“Stress is just as physical as it is mental. The example I like to use for this is that I'm very afraid of snakes. So if all of a sudden, if I looked up and a boa constrictor crawled up on my bookshelf, a couple of things would happen immediately. My heart rate would go up, my blood pressure would go up, the hair on my body would stand on end, I would start to sweat. My respiratory rate would go up. I can probably make some of those things happen just by thinking about a snake on the bookshelf behind me. But those physical changes would manifest immediately. Snake is 6 feet behind me, hasn't bitten me, hasn't even touched me, but there’s fear and stress and fight or flight. All of a sudden, the sympathetic nervous system is firing. Now, we're living in ‘the snake behind me on the bookshelf’ all the time. The threat of COVID, the second wave, the new variants, the economy constantly coming at us. So our sympathetic nervous systems are constantly firing. And we are in a state of fight or flight virtually all the time, some of us even in our sleep.
“And we are in a state of fight or flight virtually all the time, some of us even in our sleep.”
This has serious implications for our microbiome. And when you think about that state of fight or flight/sympathetic versus a parasympathetic, calmed down state, it's not just the changes in the microbiome that we see, but the stress can reshape our microbiome in a negative way. It can change the actual populations of bacteria. There was a very famous study done where they looked at the microbiome of college students right in the middle of finals and they saw that within hours, certain bacterial species could be increased 1,000 fold within a couple of hours in an acutely stressed state. That's why college students get sick around exam time. It's not because all of a sudden there's more germs; it’s because their immune system is compromised because of the stress. And that immune system is compromised because of what's going on in the microbiome, which is affected by stress.
When you think about blood flow, fight or flight happens so we can run away from the snake, and what that does is pull blood away from the digestive tract, from the brain, et cetera, and sends it to the large organs like your quads and your glutes and your hamstrings, because you need to run away. So the blood distribution throughout our body is very different in a stress state, and that is also imbalanced. The hormones are imbalanced, all of that. You can't change a stressful situation, but you can change your response to it.”
Want more? This is an excerpt from a longer convo with Robynne Chutkan, MD — listen or watch here!