Cannabis users have long reported, anecdotally, that the drug can ease gastrointestinal woes, including irritable bowel syndrome and inflammatory bowel disease.
Now some animal research published in Cell goes a few tentative steps to explain why.
The mice study found that endocannabinoids, molecules produced by the body that share features with the cannabinoids in cannabis, may be able to block pathogenic gut bacteria before they can lead to disease.
In the research, mice with elevated levels of endocannabinoid 2-arachidonoyl glycerol (2-AG) were protected from infection by Enterobacteriaceae pathogens resident in the gut.
2-AG directly modulated pathogen function by shutting down the genes needed for some the intestinal bacteria to colonize, multiply and cause disease.
Study leader Vanessa Sperandio, Ph.D. and her colleagues at the University of Texas Southwestern Medical Center genetically altered mice to overproduce 2-AG and then infected these mice and some of their litter mates used as controls with Enterobacteriaceae, which attacks the colon and causes inflammation and diarrhea.
The altered mice “developed only mild symptoms compared with the more extreme gastrointestinal distress exhibited by their littermates,” a UTSW statement about the study noted. Their colons showed far lower inflammation and signs of infection, and they cleared the infection days faster than the control mice that didn't have high 2-AG levels.
Further experiments showed that 2-AG could exert these effects, not just on Enterobacteriaceae, but also on C. rodentium, S. typhimurium, and E. coli. In all cases the effect was through blocking a bacterial receptor known as QseC. When this receptor senses the host signalling molecules epinephrine and norepinephrine, it triggers a molecular cascade necessary to establish infection. Plugging this receptor with 2-AG prevents this virulence program from activating, helping to protect against infection.
Coming back to the relevance to cannabis, the drug raises levels of cannabinoids in the blood, which in turn might also be expected to block QseC like the endogenous endocannabinoid 2-AG did in this experiment.
Clearly, more research is needed, but it’s an interesting early insight into how cannabis might helps gastrointestinal ailments, and an area well worth keeping an eye on.