Resilience of the oral microbiome

Abstract

The composition of the oral microbiome has been reviewed previously. 5 Representatives of the Bacteria, Archaea, fungi, protozoa and viruses are present. Recent studies have revealed major new branches of the Bacteria and Archaea. The Candidate Phyla Radiation group within the domain Bacteria may make up to half of bacterial life on earth and members of this group appear to be ubiquitous. 6,7 Interestingly, the organisms within this group studied thus far are small in size, typically passing through filters with a poresize diameter of 0.2 µm, and have small genomes which lack some genes encoding essential functions. 8 This makes them dependent on other bacteria for growth, either growing closely together in an epibiotic way or demonstrating frank parasitism by invading the cells of other bacteria. 9 Three Candidate Phyla Radiation candidate phyla are found in the mouth: Candidatus Saccharibacteria (originally described as Candidate Division TM7), Candidatus Absconditabacteria (SR1), and Candidatus Gracilibacteria (GN02).Representatives of Saccharibacteria have been cultivated in association with Actinomyces species. 9,10 An analogous group, the DPANN This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Microbiome and Cancers of the Esophagus: A Review

“…Given that some studies have identified networks of bacteria present in diseased states, it is possible that pathogenic bacteria are acting in consortia with other microorganisms to drive community-level shifts in the microbiome towards a diseased state. Due to the considerable overlap in the functional potential of bacterial species, some studies have suggested that a better understanding of disease etiology may be obtained by studying the functional activities of microbes, as opposed to attempting to identify a specific microbial composition related to disease [ 119 , 182 ]. Functional analyses are warranted in the future, using techniques in metabolomics, proteomics, metagenomics, and metatranscriptomics to study changes in functional profiles of the microbiome associated with EC.…”

“…Host genetics contribute in shaping the oral microbiome, but twin studies suggest environmental and lifestyle factors are the main drivers in shaping oral microbial communities [ 116 , 117 , 118 ]. Previous studies have examined the impact of various sociodemographic and lifestyle variables, including diet [ 119 ], geography [ 120 ], cohabitation [ 121 ], and race/ethnicity [ 120 , 122 ], but current evidence suggests these factors may only account for a small proportion of the inter-individual variation seen in the oral microbiome [ 103 ]. Perhaps one of the most important factors that modifies the oral microbiome is oral health [ 119 ].…”

“…Previous studies have examined the impact of various sociodemographic and lifestyle variables, including diet [ 119 ], geography [ 120 ], cohabitation [ 121 ], and race/ethnicity [ 120 , 122 ], but current evidence suggests these factors may only account for a small proportion of the inter-individual variation seen in the oral microbiome [ 103 ]. Perhaps one of the most important factors that modifies the oral microbiome is oral health [ 119 ]. Epidemiological evidence suggests poor oral health is linked to EC risk, and this relationship may involve alterations in the oral microbiome related to poor oral health conditions.…”

Impact of Oral Microbiota on Flavor Perception: From Food Processing to In-Mouth Metabolization

“…For example, alterations of the oral microbiota occur in individuals with diabetes. It has been suggested that an increase in blood glucose concentration in diabetic patients disrupts the homeostasis of the oral microbiota [ 28 ]. In obese patients, a significant decrease in microbial diversity has been observed in comparison with healthy individuals [ 29 ], while this difference was significantly less noticeable at the level of the gustatory papillae [ 5 ].…”

“…In xerostomia (dry mouth feeling) caused by Sjogren’s syndrome (altered salivary glands), an increase in infections caused by nonoral bacteria has been shown [ 30 ]. As saliva plays a key role in the maintenance of oral heath, a decreased salivary flow, and therefore reduced immune protection by saliva, likely explains this disorder [ 28 ].…”