Crohn’s disease is associated to an imbalance in the oral microbiota

Chinese researchers discovered that the oral microbiota of patients with chronic inflammatory bowel disease is less diversified than that of healthy people.


Pr. Martine Bonnaure-Mallet, a researcher at the Institut National de la Santé et de la Recherche Médicale(Inserm), reminds us that our mouth hosts over 700 species of bacteria which, together with naturally present fungi and viruses, contribute to the good health of our oral cavity. But when this balance is compromised, problems may occur: cavities, gum disease (gingivitis), and even cardiovascular diseases or colorectal cancer.

The intestinal microbiota is depleted in patients with CIBD

Chinese researchers from the University of Beijing therefore assumed that this microbiota could also play a role in the development of chronic inflammatory bowel diseases (CIBD) such as Crohn’s disease or ulcerative colitis. These diseases are characterized by severe abdominal pain and diarrhea (sometimes bloody) caused by inflammation of the gastrointestinal lining. Studies have already shown that the intestinal microbiota of people with this type of disease is much less diversified compared to healthy individuals. To assess whether the same is true with the oral microbiota, scientists collected saliva samples from 54 patients with ulcerative colitis, 13 with Crohn’s disease and 25 healthy volunteers.

Oral microbiota as a marker for CIBD

Analyses revealed that oral microbial community of patients with CIBD is less diversified than that of healthy volunteers: their flora has higher levels of some bacterial populations and lower levels of others. They also produce more substances that promote oxidative stress and virulence, both harmful to oral tissues. The researchers also indicated that differences were observed between the two subject groups (related to the profile of bacterial communities but with no link with symptom severity or individuals' origin). According to them, this study suggests that the oral microbiota is disrupted in patients with inflammatory bowel diseases. They believe that this imbalance–called dysbiosis–could be a marker for CIBD and a mean to identify patients who are more at risk of developing CIBD.



Xun Z, Zhang Q, Xu T, Chen N and Chen F (2018). Dysbiosis and Ecotypes of the Salivary Microbiome Associated With Inflammatory Bowel Diseases and the Assistance in Diagnosis of Diseases Using Oral Bacterial Profiles. Front. Microbiol. 9:1136. doi: 10.3389/fmicb.2018.01136