Abstract
Over the past few decades, there has been a clear increase in the prevalence of asthma in westernized countries. Both experimental and epidemiological data indicate that environmental factors, such as an individuals diet and commensal flora can have profound effects upon the susceptibility and progression of inflammatory diseases. Short-chain fatty acids (SCFAs), end-products of the colonic fermentation of dietary fibers by bacteria, have been shown to exert protective effects upon cardiovascular and intestinal inflammation; however, their impact on lung inflammation remains to be determined. We have found that mice treated with SCFAs exhibit an accelerated resolution of house-dust mite (HDM) induced allergic airway inflammation. Although the antigen presentation capacity of dendritic cells (DCs) isolated from SCFA-treated mice was normal, such DCs failed to fully polarize cells towards Th2 or Th17 subtypes. Comparatively, mice that were fed a low-fiber diet (LFD)- reducing the availability of endogenous SCFAs - exhibited an exacerbated airway inflammation when exposed to HDM. Indeed, LFD-fed mice had an increased bronchoalveolar lavage (BAL) cellular infiltrate and eosinophilia, along with significantly more systemic HDM-specific IgE and IgG1 antibodies. Our results show that fiber and SCFAs have intrinsic immunomodulatory functions with the ability to accelerate the resolution of allergic airway inflammation.
- © 2012 ERS
