Fusobacterium nucleatum and alteration of the oral microbiome: from pregnancy to SARS-COV-2 infection.

OBJECTIVE: The human being has evolved in close symbiosis with its own ecological community of commensal, symbiotic and pathogenic bacteria. After the intestinal microbiome, that of the oral cavity is the largest and most diversified. Its importance is reflected not only in local and systemic diseases, but also in pregnancy since it would seem to influence the placental microbiome. MATERIALS AND METHODS: This is a literature review of articles published in PubMed about Fusobacterium Nucleatum and both its implications with systemic and oral health, adverse pregnancy outcomes, flavors perception and its interference in the oral-nasal mucosal immunity. RESULTS: It is in maintaining the microbiome's homeostasis that the Fusobacterium nucleatum, an opportunistic periodontal pathogen of the oral cavity, plays a crucial role both as a bridge microorganism of the tongue biofilm, and in maintaining the balance between the different species in the oral-nasal mucosal immunity also by taste receptors interaction. It is also involved in the flavor perception and its detection in the oral microbiome of children from the first days of life suggests a possible physiological role. However, the dysbiosis can determine its pathogenicity with local and systemic consequences, including the pathogenesis of respiratory infections. CONCLUSIONS: It is interesting to evaluate its possible correlation with Sars-CoV-2 and the consequences on the microflora of the oral cavity, both to promote a possible broad-spectrum preventive action, in favor of all subjects for whom, by promoting the eubiosis of the oral microbiome, a defensive action could be envisaged by the commensals themselves but, above all, for patients with specific comorbidities and therefore already prone to oral dysbiosis.

Seven secrets of COVID-19: fever, ACE2 receptors, gut-lung axis, metabolomics, microbiomics, probiotics, diet

The aim of this work is to investigate 7 secrets of COVID-19 (fever, ACE2 receptors, gut-lung axis, metabolomics, microbiomics, probiotics, diet), hoping to reveal a small part of some of these and to increase anyhow the knowledge on SARS-CoV-2 and its weaknesses to be able to defeat it. In particular, in the opinion of the authors, significant improvements in contrasting the Coronavirus, and the pandemics that will follow, could derive from the use of “omics” disciplines, namely metabolomics (the stethoscope of the future) and microbiomics (an unrecognized player). The discovery of new biomarkers using metabolomics could be used in clinical practice as predictive diagnostic tools or to evaluate the effectiveness and toxicity of a drug, in order to be able to provide the patient with a personalized, tailor-made medicine: precision medicine. Our understanding of the role of the gut microbiome in COVID-19 infection remains in its infancy, but future research may potentially aid our understanding of viral infection, and create new ways in which we might treat and prevent it. We strongly believe that the 3 M's (Metabolomics, Microbiomics and Machine learning [Artificial Intelligence]) will be the right route to the future for risk assessment, early diagnosis, patient management and decision-making. By now, probiotics could help, fighting face to face against the virus. Moreover, the diet may be a key driver in determining the severity of COVID-19 and further studies are needed to explore the secret language between diet, bacteria, viruses and metabolites in determining individualized susceptibility or resilience to COVID-19. © 2021. All Rights Reserved.