Oral Microbiota, Intestinal Microbiota and Inflammatory Bowel DiseasesAuthor(s): Bourgeois D, Weiler D and Carrouel F
There exists a close relationship between the human host and the intestinal microbiota, a mixed community of microorganisms that protect the intestine from being colonised by exogenous pathogens. The intestinal microbiota plays a crucial role in the nutrition and modulation of the host’s immune homeostasis. Dysbiosis is a microbial imbalance between pathogenic and protective bacteria: the former can become dominant and the latter underrepresented, leading to a degraded microbial diversity . In a healthy individual, the microbiota is composed of bacteria, fungi, viruses and yeasts. The host/microbiota coexists in mutual harmony, named symbiosis, allowing both to function properly . It should be noted that the balance of the intestinal microbial ecosystem can be disrupted by a number of factors, such as antibiotics, vaccinations, certain foods and stress. An intestinal bacterial disorder primarily manifests itself in terms of quantitative changes in bacterial location and in the biological characteristics of the intestinal flora. The intestinal immune system does not tolerate any modification of the gut microbiota.