How microbes quietly control our bodies, brains and the planet

They may be invisible to the naked eye, but microbes are making a big impact ... even influencing our ‘happy hormones’. Researchers are uncovering how these microscopic organisms can help solve some of our biggest challenges - from improving our mental health to fighting antibiotic-resistant infections.

Microbes are the building blocks of everything in our world – yet we often don’t realise just how much they affect everything around us.

From boosting our immunity to communicating with our brain to influence our happiness and of course maintaining plant health – microbes have a huge impact on our lives.

Dr Jake Robinson, a Research Fellow in Restoration Genomics, is part of a dynamic team at Flinders University investigating the complexity and far-reaching effects of microbes.

At a fundamental level, microbes form the foundations of ecosystems, having functional roles in maintaining or affecting plant health, and in storing and releasing carbon and nitrogen. 

“Without microbes, biodiversity would collapse,” explains Dr Robinson. 

Microbes from the environment also have significant influence on human function. They play a vital role in training and developing our immune systems – educating our immune systems from the day we’re born.

“They stimulate the production of tiny armies of immune cells so that we can fend off pathogens (bacteria or viruses) that are detrimental to our good health,” says Dr Robinson. 

“We’ve co-evolved with some of these microbes, and they provide essential benefits through breaking down our food, providing energy and various health-sustaining chemicals.”

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The secret intelligent gut ingredient

New research is exploring the surprising ways tiny microbes might be affecting what goes on inside our bodies.

Microbes in our gut can communicate with our brain through the microbiota-gut-brain axis – a two-way communication highway that links a person’s gastrointestinal tract to the central nervous system.  

The influence extends further. A remarkable 95 per cent of the body’s serotonin (the ‘happy hormone’) is found in the gut, and microbes play a crucial role in its synthesis. And in animals, gut microbes have been shown to influence sexual preference, food decisions and aspects of mental health.  

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Researchers are also studying  how things like human activity, government decisions, and changes in the environment affect the types of microbes we come into contact with—some that help keep us healthy, and others that can make us sick.

Dr Robinson’s book, Invisible Friends: How Microbes Shape Our Lives and the World Around Us helps explain how microbes ultimately shape human populations – and can even affect certain groups more than others.

“Some social groups may be unequally exposed to 'good’ or ‘bad’ microbes which means they might not get the same health benefits - or could face more risks - depending on their environment.”

“They have far-reaching influence – beyond most people’s expectation.”

Healthy soils promote healthy humans

Ecosystems can be restored using cutting-edge microbiome science, with Flinders’ Associate Professor Martin Breed exploring the wider implications of good natural environments influencing good human health.

Microbiome science is helping restore damaged ecosystems, and Flinders’ Associate Professor Martin Breed is exploring how healthy natural environments can lead to better human health.

“Healthy soils support vegetation that improves air quality, buffers noise and can moderate temperatures creating spaces that support our body systems like the nervous and immune system,” says Associate Professor Breed.

“However when soil is damaged, it can release harmful particles into the air and reduce the number of helpful microbes in the atmosphere which can lead to inflammation and may even affect mental health.”