The Predominant Oral Microbiota Is Acquired Early in an Organized Pattern

Abstract

The human oral cavity is sterile prior to birth, and we have limited knowledge of how complex oral communities are assembled. To examine bacterial acquisition and community assembly over the first year of life, oral samples from a cohort of nine infants and their mothers were collected, and bacterial community composition was studied by 16S rRNA gene sequencing. Exogenous species including skin and environmental bacteria were present initially, but were quickly replaced by a small, shared microbial community of species common to all infants and adults. Subsequent ordered microbial succession and the formation of increasingly complex communities was observed. By one year of age oral microbial community composition converged to a profile that was remarkably similar among children. The introduction of new nutrient sources, but not tooth eruption, was associated with increasing complexity. Infants had fewer species than mothers, mostly accounted for by the lack of certain anaerobes, and showing that the acquisition and assembly of oral microbial communities continues past infancy. When relative abundance was considered, a shared set of species accounted for the majority of the microbial community at all ages, indicating that the dominant structure of the oral microbiome establishes early, and suggesting that it persists throughout life.

Deep metagenomics examines the oral microbiome during dental caries, revealing novel taxa and co-occurrences with host molecules

“…In a recent study, Rothia dentocariosa and Rothia aeria were associated with good dental health (31), while in another study R. dentocariosa was associated caries (56), indicating that the role of this genera in caries development remains nebulous. The genera Rothia, Neisseria, and Haemophilus were recently documented to be important mediators of cell-cell interactions within the early biofilm derived from healthy individuals (57), are among the first colonizers of the oral cavity after birth (58), and they were indeed largely health-associated in this study. As with Rothia, Prevotella spp.…”

Cyclic Di-adenosine Monophosphate Regulates Metabolism and Growth in the Oral Commensal Streptococcus mitis

“…Streptococcus mitis ( S. mitis ) is one of the predominant members of the oral microbiota of healthy individuals [ 26 ]. It colonizes most surfaces of the oral cavity [ 26 ], and a commensal relationship is established between S. mitis and the host early in life [ 27 ]. However, S. mitis is an opportunistic pathogen that can invade the circulatory system and is commonly associated with gram-positive bacteremia in immune compromised individuals and in infective endocarditis [ 28 , 29 , 30 ].…”

The relationship between cigarette smoking and the tongue microbiome in an East Asian population

“…Oral microbiomes were reported to have ethnicityspecific signatures in another study [7], and genetic variations of the host were reported to influence oral microbiomes' structure [8,9]. In addition, the predominant oral microbiota were reported to be acquired early and persist through life [10]. Therefore, the effect of cigarette smoking on the overall oral microbiome structure could vary depending on geographic or ethnicity background.…”