systemic diseases | Understanding the interaction between the intestinal microbiota, pathogens and the human host could lead to new strategies, notably by modifying the composition of the intestinal microbiota. Helicobacter pylori, a bac- terium known to irritate the stomach lining and induce chronic gastritis, as well as poor periodontal health.5 This observation is sup- ported by existing literature on the subject, which sug- gests that dental plaque may harbour H. pylori and cause recurrences of gas- tric infection. A 2017 study by Hujoel and Lingström traced an overview of the historical role of nutrition in the de- velopment and prevention of dental caries, gingival bleeding and periodontal disease.6 Given how much recommendations on nu- trition have changed over time—the World Health Organization has only since 2015 the restriction of sugar intake, for example—it is interesting to see that the current evidence suggested a low-carbo- hydrate diet high in non-vegetable fats, micronutrients (e.g. vitamin C and B12) and protein was correlated with periodontal health. However, the ability to absorb these nutrients can be influenced by gastrointestinal health. As the Canadian Society of Intestinal Research has re- ported, the improper functioning of the gastrointestinal tract can reduce nutrient absorption, leading to vitamin and mineral deficiencies that may cause oral lesions and tongue inflammation. recommended Editorial note: A list of references can be obtained from the publisher. prevention 1 2018 27 Prof. Denis Bourgeois for concern. Understanding the impact of such bacteria and yeasts in the interdental spaces within an oral envi- ronment, including, of course, the salivary environment —which have the potential to spread at any time of their lives within the digestive tract—is a priority. The relationship between the two Though there is still much to be learnt about the inter- action between the oral and intestinal microbiota, numer- ous recent studies have shed some light on it. By exam- ining the oral health of patients with dyspepsia who were candidates for diagnostic upper gastrointestinal endos- copies, Zaheda et al. found a direct relationship between