"There are many reasons why we want to help improve gastrointestinal health, both for those who already have problems and for the prevention of other pathologies related to intestinal inflammation, such as arthritis or cardiovascular diseases," pointed out Gary Perdew, lead author of the study.
When the intestinal wall is healthy, the organ is protected from toxins and other microorganisms that can be harmful, while allowing the nutrients to continue their journey.
And, according to Perdew, the key to the process may be a receptor in the intestine called the Aryl or AHR hydrocarbon receptor, which helps the body regulate its reaction to certain environmental pollutants, as well as trigger other responses to toxin exposure.
In their research, Perdew and his team observed that some vegetables, such as broccoli, Brussels sprouts or cabbage, contain an organic chemical called indole glucosinolate, which breaks down into other compounds in the stomach, including indolocarbazole (ICZ).
When ICZ activates the Aryl hydrocarbon receptor (AHR) in the intestinal wall, it helps maintain a healthy balance in the intestinal flora and the immunological surveillance, while improving the barrier function against host organisms, according to the researchers.
And this can help prevent certain pathologies, like some tumours or Crohn's disease, caused by inflammation in the walls of the intestine.
According to Perdew, hyperactivation of AHR may cause toxicity, but the use of broccoli to activate the receptor locally, in the intestine, instead of systematically might help in preventing some of these problems.
"Dioxin, for example, activates this receptor, and if the dioxin hyperactives it, it will cause toxicity. But the interesting thing is that activating it locally and naturally does not cause a systemic activation," he explained.
The researchers used two gene lines from mice in the study to focus on the AHR. One line had a low capacity to bind ICZ to the AHR, while the other line had a high capacity.
They added 15 percent of broccoli to the diets of both groups of mice, and after adding a substance that causes digestive problems, the researchers found that the mice with a greater ability to bind both compounds were better protected against a digestive problem inducing chemical.
The amount used in the study would equal 3.5 cups of broccoli per day, according to Perdew. "It may sound like a lot, but it is not really if you keep in mind that other vegetables can have the same effect," he pointed out.