Relationship between Campylobacter rectus and periodontal status during pregnancy

Metabarcoding analysis of oral microbiome during pregnancy

Pregnancy is a dynamic physiological process involving significant hormonal, immune, and metabolic changes to support fetal growth and development. This study investigates the changes in salivary microbiome and biochemical markers from the second to the third trimester of pregnancy. Saliva samples were collected from 45 pregnant women enrolled in the Qatar Birth Cohort study at two time points (second and third trimesters). DNA was extracted and subjected to 16S rRNA gene sequencing using Oxford Nanopore Technology. Microbial diversity and taxonomic analyses were performed, along with correlation analyses between microbial abundance and clinical parameters. Biochemically, significant increases in BMI, pulse rate, HbA1c, LDL, total cholesterol, and triglycerides were observed in the third trimester compared to the second. Microbial diversity analysis revealed significant changes in microbial richness and composition. Taxonomy analysis showed a significant 3-fold increase in Bacteroidota. Also, a significant decline in Selenomonas and a significant increase in Veillonella, specifically Veillonella dispar and Veillonella atypica, as well as an increase in Granulicatella were observed in the third trimester, along with a significant decrease in Streptococcus sanguinis. Correlation analysis during the second trimester revealed positive associations between BMI, cholesterol, LDL, and Selenomonas, and negative correlations with Streptococcus and Gemella. In the third trimester, BMI was negatively correlated with Campylobacter, glucose levels were negatively correlated with Neisseria, and triglyceride levels were negatively correlated with Prevotella. These findings highlight significant biochemical and microbial shifts during pregnancy, underscoring the importance of monitoring oral health and metabolic changes in pregnant women.

Supragingival microbiome variations and the influence of Candida albicans in adolescent orthodontic patients with gingivitis

Introduction

Gingivitis is a prevalent complication in adolescents undergoing fixed orthodontic treatments. However, changes in the supragingival microbiome associated with gingivitis and the impact of Candida albicans remain elusive. Therefore, we investigated supragingival microbiome discrepancy and C. albicans colonization in adolescent orthodontic patients with gingivitis.

Methods

Dental plaques were collected from 30 gingivitis patients and 24 healthy adolescents, all undergoing fixed orthodontic treatment. The supragingival microbiome composition was analyzed using 16S rRNA sequencing. C. albicans colonization was determined using fungal culture and real-time quantitative polymerase chain reaction.

Results

Our analysis revealed significantly heightened microbial diversity in the Gingivitis group. Notably, patients with gingivitis exhibited an enrichment of periodontal pathogens, such as Saccharibacteria (TM7) [G-1], Selenomonas, Actinomyces dentalis, and Selenomonas sputigena. Additionally, 33% of the gingivitis patients tested positive for C. albicans, exhibiting significantly elevated levels of absolute abundance, while all healthy patients tested negative. Significant differences in microbial composition were also noted between C. albicans-positive and -negative samples in the Gingivitis group.

Conclusion

Significant disparities were observed in the supragingival microbiome of adolescent orthodontic patients with and without gingivitis. The presence of C. albicans in the supragingival plaque may alter the microbiome composition and potentially contribute to gingivitis pathogenesis.

Dynamic Changes in Intestinal Gene Expression and Microbiota across Chicken Egg-Laying Stages

Eggs are a vital dietary component for humans, and it is beneficial to increase egg production to support poultry farming. Initially, the egg production rate rises rapidly with young hens until it reaches its peak, and then it declines gradually. By extending the duration of peak egg production, the hens' performance can be enhanced significantly. Previous studies found dynamic changes in gut microbiota during egg-laying, and several species of microbiota isolated from the chicken gut improved egg-laying performance. However, the interaction between microbes and host gene expression is still unclear. This study provides a more comprehensive understanding of chicken egg-laying by examining dynamic alterations in the microbiota of the entire intestinal tract (i.e., duodenum, jejunum, and ileum) and gene expression. The microbial community in the intestine underwent significant changes during different egg-laying periods (i.e., pre-, peak-, and late-laying periods). Metagenomic functional analysis showed that the relative abundance of biosynthesis of amino acids, secondary metabolites, and cofactors decreased significantly in the duodenum, jejunum, and ileum of aging hens. The relative levels of aldosterone, GnRH, insulin, growth hormone, and other hormone-related pathways increased dramatically in the intestinal microbiota during egg-laying, but only in the microbiota located in the duodenum and ileum. Transcriptome analysis suggested that genes associated with various transport processes were upregulated consistently in the small intestine during egg-laying; genes involved in the development of intestinal structure were down-regulated; and genes involved in response to DNA damage and stress were consistent with changes in laying rate. The abundance of Lactobacillus was related to the expression of ANGPTRL1, ANGPTRL2, ANGPT1L, and NOXO1 in the duodenum; Muricomes was correlated significantly with NFKBIZ, LYG2, and IRG1L expression in the jejunum; and Campylobacter was correlated positively with the expression of KMT2A and USF3 in the ileum. These results indicated that the intestinal microbiota and host gene expression may influence egg production jointly.

Identification of the specific microbial community compositions in saliva associated with periodontitis during pregnancy

OBJECTIVE

To identify the specific microbial community compositions in saliva associated with periodontitis during pregnancy.

MATERIALS AND METHODS

Unstimulated saliva samples were collected from 53 pregnant women during weeks 24-28 of gestation, and the V3-V4 regions of the 16S rRNA gene were amplified from isolated saliva DNA and sequenced. Phylum-, genus-, and species-level taxonomic compositions were separately compared between subjects with (n = 12) and without (n = 41) periodontitis.

RESULTS

Taxa were selected using the random forest algorithm to distinguish subjects with periodontitis at each taxonomic level, and principal component biplots were constructed to visualize the composition of selected taxa in each subject. The genus-level biplot indicated that 44 subjects clustered around the origin. The prevalence of periodontitis was significantly higher among subjects outside the cluster compared with subjects inside the cluster (6/9 [67%] vs. 6/44 [14%], respectively; p = 0.002). Subjects outside the cluster also had significantly decreased abundance of Neisseria and increased abundances of several putative periodontopathic genera. Phylum- and species-level biplots failed to discriminate subjects with periodontitis more efficiently than the genus-level biplot.

CONCLUSIONS

The specific taxonomic composition of the saliva microbiota in pregnant women with periodontitis could be clearly identified at the genus level.

CLINICAL RELEVANCE

The formula developed based on the present findings, (%Treponema + %Tannerella + %Filifactor + %Anaeroglobus)/%Neisseria, can be used to predict periodontitis during pregnancy with sensitivity and specificity values of 0.67 (8/12) and 0.95 (39/41), respectively.

Physiological Changes and Interactions Between Microbiome and the Host During Pregnancy

In recent years, it has become clear that microbiome play a variety of essential roles in human metabolism, immunity, and overall health and that the composition of these microbiome is influenced by our environment, diet, weight, hormones, and other factors. Indeed, numerous physiological and pathological conditions, including obesity and metabolic syndrome, are associated with changes in our microbiome, referred to as dysbiosis. As a result, it is not surprising that such changes occur during pregnancy, which includes substantial weight gain and significant changes in metabolism and immune defenses. The present review relates physiological changes during pregnancy to alterations in the microbial composition at various sites, including the gut, oral cavity, and vagina. Pregnancy has been linked to such microbial changes, and we believe that, in contrast to certain disease states, these microbial changes are vital for a healthy pregnancy, probably through their influence on the mother’s immunological, endocrinological, and metabolic status.

Clinical study showing a lower abundance of Neisseria in the oral microbiome aligns with low birth weight pregnancy outcomes

OBJECTIVES

The objective of this study was to examine the association between the oral microbiome and pregnancy outcomes, specifically healthy or preterm low birth weight (PLBW) in individuals with and without periodontal disease (PD).

MATERIAL AND METHODS

In this prospective clinical trial, we recruited 186 pregnant women, 17 of whom exhibited PD and delivered PLBW infants (PD-PLBW group). Of the remaining women, 155 presented PD and delivered healthy infants; 18 of these subjects with similar periodontal condition and age matched to the PD-PLBW group, and they became the PD-HD group. From the total group, 11 women exhibited healthy gingiva and had a healthy delivery (HD) and healthy infants (H-HD group), and 3 exhibited healthy gingiva and delivered PLBW infants (H-PLBW group). Periodontal parameters were recorded, and subgingival plaque and serum were collected during 26-28 gestational weeks. For the plaque samples, microbial abundance and diversity were accessed by 16S rRNA sequencing.

RESULTS

Women with PD showed an enrichment in the genus Porphyromonas, Treponema, and Filifactor, whereas women with healthy gingiva showed an enrichment in Streptococcus, Actinomyces, and Corynebacterium, independently of the birth status. Although no significant difference was found in the beta diversity between the 4 groups, women that had PLBW infants presented a significantly lower abundance of the genus Neisseria, independently of PD status.

CONCLUSION

Lower levels of Neisseria align with preterm low birth weight in pregnant women, whereas a higher abundance of Treponema, Porphyromonas, Fretibacterium, and Filifactor and a lower abundance of Streptococcus may contribute to periodontal disease during pregnancy.

CLINICAL RELEVANCE

The oral commensal Neisseria have potential in the prediction of PLBW.

Oral microbiome shifts during pregnancy and adverse pregnancy outcomes: Hormonal and Immunologic changes at play

Because of hormonal and immunologic changes, there are significant changes in the oral microbiome that emerge during pregnancy. Recent evidence further suggests that there is an association between the presence of periodontal disease and a pregnancy‐associated oral dysbiosis. Although this oral dysbiosis and pathogenic periodontal bacteria are considered to be associated with adverse pregnancy outcomes, it is still not clear how an oral dysbiosis during pregnancy can modulate oral diseases and birth outcomes. To develop preventive or therapeutic interventions, it is critical to understand the oral microbiome changes that emerge during pregnancy and their association with adverse pregnancy outcomes. In the present review, we summarize the current literature on normal changes in the oral microbiome that occur during pregnancy; the pathogenic changes in the oral microbiome believed to occur in association with adverse pregnancy outcomes; and the association between the placental microbiome and the oral microbiome.

Oral microflora and pregnancy: a systematic review and meta-analysis

Understanding changes in oral flora during pregnancy, its association to maternal health, and its implications to birth outcomes is essential. We searched PubMed, Embase, Web of Science, and Cochrane Library in May 2020 (updated search in April and June 2021), and conducted a systematic review and meta-analyses to assess the followings: (1) oral microflora changes throughout pregnancy, (2) association between oral microorganisms during pregnancy and maternal oral/systemic conditions, and (3) implications of oral microorganisms during pregnancy on birth outcomes. From 3983 records, 78 studies were included for qualitative assessment, and 13 studies were included in meta-analysis. The oral microflora remains relatively stable during pregnancy; however, pregnancy was associated with distinct composition/abundance of oral microorganisms when compared to postpartum/non-pregnant status. Oral microflora during pregnancy appears to be influenced by oral and systemic conditions (e.g. gestational diabetes mellitus, pre-eclampsia, etc.). Prenatal dental care reduced the carriage of oral pathogens (e.g. Streptococcus mutans). The Porphyromonas gingivalis in subgingival plaque was more abundant in women with preterm birth. Given the results from meta-analyses were inconclusive since limited studies reported outcomes on the same measuring scale, more future studies are needed to elucidate the association between pregnancy oral microbiota and maternal oral/systemic health and birth outcomes.

Pregnancy and Dentistry: A Literature Review on Risk Management during Dental Surgical Procedures

Background: Pregnancy is a unique moment in a woman’s life, accompanied with several physiologic changes that have an impact on oral health. Aim of the study: The purpose of the present study was to conduct a critical review of published literature regarding pregnancy and dentistry, the most frequent oral diseases that are encountered during pregnancy, their correlation to adverse pregnancy events, and safe dental treatments that can be performed during pregnancy. Methods: A Medline/COCHRANE search was carried using specific keywords and MeSH terms, combined with the boolean operators “OR” and “AND”. Results: The search led to 146 publications including guidelines, meta-analyses, systematic and non-systematic reviews, published between 2000 and 2021. Discussion and conclusions: Due to the increased inflammatory and immune body response that characterizes pregnancy, periodontal conditions are often aggravated during pregnancy and periodontal disease encountered frequently in pregnant patients. There are conflicting study results in the literature regarding the association between periodontitis and adverse pregnancy outcomes. Periodontal treatment did not show a significant reduction in the adverse outcomes. Many dentists, often due to lack of information, are reluctant to provide dental treatment to pregnant women. However, preventive and restorative dental treatment is safe during pregnancy. Diagnostic radiographs may be performed after the first trimester if absolutely necessary. Analgesics (such as paracetamol) and anesthetics (such as lidocaine) are also considered safe. In case of infection, antibacterial drugs such as amoxicillin, ampicillin, and some cephalosporines and macrolides can also be prescribed. Organogenesis takes place in the first trimester, the time during which the fetus is susceptible to severe malformations (teratogenesis). The ideal time to perform dental treatment is the second trimester (week 17 to 28). However, acute pain or infections make the intervention of the dentist absolutely necessary and emergency treatment can be performed during the whole pregnancy period.

Dysbiosis of the Human Oral Microbiome During the Menstrual Cycle and Vulnerability to the External Exposures of Smoking and Dietary Sugar

Physiological hormonal fluctuations exert endogenous pressures on the structure and function of the human microbiome. As such, the menstrual cycle may selectively disrupt the homeostasis of the resident oral microbiome, thus compromising oral health. Hence, the aim of the present study was to structurally and functionally profile the salivary microbiome of 103 women in reproductive age with regular menstrual cycle, while evaluating the modifying influences of hormonal contraceptives, sex hormones, diet, and smoking. Whole saliva was sampled during the menstrual, follicular, and luteal phases (n = 309) of the cycle, and the participants reported questionnaire-based data concerning their life habits and oral or systemic health. No significant differences in alpha-diversity or phase-specific clustering of the overall microbiome were observed. Nevertheless, the salivary abundances of genera Campylobacter, Haemophilus, Prevotella, and Oribacterium varied throughout the cycle, and a higher species-richness was observed during the luteal phase. While the overall community structure maintained relatively intact, its functional properties were drastically affected. In particular, 11 functional modules were differentially abundant throughout the menstrual cycle, including pentose phosphate metabolism, and biosynthesis of cobalamin and neurotransmitter gamma-aminobutyric acid. The menstrual cycle phase, but not oral contraceptive usage, was accountable for greater variations in the metabolic pathways of the salivary microbiome. Further co-risk factor analysis demonstrated that Prevotella and Veillonella were increased in current smokers, whereas high dietary sugar consumption modified the richness and diversity of the microbiome during the cycle. This is the first large study to systematically address dysbiotic variations of the oral microbiome during the course of menstrual cycle, and document the additive effect of smoking and sugar consumption as environmental risk factors. It reveals the structural resilience and functional adaptability of the oral microbiome to the endogenous hormonal pressures of the menstrual cycle, while revealing its vulnerability to the exogenous exposures of diet and smoking.

Oral microbiome and pregnancy: A bidirectional relationship

The oral cavity contains the second most complex microbial population within the human body, with more than 700 bacterial organisms. Recent advances in Next Generation Sequencing technology have unraveled the complexities of the oral microbiome and provided valuable insights into its role in health and disease. The human oral microbiome varies dramatically during the different stages of life, including pregnancy. The total viable microbial counts in pregnant women are known to be higher compared to non-pregnant women, especially in the first trimester of pregnancy. A balanced oral microbiome is vital for a healthy pregnancy, as perturbations in the oral microbiome composition can contribute to pregnancy complications. On the other hand, physiological changes and differences in hormonal levels during pregnancy, increase susceptibility to various oral diseases such as gingivitis and periodontitis. A growing body of evidence supports the link between the composition of the oral microbiome and adverse pregnancy outcomes such as preterm birth, preeclampsia, low birth weight among others. This review aims to summarize the dynamics of oral microbiome during pregnancy and to discuss the relationship between a dysbiotic oral microbiome and pregnancy complications.

Unculturable and culturable periodontal-related bacteria are associated with periodontal inflammation during pregnancy and with preterm low birth weight delivery

Recent studies revealed culturable periodontal keystone pathogens are associated with preterm low birth weight (PLBW). However, the oral microbiome is also comprised of hundreds of 'culture-difficult' or 'not-yet-culturable' bacterial species. To explore the potential role of unculturable and culturable periodontitis-related bacteria in preterm low birth weight (PLBW) delivery, we recruited 90 pregnant women in this prospective study. Periodontal parameters, including pocket probing depth, bleeding on probing, and clinical attachment level were recorded during the second trimester and following interviews on oral hygiene and lifestyle habits. Saliva and serum samples were also collected. After delivery, birth results were recorded. Real-time PCR analyses were performed to quantify the levels of periodontitis-related unculturable bacteria (Eubacterium saphenum, Fretibacterium sp. human oral taxon(HOT) 360, TM7 sp. HOT 356, and Rothia dentocariosa), and cultivable bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum and Prevotella intermedia) in saliva samples. In addition, ELISA analyses were used to determine the IgG titres against periodontal pathogens in serum samples. Subjects were categorized into a Healthy group (H, n = 20) and periodontitis/gingivitis group (PG, n = 70) according to their periodontal status. The brushing duration was significantly lower in the PG group compared to the H group. Twenty-two of 90 subjects delivered PLBW infants. There was no significant difference in periodontal parameters and serum IgG levels for periodontal pathogens between PLBW and healthy delivery (HD) groups. However, ordinal logistic regression analysis revealed that a higher abundance of Treponema denticola, Prevotella intermedia, Fretibacterium sp. HOT360 and lower levels of Rothia dentocariosa were significantly associated with the presence of periodontal disease during pregnancy. Moreover, the amount of Eubacterium saphenum in saliva and serum IgG against Aggregatibacter actinomycetemcomitans were negatively correlated with PLBW. Taken together, unculturable periodontitis-associated bacteria may play an important role both in the presence of periodontal inflammation during pregnancy and subsequent PLBW.

Effectiveness of an oral care tablet containing kiwifruit powder in reducing oral bacteria in tongue coating: A crossover trial

OBJECTIVES

The aim of this study was to investigate the effect of an oral care tablet containing kiwifruit powder on oral bacteria in tongue coating compared with tongue brushing.

MATERIAL AND METHODS

Thirty-two healthy, young adults were enrolled, and a crossover clinical trial was conducted. The volatile sulfur compound (VSC) concentration, Winkel tongue-coating index (WTCI), and the number of total bacteria in addition to Fusobacterium nucleatum in tongue coating were measured. We instructed subjects to remove tongue coating by tongue brush for Intervention I, to keep the oral care tablet containing kiwifruit powder on the tongue dorsum and to let it dissolve naturally for Intervention II, and three oral care tablets 1 day before the measurement for Intervention III.

RESULTS

There were significant differences in terms of the level of H2 S, VSC, and WTCI at Intervention I and all evaluation values at Intervention II. There were significant differences in terms of the level of H2 S, VSC, WTCI, the number of total bacteria, and F. nucleatum at Intervention III. The value of WTCI, the number of bacteria, and F. nucleatum decreased significantly after taking the oral care tablets than after tongue brushing. When compared with Interventions I and III, Intervention III showed the effective results; there were significant differences in the number of total bacteria and F. nucleatum between tongue brushing and taking tablets.

CONCLUSIONS

These results suggested that the oral care tablet containing kiwifruit powder could be effective in reducing total bacteria and F. nucleatum in tongue coating when compared with tongue brushing.

Correlation of periodontal and microbiological evaluations, with serum levels of estradiol and progesterone, during different trimesters of gestation

Our purpouse was to identify quantitatively and qualitatively the subgingival flora in different gestational trimesters, compared to non-pregnant women; evaluating the correlations between epidemiological characteristics, clinical diagnosis, microbiological findings and levels of estradiol and progesterone. 52 pregnant women divided into 3 groups, according to the gestational trimester and 15 non-pregnant patients, without hormonal contraceptives, were evaluated. Plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were evaluated. Subgingival biofilm samples were processed by the qPCR technique and the serum levels of estradiol and progesterone quantified by chemiluminescence. Clinical diagnosis during gestation was correlated with the total bacterial count. A higher prevalence of Tannerella forsythia (Tf) was identified in first trimester of pregnancy and this periodontopathogen was correlated with the diagnosis of gingivitis among pregnant women. Porphyromonas gingivalis (Pg) showed a positive correlation with progesterone levels in the first trimester. High prevalence of periodontopathogens was noticed in this population. Clinical diagnosis in gestation was positively correlated with the total amount of bacteria, without influence of the hormonal levels or the epidemiological factors evaluated. The presence of Tf favored occurrence of gingivitis during pregnancy and the progesterone levels in the first trimester enhanced the growth of Pg.

Keystone Species in Pregnancy Gingivitis: A Snapshot of Oral Microbiome During Pregnancy and Postpartum Period

It is well known that pregnancy is under the constant influence of hormonal, metabolic and immunological factors and this may impact the oral microbiota toward pregnancy gingivitis. However, it is still not clear how the oral microbial dysbiosis can modulate oral diseases as oral microbiome during pregnancy is very poorly characterized. In addition, the recent revelation that placental microbiome is akin to oral microbiome further potentiates the importance of oral dysbiosis in adverse pregnancy outcomes. Hence, leveraging on the 16S rRNA gene sequencing technology, we present a snapshot of the variations in the oral microbial composition with the progression of pregnancy and in the postpartum period and its association with pregnancy gingivitis. Despite the stability of oral microbial diversity during pregnancy and postpartum period, we observed that the microbiome makes a pathogenic shift during pregnancy and reverts back to a healthy microbiome during the postpartum period. Co-occurrence network analysis provided a mechanistic explanation of the pathogenicity of the microbiome during pregnancy and predicted taxa at hubs of interaction. Targeting the taxa which form the ecological guilds in the underlying microbiome would help to modulate the microbial pathogenicity during pregnancy, thereby alleviating risk for oral diseases and adverse pregnancy outcomes. Our study has also uncovered the possibility of novel species in subgingival plaque and saliva as the key players in the causation of pregnancy gingivitis. The keystone species hold the potential to open up avenues for designing microbiome modulation strategies to improve host health during pregnancy.

Pregnancy-induced periodontal inflammation: Influence of salivary cytokines and antimicrobial proteins

The aim of this study was to evaluate the association between pregnancy-induced periodontal inflammation and levels of some salivary cytokines and antimicrobial proteins (AMPs). The study was a cohort longitudinal study that included pregnant women attending a secondary health facility. Consented participants had oral examination and saliva sampling during pregnancy and post-partum (three months after pregnancy). Saliva samples were used for the analysis of cytokines (TNF-α, IFN-gamma and IL-1β) and AMPs (Lactoferin, Lysozyme, and β defensin-1) using ELISA. Data are presented as median with interquartile range and compared using related sample Wilcoxon signed rank test. Correlations between levels of the salivary factors and indices of periodontal inflammation were determined using Spearman’s correlation test. Salivary flow rate, pH, levels of salivary IL-1β and IFN-gamma were significantly lower; while gingival index, periodontal index and level of salivary TNF-α were significantly higher during pregnancy compared with postpartum period. However, salivary lactoferin, lysozyme and β defensin-1 did not show significant difference comparing during pregnancy and postpartum period. Level of salivary IFN-gamma showed negative correlation with gingival index while level of salivary TNF-α showed positive correlation with gingival and periodontal indices. Lower levels of salivary IL-1β and IFN-gamma along with higher TNF-α concentration during pregnancy suggest their contributions to the pathophysiology of pregnancy-induced periodontal inflammation.

Periodontal diseases and adverse pregnancy outcomes: Is there a role for vitamin D?

Studies have shown a relationship between maternal periodontal diseases (PDs) and premature delivery. PDs are commonly encountered oral diseases which cause progressive damage to the periodontal ligament and alveolar bones, leading to loss of teeth and oral disabilities. PDs also adversely affect general health by worsening of cardiovascular and metabolic diseases. Moreover, maternal PDs are thought to be related to increasing the frequency of preterm-birth with low birth weight (PBLBW) in new-borns. Prematurity and immaturity are the leading causes of prenatal and infant mortality and is a major public health problem around the world. Inflamed periodontal tissues generate significantly high levels of proinflammatory cytokines that may have systemic effects on the host mother and the fetus. In addition, the bacteria that cause PDs produce endotoxins which can harm the fetus. Furthermore, studies have shown that microorganisms causing PDs can get access to the bloodstream, invading uterine tissues, to induce PBLBW. Another likely mechanism that connects PDs with adverse pregnancy outcome is maternal vitamin D status. A role of inadequate vitamin D status in the genesis of PDs has been reported. Administration of vitamin D supplementation during pregnancy could reduce the risk of maternal infections and adverse pregnancy outcomes. As maternal PDs are significant risk factors for adverse pregnancy outcome, preventive antenatal care for pregnant women in collaboration with the obstetric and dental professions are required.

Pregnancy, parity and periodontal disease

Many women believe that their dental condition deteriorated during pregnancy or as a result of having children. Epidemiological studies have reported an association between higher parity and tooth loss, and higher parity and periodontal attachment loss. Several possible explanations for this association exist. First, hormonal changes during pregnancy affect the immune response to bacterial plaque and drive vascular and gingival changes that may contribute to heightened gingival inflammation. These changes are transient, without irreversible loss of periodontal attachment, and post-partum resolution can be expected for most women. For women with destructive periodontal disease, the effects of pregnancy and parity are unclear. Second, it is also plausible that parity and socioeconomic position (SEP) have shared risk factors, increasing the incidence of disease or influencing its management. Education, one aspect of SEP, is an important determining factor for women's fertility rate, with a gradient of fewer children with higher educational attainment. Higher levels of education are also favourably associated with behaviours conducive to oral health, and a lower incidence of damaging health behaviours. Thus, the potential for confounding is considerable. This review examines the literature on the association between pregnancy, parity and periodontal health, and explores sociobehavioural mechanisms for the observed association.

Pregnancy and periodontal disease: does exist a two-way relationship?

Periodontal disease (PD) is an inflammatory disease of the tissues supporting the teeth. PD affects 65 million adults over the age of 30 years in the USA, and worldwide 5 to 70% of adults. Women who develop PD during pregnancy, it's estimated 1 woman in 5, may have a higher risk of adverse pregnancy outcomes. PD during pregnancy starts by dental plaque and is increased by the action of pregnancy hormones. In order to study the effect of PD on adverse pregnancy outcomes, we have performed this narrative review summarising the current studies about the influence of PD on pregnancy. Periodontal pockets are a reservoir of oral microbiota. Modifications in oral microbiota may be considered as a potential mechanism for developing PD during pregnancy. PD is surely caused by bacteria, but the progression and worsening are due to a host immune response. The inflammation caused by PD is not limited to the oral cavity. It is hypothesized that episodes of bacteraemia and dissemination of endotoxins from periodontal pockets can induce the activation of the systemic immune response. In conclusion our narrative review shows that there's no relationship between PD and adverse pregnancy outcomes, and PD treatment during pregnancy does not confer a general protection against adverse pregnancy outcomes.

Porphyromonas gingivalis and adverse pregnancy outcome

Porphyromonas gingivalis is a Gram-negative, anaerobic bacterium considered to be an important pathogen of periodontal disease that is also implicated in adverse pregnancy outcome (APO). Until recently, our understanding of the role of P. gingivalis in APO has been limited and sometimes contradictory. The purpose of this review is to provide an overview of past and current research on P. gingivalis that addresses some of the controversies concerning the role of this organism in the pathogenesis of APO.

Longitudinal study on clinical and microbial analysis of periodontal status in pregnancy

This study was aimed to provide a longitudinal overview of the subgingival bacterial microbiome using fluorescence in situ hybridization (FISH) technique, in women in the second trimester of pregnancy (between 14 and 24 weeks), and 48 h and 8 weeks postpartum. Of 31 women evaluated during pregnancy, 24 returned for the 48-h and 18 for their 8-week exams postpartum. Probing depth (PD), bleeding on probing, clinical attachment level, and presence of calculus were recorded. Subgingival plaque samples were collected, and FISH was used to identify the numbers of eight periodontal pathogens. Friedman test was used to compare differences between follow-up examinations, followed by a multiple comparison test for a post hoc pairwise comparison. Clinically, a significantly greater number of teeth with PD = 4-5 mm were found during pregnancy than on postpartum examinations. Microbial analysis showed a statistically significant decrease in cell count over the study period for Prevotella nigrescens. P. intermedia, Campylobacter rectus, and Porphyromonas gingivalis also decrease, although not significantly, and Aggregatibacter actinomycetemcomitans increased. No significant changes were found for Fusobacterium nucleatum, Treponema denticola, or Tannerella forsythia. Our data demonstrate a change in the subgingival microbiota during pregnancy, at least for P. nigrescens.

Effect of Camphylobacter rectus on Serum Iron and Transferrin- In-Vivo Findings

BACKGROUND AND AIM

Periodontopathogens require iron constituents for their growth and metabolism in subgingival crevice. In this study, C.rectus was detected and quantified by using 16s rDNA based PCR in chronic periodontitis and compared with the levels of serum iron, total iron binding capacity and transferrin in chronic periodontitis and healthy sites.

MATERIALS AND METHODS

One hundred twenty subjects divided into chronic periodontitis and healthy controls. Deep subgingival plaque was collected and genomic DNA was extracted from each sample analysed for C.rectus using 16s rRNA based PCR analysis. Blood samples were collected from both groups for estimation of serum iron, serum total iron binding capacity and serum transferrin levels. The quantified bacterial count was compared with blood samples. C. rectus was detected in both groups.

RESULTS

There was significant increase in bacterial count in chronic periodontitis (p<0.05). Serum iron level was significantly raised in healthy group. TIBC and transferrin levels were elevated in periodontitis. Although these differences were non-significant. Regression analysis showed significant linear relationship between C.rectus counts and decreasing iron levels and consequently increasing serum transferrin and TIBC (p<0.05).

CONCLUSION

The preliminary in vivo findings suggests C.rectus requires iron as a significant source of nutrition for its survival and growth form its hosts in deeper subgingival sites.

Relationship between gingival inflammation and pregnancy

An increase in the prevalence and severity of gingival inflammation during pregnancy has been reported since the 1960s. Though the etiology is not fully known, it is believed that increasing plasma sex steroid hormone levels during pregnancy have a dramatic effect on the periodontium. Current works of research have shown that estrogen and progesterone increasing during pregnancy are supposed to be responsible for gingivitis progression. This review is focused not only on epidemiological studies, but also on the effects of progesterone and estrogen on the change of subgingival microbiota and immunologic physiological mediators in periodontal tissue (gingiva and periodontal ligament), which provides current information about the effects of pregnancy on gingival inflammation.

Effect of intensive oral hygiene regimen during pregnancy on periodontal health, cytokine levels, and pregnancy outcomes: a pilot study

BACKGROUND

Data are limited on the potential effect of intensive oral hygiene regimens and periodontal therapy during pregnancy on periodontal health, gingival crevicular fluid (GCF) and serum cytokines, and pregnancy outcomes.

METHODS

A clinical trial was conducted on 120 community-dwelling, 16- to 35-year-old pregnant women at 16 to 24 weeks of gestation. Each participant presented with clinical evidence of generalized, moderate-to-severe gingivitis. Oral hygiene products were provided, together with instructions for an intensive daily regimen of hygiene practices. Non-surgical therapy was provided at baseline. Oral examinations were completed at baseline and again at 4 and 8 weeks. In addition, samples of blood and GCF were collected at baseline and week 8. Mean changes in clinical variables and GCF and serum cytokine levels (interleukin [IL]-1β, IL-6, tumor necrosis factor [TNF]-α) between baseline and week 8 were calculated using paired t test. Pregnancy outcomes were recorded at parturition.

RESULTS

RESULTS indicated a statistically significant reduction in all clinical variables (P <0.0001) and decreased levels of TNF-α (P = 0.0076) and IL-1β (P = 0.0098) in GCF during the study period. The rate of preterm births (<37 weeks of gestation) was 6.7% (P = 0.113) and low birth weight (<2,500 g) was 10.2% (P = 1.00).

CONCLUSIONS

Among the population studied, intensive instructions and non-surgical periodontal therapy provided during 8 weeks at early pregnancy resulted in decreased gingival inflammation and a generalized improvement in periodontal health. Large-scale, randomized, controlled studies are needed to substantiate these findings.

Increased periodontal inflammation in women with preterm premature rupture of membranes

OBJECTIVES

To evaluate possible differences in periodontal inflammatory, microbiological and clinical parameters between women with preterm premature rupture of membranes (PPROM) and controls with uncomplicated pregnancies.

MATERIALS AND METHODS

Fifty-six women (32 test (PPROM) and 24 controls (uncomplicated pregnancies)) were examined at three time-points (T1: gestational weeks 20-35, T2: within 48 h after parturition, T3: 4-6 weeks after parturition). The examinations included assessment of the Periodontal Screening Index, collection of gingival crevicular fluid (GCF) and subgingival as well as vaginal bacterial sampling.

RESULTS

Periodontal inflammation was found to be higher in the test compared with the control group (p < 0.05) and decreased over time in both groups (p < 0.05). Microbiological outcomes showed no intergroup differences (p > 0.05) in prevalence of bacteria, but a decrease in subgingival periodontopathogens from T1 to T2 in the test group (p < 0.05) was observed. Interleukin (IL)-1β levels in GCF at T2 were not different between groups (p > 0.05). In women with PPROM, GCF levels of IL-8 (p < 0.05) and C-reactive protein (p < 0.05) were lower and IL-10 levels higher (p < 0.05) compared with controls.

CONCLUSIONS

Periodontal inflammation is elevated during pregnancy and seems to be more pronounced in women with PPROM.

CLINICAL RELEVANCE

The findings of the present study revealed an association between periodontal inflammation and PPROM, thus emphasizing the importance of optimizing self-performed oral hygiene in pregnant women.

Bi-directional relationship between pregnancy and periodontal disease

During pregnancy profound perturbations in innate and adaptive immunity impact the clinical course of a number of infectious diseases, including those affecting periodontal tissues. Conversely, it has been suggested that periodontal infections may increase the risk of adverse pregnancy outcomes. In this review, a summary of the literature associated with the bidirectional relationship between pregnancy and periodontal disease as well as the possible mechanisms behind this interaction were examined.

Relationship between halitosis and periodontal disease - associated oral bacteria in tongue coatings

AIM

The objective of our study was to investigate the relationship between halitosis and oral bacteria in tongue coating (TC) and saliva samples from patients with halitosis, and to evaluate the effect of tongue cleaning on halitosis.

METHODS

Ninety-four participants complaining of oral malodour were included in the study. Organoleptic (OR) values, volatile sulphur compound (VSC) concentrations determined by gas chromatography and TC scores were used as clinical parameters of halitosis. Quantitative real-time polymerase chain reactions were used to determine the numbers of periodontal disease-associated oral bacteria.

RESULTS

There was a significant correlation between TC scores and OR values, methylmercaptan (CH3 SH) concentrations and VSC concentrations (Spearman's rank-correlation coefficient test, P < 0.01). There was also a positive correlation between the clinical parameters of halitosis and total bacterial numbers and Prevotella intermedia, Fusobacterium nucleatum and Campylobacter rectus concentrations in the TC samples. However, there was no similar correlation with respect to the saliva samples. The participants were sub-divided into two groups based on whether they had the habit of tongue cleaning or not. The participants with the habit of tongue cleaning had significantly lower OR scores, VSC concentrations and P. intermedia, F. nucleatum and C. rectus levels than the other participants (Mann-Whitney U-test, P < 0.05).

CONCLUSION

These results suggested that periodontal disease-associated oral bacteria in TCs are closely related to halitosis and that tongue cleaning may be an effective method for improving halitosis.

Anticardiolipin in porphyromonas gingivalis antisera causes fetal loss in mice

β2-glycoprotein I (β2GPI)-dependent anticardiolipin autoantibodies (aCl) are associated with thrombosis and fetal loss. Some microbial pathogens can induce pathogenic antibodies cross-reactive with β2GPI. Sera from a significant percentage of periodontitis patients contain aCl, and some periodontal pathogens contain antigens with peptide sequences having homology to β2GPI. We hypothesized that antibodies raised against P. gingivalis (aPg) contain pathogenic aCl that induce fetal resorption. We immunized mice with β2GPI, P. gingivalis W83, or an arg-gingipain-defective mutant of P. gingivalis (HF18). IgG fractions of aPg were immunoabsorbed to remove aCl-like antibodies (abs-aPg). IgG fractions were administered intravenously into tail veins of mated BALB/c females at day 0 of pregnancy. At day 15, the proportions of fetal resorptions were evaluated. The prevalence of fetal loss was significantly greater in the aPg group than in the control IgG group (21.2% vs. 5.3%, p = .001), and greater in the aPg group than in the abs-aPg group (21.2% vs. 12%, p < .05). There were no fetal resorptions observed in the aPgHF18 group (p = .0005 compared with aPg, p = .17 compared with control). aPg antibody contains activity consistent with pathogenic aCl, and the antigen inducing the antibodies that cause increased fetal loss may be on the arg-gingipain protease of P. gingivalis.

Effect of pregnancy on gingival inflammation in systemically healthy women: a systematic review

AIM

To obtain an overall quantitative estimate of the association between pregnancy and gingival inflammation.

MATERIAL AND METHODS

Medline and EMBASE databases were searched through August 2011. Prospective cohort or cross-sectional studies assessing the effect of pregnancy on gingival inflammation evaluated by the gingival index (GI) and/or bleeding on probing were included. Meta-analyses were performed if possible.

RESULTS

Forty-four articles representing 33 studies (14 cohort and 19 cross-sectional) were included. Meta-analyses, performed whenever possible, revealed (1) a significantly lower GI in pregnant women in the first term compared with those in their second or third term of pregnancy; (2) a lower mean GI score in post-partum women compared with women in their second [WMD = 0.143; 95% CI (0.031; 0.255); p = 0.012] or third term [WMD = 0.256; 95% CI (0.151; 0.360); p < 0.001] of pregnancy, when considering cohort studies; (3) Non-pregnant women had lower mean GI values than women in their second or third term of pregnancy. Small changes in plaque levels were reported.

CONCLUSION

Despite the limited number of studies included in the meta-analyses, the present systematic review confirms the existence of a significant increase in GI throughout pregnancy and between pregnant versus post-partum or non-pregnant women, without a concomitant increase in plaque levels.

Comparison of aerobic conjunctival bacterial flora in pregnant, reproductive-aged and postmenopausal women

AIM

To evaluate the effect of hormonal status on aerobic conjunctival flora in women.

METHODS

One hundred fifty-eight women [reproductive-aged (n=55), pregnant (n=51), and postmenopausal (n=52)] who admitted to outpatient clinic of Obstetrics and Gynecology Department of Denizli State Hospital were enrolled. Age, body-mass index (BMI), obstetric history, cigarette smoking, drug usage, presence of systemic disease, and intraocular pressure (IOP) were recorded for each patient. The samples were taken from the lower fornix with two culture swabs and directly incubated in culture containing 5% sheep blood, eosin-methylene blue and chocolate agar. The other swab specimen was Gram stained. All growths and microscopic results were analyzed.

RESULTS

The coagulase-negative Staphylococcus was the predominant organism isolated in the conjunctival samples in both three groups. The aerobic microorganism growth rate for all isolated aerobic organisms revealed no significant change in the three groups (P >0.05). The conjunctival culture positivity rates were similar in the three groups (49% in reproductive-aged, 57% in pregnant and 58% in postmenopausal women) (P >0.05). Age, IOP, BMI, gravidity, parity, cigarette smoking, drug usage, and presence of systemic diseases did not have an effect on culture positivity in three groups.

CONCLUSION

Results of this study showed that conjunctival aerobic flora and bacterial colonization did not differ between reproductive-aged, pregnant and postmenopausal women.

Toll-like receptor 4 mediates intrauterine growth restriction after systemic Campylobacter rectus infection in mice

Campylobacter rectus is associated with fetal exposure and low birthweight in humans. C. rectus also invades placental tissues and induces fetal intrauterine growth restriction (IUGR) in mice, along with overexpression of Toll-like receptors (TLR4), suggesting that TLR4 may mediate placental immunity and IUGR in mice. To test this hypothesis we examined the effect of in vitro TLR4 neutralization on trophoblastic proinflammatory activity and studied the IUGR phenotype in a congenic TLR4-mutant mouse strain after in vivo C. rectus infection. Human trophoblasts were pretreated with TLR4 neutralizing antibodies and infected with C. rectus; proinflammatory cytokine production was assessed by cytokine multiplex assays. Neutralizing TLR4 antibodies significantly impaired the production of proinflammatory cytokines in trophoblastic cells after infection in a dose-dependent manner. We used a subcutaneous chamber model to provide a C. rectus challenge in BALB/cAnPt (TLR4(Lps-d) ) and wild-type (WT) females. Females were mated with WT or TLR4(Lps-d) males once/week; pregnant mice were infected at (E)7.5 and sacrificed at (E)16.5 to establish IUGR phenotypes. Maternal C. rectus infection significantly decreased fetal weight/length in infected WT when compared with sham WT controls (P < 0.05, analysis of variance). However, infected TLR4(Lps-d -/-) mice did not show statistically significant differences in fetal weight and length when compared with WT controls (P > 0.05). Furthermore, heterozygous TLR4(Lps-d +/-) fetuses showed IUGR phenotype rescue. We conclude that TLR4 is an important mediator of trophoblastic proinflammatory responses and TLR4-deficient fetuses do not develop IUGR phenotypes after C. rectus infection, suggesting that placental cytokine activation is likely to be mediated by TLR4 during low birthweight/preterm birth pathogenesis.

Relationship between periodontal diseases and preterm birth: recent epidemiological and biological data

For ten years, the incidence of preterm birth does not decrease in developed countries despite the promotion of public health programs. Many risk factors have been identified including ethnicity, age, tobacco, and infection. However, almost 50% of preterm birth causes remain unknown. The periodontal diseases are highly prevalent inflammatory and infectious diseases of tooth supporting tissues leading to an oral disability. They influence negatively general health worsening cardiovascular diseases and diabetes. Periodontal diseases have been also suspected to increase the rate of preterm birth, but data remain contradictory. The objective of this review is to present the principal results of epidemiological, biological, and interventional studies on the link between periodontal diseases and preterm birth. The conclusions of this work underline the importance for the physician/obstetrician to identify women at risk for preterm birth and to address these patients to dentist for periodontal examination and treatment in order to limit adverse pregnancy outcomes.

Birth weight of infants of mothers with aggressive periodontitis

BACKGROUND

It was hypothesized that if periodontal infections predispose low birth weights and premature birth, then such outcomes should be apparent when the mother has aggressive periodontitis (AgP).

METHODS

Birth weight data were collected by questionnaire from females with AgP, their periodontally healthy siblings, and unrelated periodontally healthy women. Both prospective and retrospective birth outcome data were used. Because many of the periodontal evaluations were performed after the births, there were incomplete data regarding most of the risk factors for low birth weight. We determined associations between mothers' periodontal diagnoses and clinical variables and the reported birth weights.

RESULTS

There were no significant differences in mean birth weights of babies born to control subjects or AgP patients. This was true whether all the births were considered or only those reported <1 or 2 years before periodontal examination. For periodontally healthy controls, 13.2% of babies born to siblings of AgP patients and 12.8% of babies born to unrelated mothers weighed <2,500 g, whereas 9.9% of those born to mothers with generalized AgP and 10.3% of those born to mothers with localized AgP weighed <2,500 g.

CONCLUSIONS

Because of the relative rarity of AgP in the population, and attendant difficulties in performing a prospective study of its association with pregnancy outcomes, we used a compromised approach using prospective data as well as weaker retrospective data assuming that disease onset was likely before the births. Our results, within the limitations of this approach, indicate no evidence that AgP in the mother predisposes low birth weights. AgP has many unique biologic characteristics that differentiate it from chronic forms of periodontal disease, and the possible lack of its association with birth weight may be another such characteristic.

Characterization of the invasive and inflammatory traits of oral Campylobacter rectus in a murine model of fetoplacental growth restriction and in trophoblast cultures

Campylobacter species (C. jejuni, C. fetus) are enteric abortifacient bacteria in humans and ungulates. Campylobacter rectus is a periodontal pathogen associated with human fetal exposure and adverse pregnancy outcomes including preterm delivery. Experiments in pregnant mice have demonstrated that C. rectus can translocate from a distant site of infection to the placenta to induce fetal growth restriction and impair placental development. However, placental tissues from human, small-for-gestational age deliveries have not been reported to harbor C. rectus despite evidence of maternal infection and fetal exposure by fetal IgM response. This investigation examined the temporal relationship between the placental translocation of C. rectus and the effects on fetal growth in mice. BALB/c mice were infected at gestational day E7.5 to examine placental translocation of C. rectus by immunohistology. C. rectus significantly decreased fetoplacental weight at E14.5 and at E16.5. C. rectus was detected in 63% of placentas at E14.5, but not at E16.5. In in vitro trophoblast invasion assays, C. rectus was able to effectively invade human trophoblasts (BeWo) but not murine trophoblasts (SM9-1), and showed a trend for more invasiveness than C. jejuni. C. rectus challenge significantly upregulated both mRNA and protein levels of IL-6 and TNFalpha in a dose-dependent manner in human trophoblasts, but did not increase cytokine expression in murine cells, suggesting a correlation between invasion and cytokine activation. In conclusion, the trophoblast-invasive trait of C. rectus that appears limited to human trophoblasts may play a role in facilitating bacterial translocation and placental inflammation during early gestation.

A critical assessment of adverse pregnancy outcome and periodontal disease

BACKGROUND

Pre-term birth is a major cause of infant mortality and morbidity that has considerable societal, medical, and economic costs. The rate of pre-term birth appears to be increasing world-wide and efforts to prevent or reduce its prevalence have been largely unsuccessful.

AIM

To review the literature for studies investigating periodontal disease as a possible risk factor for pre-term birth and adverse pregnancy outcomes.

MAIN FINDINGS AND CONCLUSION

Variability among studies in definitions of periodontal disease and adverse pregnancy outcomes as well as widespread inadequate control for confounding factors and possible effect modification make it difficult to base meaningful conclusions on published data. However, while there are indications of an association between periodontal disease and increased risk of adverse pregnancy outcome in some populations, there is no conclusive evidence that treating periodontal disease improves birth outcome. Based on a critical qualitative review, available evidence from clinical trials indicates that, although non-surgical mechanical periodontal treatment in the second trimester of pregnancy is safe and effective in reducing signs of maternal periodontal disease, it does not reduce the rate of pre-term birth. Clinical trials currently underway will further clarify the potential role of periodontal therapy in preventing adverse birth outcomes. Regardless of the outcomes of these trials, it is recommended that large, prospective cohort studies be conducted to assess risk for adverse pregnancy outcome in populations with periodontal disease. It is critical that periodontal exposure and adverse birth outcomes be clearly defined and the many potential confounding factors and possible effect modifiers for adverse pregnancy outcome be controlled in these studies. If periodontal disease is associated with higher risk of adverse pregnancy outcome in these specific populations, large multicenter randomized-controlled trials will be needed to determine if prevention or treatment of periodontal disease, perhaps combined with other interventions, has an effect on adverse pregnancy outcome in these women.