BETA
This is a BETA experience. You may opt-out by clicking here

More From Forbes

Edit Story

Are You Nervous From Butterflies, Or Are Butterflies Making You Nervous?

Following
This article is more than 5 years old.

"It's all in your head," has been a commonly-used phrase for anyone with an excessive amount of rumbling in their stomach, classically referred to as "butterflies in your stomach." That uncomfortable, yet at times exciting, feeling one gets right in the gut, either from being nervous or being excited. Sometimes it's a good feeling, in the setting of anticipating a challenging or exciting activity. More often it's felt in the setting of something scary, anxiety-inducing, or stressful. But for the most part, it's been typically thought that the nerves in your head are triggering the nerves in your gut. Or is it the other way around?

With increasing research being performed in the field of the brain-gut connection, and with increasing in depth understanding of the gut microbiome (the billions of 'healthy' bacteria that live and thrive in the gastrointestinal tract), several studies in both animals and humans have demonstrated that perhaps substances in some of the food we eat is triggering irregular gut function, leading to increased anxiety. A 2015 study in Nature looked at dietary emulsifiers (substances contained in many processed foods), and their impact on the gut microbiome in mice. The study found that commonly used emulsifiers, specifically carboxymethylcellulose and polysorbate-80, led to substantial intestinal inflammation and colitis due to altered bacterial species in the host intestinal tract. A 2017 study in Gut used a human intestinal study model, and also found that exposure to these substances similarly altered the gut bacterial content, leading to chronic intestinal inflammation.

A more recent study, published this month in Scientific Reports, investigated whether exposure to such emulsifiers, known to alter gut bacteria, has an impact on behavior. This concept of the brain-gut connection, although more recently hitting the science and media world, is not new.  In the late nineteenth century, Professor William James reported his findings in the journal Mind, stating that bodily functions precede emotions, and that these internal functions are what trigger emotions, and not vice versa. He uses the example of an individual seeing a bear, running from the bear, and that the act of running away from something dangerous is what triggers the emotion of fear. As we don't have too many bears running wild today, but we do have increased exposure to new substances, and increased ability to assess physiologic changes, current investigators use emulsifiers and mice intestines, as opposed to bears chasing humans. Using the same substances found to cause gut inflammation (dietary emulsifiers carboxymethylcellulose and polysorbate-80), the research group, based at Georgia State University in Atlanta,  found that increased exposure to dietary emulsifiers led to not only increased intestinal inflammation, but also to altered anxiety and social behaviors in their mouse behavior model. Gut irritation, colloquially known as 'butterflies in the stomach,' led to behavior changes.  As Professor Williams had proposed back in the late 1800's, bodily change can lead to the change in emotion; it's not always emotion leading to the bodily change.

Perhaps a more puzzling  finding of the recent study was that emotions and behaviors changed differently for male versus female mice. Giving the same emulsifiers to all study subjects, male gut bacteria had different alterations than those of females, and while both sexes demonstrated behavior changes, these behavior changes differed between genders. Granted, we're talking mice here. But there continues to be increasing evidence of a veritable brain-gut connection, likely due to intestinal bacterial populations.  What follows is the question regarding methods to combat these changes in gut microbiota using probiotics. If bacteria are altered by dietary intake, and these bacteria are, in turn,  altered yet again by intake of another substance, will that impact the brain? The jury remains out on this one.  While probiotics can, indeed alter the intestinal bacterial population, especially in individuals taking antibiotics.  pushing that to stating that taking probiotics alters brain health remains a bit of a stretch.

Follow me on Twitter or LinkedInCheck out my website or some of my other work here