We may finally know why marijuana helps people with chronic gut problems

site  8/14/2018
As John Mayer tells us (and tells us, and tells us), your body is a wonderland. When it comes to microbial life, this holds especially true for your gut. There, hundreds of residential species eat, breed, and excrete waste. Somehow, your intestines manage to thrive with this zoo inside them—for the most part. In some cases things aren’t so wonderful: your gut starts attacking itself in an autoimmune response that’s bad for microbes and host alike.
As John Mayer tells us (and tells us, and tells us), your body is a wonderland. When it comes to microbial life, this holds especially true for your gut. There, hundreds of residential species eat, breed, and excrete waste. Somehow, your intestines manage to thrive with this zoo inside them—for the most part. In some cases things aren’t so wonderful: your gut starts attacking itself in an autoimmune response that’s bad for microbes and host alike.

People with this condition, known as inflammatory bowel diseases like Crohn’s disease or ulcerative colitis, face a chronic problem. Current treatment options are laden with side effects and require constant tweaking to remain effective. Some of those people have turned to marijuana for treatment—but their stories about how it has helped them have remained just that, stories, until now. A new study from University of Massachusetts and University of Bath researchers is the first to demonstrate the physical process by which cannabis affects IBD, opening up the possibility of creating new drugs to treat these chronic ailments.

Although numerous IBD patients use cannabis products to help treat their illness, and the phenomena has been subject to some medical research, nobody knew exactly how the medically active parts of marijuana (known as cannabinoids) had an anti-inflammatory effect on irritated bowels before this study. Ironically, however, the researchers weren’t even looking for this precise answer; they just happened upon it in the course of trying to understand how the healthy intestine regulates itself.

In the gut, a thin layer of epithelial cells mediates between our bodies and the microbial “zoo” living within. Beth McCormick of the University of Massachusetts has been studying the role these cells play in regulating the gut microbiome for well over a decade, and the starting point for this current research was her prior discovery of a chemical pathway by which epithelial cells help neutrophils, a kind of white blood cell, to cross into the gut and eat up some of the microbes. But that was clearly only half of the answer. In order to produce balance, something else had to stop too many neutrophils from getting in and killing peaceful microbes and even the gut itself—leading to IBD.