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Previous research has revealed that youngsters who develop inside a house with a dog are less likely to develop severe allergies and today a new study from a united states team of researchers finds that gut bacteria are likely involved for the reason that relationship.
According to a study published Monday in the Proceedings of the Nas (PNAS), mice that were subjected to dust from houses where pet dogs are allowed both inside and outdoors had their community of gut microbes altered and experienced a diminished immune system reaction to common allergens.
The study team seemed to be able to identify a specific bacterial species, Lactobacillus johnsonii, that’s critical in safeguarding air passages against both allergens and viral infection.
“We attempted to investigate whether being exposed to a distinct house dust microbiome related to indoor/outdoor dogs mediated a protective effect through manipulation of the gut microbiome and, by extension, the host immune response,” said study author Susan Lynch, an affiliate professor of gastroenterology in the University of California, Bay area.
“The outcomes in our study indicate this will probably be one mechanism through which environmental surroundings influences immune responses in early life,” she added.
The researchers noted that while their outcome was obtained using tests of lab mice C the results also indicate a mechanism explaining the lowered allergy risk among children raised with dogs.
Mice in the study were subjected to cockroach or protein allergens. They found that the mice’ inflammatory responses within the lungs were significantly cut in mice that were exposed to dog-associated dust, when compared with both mice which were subjected to dust from dog-free homes and mice not subjected to any dust.
L. johnsonii was one species of gut bacteria that appeared to convey a lesser inflammation response according to initial results. When researchers fed this species alone to the mice, they discovered that it led to the aversion from the airway inflammation reaction to allergens or perhaps respiratory syncytial virus (RSV) infection. Severe RSV infection in infants is related with elevated risk of developing asthma.
The researchers also found that the beneficial effects were related to lowered numbers and activity of asthma-associated immune cells.
While the amount of protection afforded by L. johnsonii was still less than that supplied by the entire complement of microbes from dog-related dust, the finding did suggest that other, readily-available bacterial species might be accustomed to provide full protection.
Lynch said her own work as well as other recent similar studies has convinced her that “the composition and performance of the gut microbiome strongly influence immune reactions and present a singular avenue for development of therapeutics for both allergic asthma along with a selection of other diseases.”
She added that her study points to alterations in the gut microbiome having wide-reaching effects beyond the digestive system.
The researchers had previously shown that a home by having an inside-outside pet was associated with a significantly more diverse house dust microbiome that augmented species found in the gastrointestinal tract of humans.
