Research targets the gut-brain axis

Research targets the gut-brain axis

Two QUT randomised control trials have been exploring the gut-brain axis and investigating the impact of improving gut microbiome on adult mental and physical health and on child behaviours.

QUT clinical psychologist Dr Esben Strodl is leading the trial of probiotics to help manage depression in adults, and QUT PhD researcher and paediatric dietitian Jacqui Palmer is conducting a trial of the effect of a prebiotic on the behaviours, stress levels and sleep patterns of children with autism.

Probiotics are live microorganisms, while prebiotics are a form of dietary fibre that feeds these microorganisms. Both probiotics and prebiotics support building and maintaining a healthy colony of gut microbiome.

Up to 150 people experiencing depression are being recruited for the probiotics trial, with participants taking a formulated combination of probiotics and magnesium orotate, or a placebo.

The trial participants are monitored over eight weeks, with their gut microbiome and nervous system activity tested before and after.

“Our research is exploring links between an imbalance of the intestinal microbiome, known as gut dysbiosis, and those biochemical pathways between the digestive system and emotional and mood centres of the brain,” said Dr Strodl, from QUT’s Institute of Health and Biomedical Innovation.

“We’re measuring the effects of the probiotic-magnesium orotate combination on both people’s physical health and mental health.

Probiotics for depression
Probiotics for Depression clinical trial team with Dr Esbsn Strodl

“In previous small pilot studies, probiotics and magnesium orotate were shown to provide positive benefits to people with depression who were not responding to commonly prescribed anti-depressant medications – and we’re hoping to see those results replicated in this larger study.

“About 30 per cent of people with depression don’t respond to medications or psychological therapies, so it’s important to explore more potential options, such as probiotics.”

Co-investigators in the trial are Dr Matthew Bambling from The University of Queensland Faculty of Medicine, and University of Sydney Medical School Adjunct Professor and Director of Medical Research at Medlab Clinical Limited Luis Vitetta. The compound being tested is Medlab’s targeted nutraceutical NRGBiotic.

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The trial by Jacqui Palmer, from the Faculty of Health School of Exercise and Nutrition Sciences, involves more than 50 children clinically diagnosed with autism spectrum disorder (ASD) aged from 4 to 10 years.

Over six weeks the children take either a placebo or the prebiotic galactooligosaccharide, which is a fermentable carbohydrate found in foods like beans and lentils. Their gut microbiota and levels of the stress hormone cortisol are measured before starting on the placebo/prebiotic and at the end of the six weeks.

Parents also complete questionnaires to help measure changes in children’s social and mealtime behaviour, sleep, diet and gastrointestinal symptoms

Jacqui Palmer“Many children with autism can be extremely fussy eaters and very rigid in their routines,” said Ms Palmer.

“This means they often have a very restricted diet and may not be getting prebiotics to help maintain good gut bacteria.  A number of studies have shown that the gut bacteria of children with ASD differs from that of children without ASD.

“There is mounting scientific evidence about the gut-brain axis and the effect that gut bacteria can have on mood, behaviour and managing stress.

“Most children diagnosed with ASD are inherently anxious and prebiotics may be one way of helping to reduce that anxiety, and perhaps lessen some of the problematic behaviours associated with ASD, such as rigidity and need for sameness, difficulty with social interactions and disturbed sleep patterns.

“If there is increased flexibility around routines and children can better cope with day-to-day activities, this could help to improve quality of family life for all family members.”