Gut bacteria cause autoimmune diseases ?

gut bacteria cause autoimmune diseases

Do gut bacteria cause autoimmune diseases?

Gut bacteria cause autoimmune diseases? Researchers discover that young mice colonized by a certain type of gut bacteria can develop auto immune diseases later in life.

Gut bacteria have wide array of roles in our bodies. They are able to make the body tolerate certain allergens like peanuts, they cause food cravings, reduce the risk of breast cancer by breaking down estrogen. Though they can be good this doesn’t apply to all gut bacteria. Being colonized by the “wrong” type can cause serious diseases later in life at least according to new research from Ghent University Hospital in Belgium.

Gut Bacteria Cause Autoimmune diseases?

The findings were published in European Molecular Biology Organization Journal.

[pullquote]”Our results demonstrate how gut health in young animals may be linked to autoimmune disease in older animals.” “The microbiome of the young mouse impacts a loss of tolerance of the secondary immune system against proteins in the nucleus of the cell. The attack of certain proteins by the body’s own immune system can subsequently lead to tissue damage and disease.” Dirk Elewaut, Professor at Ghent University Hospital in Belgium, one of the lead authors of the study. [/pullquote]

In the study researchers used mice lacking lymph structures like nodes, tonsils and the spleen. In these structures lymphocytes, an important immune cell, is activated. 25% of mice lacking these immune system structures develop antibodies against components in the nucleus of the cell. These anti-nuclear antibodies (ANA) are a hallmark of autoimmune diseases.

After excluding several factors that could trigger autoimmune diseases researchers looked at the signals sent between the immune system and the microbiome, gut bacteria. It turned out the types of gut bacteria in mice, influenced if these autoimmune antibodies were produced. Using antibiotics to kill off these harmful gut bacteria reduced the levels of harmful antibodies. It seemed gut bacteria was the cause of autoimmune diseases.

Researchers conclude that mice developing autoimmune diseases did so under the influence of a certain types of gut bacteria colonizing the gut. These bacteria , segmented filamentous bacteria (SFB), are related to the nasty bacteria clostridia dificile known to cause serious cases of diarrhea, so severe it can kill people affected.

Using a mice model lacking lymphoid structures meant more of these “bad” SFB bacteria. Resulting in a greater likelihood the immune system would form ANAs, causing autoimmune diseases. This doesn’t mean these bacteria causes autoimmune diseases in people, at least not yet, but this research does open some new ways of studying what causes autoimmune diseases. Considering the many functions of gut bacteria it isn’t far-fetched that the “wrong” type of gut bacteria cause autoimmune diseases.

Image Credit: cesar harada via flickr.com, CC BY-NC-SA 2.0