Eat your bacteria
It's not surprising that we humans are sometimes referred to as "superorganisms" made up of bacteria and human cells—we have trillions of bacteria living in our gut, and they outnumber, by far, our own cells. This notion might be a little . . . creepy, but the reality is that we need those bugs in our gut.
"The human race evolved with bacteria, and we've developed a symbiotic relationship with bacteria," says AHFMR Senior Scholar Dr. Karen Madsen from the University of Alberta. "Our intestines provide a home for bacteria, and the bacteria are vital to our health because they aid in proper digestion and [they] support immune-system functioning. Signals pass back and forth between the bacteria in our gut, the epithelial cells that line the intestine, and the cells of the immune system."
Dr. Madsen studies how intestinal bacteria influence the development and progression of IBD. One of the characteristics of IBD is a "leaky gut". This occurs when spaces develop between the cells of the intestinal wall, and toxins—in the form of displaced bacteria and fragments of food—are allowed to leak into the bloodstream. Some bacteria that live in the gut release small peptides (fragments of proteins) that make the intestine less leaky. "We're investigating how these peptides work and how they signal the epithelial cells," explains Dr. Madsen. "We want to isolate them, in the hope that we could develop a treatment for those patients who have 'leaky guts'."
Another characteristic of IBD is an imbalance in the bacteria that live in the intestine. The strains of intestinal bacteria in most IBD patients are different from those in healthy people. A key question is whether the changes in bacterial populations are a consequence of inflammation or a cause of it. We might expect active inflammation to give rise to some obvious changes, but research by Dr. Madsen and others has shown that many changes occur before inflammation.
These observations have led to the use of probiotics—so-called good bacteria—to treat IBD. Several clinical trials have shown that probiotics are effective in treating ulcerative colitis. In recent studies, both adult and pediatric patients with ulcerative colitis were given probiotic supplements, with the result that their remission rates increased significantly. However, for reasons unknown, probiotics do not appear to be as effective in treating Crohn's disease.
Dr. Madsen points out that treatment with probiotics does not mean simply adding bacteria to certain foods. "In some diseases, we may not want to treat people with live bacteria. It would be much better to isolate the active agents. That's why basic research on identifying these agents and how they work is so important."
Probiotics are living micro-organisms, usually bacteria, that can affect the host in a beneficial manner.
Prebiotics are indigestible food ingredients that stimulate the growth and activity of probiotic bacteria already established in the intestine.
Synbiotics are combinations of a probiotic and a prebiotic.