We may finally know why marijuana helps people with chronic bowel problems
As John Mayer tells us (and tells us, and tells us), your body is a wonderland. When it comes to microbial life, this is especially true for your gut. There, hundreds of residential species eat, reproduce and excrete waste. Somehow your intestines manage to thrive with this zoo inside, for the most part. In some cases, things are not so great: your gut begins to attack itself in an autoimmune response that is bad for the germs and for the host.
People with this condition, called inflammatory bowel disease like Crohn’s disease or ulcerative colitis, face a chronic problem. Current treatment options are loaded with side effects and require constant adjustments to remain effective. Some of these people turned to marijuana for treatment, but their stories of how it helped them have remained like that, stories, until now. A new study by researchers at the University of Massachusetts and the University of Bath is the first to demonstrate the physical process by which cannabis affects IBD, opening up the possibility of new drugs to treat these chronic conditions.
Although many IBD patients use cannabis products to help treat their disease and the phenomenon has been the subject of medical research, no one knew exactly how the medically active parts of marijuana (called cannabinoids) had an anti-inflammatory effect on irritated bowels before that. to study. Ironically, however, the researchers weren’t even looking for that precise answer; they stumbled upon it while trying to figure out how the healthy gut is regulated.
In the intestine, a thin layer of epithelial cells mediates between our body and the microbial “zoo” that lives there. Beth McCormick of the University of Massachusetts has been studying the role of these cells in regulating the gut microbiome for more than a decade, and the starting point for this current research was her earlier discovery of a chemical pathway by which epithelial cells help neutrophils, a kind of white blood cell, to pass through the intestine and eat some of the germs. But that was clearly only half the answer. In order to produce a balance, something else had to prevent too many neutrophils from entering and killing peaceful microbes and even the gut itself, which led to IBD.
The answer, reported in the new study published Monday in the Clinical investigation journal, is a different pathway, also in the epithelial cells of the intestinal mucosa. This chemical pathway produces substances that prevent neutrophils from passing through epithelial cells and entering the intestine. And it turns out that these substances, at least in mice, are endocannabinoids. These fatty substances bind to the same chemical receptors that the cannabinoids found in, well, cannabis. Patients missing this secondary path “were more likely to develop ulcerative colitis,” says McCormick.
While current research is in mice, it also suggests a possible outcome in humans. This would help explain why cannabinoids seem to provide relief to people with IBD, as they essentially perform the same regulatory function that endocannabinoids would if the body produced them on its own. More research is needed, of course, but McCormick says this opens up the possibility of creating new treatments for IBD that work on the new path, including, perhaps, therapeutic agents extracted from marijuana.
And that’s not all, says Vanderbilt University gastroenterologist Richard Peek, who was not involved in the new study. McCormick’s findings “may not be just gut-specific,” says Peek. Epithelial cells are found on the surface of organs throughout the body, so this mechanism of action may exist in other systems as well, he says. It would also change our understanding of autoimmune responses elsewhere in the body.
This is good news for the 1.6 million Americans who currently suffer from IBD. But given how often cannabis is a treatment for IBD, some might wonder why researchers haven’t looked for its mechanism of action in the gut before. In part, that’s because cannabis research tends to be politicized, Peek says. He believes this discovery may open up new possibilities for the legalization of medical marijuana. For McCormick, their “unbiased approach” was the key to finding this result: they weren’t looking to explain the mechanism of action of cannabis, they just found it. “Sometimes, as they say in the field, the blind squirrel finds the nut,” she says.