10. Trust your gut? In this economy?

Hi friends,

Welcome to the tenth dispatch of How Humans Flourish, a research-informed newsletter on how humans thrive. 

I have to say, when reading the literature on what makes a life worth living, one of the more rewarding findings is the way in which I’m provided an alternative lens to contextualize human behavior. It’s too easy (and dare I say lazy) to point to political leanings or economic philosophies as a way to interpret the consummate decisions human beings make on a daily basis. Each one of us is a universe unto ourselves (figuratively and biologically), and personally, I find great delight in unearthing new and profound ways to understand myself and those around me.

This is why for the month of March, we are reading “The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health” by Dr. Emeran Mayer, Director of UCLA’s Center for Neurobiology of Stress. Because as we map different drivers for human flourishing, it’s also important to map the interconnectedness of the body (more on this idea later). 

But before diving in, an important point to note is that Dr. Mayer’s patients come to him after they’ve tried everything to cure their severe gastrointestinal issues– from visiting multiple gastroenterologists to experimenting with the latest colonic cleanse and/or juice fast. And so, when they arrive in his clinic, in order to get to the heart of the matter, he first tries to understand their adverse life experiences. 

Why adverse? 

Because according to Dr. Mayer, “The gut is connected to the brain through thick nerve cables that can transfer information in both directions and through communication channels that use the bloodstream... Many of the gut signals reaching the brain will not only generate gut sensations, such as the fullness after a nice meal, nausea and discomfort… but will also trigger responses of the brain that it sends back to the gut, generating distinct gut reactions. And the brain doesn’t forget about these feelings, either. Gut feelings are stored in vast databases in the brain, which can later be accessed when making decisions. What we sense in our gut will ultimately affect not only the decisions we make about what to eat and drink, but also the people we choose to spend time with and the way we assess critical information as workers, jury members, and leaders.” (Mayer, pg. 12  Kindle)

The idea that the gut has something to say if we listen closely may seem reminiscent of the famous pop culture proverb “listen to your gut,” but of course, Dr. Mayer takes it further.

“Many adult brain disorders, including anxiety, depression, schizophrenia, autism… are now considered neurodevelopmental disorders, meaning that the basic brain changes start very early in life, many of them already in utero… Stress is a major factor that influences these neurodevelopment changes, and there are at least two major pathways by which early adversity can affect the brain-gut axis: one is by epigenetic modification of the stress response system and the brain-gut axis; the other one is through stress-induced changes in the gut microbiota and their products, which can further affect the brain. This means if we really want to have a major and long-lasting impact on the development and trajectory of these devastating diseases, interventions will have to start very early in life. Once the adult patient comes to the clinic with the full-blown syndrome, most treatments will be largely symptomatic and transient…”

He goes on to describe the series of research that catalyzed the question of whether the symptoms of his patients could be caused by childhood programming of their brain-gut axis. He writes, “I knew by then that adverse childhood events predisposed adults to anxiety, panic attacks, and depression. But other than a few reports linking IBS symptoms to past sexual abuse, no one knew whether these sorts of events caused gastrointestinal pain and altered bowel habits, and we had absolutely no idea if alterations in our gut microbes were involved in these processes. 

When we stressed mother rats by separating them from their pups for three hours a day during the first weeks of life, as Paul Plotsky had, the pups later showed many IBS-like features. In IBS patients, normal gut activity can cause abdominal pain, cramping, and visible bloating of the stomach—all of which stem largely from a hypersensitive and hyperresponsive gut. The majority of patients also have elevated levels of anxiety, and a good percentage suffer from an anxiety disorder or depression. In our experiments, the rats that had experienced a less nurturing childhood presented with similar traits. The animals were more anxious, their intestines were more sensitive, and when stressed they would excrete more small stool pellets, the rat equivalent of diarrhea. Anyone who’s ever had to run to the bathroom before a big presentation or job interview knows the feeling, but IBS patients—and our rats—suffer from such stress-induced symptoms all the time... 

Is the story in humans more complicated than originally thought?...

Doctors generally spend much more time asking patients about the details of their bowel habits and checking blood pressure and cholesterol levels than they do exploring their risk factors related to early life experiences. Yet a recent study of close to 54,000 randomly selected Americans showed that children or teenagers who experience adverse events have a higher likelihood of suffering from poor health, a heart attack, stroke, asthma, and diabetes as adults. The risk for such negative adult health outcomes increased with the number of adverse experiences participants endured before the age eighteen... The majority of these questions explored situations in which the stability in the family was disrupted and the nurturing interaction between the primary caregiver and child was compromised…“ (Mayer, pg. 110-127)

Stress, a caregiver’s nurturance, and irritable bowels… oh my!

We’ll dive deeper down the rabbit hole next week.

With gratitude,