Jeremy London, cardiac surgeon: "Ninety percent of serotonin, the neurotransmitter of well-being, is produced in the gastrointestinal tract."

Gut health has a much greater influence on overall well-being than we realize . Heart surgeon Jeremy London has pointed out that the gut not only digests food, but also plays key roles in the immune and emotional systems.

“Ninety percent of serotonin , the neurotransmitter of well-being, is produced in our gastrointestinal tract,” the specialist stated. This substance is linked to mood, motivation, and a sense of calm, so its proper production is essential for emotional balance. Furthermore, the gut is connected to the brain through a communication network known as the gut-brain axis . This relationship allows what happens in the digestive system to have a direct impact on mood, stress, and mental health.

"There is constant communication between our brain and our stomach. Imbalances here can cause mood swings, heightened stress response, anxiety, and even depression ," the specialist warned. Furthermore, this imbalance in the gut "can cause nutritional deficiencies, which is a known risk factor for a variety of chronic diseases."

London highlighted another striking fact: “70% of our body's immune function lives in our gut.” This means that maintaining a healthy digestive system not only helps us digest food better, but also protects us from viruses, bacteria, and toxins. When this balance is disrupted—due to poor nutrition or antibiotic use, for example—dysbiosis can occur. This situation leads to nutritional deficiencies, fatigue, inflammation, and, in some cases, mood disorders such as anxiety or depression.

For Jeremy London, the key is taking care of your diet. “The foundation is a balanced diet with whole foods, healthy fiber, and plenty of essential fatty acids ,” he explained. However, he acknowledges that this isn't always easy, which is why he takes prebiotics and probiotics as a daily supplement. Probiotics are beneficial bacteria that help maintain a healthy microbiota. They are found in fermented foods like yogurt, kefir, and sauerkraut. Prebiotics , on the other hand, are plant fibers that feed these good bacteria. They are found in bananas, onions, leeks, oats, and artichokes.

Research into the gut and its relationship with the brain has grown in recent years. There is growing evidence that a balanced microbiota can help reduce stress, improve sleep, and enhance concentration.