We were interested to know what the impact of chronic antibiotic use might be on risk of a disease like inflammatory bowel disease, which includes Crohn’s disease and ulcerative colitis. This has been prompted by really strong data that has emerged regarding the microbiome or the normal flora that are in people’s bodies and if it has a role in predicting who might develop inflammatory bowel disease. At the same time, we know that people are increasingly prescribed antibiotics throughout childhood and adulthood, and it’s really well known that antibiotics do alter the microbiome. So we tested the hypothesis that if we just look at a broad level of antibiotic usage, does it potentially predict the risk of developing inflammatory bowel disease? And we did indeed find that people who chronically used antibiotics did seem to have a higher risk of developing Crohn’s disease. And I think this does speak to the likelihood that the microbiome is an important risk factor for Crohn’s disease. But also I think broadly speaking does kind of give additional pause for us, with respect to how we think about using antibiotics that using them without a very strong indication might have some long-term detrimental impact, given that it might impact the microbiome. And that’s such an important factor in a lot of chronic diseases.
I think that one of the key questions going forward is: what is it that modifies the microbiome? Are there things that we do in our daily lives that might have an impact on our microbiome and affect chronic disease risk? So, that also includes diseases like colorectal cancer, as well as other gastrointestinal disorders, but even more broadly speaking chronic disease, like heart disease or other types of cancer. So there is that real important need to understand what are modifiable risk factors that impact the microbiome. We did some research that did show, for example, that you could use dietary factors or dietary patterns, and try to modify those to affect the microbiome in ways that could be important for human health. We did show that those diets that seem to promote the growth of that, in turn, metabolize sulfur actually is associated with a risk of developing colorectal cancer. It does suggest that if we can modify our diet to try to reduce the abundance of those bacteria in the gut, that could have an impact in prevention of chronic diseases like colon cancer.
I think that there’s certainly evidence that diet effects chronic levels of inflammation, and that in turn, might impact chronic disease. I can just provide an additional link to that. We also have shown that diet directly affects chronic inflammatory markers. So then it gives us another link between diet, inflammation, inflammatory markers, and risk of developing diseases. I think putting all that together could be a very powerful model to think about harnessing our ability to manipulate the gut microbiome going forward for therapeutic purposes.