an apple a day ... fiber in fruits and vegetables can relieve asthma.
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fiber consumed in fruits and vegetables appears to help calm the activity of overzealous immune system which leads to conditions such as irritable bowel syndrome, Crohn's disease, and perhaps even colon cancer. Now it seems that a diet rich in fiber can also repel asthma, an inflammatory disease that constricts the airways of the lung, changing how certain immune cells are produced in bone marrow.
When we eat abundant fruit and vegetables, the bacteria that occur naturally in our intestines help us to digest the fiber. Microbes are fiber "soluble" such as pectin found in apples, pears, berries, citrus fruits and onions and simmer in specific types of fatty acids that interact with immune cells, helping to keep the inflammation under control. This anti-inflammatory effect extends beyond the gastrointestinal tract is less clear. But fatty acids in question are able to circulate through the bloodstream, may clash with the immune cells throughout the body.
This could mean that the influences of dietary fiber other inflammatory diseases such as asthma. It is known that asthma has increased in westernized countries since the 1960s, in which the amount of fiber consumed also decreased. In addition, asthma is not as common in less developed areas, such as Africa, where fruit and vegetables are a big part of the diet.
To test a possible link, Benjamin Marsland immunologist at the University of Lausanne in Switzerland and colleagues put one group of mice a diet low in fiber. After 2 weeks, the researchers sniff the animals a derivative of dust mite allergen (a key trigger allergy and asthma human). These mice showed exaggerated asthmatic responses, including inflammatory compounds in the lungs and narrowed airways causing wheezing and shortness of breath so familiar to asthmatic patients.
Moreover, mice that ate a diet rich in pectin for 2 weeks to obtain the extract of dust mites showed reduced inflammatory response. The levels of immune cells called eosinophils and immunoglobulin E antibodies, both generally increased in allergy and asthma have been almost halved, and the mice showed less constricted their airways.
To see if intestinal bacteria were responsible for the benefits of fiber to mediation, the scientists analyzed the mouse droppings on a normal diet, low and high fiber. In animals given pectin types of bacteria most able to produce anti-inflammatory fatty acids were about twice as common than other most common bacteria in a diet low in fiber. A closer examination, the researchers found proportionately higher amounts of fatty acids not only in the stools of pectin-eat mice, but also in their blood.
were the fatty acids in the blood tells the immune system to reverse, and this message was enough to call trigger an asthma attack? To find out, the researchers injected mice with propionate, one of these fatty acids. After 2 weeks, the rodents again showed reduced inflammatory markers and less airway constriction in response to treatment of dust mites, the team announced today online Nature Medicine . In addition, the key immune cells called dendritic cells behave differently. The dendritic cells can either reduce the activity of the immune system or rise of the response, depending on the signals they send to other types of immune cells. In mice on a diet rich in fiber, dendritic cells were less able to turn on cells called effector, which are key players in allergic asthma in mice and humans.
In the final phase of the experiment, the researchers found that the mice that received propionate were actually produce more immature cells "precursors" that develop into dendritic cells that protect against asthma . "Our study is the first to show that diet can influence the production of immune cells in the bone marrow, which could have important implications as the precursors of immune cells leave the bone marrow and spread to tissues throughout the body including the lungs, "Marsland said.
by Gary Huffnagle, an immunologist at the University of Michigan, Ann Arbor, researchers predicted that if compounds produced by bacteria influence the asthma, they would in the lung tissue. the channel connection events dietary changes, altered metabolism of the intestinal bacteria, a change in the production of immune cells in the bone marrow, and the relief of inflammation asthma is an exciting development, he said. "No one has ever put that together before. The study is a great convergence of observations. "
rigorous scientific work must be done, Marsland believes, to check whether dietary supplements, including purified propionate, or similar fatty acid, may be beneficial for people with asthma or those who do not have access to fruits and vegetables. at the same time, he said, a balanced diet high in fiber is the best way to get the anti-inflammatory benefit.
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