What happens in your gut affects what happens in your brain (among other things). The gut-brain connection was once thought to travel in one direction—from the brain to the gut. The most obvious brain-to-gut manifestation of this connection is the stomach ache you experience during a stressful event. But we now know that the gut-brain connection is bidirectional. Your digestive events affect your mood and how you think. Now that’s interesting.

Most people think of their digestive tracts as a food processor of sorts. Food in, nutrients absorbed, poop out, end of story. Not quite, my friends. The digestive plot thickens when we consider the 100 trillion bacteria teeming inside us. These bacteria make up 90 percent of the cells in our body—and they contain 99 percent of the DNA we house. Chew on that for a bit (as always, adequate chewing please).

A recent study published in the journal Gastroenterology highlights the gut connection nicely. Using functional MRI testing, researchers found that consumption of fermented milk with probiotics twice daily in healthy women affected activity of brain regions that control central processing of emotion and sensation.

“Our findings indicate that some of the contents of yogurt may actually change the way our brain responds to the environment. When we consider the implications of this work, the old sayings, ‘you are what you eat’ and ‘gut feelings’ take on new meaning,” stated lead researcher, Kirsten Tillisch, MD. “There are studies showing that what we eat can alter the composition and products of the gut flora—in particular, that people with high-vegetable, fiber-based diets have a different composition of their microbiota, or gut environment, than people who eat the more typical Western diet that is high in fat and carbohydrates. Now we know that this has an effect not only on metabolism but also affects brain function.”

I believe we will hear a lot more about the gut-brain connection in the coming months and years. And the gut-immune connection. And the gut-heart connection. And the gut-joint connection. And the gut-whole body connection. Truly, our guts are in control of our health. So it’s time we started to optimize our health by optimizing our digestion.