The gut is also our largest sensory organ, with a surface area 40 times that of our skin! One of its central functions is to gather information for the brain, communicating that we’re getting enough nutrients, how our immune cells are functioning, and what our hormones are up to.

What is the vagus nerve?

The vagus nerve mediates an on-going, complex “conversation” between the gut and the brain. How well it facilitates the gut-brain conversation can impact our health in multiple ways, including our mental health. Research suggests that the diversity of the microbiome can enhance the functioning of the vagus nerve. Beneficial bacteria may affect vagus nerve activity via the microbiome, impacting communication with the brain and helping with stress regulation. ⁠

The importance of maintaining the health of the exquisitely sophisticated organ we call the gut and its resident microbiome is clear. But what exactly do we mean by a “healthy” gut? A healthy gut contains a diverse population of microbes, creating a balance of beneficial and “bad” bacteria. The presence of some “bad” bacteria helps the immune system recognize which microbes to fight.

In an unbalanced microbiome, “bad” bacteria - the pathogenic kind that can cause infections or give us food poisoning - flourish. This triggers a response from the immune system - get those bad bacteria out! - and results in increased inflammation which has been linked to depression. Although the exact nature of the relationship between inflammation and depression isn’t yet fully understood, studies suggest that a balanced microbiome may help create the conditions for a healthy symbiotic relationship between our gut and our mind. 

The gut is an ecosystem whose complexity continues to emerge. Having a healthy gut means having enough good bacteria, along with a scattering of “bad.” In other words, rather than trying to eliminate the bad, the way to achieve gut health is to faithfully tend the good. So what can we do to nourish our hard-working gut? Probiotic-rich foods like raw kombucha, kefir, yogurt, and sauerkraut feed the beneficial bacteria in the microbiome and help maintain its balance. Accepting the bad with the good doesn't just help sustain us during difficult times. It also helps us keep our guts healthy!

It’s certainly not as simple as saying that drinking kombucha will make you happy - other than, of course, by way of its deliciousness. But as connections continue to emerge between microbiome diversity, the functionality of the nervous system, mental health, and the food we eat, promising implications for the benefits of a healthy gut may follow. Until then, enjoy your kombucha!  Cheers!