Featured Research

from universities, journals, and other organizations

Dietary fibers protect against asthma, study suggests

Date:
January 6, 2014
Source:
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung
Summary:
The Western diet probably has more to do with the asthma epidemic than has been assumed so far, because developing asthma is related to the amount of fruit and vegetables consumed. Gut bacteria ferment the dietary fibers contained in them and fatty acids enter the blood as a result, influencing the immune response in the lungs. This has been shown by a Swiss research project.

The Western diet probably has more to do with the asthma epidemic than has been assumed so far because developing asthma is related to the amount of fruit and vegetables consumed. Gut bacteria ferment the dietary fibers contained in them and fatty acids enter the blood as a result, influencing the immune response in the lungs. This has been shown by a research project funded by the Swiss National Science Foundation (SNSF).

In the West, an increasing number of people have developed allergic asthma in the past fifty years. But dietary habits have also changed during the same period: fruit and vegetables are playing an ever smaller role in people's diets. Now new results suggest that these two developments are not merely simultaneous, they are also causally linked. A team of researchers led by Benjamin Marsland from Lausanne University Hospital (CHUV) has shown in experiments with mice that the lack of fermentable fibers in people's diet paves the way for allergic inflammatory reactions in the lungs.

Influence extends to the lungs Researchers have already known for some time that the microbial diversity in the gut when digesting and fermenting fibers plays a significant role in preventing intestinal cancer. "We are now showing for the first time that the influence of gut bacteria extends much further, namely up to the lungs," says Marsland. His team either put mice on a standard diet with four percent fermentable fibers or gave them low-fiber food with merely 0.3 percent fermentable fibers. This low-fiber food is largely comparable to the Western diet, which contains no more than 0.6 percent fibers on average.

When the researchers exposed the mice to an extract of house dust mites, the mice with the low-fiber food developed a stronger allergic reaction with much more mucus in the lungs than the mice with the standard diet. Conversely, a comparison between mice on a standard diet and mice who received food enriched with fermentable fibers likewise showed that these dietary fibers have a protective influence.

This protection is the result of a multi-level reaction chain, as Marsland's team has now shown. First the fibers reach the intestine, where they are fermented by bacteria and transformed into short-chain fatty acids. These acids then enter the bloodstream and influence the development of immune cells in the bone marrow. Attracted by the extract of house dust mites, these immune cells wander into the lungs, where they eventually trigger a weaker allergic response.

Another reason why fruit and vegetables are good for you Marsland thinks that the results obtained by his group are clinically relevant not only because the share of plant fibers in Western diets is comparable to the low-fiber food of the mice, but also because the examined aspects of the immune system are virtually indistinguishable in mice and humans. Many questions still remain unanswered. "We plan to conduct clinical studies to find out how a diet enriched with fermentable fibers affects allergies and inflammations." It is already sufficiently clear, however, that here is another reason why one should eat more fruit and vegetables.


Story Source:

The above story is based on materials provided by Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. Note: Materials may be edited for content and length.


Journal Reference:

  1. Aurιlien Trompette, Eva S Gollwitzer, Koshika Yadava, Anke K Sichelstiel, Norbert Sprenger, Catherine Ngom-Bru, Carine Blanchard, Tobias Junt, Laurent P Nicod, Nicola L Harris, Benjamin J Marsland. Gut microbiota metabolism of dietary fiber influences allergic airway disease and hematopoiesis. Nature Medicine, 2014; DOI: 10.1038/nm.3444

Cite This Page:

Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. "Dietary fibers protect against asthma, study suggests." ScienceDaily. ScienceDaily, 6 January 2014. <www.sciencedaily.com/releases/2014/01/140106094430.htm>.
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. (2014, January 6). Dietary fibers protect against asthma, study suggests. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/01/140106094430.htm
Schweizerischer Nationalfonds zur Foerderung der wissenschaftlichen Forschung. "Dietary fibers protect against asthma, study suggests." ScienceDaily. www.sciencedaily.com/releases/2014/01/140106094430.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) — Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) — Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) — Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) — Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins