How stress leads to bloating and what we can do about it.
TL;DR: Stress (psychological & physiological) can lead to increased inflammation in our intestines and decrease how well we absorb food. Poor absorption makes more food available to our gut microbes, which produce gas and bloating. (about 7 min read)
Metabolic tips for reducing stress and bloating:
Stay hydrated to help food get absorbed across your gut and into your blood faster!
Take breaks to stretch and move around throughout the day: increased circulation helps absorb food, reduce inflammation, and break up pockets of gas so they move through your intestines with less uncomfortable build-up.
Get enough fiber (25g per day) in your diet and reduce simple carbs when you aren’t moving to reduce gut inflammation and IBS symptoms.
Stress, quite literally, is a gut feeling. Stress - both psychological, like a stressful work deadline, and physiological, like not getting enough sleep - causes a number of changes that hurt our guts. Some of those immediate changes include decreased blood flow to our intestines and slower absorption of food. This means that our gut microbes spend more time with our food and have more time to turn it into gas before we can absorb that food into our bloodstream (even if the microbes themselves are “good” and our microbiome is “healthy”). Extra gas = uncomfortable bloating.
If we stay stressed out for too long, these short-term changes compound on each other. Remember that stress = metabolic imbalance, and chronic stress leads to inflammation. When our guts (aka intestines, if you want to be technical about it) get inflamed, we can get bloated or have other gastrointestinal (GI) issues like diarrhea, constipation, IBS, and/or leaky gut syndrome*.
Stress increases cortisol, which moves more blood toward your muscles and away from your guts. Your brain’s first (probably unconscious) response to stressful situations is literally to try to get you to run away from the problem. There’s a release of cortisol and one of cortisol’s actions is to move more blood toward your muscles and away from your intestines. This preps you to move fast, but the trade-off is that you digest slow.
Cortisol also interferes with insulin signaling, which raises the amount of insulin that needs to be released into your blood to bring your blood glucose levels (BGLs) down after eating if you don’t move around. Extra insulin itself is stressful and leads to insulin insensitivity, and eventually, type II diabetes.
Slower absorption of food from your gut into your blood increases the amount of gas that your gut microbes produce. This is because there’s more time for the food to sit with your gut microbes. Bloating is always caused by something not getting absorbed across our intestines - sometimes it’s a molecule we can’t digest (like the lactose in cheese on pizza if we’re lactose intolerant), sometimes it’s a molecule we just don’t digest fast enough (like the glucose overload from binging sugar cookies at our desk instead of taking a proper break).
Diets that are low in fiber and high in simple carbs increase gut inflammation. Fiber is an important mediator between your gut microbes (all the bacteria and yeast that are supposed to live in our intestines) and your immune system. Our gut microbes will break down fiber into molecules that let our immune cells know everything is okay. When we don’t get enough fiber, our immune cells that patrol our intestines don’t get the “a-okay” signal and start getting aggro at the intestinal border.
To add insult to injury, diets that are low in fiber are often higher in simple carbohydrates. Overwhelming our intestinal cells with too much sugar causes a traffic jam of sorts, since we can only transport so much of a certain molecule across our intestines at once. This increases gas production. AND it also causes biochemical stress to our intestinal cells by producing too many “reactive oxygen species” (this is the biochemical term for “oxidants”; you have probably heard of “anti-oxidants” that help reduce inflammation and/or slow aging and/or prevent disease. Well, like the name implies, anti-oxidants counteract oxidants, which are the things that increase inflammation, quicken aging, and progress disease.)
“Burnout” could be a pretty good description for how stress burns your gut nerves out. There’s been a lot of research showing that stress from high sugar, low fiber diets mess up the nerves that serve our intestines, and that this is partly due to increased reactive oxygen species*. Our intestines have a layer of smooth muscle cells that need to contract in order for food to continue moving down the line from our stomachs toward our butts. If the nerves aren’t communicating with the intestine’s smooth muscle properly, then food doesn’t move through. This, again, slows digestion, leads to possible gas build-up, and constipation.
Staying hydrated increases how fast you can absorb food. Staying hydrated helps balance the osmotic pressure in your guts and makes it easier for your intestinal cells to transport nutrients into the bloodstream and get them out of the intestines faster*. This also reduces the time those nutrients spend with your microbes, thereby reducing gas production.
Moving around throughout the day increases circulation and reduces gut inflammation. Again, anything you can do to bring blood back to the intestines is going to speed up digestion and absorption. Increasing circulation also helps reduce cortisol levels so the signals to move blood away from your guts to your muscles will go away faster when you take breaks to stretch and move throughout the day. More movement = less stress = less cortisol = more metabolic balance!
Metabolic tips for reducing stress and bloating:
Stay hydrated to help food get absorbed across your gut and into your blood faster!
Take breaks to stretch and move around throughout the day: increased circulation helps absorb food, reduce inflammation, and break up pockets of gas so they move through your intestines with less uncomfortable build-up.
Get enough fiber (25g per day) in your diet and reduce simple carbs when you aren’t moving to reduce gut inflammation and IBS symptoms.
Konturek, P.C. et al., (2011) Stress and the gut: Pathophysiology, clinical consequences, diagnostic approach, and treatment options. Journal of Physiology and Pharmocology.
Chandraeskharan, B. et al., (2011) Colonic motor dysfunction in human diabetes is associated with enteric neuronal loss and increased oxidative stress. Neurogastroenterol Motil.
Bipat and Toelsie. (2018) Drinking water with consumption of a jelly-filled doughnut has a time-dependent effect on the postprandial blood glucose level in healthy young individuals. Clin Nutr ESPEN.
