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*The following was presented at a conference hosted by Food for the Brain – for further information see www.foodforthebrain.org*

The Gut-Brain Superhighway

At the Smart Kids Conference 2025, Dr. Karen Jensen explored the gut-brain axis and its critical role in physical and mental health. She explained how the gut microbiome acts as a communication hub between the gut and the brain, influencing everything from mood and behaviour to immune function and chronic illness.

What Is the Gut Microbiome?

The gut is home to trillions of microorganisms—bacteria, viruses, fungi, and more—collectively known as the microbiome. This ecosystem supports digestion, produces essential neurotransmitters like serotonin and dopamine, and regulates the immune system. Disruptions to this balance, known as dysbiosis, can significantly impact health.

Gut-Brain Pathways

Communication between the gut and brain is a two-way street, involving the vagus nerve, neurotransmitters, the HPA axis, and immune signals. Healthy gut microbes produce beneficial compounds like short-chain fatty acids (SCFAs) that support brain function. Dysbiosis can disrupt these pathways, contributing to inflammation, anxiety, and cognitive issues.

Dysbiosis and Mental Health

Research links gut imbalance to mental health disorders including anxiety, depression, ADHD, and autism. Children with dysbiosis may experience fatigue, poor concentration, stomachaches, mood swings, and skin issues. The gut also influences other systems, including the heart, lungs, and skin.

Diet, Sugar, and Ultra-Processed Foods

Modern diets high in ultra-processed foods (UPFs), sugar, and artificial additives contribute to dysbiosis and gut inflammation. UK children consume a majority of their calories from UPFs by age seven. These foods can increase the risk of mood disorders, behavioural issues, and even food addiction.

The Importance of Fibre

Fibre is vital for feeding beneficial bacteria and maintaining a healthy gut. Prebiotics, probiotics, and postbiotics all play a role in gut health and, by extension, mental well-being. Yet most UK children fall far short of the recommended daily fibre intake.

Stress and the Gut

Chronic stress alters gut bacteria and increases gut permeability, which can lead to systemic inflammation. Stress hormones like cortisol impact the gut-brain axis. Rebuilding a healthy gut microbiome can help normalise the stress response and support emotional balance.

Supporting Gut Health in Children

To support the gut-brain connection, focus on a diet rich in whole foods, fibre, fermented foods, and hydration. Avoid unnecessary antibiotics and reduce stress through lifestyle practices like mindfulness and gratitude. These strategies can make a meaningful difference in children’s mood, behaviour, and cognitive function. Perhaps this should be prioritised in schools and taught from the early years?

Final Thoughts

Dr. Jensen’s presentation made one thing clear: the gut and brain are deeply connected. Supporting gut health isn’t just about digestion—it’s a foundational aspect of mental and emotional wellness, especially for children and teens in today’s high-stress, low-nutrient environment.