The digestive system provides the nutrients that sustain the entire body and has a close relationship with the brain, yet it often does not receive the attention it deserves, according to Dr. Nguyen Thi Lam.

Associate Professor Dr. Nguyen Thi Lam, former Deputy Director of the National Institute of Nutrition in Vietnam, explains that the digestive tract is closely connected to the brain. Scientists often refer to this relationship as the “gut-brain axis.” The brain influences the activities and functions of the intestines, while the gut microbiome can affect emotions and behavior.

Frequent stress can lead to digestive disorders. Many people experience nausea, butterflies in the stomach, or restlessness when they are anxious or excited. Being excessively hungry or overly full can also affect mood and work performance. Brain health and psychological well-being both play important roles in the body's ability to defend itself against disease. Therefore, maintaining good digestive health is essential for overall well-being.

Professor Michael Gershon of Columbia University famously described this concept in his work The Second Brain, writing that the stomach and intestines contain a fascinating and dynamic internal world. Scientific research has shown that the enteric nervous system functions in ways similar to the brain in our heads. It can independently control intestinal muscles, sense the contents of the gut, and regulate digestive processes without direct commands from the central nervous system.

Although this “second brain” is not responsible for conscious thought, it still influences our mental state. For example, hunger can make us feel uneasy or irritable. The digestive system also plays a major role in overall health because approximately 70% of the body's immune system is located within the gut lining.

While the brain directs the body's activities, the digestive system determines how the body is nourished and sustained. It receives food, breaks it down, and converts it into nutrients that fuel every organ and system. As Dr. Lam explains, “When the body receives sufficient energy and nutrients, the brain is also satisfied, allowing us to feel comfortable and focused in our daily activities.”

How to Maintain a Healthy Digestive System

Despite its importance, the second brain is often neglected. In reality, the digestive system is highly vulnerable to damage. Many everyday habits can negatively affect digestion, including:

• Irregular eating schedules
• Late-night meals
• Consuming food prepared under poor hygiene conditions
• Poor nutrition
• Insufficient fiber intake
• Lack of beneficial gut bacteria
• Smoking
• Excessive alcohol consumption
• Physical inactivity

As a result, digestive diseases are among the most common internal medicine conditions in Vietnam. According to information presented at the Global Microbiome Network Conference organized by the Vietnam Institute of Gastroenterology and Hepatology in Hanoi in September 2019, digestive disorders affect nearly 10% of the population. These conditions range from mild problems such as constipation, indigestion, acid reflux, belching, and bloating to more serious illnesses including stomach ulcers, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and cancer.

To protect the health of the “second brain” and strengthen the immune system, Dr. Lam recommends maintaining healthy daily habits, following a balanced diet, and choosing foods that support digestive health, such as vegetables, fruits, and yogurt.

Fruits and vegetables are rich in dietary fiber, which helps promote digestion and accelerate the removal of waste from the body. This process may reduce the accumulation of harmful substances in the digestive tract.

Yogurt contains millions of beneficial bacteria and fermentation products that contribute to long-term digestive health. According to Professor Olivier Goulet, Head of Pediatric Gastroenterology, Hepatology, and Nutrition at Hôpital Necker Enfants Malades and Paris Descartes Medical School in France, regular yogurt consumption may help support the treatment of acute infectious diarrhea and may contribute to preventing acute gastroenteritis.

In addition, the nutrients found in fermented yogurt are often easier for the body to absorb, helping to support and protect the organs of the digestive system.

Taking good care of your digestive system benefits not only your “second brain” but also the actual brain within your skull, while contributing positively to the health of your entire body.