Dear Colleagues,

The aim of this Special Issue is to produce recommendations that are likely to preserve the symbiotic balance between the host and oral microbiota in healthy adults. Our reflections must focus on the impact that behavioral determinants (nutrition, tobacco, alcohol, etc.), the determinants of oral health (oral care products, oral care, etc.), can have on bacterial dysregulation.

The rationale of this issue is that oral health might biologically increase systemic inflammation, lead to immune dysregulation, and alter gut microbiota, thereby possibly influencing colorectal carcinogenesis or other chronic diseases. This intrinsic property of the oral cavity provides immense possibilities for a diverse range of microbiota. Once the symbiotic balance between the host and the microbiota is lost, these microbiota may become involved in disease. Although caries and periodontitis are clearly bacterial diseases, they are not infectious diseases in the classical sense, because they result from a complex interaction of a number of factors: Commensal microbiota, host susceptibility and environmental factors, such as diet and smoking

One interrogation is the role played by toothpaste, mouthwashes in the balance of the oral microbiota. Like other hygiene products, toothpaste is likely to contain endocrine disruptors. The most widespread of these present in toothpaste are butylparaben and propylparaben, as well as triclosan, which are doubly undesirable because they are antibacterial preservatives to which bacteria can potentially develop a resistance and which can induce microbiota dysbiosis. By modifying oral microbiota, the presence of allergens which are more or less antibacterial preservatives used in oral hygiene products (toothpaste/mouthwashes) could, if ingested, disrupt gastrointestinal flora and, thus, create a favorable environment for the development and/or persistence/chronicity of Crohn’s disease through maintained intestinal inflammation. Understanding the interaction between diet, oral care cosmetics, intestinal microbiota, pathogens and the human host could lead to new strategies, notably by modifying the composition of intestinal microbiota. Understanding the change in the composition of the oral microbiota and its potential impact on the gut microbiota would be a significant advance. The reinstatement of normal oral microbial ecology, the efforts to restore microbial assemblage integrity and restoration of mucosal immune homeostasis may help reduce the cause, predisposing and permissive factors of inflammatory bowel disease (IBD) and Crohn’s disease (CD). All these observations open up new research avenues.

Prof. Dr. Denis Bourgeois
Guest Editor

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• food quality
• toothpaste
• mouthwashes
• chlorhexidine
• behavioral consumer
• endocrine disruptors
• oral microbiota
• oral care
• environmental factors