are foods with enough fiber. Barley also falls under these high-fiber foods. But why exactly fiber?

The function of microbiota
Fiber can be divided into two groups, fermentable, and non-fermentable fiber. Fermentable fibers we can digest ourselves in our small intestine. Non-fermentable fiber, which we also find in barley, our body cannot digest itself. However, some of the bacteria in the gut can, making the nutrients from it suitable for absorption into our bodies. As mentioned by the Nutrition Center, fiber also stimulates the growth of bacteria in the gut. This may not sound beneficial, but these specific types of bacteria are actually essential to our health. Conversely, these bacteria get some of their energy from our food. They also produce vitamin K, essential for blood clotting, and these good bacteria help in the defense against pathogenic bacteria. This cooperation is thus beneficial to both humans and bacteria.

Other functions of the microbiota are sometimes less well known, but no less important. For example, they train the immune system and therefore play a role in preventing allergies. In recent years, the microbiota has also increasingly been called the “second brain” because of its influence on our mental health, both in relation to depression and autism, and to lowering the risk of Alzheimer’s and other brain diseases. And apparently it can also help with lowering cholesterol and blood sugar levels. But how does this work?

Butyrate as an energy source
One of the substances released during the digestion of barley is the substance butyrate, also known as butyric acid. In everyday life, encountering this substance is not very beneficial, as it has quite a pungent odor, which you will encounter in sweat, strong cheeses, and rancid butter. For our intestinal cells, however, it is one of the most important sources of energy. Butyrate cannot be extracted from barley by the body itself. This requires breaking down the non-fermentable dietary fibers, which can only be done with the help of specific intestinal bacteria.

A good energy supply for the intestinal cells ensures a healthy intestine. The absorption of nutrients is then optimal, which contributes to healthy blood sugar levels. Fiber also reduces the absorption of bile salts, which requires the gallbladder to produce more bile salts. These are made from cholesterol, which is absorbed from the blood and thus stimulates lowering of cholesterol levels in the blood.

Preventing obesity?
For children with obesity, this is good news. In the last 4 years, the number of obese children between the ages of 4 and 12 has increased from 11.9% to 15.5%. Health experts point out that this is a growing problem that needs to be addressed to ensure the health of children. In fact, in addition to their weight problems, these children are also at greater risk of developing diabetes and high cholesterol. So providing these children with enough non-fermentable dietary fiber in their diets, such as barley, may already help prevent this.

But can this also help reduce the risk for children to become overweight? That’s a more complicated problem, for the cause of the increasing obesity among children is mainly attributed to a combination of too little exercise and/or too much (unhealthy) food in this age group. But genetic factors can also play a role, as can certain diseases that make it difficult to maintain a healthy weight. A study done in Nijmegen shows that the microbiota in obese children has a different composition than in healthy children. Maintaining a healthy microbiota could therefore certainly play a role in preventing obesity.

Healthy lifestyle
The main way you maintain a healthy microbiota is by eating enough fiber. Even better is to make sure you get enough of those dietary fibers, the non-fermentable ones, which also help to lower the risk of diabetes and high cholesterol. In addition to barley, you can find these fibers in brown beans, bananas, oatmeal, muesli, and whole grain products like pasta and bread.

Other things you can do to maintain a good diet are to eat a variety of foods, to avoid sugary foods, and to drink mostly water (instead of lemonade or soda). In addition to nutrition, exercise is also essential to a healthy lifestyle. For children, playing outside is not only good exercise, but it also gives the immune system a boost, which in turn is beneficial for a healthy bacterial composition in the gut. Children in particular, who are still developing their microbiota, will continue to benefit from this later in life.

Sources:
– https://www.voedingscentrum.nl/encyclopedie/microbioom
– Overweight figures | Nederlands Jeugdinstituut (nji.nl)
– Fibre-rich food – Maag Lever Darm Stichting (mlds.nl)
– https://www.mlds.nl/hoe-gezond-is-jouw-buik/artikelen/vezels-voor-dummies/
– Matsuoka, T., Hosomi, K., Park, J. et al. Relationships between barley consumption and gut microbiome characteristics in a healthy Japanese population: a cross-sectional study. BMC Nutr 8, 23 (2022). https://doi.org/10.1186/s40795-022-00500-3
– Martínez, I., Lattimer, J. M., Hubach, K. L., Case, J. A., Yang, J., Weber, C. G., Louk, J. A., Rose, D. J., Kyureghian, G., Peterson, D. A., Haub, M. D., & Walter, J. (2013). Gut microbiome