Asthma and high fibre diet Linked
by FFE Health News Staff
A study funded by the Swiss National Science Foundation (SNSF) suggests that eating fruits and vegetables is related to lower risk of allergic asthma.
Trends show that as fruits and vegetables appear in decreasing amounts in Western diets, rates of allergic asthma have gone up. To test how the two instances are related, the Swiss team led by Lausanne University Hospital (CHUV) assistant professor Benjamin Marsland studied dietary fibre intake in laboratory mice and its effect on the immune system in the lungs.
The study published in Nature Medicine is built on the fact that having a gut rich in microbes that digest fibre help prevent cancer of the intestines. The professor said ‘We are now showing for the first time that the influence of gut bacteria extends much further, namely up to the lungs.’
To investigate their hypothesis, the researchers tested three groups of mice on different diets. The first group was put on a low-fibre diet comparable to a Western diet; the second on a standard diet of 4% fermentable fibre and the third on a fibre-enriched standard diet. House dust mites were used to provoke an allergic reaction.
They found out that the group on the fibre-enriched diet showed a stronger protective effect than those on the 4% fibre diet. The group on the low-fibre diet meanwhile exhibited the strongest allergic reaction and had more mucus in the lungs.
The researchers traced the protective effect to the creation of short-chain fatty acids as a result of fibre fermentation in the gut. These short-chain fatty acids have a direct effect on the development of immune cells that are responsible for the allergic response in an inflamed lung.
Professor Marsland said that the study is relevant because the low-fibre diet used on the mice was comparable to the Western diet and that the immune system of mice is comparable to that of humans.
The professor said much still needs to be studied about the effects of fibre-rich diet on allergies and inflammations. But he believed the study should serve to motivate people to eat more fruits and vegetables.