Stress is one of those triggers – like diet or antibiotics – that can throw our gut bugs (our microbiome) badly out of balance.
We know from recent scientific studies that the gut-brain connection is a much deeper one than we could ever have imagined, and the connection goes both ways.
Studies on both mice and humans show that the more diverse our microbiome is, the more resilient we are to stress.
Can this really be true? If so, how can we work it to our advantage?
If we’re severely stressed, our microbiome takes a hit (more on this below). But it also works in reverse: when our microbiome is thrown out balance by something or a combination of things, WE take a hit. How? We become less robust and more stressed.
This is some pretty crazy sh*t! It shows a deeply connected, truly symbiotic relationship between us and those little bacteria. They look after us, and we need to look after them too.
For a look at the host of reasons your microbiome may be out of balance, check out Why Your Gut is Broken
You’ve probably spotted that this also sets up the possibility of a bad feedback loop: we get stressed and our microbiome suffers, then we feel the stress even more, and so on.
We can break that loop by boosting our friendly gut bugs with probiotics and by getting our diet right.
Stress upsets our good bacteria
At any given time we have a balance of good and bad microbes living in and on us. It’s kind of icky when you stop and think about it but there’s a huge ecosystem of trillions of them.
These bacteria are not just hanging around. They are literally wired into our immune system, metabolism and central nervous system helping us humans to function properly. By the way they’re doing the same in every other animal on the planet too!
Given how closely interconnected we are, it’s not surprising that when we’re chronically stressed it can affect our gut bugs too.
Studies with mice have shown that stress increases the amount of bad bacteria in the gut, throwing the ecosystem out of balance. Mice are considered to be sufficiently similar to humans for these studies to give us strong clues of what’s going on in own bodies.
There have also been human studies. So far these have focused on short, acute stress rather than the chronic stress that most of us have (thank you modern life!)
So for example, we know that after a stroke our microbiome changes for the worse. It becomes less diverse with unfriendly species gaining ground.
It’s also known that people who suffer from Post Traumatic Stress Disorder (PTSD) have lower levels of three particular bacteria. However it’s not yet clear if lower levels of those bacteria make us more susceptible to PTSD or follow from having PTSD.
Anything like stress that upsets our gut bugs leads sooner or later to our digestion malfunctioning. This leads to absorbing less nutrients from the food we eat. These nutrients are the vital building blocks that enable our body to function and heal.
Without enough of the right nutrients our body is weaker. We find it harder to get and stay well. We catch more coughs and colds and may end up taking more antibiotics.
Taking antibiotics is necessary sometimes but it always damages our microbiome and therefore weakens our immune system. This can lead to a cycle of more antibiotic use, more damage to the microbiome, lowered immunity and yet more antibiotics
Brain On Fire
A scientific review in 2016 found that our microbiome plays a huge role in how our body responds to stress and in particular our brain.
They described our microbiome as the ‘regulator’ that determines the level of inflammation in our brain (‘neuroinflammation’). For a quick intro to the subject of inflammation check out Inflammation: Putting Out The Fire
This also fits with what we know about our friendly bacteria helping our immune system to find the correct level of response to threats, like turning a thermostat up and down. More details here: Supercharge Your Body to Crush Autoimmune Conditions
In this scientific review the authors talk about ‘microglia’. These are immune cells in our brain and central nervous system, a bit like little soldiers defending our brain and nerve cells from attack by pathogens.
The authors say: ‘diverse gastrointestinal microbiota is essential for the continuous preservation of healthy microglia and proper brain function throughout our lifespans’
In other words if we want our brain to function properly throughout our entire life (yes please!!) we MUST have a rich and healthy microbiome
Get By With a Little Help From Our Friends
One thing that’s clear from both mouse and human studies is that our friendly bacteria help us cope with stress.
In one study, for example, levels of the stress hormone cortisol were significantly lower in people taking probiotics as compared to those taking a placebo. This had the effect of boosting the subjects resilience to stress and improved their emotional responses.
In other words boosting our microbiome will help us to feel positive in the face of stress, as opposed to feeling bummed out and hopeless, overwhelmed by a torrent of negative thoughts.
When we take a step back to look at the bigger picture, there’s no question that chronic stress can damage our microbiome. However there’s more to it than that, as we now know that our microbiome also plays a big role in PROTECTING us against stress.
Armed with this knowledge we can engineer ourselves to be more resilient to life’s stresses and strains by taking care of our old friends, the bacteria.
It can be act of daily self-care, for example by eating a little live, cultured food with every meal and by avoiding processed food altogether. Check out Clean Eating: More Than Just An Elitist Fad
I also suggest some gut-friendly coping strategies here: 7 Stress Busting, Gut Soothing Strategies