Nicola Harris

We investigate how the organisms most commonly inhabiting the intestine of people living in developing countries, the microbiota and helminth parasites, interact with the host immune system.

Our ongoing projects fall into two main categories, The first investigates how we can prevent the damage inflicted by intestinal helminth infection (nutrient malabsorption, growth retardation, anemia), whilst the second investigates the well described link between intestinal helminth infection and protection against so called 'western' diseases such as allergy, inflammatory bowel disease, autoimmunity and obesity (metabolic syndrome).

Project One: Investigating how cells associated with the type 2 immune system function to promote health and limit helminth infection.

Approximately one third of the worlds population, mainly children living in improvised conditions, live with intestinal helminth infection which can cause growth retardation, school absenteeism and cognitive impairment trapping communities in poverty. This project specifically investigates the impact of cells associated with type two immunity (alternatively activated macrophages, eosinophils, ILC2s, Th2 cells) on protecting the infected individuals with the ultimate goal of improving our understanding of these complex parasites and developing vaccines. Our work aims to:

i) intestinal function during healthily states and following helminth infection,

ii) parasite viability and ability to establish infection,

iii) wound healing in response to tissue damage caused by helminths.

Project Two: Investigating how helminth interactions with our gut microbiota influences disease.

Much excitement has surrounded the finding that the gut microbiome can determine our health status, leading to calls for the development of microbial-based interventions for various disease states including allergy, inflammatory bowel disease and Metabolic Syndrome. Current approaches for developing such interventions involves studies in which investigators attempt to link microbial populations to disease by comparing healthy and diseased individuals living within westernized societies. Yet even healthy individuals living in westernized countries harbor a “dysbiotic” microbiota that is lacking in complexity as compared to the microbiota found in individuals living in developing countries. This has been hypothesized to result from modern diets that are low in fiber, and high in fats and sugar. We have recently published a seminal paper providing evidence that helminth infection also promotes the existence of a healthy microbiota and that this microbiota can provide protection against allergic diseases in animal models. Thus we hypothesize that a helminth-altered microbiota likely represents the “natural” or “ancient” microbiota that humans evolved with over millennia. We are now actively engaged in determining:

i) how helminth infection alters gut microbial communities

ii) whether helminth altered gut microbial communities can prevent other western diseases, including Metabolic syndrome.

These studies are expected to lead to the identification of novel microbial-based therapeutics for a wide range of inflammatory disorders.

We are currently seeking motivated and talented honors and PhD students