A study in soil, food and mental wellbeing

DEAKIN University’s Food & Mood Centre is currently undertaking world-leading research into the impact the food we eat has on our microbes, and by extension, our mental and brain health.

The study is centred around the trailblazing Farm My School regenerative farm housed at Bellarine Secondary College’s Drysdale campus, its growing practices and the influence this has on the people who consume the food grown on the farm.

Professor Felice Jacka, who has led the Food & Mood Centre since it was established in 2017, said the microbes in our gut influence virtually every aspect of our physical and mental health.

It has also become clear in recent years, she said, that soil is a source of healthy microbes and as such, the soil in which we grow food is critically important, not just to the nutrient profile of that food, but also the tens of thousands of phytochemicals that are present in plant foods that the human body has evolved receptors to.

However, modern agricultural techniques, including monocropping, intensive ploughing, tilling and the use of pesticides, may be stripping the topsoil of the microbes required to grow nutrient-dense produce, with 90 per cent of healthy topsoil across the globe at risk of being lost by 2050.

“Even organic farming really can fall very, very short of the conditions for which we have evolved to grow and consume food,” Professor Jacka said.

By contrast, the team behind the Farm My School project use regenerative farming practices, meaning a diversity of crops are grown together, tilling is avoided and the microbes in the soil are fed with compost and quality mulch.

“We’re wanting to understand whether the microbial diversity in the gut and in the mouth of students at Bellarine Secondary College who are working on the farm and hopefully consuming the vegetables, will be different to the microbial profile of students at another high school in the area that’s very similar demographically but doesn’t have a [regenerative] farm,” Professor Jacka said.

To investigate this, 15 students from Bellarine Secondary College and 15 students from Geelong High School will contribute both a poo sample and an oral swab to the study.

The DNA of all the microbes collected will then be sequenced.

“We don’t know what we’ll see. It may be that we don’t have enough kids in the study to see a difference. It may be that it varies enormously depending on whether the kids are actually eating the produce or not,” Professor Jacka said.

The information gathered through this initial pilot study is intended to inform a much larger and more comprehensive study in the future, with the ultimate aim being the scaling up of the Farm My School model to every school in Victoria that has available land and for that food to be used for school lunch programs.

The study is set against a backdrop of rising mental distress in young people across the country and ongoing unhealthy eating habits, with fewer than five per cent of Australians meeting basic dietary guidelines and teenagers consuming, on average, seven serves of junk food a day.

“We need to retrain young people to have a more diverse palate, to understand where food comes from, the importance of food to every single aspect of their physical and mental health,” Professor Jacka said.

“We’re looking at the next generation being incredibly sick.

“We already know that rates of autoimmune diseases have increased enormously, and we now believe that that may be due to our microbiomes because as people have become moved from traditional societies to more western societies, we see that the diversity of their microbes dramatically reduces.”