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Towards a deeper understanding of the vaginal microbiota.
France, M, Alizadeh, M, Brown, S, Ma, B, Ravel, J
Nature microbiology. 2022;7(3):367-378
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The vaginal microbiota of reproductive-age cisgender women is often dominated by a single species of Lactobacillus and this is associated with good vaginal health. This review looks at the current understanding of the vaginal microbiota and its connection with host health. Women with vaginal microbiota that are not dominated by Lactobacillus species are often diagnosed with bacterial vaginosis (BV). They have an increased risk for sexually transmitted infections (STI), spontaneous preterm birth, prevalence of human papillomavirus (HPV), increased risk for cervical cancer, urinary tract infections and pelvic inflammatory disease. Factors that affect the vaginal microbiota composition are race, age, pre puberty and menopause where levels of circulating oestrogen are lower. Efforts to modulate the vaginal microbiota with antibiotics, oestrogen therapy, lactic or boric acid and vaginal probiotics have not been that successful. Vaginal microbiota transplants (VMT) are a potential approach to treat recurrent BV but further studies are needed.
Abstract
The human vaginal microbiota is a critical determinant of vaginal health. These communities live in close association with the vaginal epithelium and rely on host tissues for resources. Although often dominated by lactobacilli, the vaginal microbiota is also frequently composed of a collection of facultative and obligate anaerobes. The prevalence of these communities with a paucity of Lactobacillus species varies among women, and epidemiological studies have associated them with an increased risk of adverse health outcomes. The mechanisms that drive these associations have yet to be described in detail, with few studies establishing causative relationships. Here, we review our current understanding of the vaginal microbiota and its connection with host health. We centre our discussion around the biology of the vaginal microbiota when Lactobacillus species are dominant versus when they are not, including host factors that are implicated in shaping these microbial communities and the resulting adverse health outcomes. We discuss current approaches to modulate the vaginal microbiota, including probiotics and vaginal microbiome transplants, and argue that new model systems of the cervicovaginal environment that incorporate the vaginal microbiota are needed to progress from association to mechanism and this will prove invaluable for future research.
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Efficacy and Safety of Lactobacillus Plantarum C29-Fermented Soybean (DW2009) in Individuals with Mild Cognitive Impairment: A 12-Week, Multi-Center, Randomized, Double-Blind, Placebo-Controlled Clinical Trial.
Hwang, YH, Park, S, Paik, JW, Chae, SW, Kim, DH, Jeong, DG, Ha, E, Kim, M, Hong, G, Park, SH, et al
Nutrients. 2019;11(2)
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Mild cognitive impairment (MCI) describes a range of symptoms that impact on cognition and memory, but not to such an extent that it seriously affects a person's day to day life. People with MCI are at higher risk of going on to develop dementia. Consumption of both probiotics and soy beans have been shown to enhance memory function in previous studies on animals and humans. In this Korean study, a randomised, double-blind, placebo-controlled trial, researchers used soybeans that had been fermented with a bacterium called Lactobacillus plantarum C29, a type of bacteria which is found in the traditional Korean food kimchi. One hundred men and women diagnosed with MCI were given capsules containing either 800 mg of dried fermented soybeans or a placebo for 12 weeks. Participants underwent a series of memory and attention tests to measure cognitive function. Researchers also looked at levels of a protein that supports nerve cells, called brain-derived neurotropic factor (BDNF) in the blood, as well as the composition of bacteria in the stool samples of the participants. The group that consumed the fermented soybeans showed greater improvements in the overall cognitive function, especially attention, compared to those who took the placebo. BDNF levels increased in the soybean group but declined in the placebo group. Increases in BDNF were associated with improvements in cognitive function. The results of this clinical trial suggest that fermented soybeans can be safely consumed by people with MCI to enhance cognitive function. The authors suggested that the increase in blood BDNF levels may be partly responsible for the improved cognitive function, and this in turn points to the importance of the so-called gut-brain axis in improving symptoms of MCI.
Abstract
Early intervention using dietary supplements may be effective in alleviating cognitive impairment among individuals with mild cognitive impairment (MCI). This study investigated the efficacy and safety of Lactobacillus plantarum C29-fermented soybean (DW2009) as a nutritional supplement for cognitive enhancement. One hundred individuals with MCI were randomly assigned to take DW2009 (800 mg/day, n = 50) or placebo (800 mg/day, n = 50) for 12 weeks. The primary outcome measure was change in the composite score of cognitive functions related to memory and attention, measured by computerized neurocognitive function tests. Associations between changes in serum brain-derived neurotrophic factor (BDNF) levels and cognitive performance for each treatment group were evaluated. Compared to the placebo group, the DW2009 group showed greater improvements in the combined cognitive functions (z = 2.36, p for interaction = 0.02), especially in the attention domain (z = 2.34, p for interaction = 0.02). Cognitive improvement was associated with increased serum BDNF levels after consumption of DW2009 (t = 2.83, p = 0.007). The results of this clinical trial suggest that DW2009 can be safely administered to enhance cognitive function in individuals with MCI. Increased serum BDNF levels after administering DW2009 may provide preliminary insight into the underlying effects of cognitive improvement, which suggests the importance of the gut-brain axis in ameliorating cognitive deficits in MCI.
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Crying Time and RORγ/FOXP3 Expression in Lactobacillus reuteri DSM17938-Treated Infants with Colic: A Randomized Trial.
Savino, F, Garro, M, Montanari, P, Galliano, I, Bergallo, M
The Journal of pediatrics. 2018;192:171-177.e1
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The causes of infant colic are unknown, but growing evidence shows a possible link with the gut microbiome. Increased inflammation has also been found in infants with colic, and this could be linked to dysbiosis. This double-blind, placebo-controlled clinical trial investigated whether supplementation with the probiotic Lactobacillus reuteri (L reuteri) DSM 17938 could reduce the crying time and modify inflammation in a group of infants with colic. Infants enrolled in the trial were less than 12 weeks old, with a healthy birth weight and predominantly breastfed. Infants with colic were given either 5 million colony-forming units (CFU) of L reuteri DSM 17938 or a placebo daily for 1 month. Crying times were significantly shortened among infants with colic given the probiotic, whilst the concentration of transcription factors for cells that help to regulate the immune system increased significantly. Infants treated with the probiotic showed an increase in the percentage of Lactobacillus and a decrease in the inflammatory marker faecal calprotectin. The authors concluded that their findings support the hypothesis that dysbiosis and inflammation may contribute to the onset of infant colic.
Abstract
OBJECTIVES To evaluate crying time, retinoid-related orphan receptor-γ (RORγ) and forkhead box P3 (FOXP3) messenger RNA levels (transcription factors that can modulate T cell responses to gut microbes), and to investigate gut microbiota and fecal calprotectin in infants treated with Lactobacillus reuteri for infantile colic. STUDY DESIGN A double-blind, placebo-controlled randomized trial was conducted in primary care in Torino from August 1, 2015 to September 30, 2016. Patients suffering from infantile colic were randomly assigned to receive daily oral L reuteri (1 × 108 colony forming unit) or placebo for 1 month. Daily crying times were recorded in a structured diary. FOXP3 and RORγ messenger RNA in the peripheral blood was assessed with real-time TaqMan reverse transcription polymerase chain reaction. Gut microbiota and fecal calprotectin were evaluated. RESULTS After infants with colic were supplemented with L reuteri DSM 17938 for 30 days, crying times were significantly shorter among infants with colic in the probiotic group compared with infants in the placebo group (74.67 ± 25.04 [IQR = 79] minutes /day vs 147.85 [IQR = 135] minutes /day [P = .001]). The FOXP3 concentration increased significantly (P = .009), resulting in decreased RORγ/FOXP3 ratios: 0.61 (IQR = 0.60) at day 0 and 0.48 (IQR = 0.28) at day 30 (P = .028). Furthermore, the probiotic increased the percentage of Lactobacillus (P = .049) and decreased fecal calprotectin (P = .0001). CONCLUSIONS Infants with colic treated with L reuteri for 30 days had a significantly decreased crying time and an increased FOXP3 concentration, resulting in a decreased RORγ/FOXP3 ratio. The treatment reduced fecal calprotectin. TRIAL REGISTRATION ClinicalTrials.gov: NCT00893711.
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Effect of Lactobacillus rhamnosus HN001 on carriage of Staphylococcus aureus: results of the impact of probiotics for reducing infections in veterans (IMPROVE) study.
Eggers, S, Barker, AK, Valentine, S, Hess, T, Duster, M, Safdar, N
BMC infectious diseases. 2018;18(1):129
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The bacteria Staphylococcus aureus (S. aureus) is found in the digestive tract, nostrils, mouth and armpits. Methicillin-resistant S. aureus (MRSA) is responsible for several difficult-to-treat infections in humans. Probiotics are emerging as an alternative to antibiotics in preventing or treating bacterial infections. This randomised controlled trial aimed to determine the ability of Lactobacillus rhamnosus (L. rhamnosus) HN001 to reduce S. aureus at several different body sites. Participants in the study were mostly male, with an average age of 64 years, and all carriers of S. aureus in one or more body sites. Participants were organised into groups depending on whether S. aureus was found within the gastrointestinal tract (GI) or in other body sites (extra-GI), and given either L. rhamnosus HN001 probiotic, or a placebo for four weeks. Subjects given the probiotic had 15% lower levels of S. aureus in their stool samples than those given the placebo at the end of the trial. They also had 73% reduced odds of methicillin-susceptible S. aureus (MSSA) presence, and 83% reduced odds of any S. aureus presence in the stool sample compared to the placebo group. No other sampling sites showed a significant difference in colonisation between the two groups. The authors concluded that use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites. The results of the study support the use of this probiotic strain for reducing the population of S. aureus in the gut. Further studies are needed to assess the effectiveness of different probiotic strains and to compare probiotics with antibiotics in reducing S. aureus in other body sites.
Abstract
BACKGROUND Infection by Staphylococcus aureus (S. aureus) is a major cause of morbidity and mortality. Colonization by S. aureus increases the risk of infection. Little is known about decolonization strategies for S. aureus beyond antibiotics, however probiotics represent a promising alternative. A randomized controlled trial was conducted to determine the efficacy of Lactobacillus rhamnosus (L. rhamnosus) HN001 in reducing carriage of S. aureus at multiple body sites. METHODS One hundred thirteen subjects, positive for S. aureus carriage, were recruited from the William S. Middleton Memorial Medical Center, Madison, WI, USA, and randomized by initial site of colonization, either gastrointestinal (GI) or extra-GI, to 4-weeks of oral L. rhamnosus HN001 probiotic, or placebo. Nasal, oropharyngeal, and axillary/groin swabs were obtained, and serial blood and fecal samples were collected. Differences in prevalence of S. aureus carriage at the end of the 4-weeks of treatment were assessed. RESULTS The probiotic and placebo groups were similar in age, gender, and health history at baseline. S. aureus colonization within the stool samples of the extra-GI group was 15% lower in the probiotic than placebo group at the endpoint of the trial. Those in the probiotic group compared to the placebo group had 73% reduced odds (OR 0.27, 95% CI 0.07-0.98) of methicillin-susceptible S. aureus presence, and 83% reduced odds (OR 0.17, 95% CI 0.04-0.73) of any S. aureus presence in the stool sample at endpoint. CONCLUSION Use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01321606 . Registered March 21, 2011.
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Disruption of the Gut Ecosystem by Antibiotics.
Yoon, MY, Yoon, SS
Yonsei medical journal. 2018;59(1):4-12
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The gut microbiome is a complex ecosystem of different micro-organisms, such as bacteria, viruses and fungi, living in the human intestines. It’s involved in numerous functions, such as extracting energy and nutrition from food, protecting against disease-causing microorganisms, and supporting the immune system of the host, and therefore affecting human health and disease. This paper is a review of studies on the effects of antibiotics on the gut microbiota. It outlines how different types of antibiotics can alter the intestinal environment and the composition of the microbes, resulting in various physiological changes that can trigger disease. Relevant mechanisms, such as inflammatory response and the use of intestinal nutrients by infectious bacteria are discussed. Finally, it discusses faecal microbiota transplantation (FMT) and probiotics as treatment approaches, aimed at restoring a disturbed intestinal environment.
Abstract
The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.
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Crosstalk between the microbiome and epigenome: messages from bugs.
Qin, Y, Wade, PA
Journal of biochemistry. 2018;163(2):105-112
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Trillions of microbes live symbiotically in and on an individual human being, most of them inside the digestive tract and communally known as the gut microbiome. The gut microbiome plays a vital role in the individual host’s health, not only by helping digest food and harvest energy, but also by regulating immune development and influencing gene expression. Diet and factors, such as infections and the use of antibiotics, can alter the balance of the microbiome and lead to various outcomes. This paper reviewed the current understanding of the ways in which the gut microbiome is capable of altering the host’s gene expression through microbial signals, including metabolites, bile acids, inflammation and altered composition. The studies highlighted in the paper show that gut microbes communicate both with local cells in the intestines and with more distant organs, such as the liver and the cardiovascular system. Through this communication, they can regulate the expression of immune cells, cancer cells, enzymes and inflammation-related molecules. The authors concluded that these interactions, or the crosstalk between the microbes and the host, demonstrate a crucial role of the gut microbiome in the host’s response to environmental signals. However, many of the mechanisms are still unclear, so further studies are needed to explain specific microbe-derived signals, affecting host gene expression, and to deepen our understanding of how lifestyle, health status and environmental exposures, such as antibiotics, regulate the microbiome and its influence.
Abstract
Mammals exist in a complicated symbiotic relationship with their gut microbiome, which is postulated to have broad impacts on host health and disease. As omics-based technologies have matured, the potential mechanisms by which the microbiome affects host physiology are being addressed. The gut microbiome, which provides environmental cues, can modify host cell responses to stimuli through alterations in the host epigenome and, ultimately, gene expression. Increasing evidence highlights microbial generation of bioactive compounds that impact the transcriptional machinery in host cells. Here, we review current understanding of the crosstalk between gut microbiota and the host epigenome, including DNA methylation, histone modification and non-coding RNAs. These studies are providing insights into how the host responds to microbial signalling and are predicted to provide information for the application of precision medicine.
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Effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota, short chain fatty acids, and immune activation in patients with irritable bowel syndrome: A pilot randomized clinical trial.
Cremon, C, Guglielmetti, S, Gargari, G, Taverniti, V, Castellazzi, AM, Valsecchi, C, Tagliacarne, C, Fiore, W, Bellini, M, Bertani, L, et al
United European gastroenterology journal. 2018;6(4):604-613
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Intestinal bacteria have a role to play in the development and symptoms of irritable bowel syndrome (IBS). The objective of this randomised controlled trial was to assess the effects of Lactobacillus paracasei CNCM I-1572 on clinical and gut microbiota-related factors in IBS. Forty IBS patients took part in the trial, and took either the probiotic or a placebo for four weeks. Lactobacillus paracasei CNCM I-1572 did not significantly improve IBS symptoms such as abdominal pain and discomfort. It did however induce a significant reduction in Ruminococcus, which has previously been associated with IBS. Patients taking the probiotic also showed a significant increase in the short chain fatty acids (SCFAs) acetate and butyrate, and a significant reduction in the pro-inflammatory cytokine interleukin-15. This pilot study shows that Lactobacillus paracasei CNCM I-1572 is able to modulate gut microbiota structure/function and reduce immune activation in IBS. As no statistically significant effect on IBS symptoms was found, further studies are necessary to determine the role of this probiotic in IBS.
Abstract
BACKGROUND Evidence suggests a role of intestinal microbiota-host interactions in the pathophysiology and symptoms of irritable bowel syndrome (IBS). OBJECTIVE The objective of this article is to assess the effects of Lactobacillus paracasei CNCM I-1572 on clinical and gut microbiota-related factors in IBS. METHODS We conducted a multicenter, randomized, double-blind, cross-over, 18-week, placebo-controlled, pilot trial assessing the effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota composition, fecal short chain fatty acid (SCFA), immunoglobulin A, and cytokines in IBS. The intestinal microbial ecosystem was characterized by 16S rRNA gene profiling. RESULTS Forty IBS patients were enrolled from five Italian centers. Lactobacillus paracasei CNCM I-1572 did not significantly improve IBS symptoms, including primary efficacy variables worst abdominal pain/discomfort and IBS degree of relief. Interestingly, Lactobacillus paracasei CNCM I-1572 induced a significant reduction in genus Ruminococcus, dominated by taxa related to Ruminococcus bromii and Ruminococcus callidus, a significant increase in the SCFAs acetate and butyrate, and a significant reduction in the pro-inflammatory cytokine interleukin-15. CONCLUSIONS This pilot study shows that Lactobacillus paracasei CNCM I-1572 is able to modulate gut microbiota structure/function and reduce immune activation in IBS. As no statistically significant effect on IBS-symptoms was found, further studies are necessary to determine the role of this probiotic in IBS. The study was registered at ClinicalTrials.gov registry under identifier NCT02371499.
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Effects of the Administration of Probiotics on Fecal Microbiota Diversity and Composition in Healthy Individuals.
Noh, CK, Kim, BS, Hong, G, Cheong, JY, Lee, KJ
Journal of neurogastroenterology and motility. 2018;24(3):452-459
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Probiotics are popular health supplements taken by the general population. The influence of probiotics on the composition of gut microbiota has not been fully evaluated, and the duration of the effects of probiotics administration is still unclear. This study aimed to investigate the changes in the composition and diversity of gut microbiota by the administration of probiotics in healthy individuals. The study was carried out in Korea. 12 healthy volunteers aged between 30 and 42 years were given probiotic capsules containing five billion colony forming units of a mixture Bifidobacterium, Lactobacillus, and Enterococcus for four weeks. Stool samples were collected at the beginning of the study, after four weeks of probiotics, and again two weeks after stopping the probiotics. The overall diversity of faecal microbiota was not significantly altered by the probiotics, but significantly decreased two weeks after stopping them. The composition of faecal microbiota was not significantly changed by the probiotics at the phylum level, but the proportions of Bacteroidetes and Actinobacteria significantly changed 2 weeks after stopping the probiotics. The proportions of Lactobacillus and Enterococcus were significantly increased by the probiotics, but the proportions of Bifidobacterium, Lactobacillus, and Enterococcus decreased two weeks after stopping the probiotics. There was no difference in the levels of calprotectin between the start and end of the study. The authors concluded that the proportion of faecal microbiota at the genus level, but not diversity, is significantly altered by the administration of probiotics in healthy people. This effect does not seem to last long, probably because of homeostasis or dietary influence.
Abstract
BACKGROUND/AIMS: Probiotics are expected to modify the composition of gut microbiota. We aimed to investigate the changes in the composition and diversity of gut microbiota by the administration of probiotics in healthy individuals. METHODS Twelve healthy volunteers with age range of 30-42 years provided baseline fecal samples. Subsequently, they took commercially available probiotic capsules (a mixture for Bifidobacterium, Lactobacillus, and Enterococcus) for 4 weeks. Fecal samples were collected at 4 weeks of administration and 2 weeks after the stop of administration. Fecal microbiota was analyzed via 16S ribosomal RNA gene sequencing. RESULTS The mean Shannon index was not significantly altered by the 4-week administration of probiotics (4.365 vs 4.556, P > 0.05). The proportion of Bacteroidetes, Actinobacteria, Firmicutes , and Proteobacteria was not significantly changed by the 4-week administration of probiotics. At the genus level, the proportions of Lactobacillus (2.138% vs 2.773%, P = 0.028) and Enterococcus (0.022% vs 2.758%, P = 0.004) significantly increased 4 weeks after the administration of probiotics, but reduced 2 weeks after the stop of administration (2.773% vs 3.292%, P = 0.064 and 2.758% vs 0.001%, P = 0.001). CONCLUSIONS The diversity of fecal microbiota is not significantly affected by 4 weeks of probiotics administration. The proportion of fecal microbiota at the genus level is significantly altered by the administration of probiotics. However, this effect does not seem to last long, probably because of homeostasis or dietary influence.
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Increased richness and diversity of the vaginal microbiota and spontaneous preterm birth.
Freitas, AC, Bocking, A, Hill, JE, Money, DM
Microbiome. 2018;6(1):117
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The bacterial community in the female lower genital tract plays an important role in the health of both mother and baby. Imbalances in the vaginal microbiota have been associated with negative reproductive outcomes, such as premature birth. Bacterial infection is thought to be an important contributor to the onset of premature labour. The objective of this study was to compare the vaginal microbiota of pregnant women who had premature births (<37 weeks) with those of pregnant women who delivered at term. Vaginal swabs were collected from 216 Canadian women at 11-16 weeks of gestational age. Of these, 170 pregnancies went to full term, and 46 women had premature births. The vaginal microbiota of women who experienced premature birth had higher richness and diversity and higher Mollicutes prevalence when compared to those of women who delivered at term. The results confirm previous reports of an association between Mollicutes and premature birth and suggest that a more diverse microbiome may contribute to the microbiome’s role in premature births.
Abstract
BACKGROUND The bacterial community present in the female lower genital tract plays an important role in maternal and neonatal health. Imbalances in this microbiota have been associated with negative reproductive outcomes, such as spontaneous preterm birth (sPTB), but the mechanisms underlying the association between a disturbed microbiota and sPTB remain poorly understood. An intrauterine infection ascending from the vagina is thought to be an important contributor to the onset of preterm labour. Our objective was to characterize the vaginal microbiota of pregnant women who had sPTB (n = 46) and compare to those of pregnant women who delivered at term (n = 170). Vaginal swabs were collected from women at 11-16 weeks of gestational age. Microbiota profiles were created by PCR amplification and pyrosequencing of the cpn60 universal target region. RESULTS Profiles clustered into seven community state types: I (Lactobacillus crispatus dominated), II (Lactobacillus gasseri dominated), III (Lactobacillus iners dominated), IVA (Gardnerella vaginalis subgroup B or mix of species), IVC (G. vaginalis subgroup A dominated), IVD (G. vaginalis subgroup C dominated) and V (Lactobacillus jensenii dominated). The microbiota of women who experienced preterm birth (< 37 weeks gestation) had higher richness and diversity and higher Mollicutes prevalence when compared to those of women who delivered at term. The two groups did not cluster according to CST, likely because CST assignment is driven in most cases by the dominance of one particular species, overwhelming the contributions of more rare taxa. In conclusion, we did not identify a specific microbial community structure that predicts sPTB, but differences in microbiota richness, diversity and Mollicutes prevalence were observed between groups. CONCLUSIONS Although a causal relationship remains to be determined, our results confirm previous reports of an association between Mollicutes and sPTB and further suggest that a more diverse microbiome may be important in the pathogenesis of some cases.
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Vaginal dysbiosis increases risk of preterm fetal membrane rupture, neonatal sepsis and is exacerbated by erythromycin.
Brown, RG, Marchesi, JR, Lee, YS, Smith, A, Lehne, B, Kindinger, LM, Terzidou, V, Holmes, E, Nicholson, JK, Bennett, PR, et al
BMC medicine. 2018;16(1):9
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Preterm premature rupture of the membranes (PPROM) is a pregnancy complication in which the amniotic sac ruptures before week 37 of the pregnancy, leading to an increased risk of infection and premature birth. Women who experience PPROM are usually given antibiotics to help prevent infections which, left untreated, could endanger their babies’ lives. It is thought that disturbances in the mum’s vaginal bacteria may be related to the risk of PPROM. In this study, researchers examined the vaginal bacteria of women with PPROM, before and after antibiotic treatment. A total of 250 pregnant women who had been identified as at risk of a premature birth were included in the study. Disturbance of the normal vaginal bacteria, characterised by low levels of Lactobacillus, was present in a third of women who went on to develop PPROM. This disturbance of the normal vaginal bacteria was made worse by antibiotic treatment particularly in women initially colonised by Lactobacillus spp. Lower levels of Lactobacillus and increased abundance of Sneathia spp. were associated with an increased likelihood of funisitis (inflammation of the umbilical cord) and sepsis in the newborn. The authors concluded that the composition of the vaginal microbiota is a risk factor for PPROM and is associated with unfavourable short-term outcomes for the mother and newborn. This highlights vaginal microbiota as a potentially modifiable risk factor for PPROM and they suggest that the routine use of antibiotics such as erythromycin for PPROM should be re-examined.
Abstract
BACKGROUND Preterm prelabour rupture of the fetal membranes (PPROM) precedes 30% of preterm births and is a risk factor for early onset neonatal sepsis. As PPROM is strongly associated with ascending vaginal infection, prophylactic antibiotics are widely used. The evolution of vaginal microbiota compositions associated with PPROM and the impact of antibiotics on bacterial compositions are unknown. METHODS We prospectively assessed vaginal microbiota prior to and following PPROM using MiSeq-based sequencing of 16S rRNA gene amplicons and examined the impact of erythromycin prophylaxis on bacterial load and community structures. RESULTS In contrast to pregnancies delivering at term, vaginal dysbiosis characterised by Lactobacillus spp. depletion was present prior to the rupture of fetal membranes in approximately a third of cases (0% vs. 27%, P = 0.026) and persisted following membrane rupture (31%, P = 0.005). Vaginal dysbiosis was exacerbated by erythromycin treatment (47%, P = 0.00009) particularly in women initially colonised by Lactobacillus spp. Lactobacillus depletion and increased relative abundance of Sneathia spp. were associated with subsequent funisitis and early onset neonatal sepsis. CONCLUSIONS Our data show that vaginal microbiota composition is a risk factor for subsequent PPROM and is associated with adverse short-term maternal and neonatal outcomes. This highlights vaginal microbiota as a potentially modifiable antenatal risk factor for PPROM and suggests that routine use of erythromycin for PPROM be re-examined.