Exploring the Maternal and Infant Oral Microbiomes: A Pilot Study.

Setting the stage for good oral health early in life is critical to long-term oral and overall health. This exploratory study aimed to characterize and compare maternal and newborn oral microbiota among mother-infant pairs. Oral samples were collected from 34 pregnant African American women and their infants at 1 to 3 months of age. Extracted 16SrRNA genes were matched to the Human Oral Microbiome Database. Alpha and beta diversity differed significantly between overall maternal and infant microbiomes. Maternal or infant alpha diversity, however, was not differentiated by maternal gingival status. Several demographic and behavioral variables were associated with, but not predictive of, maternal oral microbiome alpha diversity. There was no association, however, among birth mode, feeding mode, and the infant oral microbiome. Megasphaera micronuciformis was the only periodontal pathogen detected among the infants. Notably, maternal gingival status was not associated with the presence/absence of most periodontal pathogens. This study provides an initial description of the maternal and infant oral microbiomes, laying the groundwork for future studies. The perinatal period presents an important opportunity where perinatal nurses and providers can provide oral assessment, education, and referral to quality dental care.

Subgingival Microbiome in Pregnancy and a Potential Relationship to Early Term Birth.

Background: Periodontal disease in pregnancy is considered a risk factor for adverse birth outcomes. Periodontal disease has a microbial etiology, however, the current state of knowledge about the subgingival microbiome in pregnancy is not well understood. Objective: To characterize the structure and diversity of the subgingival microbiome in early and late pregnancy and explore relationships between the subgingival microbiome and preterm birth among pregnant Black women. Methods: This longitudinal descriptive study used 16S rRNA sequencing to profile the subgingival microbiome of 59 Black women and describe microbial ecology using alpha and beta diversity metrics. We also compared microbiome features across early (8-14 weeks) and late (24-30 weeks) gestation overall and according to gestational age at birth outcomes (spontaneous preterm, spontaneous early term, full term). Results: In this sample of Black pregnant women, the top twenty bacterial taxa represented in the subgingival microbiome included a spectrum representative of various stages of biofilm progression leading to periodontal disease, including known periopathogens Porphyromonas gingivalis and Tannerella forsythia. Other organisms associated with periodontal disease reflected in the subgingival microbiome included several Prevotella spp., and Campylobacter spp. Measures of alpha or beta diversity did not distinguish the subgingival microbiome of women according to early/late gestation or full term/spontaneous preterm birth; however, alpha diversity differences in late pregnancy between women who spontaneously delivered early term and women who delivered full term were identified. Several taxa were also identified as being differentially abundant according to early/late gestation, and full term/spontaneous early term births. Conclusions: Although the composition of the subgingival microbiome is shifted toward complexes associated with periodontal disease, the diversity of the microbiome remains stable throughout pregnancy. Several taxa were identified as being associated with spontaneous early term birth. Two, in particular, are promising targets of further investigation. Depletion of the oral commensal Lautropia mirabilis in early pregnancy and elevated levels of Prevotella melaninogenica in late pregnancy were both associated with spontaneous early term birth.

The oral microbiome and inflammation in mild cognitive impairment.

Inflammation and immune mechanisms are believed to play important roles in Alzheimer's disease pathogenesis. Research supports the link between poor oral health and Alzheimer's disease. Periodontal disease and dental caries represent the two most common infections of the oral cavity. This study focused on a precursor to Alzheimer's disease, mild cognitive impairment (MCI). Using 16S rRNA sequencing, we characterized and compared the oral microbiome of 68 older adults who met the criteria for MCI or were cognitively normal, then explored relationships between the oral microbiome, diagnostic markers of MCI, and blood markers of systemic inflammation. Two taxa, Pasteurellacae and Lautropia mirabilis were identified to be differentially abundant in this cohort. Although systemic inflammatory markers did not differentiate the two groups, differences in five cerebrospinal fluid inflammatory mediators were identified and had significant associations with MCI. Because inflammatory markers may reflect CNS changes, pursuing this line of research could provide opportunities for new diagnostic tools and illuminate mechanisms for prevention and mitigation of Alzheimer's disease.

Characterizing the Subgingival Microbiome of Pregnant African American Women.

OBJECTIVE: To generate preliminary data about the subgingival microbiome of pregnant African American women to calculate power for a future larger study and to explore associations among the microbiome, periodontal inflammation, and preterm birth. DESIGN: Comparative descriptive pilot study design. SETTING: Urban area in the southeastern United States. PARTICIPANTS: Thirty-four African American women in the third trimester of pregnancy. METHODS: Based on visual assessment, participants were placed in two groups: healthy gingiva and gingivitis. Saliva samples were analyzed for interleukin-1ß (IL-1ß), matrix metalloproteinase-8 (MMP-8), and C-reactive protein (CRP). DNA was extracted from subgingival plaque samples, and amplicons of the fourth hypervariable region were sequenced. RESULTS: We found no differences in overall microbiome diversity between the healthy gingiva (n = 22) and the gingivitis (n = 12) groups although significant differences were found among the bacterial taxa present. The gingivitis group had greater levels of salivary IL-1ß and MMP-8, whereas CRP was not different between groups. Overall microbiome diversity was positively associated with the CRP level. We found no significant relationships among the subgingival microbiome, periodontal inflammation, and preterm birth. CONCLUSION: Gingivitis in pregnancy did not appear to shift the overall composition or diversity of the subgingival microbiome although differences in several bacterial taxa suggest that inflamed gingiva in pregnant women are associated with a disruption in the stability of the subgingival microbiome. A correlation between the abundance of bacteria and CRP also suggests an association between the microbiome and systemic inflammation. These findings provide support for future research about how the oral microbiome and progression of periodontal disease in pregnant women link with adverse pregnancy outcomes.

The impact of fatigue on the development of postpartum depression.

BACKGROUND: Previous research suggests early postpartum fatigue (PPF) plays a significant role in the development of postpartum depression (PPD). Predicting risk for PPD via early identification of PPF may provide opportunity for intervention. OBJECTIVE: To replicate and extend previous studies concerning the impact of PPF on symptoms of PPD and to describe the relationships among PPF, PPD, and other variables using the theory of unpleasant symptoms. DESIGN: Correlational, longitudinal study. SETTING: Participants' homes. PARTICIPANTS: Convenience sample of 42 community-dwelling women recruited before 36 weeks of pregnancy. MAIN OUTCOME MEASURES: PPF, depressive symptoms, and stress measured during prenatal weeks 36 to 38, and on Days 7, 14, and 28 after childbirth. Salivary cortisol was measured as a physiological marker of stress. RESULTS: Significant correlations were obtained between PPF and symptoms of PPD on Days 7, 14, and 28, with Day 14 PPF levels predicting future development of PPD symptoms in 10 of 11 women. Perceived stress, but not cortisol, was also correlated with symptoms of PPD on Days 7, 14, and 28. Women with a history of depression had elevated depression scores compared to women without, but no variable was as effective at predicting PPD as PPF. CONCLUSIONS: Fatigue by Day 14 postpartum was the most predictive variable for symptoms of PPD on Day 28 in this population.

Leptin, hunger, and body weight: Influence of gender, tobacco smoking, and smoking abstinence.

Leptin is a hormone involved in body weight and hunger regulation, and may contribute to the inverse relationship between cigarette smoking and body weight. Leptin levels, body mass indices (BMIs), and hunger ratings were determined in 22 nonsmokers (12 male, 10 female) and 19 cigarette smokers (11 male, 8 female). Smokers were tested after ad lib smoking and following a 24-h smoking abstinence period; nonsmokers came to the laboratory once. Leptin levels were not different among the groups. Hunger ratings, however, were higher after smoking abstinence compared to after ad lib smoking and nonsmokers (Ps<.05); levels of hunger did not differ between ad lib smokers and nonsmokers. Men reported higher hunger levels than did women, but women had higher serum leptin levels than did men, regardless of smoking condition (P<.05). Leptin levels were correlated with BMI (P<.05) among smokers only. This first study on leptin responses in female smokers suggests that leptin levels do not change following a 24-h smoking abstinence period and that leptin may not contribute to increased hunger following smoking abstinence.

Immune dysregulation and glucocorticoid resistance in minority and low income pregnant women.

Chronic prenatal stress contributes to poor birth outcomes for women and infants. Importantly, poor birth outcomes are most common among minority and low income women. To investigate underlying mechanisms, we tested the hypothesis that chronic stress related to minority or low income status is associated with glucocorticoid resistance as indicated by disruption in the cytokine-glucocorticoid feedback circuit. Home visits were conducted during which 3rd trimester pregnant women completed stress and depression surveys and provided blood for pro- and anti-inflammatory cytokines. Saliva was collected 5 times the preceding day for diurnal cortisol levels. For statistical analyses, women were grouped 3 ways, by race, income, and the presence or absence of either of those risk factors; this last group was labeled high or low general risk. Immune regulation was evaluated by evidence of a functioning negative feedback relationship between cytokines and cortisol. Of 96 participants, 18 were minority, 22 of low income, and 29 either minority or low income (high general risk). Pearson partial correlation identified a significant negative relationship between cortisol area under the curve (AUC) and pro- to anti-inflammatory cytokine ratios in the low general risk women (i.e., Caucasian, higher income) including IFNγ/IL10 (r=-0.73, p<0.0001), IL6/IL10 (r=-0.38, p=0.01), IL1ß/IL10 (r=-0.44, p=0.004) and TNFα/IL10 (r=-0.41; p=0.005); no such correlations existed in the high general risk women (i.e., minority, low income) for (IFNγ/IL10: r=-0.25, p=0.43; IL6/IL10: r=0.12, p=0.70; IL1 ß/IL10: r=0.05, p=0.87; TNFα/IL10: r=0.10; p=0.75), suggestive of glucocorticoid resistance. Cortisol levels throughout the day also were higher in minority and high general risk groups (p<0.05). Without cytokine glucocorticoid feedback, a pregnant woman's ability to regulate inflammation is limited, potentially contributing to adverse maternal and infant outcomes.