A racing mind, sweaty hands and a vague sense that something is wrong can precede a sudden decision. People often describe that experience as a gut instinct, whether the choice concerns an everyday matter, a dream home or a future spouse.

Science confirms that the gut and brain communicate extensively, but that does not mean every gut feeling points toward the right choice. Researchers distinguish intuitive decision making from the biological connection linking the digestive system and brain.

Evidence shows that this communication can influence emotions and cognition. However, there is little scientific support for the idea that sensations coming from the gut reliably produce better decisions.

Emotions also do not originate in the gut, according to researchers. They begin in the brain, even though information constantly travels in both directions through the gut-brain connection.

“Yes, it’s true that there is a significant exchange of information between the gut and the brain — and the gut-brain axis is one of the most actively communicating systems in the body,” says Julia Zumpano, a registered dietician and nutritionist with the Cleveland Clinic.

The gut contains what is commonly called a second brain, the enteric nervous system. Made up of more than 500 million neurons, it is the most complex neural network outside the brain and gathers information that is sent back to the brain, according to the Cleveland Clinic.

The vagus nerve is a major conduit within this relationship. It carries signals among the brain, gut and other internal organs while serving as a main channel for the body’s inflammatory immune response to bacteria, viruses and disease.

Those messenger systems can shape sensations including hunger, urgency, nausea and pain. They can also influence processes involving emotion and cognition, while sleep, metabolism, immune function, mood and mental health are affected by the connection.

The existence of this biological communication does not make an instinct correct. Following a feeling while buying a dream home can lead to overspending and bankruptcy, while trusting the gut in romance can still end with a broken heart.

Peter Holzer, a neuroscientist at the Medical University of Graz in Austria, examined the subject in a 2022 paper titled “Gut Signals and Gut Feelings: Science at the Interface of Data and Beliefs.” He wrote that the gut-brain axis enables the brain to “‘know’ the internal state of the body.”

“Functional imaging studies have shown that information coming from the gut reaches brain regions relevant to emotion, affect (mood) and cognition,” Holzer wrote. He said the communication network contributes to interoception, which integrates information from internal organs and affects brain activity and behavior.

Holzer also challenged the term gut instinct as an oversimplification. Despite the depth of communication between the two systems, he emphasized, “Feelings or emotions do not originate in the gut but are generated in the brain.”

Dr. Emeran Mayer, a gastroenterologist and neuroscientist at the University of California, Los Angeles, helped transform discussion of the connection with a review paper published more than a decade ago in Nature Reviews Neuroscience. He later wrote “The Mind-Gut Connection” and produced research examining effects involving conditions ranging from Alzheimer’s to depression.

Traditional Chinese medicine and other Asian traditions have emphasized links between mind and body for thousands of years. In a 2024 paper, lead Chinese researcher Tingting Luo wrote that growing evidence indicates gut microbiota can influence the onset and progression of diseases affecting multiple organ systems through the gut-organ axis.

Zumpano recommends supporting gut health with a varied diet rich in plants, fiber, nuts, seeds, legumes, fruits, vegetables and whole grains. Fermented foods such as miso, kimchi, natto, sauerkraut, yogurt and kefir, along with prebiotic foods and Omega 3 sources including salmon, tuna and mackerel, are also included.

She advises reducing sugar and highly processed foods while staying hydrated, preferably with water. There is no quick solution, but Zumpano says dietary changes can provide benefits over time by supporting helpful gut bacteria, improving gut health and reducing inflammation.