Dietary fiber can relieve asthma

06/01/2014

High fiber diet can relieve allergic asthma. This has been observed at least in mice. Here, fiber-rich food influences the development of immune cells. A research team led by Benjamin Marsland from the University Hospital Lausanne (CHUV) proved this in tests on mice.

During the study, it was found that the lack of fermentable fibers in the diet can cause allergic inflammation in the lungs. So far, it has only been known that intestinal microbial diversity, when digested and fermented into fibers, plays an important role in the prevention of colorectal cancer. “We now show for the first time that the influence of intestinal bacteria goes much further, namely to the lungs”, says Marsland.

Over the past 50 years, there has been an increase in new cases of allergic asthma. This development has been observed both in industrialized and developing countries. At the same time, the consumption of vegetables and fruits dropped as well. These foods are rich in fibers and known for their alleviating effect of various intestinal diseases.

In mice, the researchers found that the fibers not only have a positive effect on the intestine, but also achieve similar effects in the lungs. For their investigations, the researchers gave a group of mice with a diet mix with four percent fibers. Another group was given a low fiber diet containing only 0.3 percent fiber. More severe allergic reactions to house dust mite were observed in this group than in the other mice. The fibers in the food changed the composition of the intestinal bacteria, which split the food better in short-chain fatty acids. These enter the bone marrow via the blood and thus positively influence the maturation of the immune cells.

In the further course of the investigations, an asthma attack was triggered with a house dust mite extract. The allergic defense reaction could be dampened by the fatty acids. The sole administration of fatty acid propionate, which results from the breakdown of fibers, could reduce the allergic inflammatory reactions in the lungs and help to relieve them. In clinical trials with subjects, researchers now hope for similar processes in the human organism with similar positive results. If you want to change your eating habits towards a high-fiber diet, you should increasingly resort to the following foods:

- Bran cereals
- Beans, legumes
- Generally peas
- spinach
- Sweet corn
- Wholemeal bread, wholemeal pasta, wholegrain rice
- Red cabbage, carrots
- Baked potatoes with skin
- Apples, bananas, oranges and all fruits

The German end and colon center in Mannheim also recommends a high-fiber or fiber-rich diet to actively prevent the increasingly common diseases of the intestine and the anus. The scientists published their results in the journal "Nature Medicine". (Fr)