Oral Microbiome In Children Research Articles

The oral microbiome of children in health and disease-a literature review.

The oral microbiome is a complex community of microorganisms residing in the oral cavity interacting with each other and with the host in a state of equilibrium. Disruptions in this balance can result in both oral and systemic conditions. Historically, studying the oral microbiome faced limitations due to culture-dependent techniques that could not capture the complexity and diversity of the microbial community. The emergence of advanced genomic technologies and the ease of sample collection from the oral cavity has revolutionized the understanding of the oral microbiome, providing valuable insights into the bacterial community in both health and disease. This review explores the oral microbiome in children, discussing its formation and dynamics in both states of health and disease, its role in various conditions such as dental caries, periodontal disease, oral cancer, cleft lip and palate, and explores its connection to several systemic consequences.

Characterization of the unique oral microbiome of children harboring Helicobacter pylori in the oral cavity

ABSTRACT Objective Helicobacter pylori infection is acquired in childhood via the oral cavity, although its relationship with the characteristics of the oral microbiome has not been elucidated. In this study, we performed comprehensive analysis of the oral microbiome in children and adults with or without H. pylori in the oral cavity. Methods Bacterial DNA was extracted from 41 adult and 21 child saliva specimens, and H. pylori was detected using PCR. 16S rRNA gene amplification was performed for next-generation sequencing. Bioinformatic analyses were conducted using Quantitative Insights into Microbial Ecology 2 (QIIME 2). Results Faith’s phylogenetic diversity analysis showed a significant difference between H. pylori-negative adult and child specimens in terms of α-diversity (p < 0.05), while no significant difference was observed between H. pylori-positive adult and child specimens. There was also a significant difference in β-diversity between H. pylori-positive and negative child specimens (p < 0.05). Taxonomic analysis at the genus level revealed that Porphyromonas was the only bacterium that was significantly more abundant in both H. pylori-positive adults and children than in corresponding negative specimens (p < 0.01 and p < 0.05, respectively). Conclusion These results suggest unique oral microbiome characteristics in children with H. pylori infection in the oral cavity.

The Bacterial Oral Microbiome in Children with Congenital Heart Disease: An Extensive Review.

Children with congenital heart disease have poorer oral health compared with healthy children. Oral diseases, such as dental caries and gingivitis, are associated with the oral microbiome. The objective of this review was to find evidence of differences in the bacterial colonization of the oral cavity of children with congenital heart disease (CHD) versus healthy children. A literature review was conducted according to predetermined criteria, including the need for controlled clinical trials. Half of the 14 studies that met the inclusion criteria reported significant differences in bacterial colonization in children with congenital heart disease. A variety of influencing factors were discussed. There is some evidence for alterations in the oral microflora as a result of physiopathological and treatment-related factors in children with CHD, but additional research is required to validate these findings.

Microbial Indicators of Dental Health, Dysbiosis, and Early Childhood Caries

Dental caries lesions are a clinical manifestation of disease, preceded by microbial dysbiosis, which is poorly characterized and thought to be associated with saccharolytic taxa. Here, we assessed the associations between the oral microbiome of children and various caries risk factors such as demographics and behavioral and clinical data across early childhood and characterized over time the salivary and dental plaque microbiome of children before clinical diagnosis of caries lesions. Children (N = 266) were examined clinically at ~1, 2.5, 4, and 6.5 y of age. The microbiome samples were collected at 1, 2.5, and 4 y. Caries groups consisted of children who remained caries free (International Caries Detection and Assessment System [ICDAS] = 0) at all time points (CFAT) (n = 50); children diagnosed with caries (ICDAS ≥ 1) at 6.5 y (C6.5), 4 y (C4), or 2.5 y of age (C2.5); and children with early caries or advanced caries lesions at specific time points. Microbial community analyses were performed on zero-radius operational taxonomic units (zOTUs) obtained from V4 of 16S ribosomal RNA gene amplicon sequences. The oral microbiome of the children was affected by various factors, including antibiotic use, demographics, and dietary habits of the children and their caregivers. At all time points, various risk factors explained more of the variation in the dental plaque microbiome than in saliva. At 1 y, composition of saliva of the C4 group differed from that of the CFAT group, while at 2.5 y, this difference was observed only in plaque. At 4 y, multiple salivary and plaque zOTUs of genera Prevotella and Leptotrichia were significantly higher in samples of the C6.5 group than those of the CFAT group. In conclusion, up to 3 y prior to clinical caries detection, the oral microbial communities were already in a state of dysbiosis that was dominated by proteolytic taxa. Plaque discriminated dysbiotic oral ecosystems from healthy ones better than saliva.

The potential impact of delivery mode and breastfeeding on oral Candida species carriage in a population of young adults.

In early life, children are exposed to microorganisms from maternal and environmental sources, which influence the development of their microbiome throughout life. Several studies have demonstrated the influence of the delivery mode and breastfeeding on the oral microbiome of children, mostly regarding bacterial colonization. However, their influence on the oral fungal carriage is still underexplored. This study aimed to assess the association of the delivery and feeding mode with the oral carriage of yeasts in adulthood. Fungal oral carriage was evaluated by collecting unstimulated saliva in 185 healthy dental students (mean age of 21.51±1.55 years old; 81.6% females). Yeast identification was performed by culture in ChromAgar Candida medium and sequencing of the 18S genes and ITS regions for determination of the species. Demographic and clinical data of each participant was recorded through questionnaires and oral examinations were performed in a subgroup of participants (n=49). Candida species were isolated in 37.5% of all participants. The prevalence of yeasts in the oral cavity was significantly higher in those who were born by vaginal delivery compared to those born by caesarean-section (p=0.035), whereas no statistically significant differences were observed regarding breastfeeding (p=0.398). Low salivary flow rate and frequency of dental visits also were associated with oral yeast carriage (p<0.05). Our study suggests a possible impact of the type of delivery on fungal colonization, which is sustained throughout life due to oral health-related factors.

Editorial: The development of the oral microbiome in children

Editorial: The development of the oral microbiome in children

Salivary microbiome in children with Down syndrome: a case-control study

BackgroundDown syndrome (DS), a most frequently occurring genetic disorder, is associated with oral morphological abnormalities and higher incidence rates of oral diseases. Recent studies have analyzed the oral microbiome to elucidate their relationships with oral diseases and general health; however, reports on the oral microbiome in individuals with DS are scarce. This study aimed to characterize the oral microbiome in children with DS.MethodsA total of 54 children aged 1–13 years were enrolled in this case-control study. Of these children, 27 had DS (Case: DS group) and 27 were age-matched healthy children (Control: ND group). Saliva in the oral cavity was collected with a swab, cultured, and tested for cariogenic and periodontopathic bacteria by quantitative polymerase chain reaction (qPCR) detection, and the salivary microbiome was analyzed using next-generation sequencing. The student’s t-test, Fisher’s exact test, Mann–Whitney U test, and permutational multivariate analysis of variance were used for statistical analysis.ResultsResults of culture and qPCR detection tests for cariogenic and periodontopathic bacteria showed no significant differences in the detected bacteria between the DS and ND groups, with the exception of a significantly higher detection rate of Candida albicans in children with DS with mixed dentition. A comparison of the salivary microbiomes by 16S sequencing showed no significant difference in α diversity; however, it showed a significant difference in β diversity. Children with DS had a higher relative abundance of Corynebacterium and Cardiobacterium, and lower relative abundance of TM7.ConclusionsThis study provided basic data on the salivary microbiome of children with DS and showed the microbiological markers peculiar to children with DS. However, further research to identify the relationship with oral diseases is warranted.

Characterization of the unique oral microbiome of children with Down syndrome

Down syndrome creates an abnormal oral environment, including susceptibility to periodontal disease at a young age, but there are no detailed studies of the oral microbiome in children with Down syndrome. In this study, we performed a comprehensive analysis of the oral bacteria of 40 children with Down syndrome and 40 non-Down syndrome children. Microbial DNA was extracted from dental plaque specimens and the V4 hypervariable region of the bacterial 16S rRNA gene was analyzed using the MiSeq platform. There were significant differences between the Down syndrome and non-Down syndrome groups in mean numbers of operational taxonomic units, and α- and β-diversity (P < 0.05). Interestingly, significant differences in α- and β-diversity between the two groups were only observed in subjects with gingival inflammation, but not in those without gingival inflammation (P < 0.05). Taxonomic analysis at the genus or species levels showed significant differences in relative abundance levels of certain bacteria between the Down syndrome and non-Down syndrome groups, including Corynebacterium, Abiotrophia and Lautropia (P < 0.05). These results suggest that children with Down syndrome may have a unique oral microbiome that could impact the development of dental diseases common in people with the syndrome.

Editorial: The development of the oral microbiome in children

Editorial: The development of the oral microbiome in children

Oral microbiome in children with dystrophic recessive epidermolysis bullosa

Was to assess bacterial load in oral wounds in children with recessive dystrophic epidermolysis bullosa (RDEB). The study comprised 77 RDEB children aged 3-18 years (mean age 9.5±3.6 years) and 27 healthy children aged 4-18 years (mean age 9.8±4.1 years) who served as controls. Swabs for bacteriological study were taken from the oral wounds in RDEB patients and non-affected corresponding oral mucosa areas in controls. The microorganism growth was assessed after 24, 48 and 72 hours of incubation (37 °C and 30 °C) with subsequent identification in automatic bacteriological analyzer MicroScan Walk Away (Simens, USA). Results. The study revealed high prevalence and concentrations of Candida albicans (in 40.3% children), Staphilococcus aureus (23.4%), Enterobacter cloacae (9.1%), and Enterobacteria (10.4%) in RDEB children. From these species, only Candida albicans was present in controls (26%). The prevalence and concentration of commensal and pathogenic species correlated positively with age and significant difference was revealed between children at the age of 3-6 and 7-10 years (p=0.001). Thus, bacterial load in oral wounds correlates with the RDEB natural history and fibrosis progression. Delayed oral wound healing was associated with microbiome shift towards biofilm-producing bacteria Staphilococcus aureus and Enterobacter cloacae. Oral wounds microbiome may be an indicator of RDEB severity and tendency to oral fibrosis. The decrease of bacterial load in the oral wounds may remove one of the healing obstacles and serve as fibrosis prevention measure.

Results from apilot study on the oral microbiome in children and adolescents with chronic nonbacterial osteomyelitis.

To analyze the composition of the oral microbiome in children and adolescents with chronic nonbacterial osteomyelitis (CNO) with respect to age distribution, gender differences, effects of medication, disease activity and the influence of body site. The oral microbiome of 20patients (12male and 8female; median age 10.3years) and 36controls were examined. Two different sites of the oral cavity were swabbed at two time points. Current medication and disease activity were evaluated and registered at these time points. Samples were subjected to amplicon sequencing of the V4 region of the 16S rRNA gene and Qiime2 was used to calculate alpha and beta diversity for multiple alternative metrics. On the basis of relative abundances of 975 different suboperational taxonomic units in high throughput next generation sequencing, asignificant shift in the composition of the oral microbiome (p < 0.02) was observed among patients being treated with different medications. There was asignificant difference in bacterial communities between the group aged 3-8 years old and the group aged 9-14years old. Significant differences were also seen in bacterial colonization on different sites in the oral cavity, but not with respect to gender or disease activity. We present first data of apilot study of the oral microbiome in children and adolescents with CNO, arare autoinflammatory bone disease. Differences of the oral microbiome of diseased children to normal adult controls revealed apossible role of the oral microbiome as modulatory target or biomarker in CNO.

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

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. 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. 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. 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.

THE OROPHARYNX MICROBIOME PROFILE OF CHILDREN WITH INFECTIOUS MONONUCLEOSIS EPSTEIN-BARR VIRAL ETIOLOGY

Relevance. The microbiota of the oral cavity is individual and the consistency of its composition provides a protective function that is regulated by the immune system. Dysbiotic changes in the oral microbiota composition lead to a devastation of local immunity and provide to the disease's development. Herpes virus infection аctivation suppresses the immune response which increases the level of oral mucosa bacteria colonization in particular during the acute course of infectious mononucleosis (IM).&#x0D; Objective: to study the features of the oral microbiome composition and its sensitivity to antibacterial drugs in patients with infectious mononucleosis and acute tonsillitis.&#x0D; Materials and methods. We examined 306 children aged 7 to 236 months. The main group (n = 280) – children with IM. Comparison group (n = 26) – children diagnosed with acute tonsillitis. The main group was divided into two subgroups: subgroup I – 234 children with MI caused by the Epstein-Barr virus (EBV), and subgroup II – 46 children with co-infection with the EBV virus and cytomegalovirus (CMV). The examination was performed according to the treatment protocol: general and biochemical analysis of blood, determination of IgM antibodies to Epstein-Barr virus and cytomegalovirus, bacteriological examination of oropharyngeal mucus, followed by determination of the sensitivity of the identified pathogens to antibacterial drugs.&#x0D; The results. In oral microbiome of children with IM caused by EBV and CMV co-infection pneumococcus dominant. In children with acute tonsillitis, Staphylococcus aureus, S. pyogenes infection, and yeast-like fungi were predominant. S. pyogenes, in children with co-infection, has a high level of resistance to β-lactam antibiotics. Higher levels of antibiotic-resistant strains were found among Enterococcus spp. Isolates, especially in children with EBV-induced MI and co-infection of EBV and CMV.&#x0D; Conclusions. The development of MI is accompanied by microecological dysbiosis of the mucous membranes of the oropharynx and tonsils, which do not provide enough level of colonization resistance, contributing to the spread of antibiotic resistance among resident and transient microbiota.

The impact of caries status on supragingival plaque and salivary microbiome in children with mixed dentition: a cross-sectional survey

BackgroundSupragingival plaque and saliva are commonly used for microbiome analysis. Many epidemiological studies have identified deciduous teeth caries as a risk factor for caries development in first permanent molar (FPM); nevertheless, to the best of our knowledge, there are no reports on the effects of deciduous teeth caries on the microbiome of healthy FPM. Additionally, it remains unclear whether saliva can be used instead of supragingival plaque for caries microbial studies. Therefore, we aimed to elucidate this issue, and to characterize and compare the oral microbiome of healthy FPMs in children with different caries statuses and that from children with and without caries in a similar microhabitat, by PacBio sequencing. Currently, few studies have investigated the oral microbiome of children using this technique.MethodsThirty children (aged 7–9 years) with mixed dentition were enrolled; 15 had dental caries, and 15 did not. Supragingival plaques of deciduous molars and maxillary FPMs, and non-stimulating saliva samples were collected. DNA was extracted and the v1–v9 regions of 16S rRNA were amplified. Subsequently, PacBio sequencing and bioinformatic analyses were performed for microbiome identification.ResultsThe microbial alpha diversity of the saliva samples was lower than that of the supragingival plaque (p < 0.05); however, no differences were detected between deciduous teeth and FPMs (p > 0.05). In addition, the alpha and beta diversity of children with and without caries was also similar (p > 0.05). Nonmetric multidimensional scaling and Adonis analyses indicated that the microbial structure of salivary and supragingival plaque samples differ (p < 0.05). Further analysis of deciduous teeth plaque showed that Streptococcus mutans, Propionibacterium acidifaciens, and Veillonella dispar were more abundant in children with caries than in those without (p < 0.05); while in FPMs plaque, Selenomonas noxia was more abundant in healthy children (p < 0.05). No differences in microorganisms abundance were found in the saliva subgroups (p > 0.05).ConclusionWe have determined that supragingival plaque was the best candidate for studying carious microbiome. Furthermore, S. mutans, V. dispar, and P. acidifaciens were highly associated with deciduous teeth caries. S. noxia may be associated with the abiding health of FPM; however, this requires additional studies.

The Oral Microbiome in Children with Black Stained Tooth

Black stain (BS) is a characteristic extrinsic discoloration, which occurs along the third cervical line of the buccal and/or lingual surfaces of teeth, particularly in the primary dentition of humans. BS is produced by oral bacteria and byproducts of saliva, but there is a controversy about related bacteria. The aim of this study was to identify the oral microbiome in tooth BS using pyrosequencing. It was hypothesized that the oral microbiome of BS in children might be related to black-pigment producing bacteria. Supragingival dental plaque was obtained from six children (mean 8.1 years) with BS and four children (mean 8.3 years) without BS. The bacterial metagenome was obtained by pyrosequencing. The BS group contained 348 operative taxonomic units (OTUs), whereas the control group had 293 OTUs. Microbial abundance and diversity were significantly higher in the BS group (p &lt; 0.05). In the heatmap, the correlation between samples was the same as the BS scale. At the genus level, six genera—Abiotrophia, Eikenella, Granulicatella, Neisseria, Porphyromonas and Streptococcus—were significantly different between the two groups (p &lt; 0.05). We suggested that compositional changes in the oral microbiome are essential, and several species in the genus Neisseria, Porphyromonas and Streptococcus may be major contributors for BS formation. Although the number of subjects was relatively limited, our study is the first species-level analysis of pyrosequencing data in BS formation.

Oral Microbiome in Children with Caries: A Systematic Review

Oral caries remains a significant public health problem and affects children with early childhood caries (ECC) and severe early childhood caries (S-ECC). However, the mechanisms of these complex multi-species communities are not well understood. This article systematically reviews the studies involving children with caries to learn the demographics of the subjects, their subjects and types of sample, the methodological approaches undertaken, the main findings, and eventually to make recommendations for future research. A search using a designated search string in the Web of Science resulted in 148 articles. A careful examination of each article based on the inclusion criteria resulted in a final 40 articles. Most of the studies were conducted in the United States and China. The studies involved mostly, but not exclusively, children with primary dentition and were having caries. Different types of subjects were sampled from different racial backgrounds and diseases. Different samples were collected, such as supragingival plaque, saliva and biofilm. Clonal analyses and anaerobic approaches were used to characterise the oral microbiome, including shotgun sequencing, pyrosequencing of 16S rRNA genes, and Pacbio sequencing. Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria were among the phyla commonly reported by the studies. Streptococcus mutans was a key aetiologic agent in the development of caries, besides Veillonella, Prevotella spp. and Lactobacillus spp. Some studies developed models and discussed the applications of oral microbiome in relation to diseases. We recommend further reviews on studies strictly on children with caries and studies involving children only for a better generalisation of the findings. More studies relating oral microbiome with dietary intake and other diseases can also be conducted.

Associations of the Oral Microbiota with Obesity and Menarche in Inner City Girls.

Alterations of the oral microbiome have been associated with obesity, possibly based on inflammatory processes mediated by bacteria. Specific bacterial strains have been associated with obesity and periodontal disease. Little is known about the oral microbiome in children. Understanding the relationship between oral health and childhood growth could help identify preventable factors contributing to obesity and related conditions, including onset of menarche which is associated with obesity. In this pilot study, we investigated the saliva microbiome among 25 girls 7-15 years old (mean 11.1) and their mothers in an inner city dental clinic in New York City. The main outcome measures were body size, presence or absence of menarche and dental practices. We examined associations of microbiome richness, diversity, and relative abundance with pubertal and demographic factors and oral health. Girls had good dental health and a typical rich oral microbiome, based on the Shannon Index of all species detected. Older girls flossed more often and younger girls had more frequent dental check-ups. Microbiome richness among girls was similar to their mothers', but diversity was greater among mothers than girls. Richness was reduced among mothers with gum bleeding, flossing and increased teeth brushing. Overweight girls had greater diversity and less richness than normal weight girls. Certain bacterial species differed in abundance with respect to whether girls had reached menarche (Flavobacteria, Actinobacteria), overweight (Megasphaera, Lactorbacillales, Lactobacillus) and gingivitis in the girls (Scardovia, Bifidobacteriales, Gemellaceae). Differences found in specific bacteria in the oral microbiome were related to body size and menarche. With increasing interest on studying microbiome variability related to the multifactorial etiology of obesity in children, saliva is capable of providing clinically informative markers of this and related conditions.

Associations of the Oral Microbiota with Obesity and Menarche in Inner City Girls

Objective: Alterations of the oral microbiome have been associated with obesity, possibly based on inflammatory processes mediated by bacteria. Specific bacterial strains have been associated with obesity and periodontal disease. Little is known about the oral microbiome in children. Understanding the relationship between oral health and childhood growth could help identify preventable factors contributing to obesity and related conditions, including onset of menarche which is associated with obesity. Methods: In this pilot study, we investigated the saliva microbiome among 25 girls 7-15 years old (mean 11.1) and their mothers in an inner city dental clinic in New York City. The main outcome measures were body size, presence or absence of menarche and dental practices. We examined associations of microbiome richness, diversity, and relative abundance with pubertal and demographic factors and oral health. Results: Girls had good dental health and a typical rich oral microbiome, based on the Shannon Index of all species detected. Older girls flossed more often and younger girls had more frequent dental check–ups. Microbiome richness among girls was similar to their mothers’, but diversity was greater among mothers than girls. Richness was reduced among mothers with gum bleeding, flossing and increased teeth brushing. Overweight girls had greater diversity and less richness than normal weight girls. Certain bacterial species differed in abundance with respect to whether girls had reached menarche (Flavobacteria, Actinobacteria), overweight (Megasphaera, Lactorbacillales, Lactobacillus) and gingivitis in the girls (Scardovia, Bifidobacteriales, Gemellaceae). Conclusions: Differences found in specific bacteria in the oral microbiome were related to body size and menarche. With increasing interest on studying microbiome variability related to the multifactorial etiology of obesity in children, saliva is capable of providing clinically informative markers of this and related conditions.

The Oral Microbiome of Children: Development, Disease, and Implications Beyond Oral Health.

In the era of applied meta-omics and personalized medicine, the oral microbiome is a valuable asset. From biomarker discovery to being a powerful source of therapeutic targets and to presenting an opportunity for developing non-invasive approaches to health care, it has become clear that oral microbes may hold the answer for understanding disease, even beyond the oral cavity. Although our understanding of oral microbiome diversity has come a long way in the past 50years, there are still many areas that need to be fine-tuned for better risk assessment and diagnosis, especially in early developmental stages of human life. Here, we discuss the factors that impact development of the oral microbiome and explore oral markers of disease, with a focus on the early oral cavity. Our ultimate goal is to put different experimental and methodological views into perspective for better assessment of early oral and systemic disease at an early age and discuss how oral microbiomes-at the community level-could provide improved assessment in individuals and populations at risk.

The Oral Bacterial Communities of Children with Well-Controlled HIV Infection and without HIV Infection.

The oral microbial community (microbiota) plays a critical role in human health and disease. Alterations in the oral microbiota may be associated with disorders such as gingivitis, periodontitis, childhood caries, alveolar osteitis, oral candidiasis and endodontic infections. In the immunosuppressed population, the spectrum of potential oral disease is even broader, encompassing candidiasis, necrotizing gingivitis, parotid gland enlargement, Kaposi’s sarcoma, oral warts and other diseases. Here, we used 454 pyrosequencing of bacterial 16S rRNA genes to examine the oral microbiome of saliva, mucosal and tooth samples from HIV-positive and negative children. Patient demographics and clinical characteristics were collected from a cross-section of patients undergoing routine dental care. Multiple specimens from different sampling sites in the mouth were collected for each patient. The goal of the study was to observe the potential diversity of the oral microbiota among individual patients, sample locations, HIV status and various dental characteristics. We found that there were significant differences in the microbiome among the enrolled patients, and between sampling locations. The analysis was complicated by uneven enrollment in the patient cohorts, with only five HIV-negative patients enrolled in the study and by the rapid improvement in the health of HIV-infected children between the time the study was conceived and completed. The generally good oral health of the HIV-negative patients limited the number of dental plaque samples that could be collected. We did not identify significant differences between well-controlled HIV-positive patients and HIV-negative controls, suggesting that well-controlled HIV-positive patients essentially harbor similar oral flora compared to patients without HIV. Nor were significant differences in the oral microbiota identified between different teeth or with different dental characteristics. Additional studies are needed to better characterize the oral microbiome in children and those with poorly-controlled HIV infections.