Obviously, not completely, but various studies have demonstrated a strong link between the experience of depression and anxiety and the health of a person’s gut. The gut has its own independent nervous system, an intricate network of 100 million neurons embedded in the gut wall. It is linked to the brain via a connection known as the gut-brain axis (GBA), and commands flow bi-directionally along this axis. However, the neural network in the gut is so sophisticated that it continues to function even when the primary neural conduit between it and the brain, the vagus nerve, is severed.
The health of the gut is related to the proper balance and functioning of the various organisms living therein. Our gastrointestinal (GI) tract contains 100 trillion microbes from a thousand diverse species, which are collectively known as the microbiome. These microbes manage digestion and metabolism. They extract nutrients from the food we eat. They program our body’s immune system. They ensure the integrity of the gut wall, which protects the body from pathogens, and can reduce bodily system inflammation. (Individuals with inflammatory diseases are prone to depression.) And they overwhelm the presence of harmful microbes. In addition, the helpful bacteria produce a large portion of the body’s neurochemicals that the brain uses to manage learning, memory, and other functions. For example, gut bacteria produce up to 95% of the body’s supply of serotonin, which is a key player in the management of mood.
There are a number of steps we can take to encourage the health of the gut microbiome:
- Take probiotic supplements and/or eat fermented foods. Fermented foods such as the following are a natural source of probiotics.
- fermented vegetables
- kefir
- kimchi
- kombucha
- miso
- sauerkraut
- tempeh
- Eat prebiotic fiber. Probiotics feed on nondigestible carbohydrates called prebiotics. This process encourages beneficial bacteria to multiply in the gut. Prebiotics include:
- asparagus
- bananas
- chicory
- garlic
- Jerusalem artichoke
- onions
- whole grains
- Eat less sugar and sweeteners. Eating a lot of sugar or artificial sweeteners may cause gut dysbiosis, which is an imbalance of gut microbes.
- Avoid taking antibiotics unnecessarily. Antibiotics are also damaging to the gut microbiome, with some research reporting that even 6 months after their use, the gut still lacks several species of beneficial bacteria.
- Use different cleaning products. Disinfectant cleaning products can disrupt the gut microbiota in much the same way as antibiotics.
