McMaster University

Forsythe Lab

Scope of Search

Microbe-based Therapeutics for Allergy and Asthma


Allergic diseases such as asthma have increased markedly in westernized countries over the past 50 years. Indeed, asthma is the most common chronic childhood illness in Canada and despite advances in research is still a major cause of morbidity.  Similarly the global burden of Food allergy has increased dramatically in recent years, especially in infants and young children. There is a clear need to identify new, effective, therapeutic strategies for allergic disease.

It has emerged that exposure to certain microbes, either naturally in the enviroment or through dietary supplementation in the form of probiotics, can provide protection against allergic disease. However, the mechanisms underlying these protective effects are largely unknown. Understanding bacteria induced immuno/neuro -regulatory responses will be key to developing novel, microbe-based, therapies for allergic disease.

In the lab we are using models of asthma and food allergy to:

  • Identify critical bacterial components and the corresponding receptors that induce a tolerogenic/regulatory immune environment in the lung and intestine.
  • Characterize the neuromodulatory actions of probiotic and prebiotics in relation to allergic responses and identify how the nervous system may contribute to the beneficial effects of these treatments.
  • Characterize the immunomodulatory actions of prebiotic human milk oligosaccharides (HMOs) in relation to their ability to reduce allergy symptoms.
  • Identify how a prebiotic effect vs direct action of on the host contributes to the beneficial effects of specific HMOs in allergy.

The microbe-dendritic cell dialogue plays a key role in the induction of a tolerogenic/regulatory immune environment by specific bacteria. AHL = acyl-homoserine lactone; CPS = cell wall-associated polysaccharide; DC-SIGN = DC-specific intercellular adhesion molecule 3-grabbing non-integrin; LPS = lipopolysaccharide; LTA = lipoteichoic acid; PGN = peptidoglycan; PSA = polysaccharide A; TLR = toll-like receptor.