Research highlights

High-Value Nutrition: products to boost immune defence against respiratory illness

The first of the National Science Challenges: High-Value Nutrition, today announced an investment of $10.9 million over three and half years, for research to accelerate the translation of New Zealand-led science into scientifically validated food products for the Asian markets. 

Dr Elizabeth Forbes-Blom, Head of Gut Immunology at the Malaghan Institute of Medical Research, is the Principal Investigator for one of the High-Value Nutrition’s priority research programmes that will investigate ways nutrition can improve immune defence against respiratory illness. This work has been allocated $3.5 million.

“Frequent colds, flu and respiratory tract infections are some of the top health issues in Asian countries. In large, densely populated cities, with low air quality and high pollution, finding foods to boost immune defence is vital. The gut is the most populace immune cell environment in the body, making it an ideal target for food to beneficially modulate immune function. Its surface area and vast microbial richness are just starting to be fully investigated with a corresponding rise in the potential to create targeted foods and beverages.” says Dr Forbes-Blom.

High-Value Nutrition has drawn together researchers from different institutions and across disciplines to deliver results through collaboration. This research team includes scientists from the Malaghan Institute as well as colleagues from Plant & Food Research, AgResearch and the Medical Research Institute of New Zealand. New Zealand is already a highly regarded food producer in Asia, and foods and beverages with scientifically validated immune defence benefits will generate new opportunities for New Zealand companies.

Dr Forbes continues, "“This is an amazing opportunity with substantial potential, but we need to define the causal relationships for food and beverage products to build immune defence and measure these food-health relationships". 

Video links about High-Value Nutrition

Early life IL-25

A growing consensus indicates strong links between our microbial signature and our immune response but does our microbial signature in early life and adulthood relate to that of our mothers, and how does this relate to health, disease and the immune system?

Researcher Catherine Plunkett has investigated the development of our gut microbiota and the cross-talk with the immune system from early life. She used two different mouse models: normal wild type mice and the other deficient in an important hormone IL-25. This hormone is known to drive the (unhelpful) T helper cell 2 (Th 2) pathway in allergy, while it paradoxically seems to play a helpful role in limiting gut inflammation.

Mice that cannot produce IL-25 develop severe gut inflammation as well as having very different microbiota as compared to ‘normal’ mice. To isolate how genetic and microbial-driven effects contribute to gut health, pups from these mice were cross-fostered twenty-four hours after birth by adoptive mothers with the different genetic makeup. As most gut microbiota are acquired after birth, cross-fostering allows the acquisition of the foster mother’s gut microbiota.

While Catherine found the pups tended to adopt the profile of the foster mother, she has now found exciting new roles for both microbes and IL-25 itself in maintaining healthy gut function.

Think you’re all human? Think again.

So you think you’re all human? Well, think again. Your body is home to trillions of minuscule passengers commonly known as bacteria.  In fact it has been estimated that there are 10 times more bacterial cells in your body than human cells!

The collections of microbes living in close association with your body, and the genes they contain, form the human microbiome. These communities live on the entire exterior of your skin, in the linings of your nasal passages and lungs, and in your gut. Whilst they may not sound entirely pleasant, these cells play many essential roles within the body.

The microbial world existing within your gut is closely linked to your health – they help break down and harvest energy from your food, provide nutrients that would otherwise be denied, and prevent the growth of the potentially bad, disease-causing bacteria. The gut microbiome has also been linked to the prevention of medical conditions as well, including allergies, inflammatory bowel disease, and even obesity.

In turn, it has been found that the food you put into your body affects the gut microbiome. The Gut Immunology team is taking a new look at health by suggesting that we are what our gut microbiota eat. Currently, they are investigating whether the gut microbiota can be targeted through nutrition in attempts to reduce the risk of inflammatory disease and maximise the chance for a healthy life.

Gut health and the flu vaccine

The role of our gut microbiome and our health is a relatively new frontier for immunology.  How these trillions of gut bacteria develop, and their interaction with our immune system is the daily work of our Gut Health research team. While the research spans several areas, a link between our gut microbiome and how well we respond to influenza vaccination is the latest subject of investigation.

When we receive a flu vaccination, our bodies react to a dead or deactivated flu strain by creating protective antibodies. Ideally we build up a memory of a disease we haven’t experienced, so if or when we encounter it out bodies know exactly how to fight it. Recent cutting-edge investigations now link gut microbiota to the development of vaccine-induced protective immunity. People with a less diverse gut microbiome tend to not respond as well to vaccination, and ironically that can be the people most vulnerable to illness; the very young and the very old.

General health, nutrition, stress and the use of antibiotics are all known to play a role in the health of our gut microbiome, and in turn the health of our immune responses.  Exactly what supports or limits vaccine efficacy and duration is unclear but establishing cellular interactions in or between the microbiota in our gut and immune cells may form part of the puzzle. Liz and the team hope to carry out a feasibility study with humans in the future.