The P4 Study: Postpartum Maternal and Infant Faecal Microbiome 6 Months After Hypertensive Versus Normotensive Pregnancy

Abstract

Objective/HypothesisTo explore potential differences in faecal microbiome between women, and their infants, who had normotensive pregnancies (NP) and those who had a hypertensive pregnancy (HP), either gestational hypertension (GH) or preeclampsia (PE).MethodsThis is a sub study of P4 (Postpartum Physiology, Psychology, and Paediatrics Study) and includes 18 mother-infant pairs: 10 NP and 8 HP (HP as defined by blood pressure > 140/90mmHg; of which 6 had PE, and 2 GH), six months postpartum. The participating mothers collected stool samples from themselves and their infants. 16S rRNA V3-V4 amplicons were used to study the faecal microbiome.ResultsThe sample of women and their infants were mostly primiparous (n =16) with vaginal birth (n = 14). At the time of faecal sampling 8 women were using hormonal contraception, and one HP woman remained on an antihypertensive. All women had blood pressure < 130/80mmHg, and 10 had high BMI (> 30). All infants had started solids, 8 were exclusively breastfed, 1 exclusively formula fed and 9 both. Three infants had been exposed to a course of antibiotics. Six months postpartum, there were no significant differences in alpha or beta diversity between the gut microbiota of HP and NP women (P > 0.05). However, a statistically significant difference was detected in alpha diversity between infants following HP and NP, with lower diversity levels in HP infants (P < 0.05). It was also found that at a genus and species level, the gut microbiota of HP women was enriched with Bifidobacterium and Bifididobacterium sp. and depleted in Barnisiella and Barnesiella intestinihominis when compared to NP women (P < 0.05). Similarly, the gut microbiota of infants born from HP was enriched in Streptococcus infantis and depleted in Sutterella, Sutterella sp., Bacteroides sp. and Clostridium aldenense compared to infants born from NP (P < 0.05).DiscussionWhile our findings are at best preliminary, due to the very small sample size, they do suggest that the presence of hypertension in pregnancy may adversely affect the maternal microbiota post-partum, and that of their infants. Further analysis of postpartum microbiome data from future studies will be important to validate these early findings and provide further evidence about the changes in the microbiota in the offspring of women following hypertensive disorders of pregnancy (HDP), including possible links to the causes of long-term cardiovascular disease, the prevalence of which is increased in women who have experienced HDP.

The Diversity of Gut Microbiota at Weaning Is Altered in Prolactin Receptor-Null Mice

“…For instance, Betaproteobacteria abundances are increased in humans with type 2 diabetes [56]. Five-year-old infants resulting from hypertensive pregnancies showed fewer Alcaligenaceae and Coriobacteriaceae families than those from normotensive pregnancies [57]. The Anaerotruncus genus, which we found to be increased in the Prlr-KO animals, is a butyrate-producing group of bacteria associated with obesity and correlates negatively with high carbohydrate-based diets but positively with total fat and the consumption of saturated fatty acids [58].…”

Role of short interpregnancy interval, birth mode, birth practices, and the postpartum vaginal microbiome in preterm birth

“…Prior research has shown that CS delivery introduces BVAB through surgical sites which follows a descending pathway into the vagina thus accentuating PPE ( 48 ) Consistent with this, Rosene and others ( 49 ) demonstrated that results from swabs and endometrial culture isolated from the genital tract of women with early postpartum endometritis predominantly comprises of microbes associated with vaginal dysbiosis including Mycoplasma, Chlamydia trachomatis , Gardnerella vaginalis , Peptococcus spp., Bacteroides spp., Staphylococcus epidermidis , group B Streptococcus, Ureaplasma urealyticum ( 49 ) Clostridium sordellii ( 50 ), Clostridium perfringens , streptococcal toxic shock syndrome ( 51 ) and Leptrotrichia amnionii a recently emerging pathogen of postpartum endometritis ( 52 ). DNA sequencing-based interrogation of the vaginal microbiome has vastly been studied in post-natal women ( 53 – 60 ). These studies have shown that a dramatic switch to a vaginal bacterial community lacking in Lactobacillus species is common after pregnancy ( 53 – 60 ).…”

“…DNA sequencing-based interrogation of the vaginal microbiome has vastly been studied in post-natal women ( 53 – 60 ). These studies have shown that a dramatic switch to a vaginal bacterial community lacking in Lactobacillus species is common after pregnancy ( 53 – 60 ). Although, majority of the aforementioned studies on the postpartum vaginal microbiome explored vaginal samples collected at 6 weeks postpartum ( 53 , 54 ) and 1-week post-delivery ( 59 ), thus early postpartum microbiological content which could be potential biomarkers of early PPE are not accounted for.…”