MORE THAN A FEELING: COULD A HEALTHIER GUT IMPROVE MENTAL HEALTH?

Healthy food leads to a healthy mindset.

Nearly one in seven people lives with a mental health disorder, yet many still lack access to adequate care.

A new University of South Australia review pulls focus to a fast-rising contender in the treatment toolkit: the gut.

UniSA researchers have examined mounting evidence that the gut and brain are deeply connected, presenting some of the strongest indications yet that shifts in our gut microbiome can influence brain chemistry and behaviour.

Strong causal evidence in animal models suggests that gut microbes can alter brain chemistry, stress responses, and behaviours.

Disrupted gut patterns in conditions such as depression and schizophrenia.

Early clinical signals that probiotics, dietary changes and faecal microbiota transplants can improve mood and anxiety.

Psychiatric medications themselves can alter the microbiome, reinforcing a two-way relationship.

Lead author and PhD candidate Srinivas Kamath says the field is moving from interesting correlations to practical potential.

“The gut–brain connection is one of the most exciting frontiers in mental health research,” says Kamath.

“We already know that the trillions of microbes in our digestive system talk to the brain through chemical and neural pathways, affecting our mood, stress levels and even cognition.

“But the big question is whether changes in gut bacteria actually drive mental illness or mirror what’s happening elsewhere in the body.”

The global stakes are high. Mental health disorders affect nearly 970 million people, with depression and anxiety among the leading causes of disability.

Up to one-third of patients do not respond to current treatments, which is why accessible, adjunct options are attracting interest.

"There’s a growing awareness that lifestyle factors such as diet, stress, and environment can shape both gut bacteria and mental wellbeing,” says co-researcher Dr Paul Joyce.

“If we can prove that gut bacteria play a direct role in mental illness, it could transform how we diagnose, treat, and even prevent these conditions.

“Microbiome-based therapies such as probiotics, prebiotics or tailored diets may offer accessible, safer, low-cost and culturally adaptable options that complement existing care.”

The following steps, according to the team, are larger, longer and more diverse studies that track gut changes over time and test whether microbiome-based therapies produce lasting benefits in real-world settings.

“Clinical trials should move beyond small, short-term studies and instead test whether microbiome-based therapies can deliver lasting benefits, especially when combined with existing treatments,” Dr Joyce says.

“By unlocking the gut’s role in mental health, we can develop practical, scalable tools for prevention and care, giving clinicians and patients new options to manage wellbeing.

“Mental health doesn’t start and end in the brain. It’s a whole-body issue – and the gut may be the missing piece of the puzzle.”