Have you ever felt a stomach knot when excited or lost your appetite during stressful times? These symptoms are not coincidental but key evidence that our gut and brain communicate continuously.
The medical and scientific communities recognize the gut asthe “second brain”of humans. Thairath Online invites you to explore this secret in depth, along with tips on selecting fermented foods to support mood and reduce depression risk.
Inside our digestive system lies a complex network of nerves called the Enteric Nervous System, containing hundreds of millions of nerve cells embedded in the gut walls. This system can operate and regulate digestion independently without commands from the main brain. Remarkably, our body produces about 90% of the "serotonin," the hormone of happiness, in the gut area.
Since the gut is the source of hormones that regulate mood, sleep, and appetite, an imbalance in the gut ecosystem sends warning signals via the vagus nerve, a fast communication highway directly connecting to the brain. This can cause feelings of irritability, anxiety, or increase the likelihood of depression.
The link between beneficial microbes and mental health
Our gut hosts trillions of microbes, both beneficial and harmful. Having an appropriate amount of good microbes, or“probiotics,”helps produce neurotransmitters beneficial to the brain and reduces inflammation in the body — and inflammation is a key factor triggering depression. Introducing good microbes into the body is like sending reinforcements to help restore mental health from within.
Fermented foods are rich sources of high-quality probiotic microbes, but not all fermented items are equally healthy. Choosing incorrectly may lead not only to a lack of good microbes but also excess sugar and sodium.
When selecting fermented foods for true gut and brain benefits, look for the label“live active cultures”such as natural-flavored yogurts or Greek yogurts without added sugar or fruit syrups.
For kimchi, choose naturally fermented varieties that have not been pasteurized at high heat, which kills microbes, and watch out for high sodium content.
For popular drinks like kombucha, carefully check sugar content on the label, as some brands add large amounts to mask sourness. Japanese-style foods like natto (fermented soybeans) and miso are excellent choices, but miso should be cooked without prolonged high heat to preserve microbial life.
Avoid fruit preserves, pickled mangoes, street vendor pickled fruits, or canned pickled vegetables preserved mainly with vinegar and sugar to extend shelf life. These typically contain almost no beneficial microbes and can promote inflammation in the body.
Although consuming probiotic-rich fermented foods supports neurotransmitter function and positively affects mood, they are "not antidepressant medications." If you or someone close experiences depression affecting daily life, consulting a psychiatrist for proper treatment combined with nutrition adjustments, sleep, and exercise is the safest and best approach.