MEDICINE

Can a gut infection change your personality? 🤒

We’ve all heard the phrase “gut feeling,” but science increasingly shows that the gut and brain are deeply linked. The trillions of microbes living in your digestive system don’t just help digest food: they produce chemicals that influence mood, cognition, and even behaviour. This raises a question: could a single gut infection permanently alter your personality? For some people, stomach bugs and long-term gut conditions have been linked to changes in anxiety, mood, and social interaction. The explanation may lie in the gut–brain axis, a two-way communication system between intestinal microbes and the central nervous system.

💡 Things to consider

• The microbiome-brain connection: Gut bacteria produce neurotransmitters such as serotonin and dopamine, the same chemicals that regulate mood and thought in the brain. If an infection wipes out protective microbes and allows harmful ones to dominate, the balance of these chemicals shifts. Studies show that such microbial imbalances can influence anxiety, depression, and even decision-making.

  

  Time to listen to your gut …

• Animal studies and human parallels: Experiments with mice have shown dramatic effects of gut bacteria on behaviour. For example, transferring bacteria from anxious mice into calm ones makes the calm mice anxious, and vice versa. Similar findings suggest probiotics may reduce anxiety or depression in animals. While human evidence is still developing, some patients report personality shifts following severe gut infections or antibiotic use. Could our microbes partly “program” our personalities?

  

  It’s not me, it’s my microbes!

• Chronic gut disorders and mood: Conditions like irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD) are often accompanied by anxiety and depression. It’s still debated whether the gut causes these mood changes, or whether the stress of living with chronic illness contributes. But the link is undeniable, and treatments aimed at restoring microbial balance are being tested as therapies for psychiatric symptoms.

🔎 Find out more

• A long read on the link between the gut and mood

🍒 The cherry on top

• 🐠 The Hardest Problem Evolution Ever Solved: Moving from water to land wasn’t just about lungs and legs — it meant reinventing eyes, skin, and even how we hold onto water itself. This video dives into why keratinized skin, not just breathing, was the true game-changer — and how all of us are still just fish carrying the ocean inside. Great if you’re into Biology!

• 👁️‍🗨️ Optical Illusions: In this lecture, Professor Alain Goriely explores the science behind optical illusions — from the famous Müller-Lyer and Poggendorff illusions to illusory triangles that exist only in our minds. He shows how visual misperceptions reveal deep truths about how the brain processes geometry, motion, and reality. A compelling watch if you’re into Maths or Psychology.

• 🌍 Understanding Populism: This short(-ish) paper unpacks the global rise of populism, from Trump and Brexit to Syriza and Le Pen. It explores how identity crises, economic insecurity, the end of Communism, and “hyperglobalisation” might have contributed to populist revolts across the West. Great if you like Politics or Sociology!

👀 Keep your eyes peeled for…

• Wednesday 10th September

  • University of Law True Crime Webinar

• Thursday 11th September

  • Christ’s College Cambridge Post 16 Choices Webinar

  • University of Worcester Biomedical Sciences vs Biochemistry Webinar

• Monday 15th September

  • RHUL Public Lecture on Pulsars

  • Queens’ College Cambridge Choosing an Oxbridge College Q+A

🗳️ Poll