Effect of probiotic supplementation in pregnant women: a meta-analysis of randomised controlled trials

Probiotics in the Prophylaxis of Premature Rupture of Membranes and Cervical Incompetence

Premature rupture of membranes (PROM) and cervical incompetence (CI) are major contributors to preterm birth, a leading cause of neonatal morbidity and mortality.

BACKGROUND/OBJECTIVES

Disorders of the vaginal microbiota, such as bacterial vaginosis, have been associated with an increased risk of PROM, CI, and subsequent preterm birth. Probiotics, particularly Lactobacillus strains, have been proposed as a preventive strategy to restore and maintain a healthy vaginal microbiome. This review aims to summarize the latest evidence on the role of probiotics in the prevention of PROM and CI.

METHODS

A comprehensive review was conducted to evaluate the effectiveness of probiotic interventions in the prevention of PROM and CI, yielding 1809 records from 2005 to 2024. Seven relevant studies were selected by searching medical databases and focusing on studies that investigated the restoration of healthy vaginal flora, the reduction of pathogenic bacteria colonization, and the modulation of immune responses by probiotics.

RESULTS

The studies analyzed suggest that probiotics may help restore healthy vaginal flora, reduce pathogenic bacterial colonization, and modulate immune responses, thereby reducing the risk of membrane rupture and cervical insufficiency. Evidence from randomized controlled trials and observational studies shows that the use of probiotics is associated with a lower incidence of PROM and preterm birth, especially in high-risk groups.

CONCLUSIONS

Probiotics emerge as a potential non-invasive and cost-effective strategy to improve pregnancy outcomes in women at risk of preterm birth due to PROM. According to our research, probiotic prophylaxis of cervical insufficiency has not yet been sufficiently investigated. Despite the promising findings, further research is needed to determine standardized probiotic formulations, optimal timing, and routes of administration. Personalized probiotic therapies may represent the future of preterm birth prevention as they offer targeted interventions based on individual microbiome composition.

Microbiota-targeted interventions and clinical implications for maternal-offspring health: An umbrella review of systematic reviews and meta-analyses of randomised controlled trials

Background

Microbes in the human body are the determinants of life-long health and disease. Microbiome acquisition starts in utero and matures during early childhood through breastfeeding. However, maternal gut dysbiosis affects the maternal-offspring microbiome interplay. Lines of evidence on dysbiosis-targeted interventions and their effect on maternal-offspring health and gut microbiome are inconsistent and inconclusive. Therefore, this study summarised studies to identify the most common microbiota-targeted intervention during pregnancy and lactation and to comprehensively evaluate its effects on maternal and offspring health.

Methods

This umbrella review was conducted by systematically searching databases such as PubMed and the Web of Science from inception to 2 September 2023. The quality was assessed using the Assessment of Multiple Systematic Reviews-2 checklist. The Grading of Recommendations Assessment, Development, and Evaluation was used for grading the strength and certainty of the studies. The overlap of primary studies was quantified by the corrected covered area score.

Results

A total of 17 systematic reviews and meta-analyses with 219 randomised controlled trials, 39 113 mothers, and 20 915 infants were included in this study. About 88% of studies had moderate and above certainty of evidence. Probiotics were the most common and effective interventions at reducing gestational diabetes risk (fasting blood glucose with the mean difference (MD) = -2.92, -0.05; I2 = 45, 98.97), fasting serum insulin (MD = -2.3, -2.06; I2 = 45, 77), glycated haemoglobin (Hb A1c) = -0.16; I2 = 0.00)), Homeostatic Model Assessment of insulin resistance (HOMA-IR) (MD = -20.55, -0.16; I2 = 0.00, 72.00), and lipid metabolism (MD = -5.47, 0.98; I2 = 0.00, 90.65). It was also effective in preventing and treating mastitis (risk ratio (RR) = 0.49; I2 = 2.00), relieving anxiety symptoms (MD = -0.99, 0.01; I2 = 0.00, 70.00), depression in lactation (MD = -0.46, -0.22; I2 = 0.00, 74.00) and reducing recto-vaginal bacterial colonisation (odds ratio (OR) = 0.62; I2 = 4.80), and with no adverse events. It also effectively remodelled the infant gut microbiome (MD = 0.89; I2 = 95.01) and prevented infant allergies. However, studies on pregnancy outcomes and preeclampsia incidences are limited.

Conclusions

Our findings from high-quality studies identify that probiotics are the most common microbiome interventions during pregnancy and lactation. Probiotics have a strong impact on maternal and offspring health through maintaining gut microbiome homeostasis. However, further studies are needed on the effect of microbiota-targeted interventions on maternal cardiometabolic health, pregnancy, and neonatal outcomes.

Registration

This umbrella review was registered with PROSPERO, CRD42023437098.

Should Pregnant Women Consume Probiotics to Combat Endocrine-Disrupting Chemical-Induced Health Risks to Their Unborn Offspring?

Endocrine-disrupting chemicals (EDCs) have become so pervasive in our environment and daily lives that it is impossible to avoid contact with such compounds, including pregnant women seeking to minimize exposures to themselves and their unborn children. Developmental exposure of humans and rodent models to bisphenol A (BPA) and other EDCs is linked to increased anxiogenic behaviors, learning and memory deficits, and decreased socio-sexual behaviors. Prenatal exposure to BPA and other EDCs leads to longstanding and harmful effects on gut microbiota with reductions in beneficial bacteria, i.e., gut dysbiosis, and such microbial changes are linked to host changes in fecal metabolites, including those involved in carbohydrate metabolism and synthesis, and neurobehavioral alterations in adulthood, in particular, social and cognitive deficits. Gut dysbiosis is increasingly being recognized as a key driver of a myriad of diseases, ranging from metabolic, cardiovascular, reproductive, and neurobehavioral disorders via the gut-microbiome-brain axis. Thus, EDCs might induce indirect effects on physical and mental health by acting as microbiome-disrupting chemicals. Findings raise the important question as to whether pregnant women should consume a probiotic supplement to mitigate pernicious effects of EDCs, especially BPA, on themselves and their unborn offspring. Current studies investigating the effects of maternal probiotic supplementation on pregnant women's health and that of their unborn offspring will be reviewed. Data will inform on the potential application of probiotic supplementation to reverse harmful effects of EDCs, especially BPA, in pregnant women unwittingly exposed to these compounds and striving to give their offspring the best start in life.

Comparison of the effectiveness of probiotic supplementation in glucose metabolism, lipid profile, inflammation and oxidative stress in pregnant women

Objective: The optimal probiotic supplementation in pregnant women has not been thoroughly evaluated. By employing a network meta-analysis (NMA) approach, we compared the effectiveness of different probiotic supplementation strategies for pregnant women. Methods: A comprehensive search across multiple databases was performed to identify studies comparing the efficacy of probiotic supplements with each other or the control (placebo) among pregnant women. Results: This NMA, including 32 studies, systematically evaluated 6 probiotic supplement strategies: Lactobacillus, Lacticaseibacillus rhamnosus and Bifidobacterium (LRB), Lactobacillus acidophilus and Bifidobacterium (LABB), Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum (LLB), multi-combination of four probiotics (MP1), and multi-combination of six or more probiotics (MP2). Among these strategies, LLB, MP1, and MP2 all contain LABB. The NMA findings showed that MP1 was the most effective in reducing fasting blood sugar (FBS) (surface under the cumulative ranking curve [SUCRA]: 80.5%). In addition, MP2 was the most efficacious in lowering the homeostasis model assessment of insulin resistance (HOMA-IR) (SUCRA: 89.1%). LABB was ranked as the most effective in decreasing low-density lipoprotein cholesterol (LDLC) (SUCRA: 95.5%), total cholesterol (TC) (SUCRA: 95.5%), and high-sensitivity C-reactive protein (hs-CRP) (SUCRA: 94.8%). Moreover, LLB was ranked as the most effective in raising total antioxidant capacity (TAC) (SUCRA: 98.5%). Conclusion: Multi-combination of probiotic strains, especially those strategies containing LABB, may be more effective than a single probiotic strain in glycolipid metabolism, inflammation, and oxidative stress of pregnant women.

Review article: Functional dyspepsia and pregnancy-Effects and management in a special population

BACKGROUND

Around 10% of Americans meet the Rome IV criteria for functional dyspepsia (FD), with a significantly higher rate in women. FD also has a higher prevalence in women below the age of 50, suggesting that women who are affected are likely to be of reproductive age. Unfortunately, there is a lack of research or evidence-based guidelines on managing FD in pregnancy.

AIMS AND METHODS

To address this issue, we aimed to perform a systematic review of the interactions between FD and pregnancy and managing pre-existing FD in the peripartum and post-partum phases using current lifestyle, pharmacological, non-pharmacological and alternative medicine interventions.

RESULTS

Due to the lack of Rome IV FD-specific data in pregnancy, we instead performed a narrative review on how existing FD interventions could be extrapolated to the pregnant population. Where possible we use the highest level of available evidence or official guidelines to answer these questions, which often involves synthesising treatment and safety evidence of these interventions in other diseases during pregnancy. Finally, we highlight current substantial knowledge gaps requiring further research for the safe management of a pregnant patient with pre-existing FD.

CONCLUSIONS

Overall, despite the paucity of knowledge of treating FD during pregnancy, providers can mitigate this uncertainty by planning ahead with the patient. Patients should ideally minimise treatment until after breastfeeding. However, interdisciplinary resources are available to ensure that minimal-risk interventions are maximised, while interventions with more risks, if necessary, are justifiable by both the patient and the care team. Future investigations should continue to elicit the mechanistic relationship between FD and pregnancy while cautiously expanding prospective research on promising and safe therapies in pregnant patients with pre-existing FD.

Drug-Induced Microbiome Changes: Considerations in Pregnancy

During pregnancy, the maternal microbiome is associated with both the health of the mother as well as the developing fetus. Several classes of drugs are known to influence the microbiome and their use in pregnancy may impact maternal/fetal outcomes and long-term health of offspring. The drug-microbiome interactions of antibiotics, proton pump inhibitors, laxatives, metformin, and probiotics will be described, along with considerations for use of these agents in pregnancy.

Lactobacillus rhamnosus Used in the Perinatal Period for the Prevention of Atopic Dermatitis in Infants: A Systematic Review and Meta-Analysis of Randomized Trials

Background

Numerous systematic reviews and meta-analyses have examined the effects of probiotics used perinatally on prevention or treatment of atopic disease in infants and children. However, to date, no review has examined randomized controlled trials of Lactobacillus rhamnosus, specifically, administered both prenatally and postnatally and its effect over a long period of time.

Objective

The objective was to determine if L. rhamnosus either used solely or in conjunction with other probiotics demonstrates a long-term preventive effect on atopic disease in pediatric patients when used perinatally.

Methods

A systematic review was undertaken to identify those studies where L. rhamnosus was used (either solely or in conjunction with other probiotics). The following databases were searched from the year 2000 through December 8, 2021: PubMed, Cochrane Reviews and Cochrane Central Database of Controlled Trials; systematic reviews were hand searched to identify randomized controlled trials (RCTs). Meta-analytic statistical techniques were then employed. Evaluation of the incidence of atopic eczema was also examined longitudinally based on timeframe. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessments were employed to determine the quality of the evidence.

Results

Eleven randomized controlled trials were identified which examined L. rhamnosus in its effect on atopy. Risk of bias was low on the majority of the domains assessed. Meta-analysis of the timeframes ≤ 2 years (RR 0.60, 95% CI 0.47–0.75; p < 0.00001) and 6–7 years (RR 0.62, 95% CI 0.50–0.75; p < 0.00001) demonstrated statistically significant reductions in atopic eczema with use of L. rhamnosus. For the 4 to 5-year (RR 0.74, 95% CI 0.55–1.00; p = 0.05) and 10–11-year (RR 0.68, 95% CI 0.37–1.27; p = 0.23) timeframes there was no statistically significant reduction. GRADE assessment for each timeframe was considered moderate in two, owing to high attrition rates in all of the studies, and low in two due to imprecision.

Conclusion

Based on the meta-analysis and GRADE assessments, the use of L. rhamnosus with or without other probiotics appears to have a positive effect in reducing the incidence of atopic eczema in pediatric patients at least out to 7 years. Attrition rates temper these findings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40257-022-00723-x.

What's new in atopic eczema? An analysis of systematic reviews published in 2019. Part 1: Risk factors and prevention

This review is part of an annual evidence update on atopic eczema (AE), providing a summary of key findings from 18 systematic reviews published in 2019 on AE risk factors and prevention. Parental atopy, particularly AE, is a risk factor for offspring AE, and this risk is augmented both by the number of parental atopic diseases present and the number of affected parents. Low-quality evidence suggests that autumn or winter birth increases childhood AE risk compared with birth in spring. There is some evidence to support filaggrin gene-environment interactions; however, this is limited by small underpowered studies. There is no evidence to suggest that polymorphisms in the -1082, -592 and -819 loci of the interleukin-10 gene increase susceptibility to AE. There is no robust evidence to support a relationship between childhood AE development and either yoghurt consumption in the first year of life, gut microbiota variants, prenatal or infantile paracetamol exposure, maternal antibiotic exposure or air pollution. Three systematic reviews investigated the effect of probiotics given during pregnancy or infancy; although low-quality evidence suggests benefits of combined probiotics, these studies were limited by significant heterogeneity. No relationship between the age at which complementary food and beverages are introduced and the risk of developing AE in infancy was identified. Consistent evidence showed no relationship between human milk feeding and infant AE development, aside from limited evidence suggesting a protective role in those with atopic heredity. This summary of recent evidence related to AE risk factors and prevention highlights the complex aetiology of AE.

The evidence for interventions in early childhood allergy prevention - towards a living systematic review: protocol

Background: Research in early childhood allergy prevention (ECAP) is flourishing and new intervention strategies have proven to be promising. Due to the dynamic nature of ECAP, gaps between what is known and how guidelines inform practice are likely. A living systematic review (LSR) can narrow this gap by incorporating new evidence as it becomes available. No efficacy comparisons across various ECAP interventions for similar outcomes have been carried out. Networks of randomised clinical trials can be evaluated in the context of a network meta-analysis (NMA). We aim to establish a LSR on the efficacy and safety of any intervention investigated in randomised controlled trials (RCT) to prevent the occurrence of allergic sensitisation (AS), symptoms or diagnoses of allergic diseases in infancy and early childhood (0-3 years). Methods: A baseline SR will synthesise the evidence from existing SRs of RCTs as well as RCTs not yet considered in these. After completion of the baseline SR we propose to conduct a LSR. Using this methodology, we aim to undertake constant evidence surveillance, three-monthly search updates, and review updates every three months, should new evidence emerge. Conclusions: The ECAP evidence landscape has undergone dramatic transformations and this process is likely to continue. As a response to this, a LSR offers the potential to allow more timely synthesis of new evidence as it emerges. Long gaps between updates of SRs makes it harder for guidelines and recommendations to be up to date. Users of information, such as parents, may be confused if they encounter new evidence that is not part of a trusted guideline. A LSR approach allows us to continuously search the literature and update the evidence-base of existing ECAP interventions resulting in a decreased timespan from evidence accrual to informing clinical practice.

The evidence for interventions in early childhood allergy prevention - towards a living systematic review: protocol

Background: Research in early childhood allergy prevention (ECAP) is flourishing and new intervention strategies have proven to be promising. Due to the dynamic nature of ECAP, gaps between what is known and how guidelines inform practice are likely. A living systematic review (LSR) can narrow this gap by incorporating new evidence as it becomes available. No efficacy comparisons across various ECAP interventions for similar outcomes have been carried out. Networks of randomised clinical trials can be evaluated in the context of a network meta-analysis (NMA). We aim to establish a LSR on the efficacy and safety of any intervention investigated in randomised controlled trials (RCT) to prevent the occurrence of allergic sensitisation (AS), symptoms or diagnoses of allergic diseases in infancy and early childhood (0-3 years). Methods: A baseline SR will synthesise the evidence from existing SRs of RCTs as well as RCTs not yet considered in these. After completion of the baseline SR we propose to conduct a LSR. Using this methodology, we aim to undertake constant evidence surveillance, three-monthly search updates, and review updates every three months, should new evidence emerge. Conclusions: The ECAP evidence landscape has undergone dramatic transformations and this process is likely to continue. As a response to this, a LSR offers the potential to allow more timely synthesis of new evidence as it emerges. Long gaps between updates of SRs makes it harder for guidelines and recommendations to be up to date. Users of information, such as parents, may be confused if they encounter new evidence that is not part of a trusted guideline. A LSR approach allows us to continuously search the literature and update the evidence-base of existing ECAP interventions resulting in a decreased timespan from evidence accrual to informing clinical practice.

Reporting of Perinatal Outcomes in Probiotic Randomized Controlled Trials. A Systematic Review and Meta-Analysis

The use of probiotic microorganisms in clinical practice has increased in recent years and a significant number of pregnant women are regular consumers of these products. However, probiotics might modulate the immune system, and whether or not this modulation is beneficial for perinatal outcomes is unclear. We performed a systematic review and meta-analysis to evaluate the reporting of perinatal outcomes in randomized controlled trials including women supplemented with probiotic microorganisms during pregnancy. We also analyzed the effects that the administration of probiotic microorganisms exerts on perinatal outcomes. In the review, 46 papers were included and 25 were meta-analyzed. Reporting of perinatal outcomes was highly inconsistent across the studies. Only birth weight, cesarean section, and weeks of gestation were reported in more than 50% of the studies. Random effects meta-analysis results showed that the administration of probiotic microorganisms during pregnancy did not have any a positive or negative impact on the perinatal outcomes evaluated. Subgroup analysis results at the strain level were not significantly different from main analysis results. The administration of probiotic microorganisms does not appear to influence perinatal outcomes. Nonetheless, future probiotic studies conducted in pregnant women should report probiotic strains and perinatal outcomes in order to shed light upon probiotics' effects on pregnancy outcomes.

Targeting the perinatal diet to modulate the gut microbiota increases dietary variety and prebiotic and probiotic food intakes: results from a randomised controlled trial

OBJECTIVE

To evaluate the hypothesis that a perinatal educational dietary intervention focused on 'eating for the gut microbiota' improves diet quality of pregnant women pre- and postnatally.

DESIGN

The Healthy Parents, Healthy Kids study is a prospectively registered randomised controlled trial designed to evaluate the efficacy of a dietary intervention in altering the maternal and infant gut microbiota and improving perinatal diet quality. Eligible pregnant women were randomised to receive dietary advice from their healthcare provider or to additionally receive a three session dietary intervention. Dietary data were collected at gestation weeks 26, 31, 36 and postnatal week 4. Outcome measures were diet quality, dietary variety, prebiotic and probiotic food intakes, energy, fibre, saturated fat and discretionary food intakes. Between-group differential changes from baseline before and after birth in these dietary measures were assessed using generalised estimating equations.

SETTING

Melbourne, Australia.

PARTICIPANTS

Healthy pregnant women from gestation week 26.

RESULTS

Forty-five women were randomised (twenty-two control, twenty-three intervention). Compared with the control group, the intervention group improved diet quality prior to birth (5·66 (95 % CI 1·65, 9·67), Cohen's d: 0·82 (se 0·33)). The intervention improved dietary variety (1·05 (95 % CI 0·17, 1·94), d: 0·66 (se 0·32)) and increased intakes of prebiotic (0·8 (95 % CI 0·27, 1·33), d: 0·91 (se 0·33)) and probiotic foods (1·05 (95 % CI 0·57, 1·53), d: 1·3(se 0·35)) over the whole study period compared with the control group.

CONCLUSION

A dietary intervention focused on 'eating for the gut microbiota' can improve aspects of perinatal diet quality during and after pregnancy.

The effect of probiotic supplementation during pregnancy on the interaction network of vaginal microbiome

AIM

To evaluate the effect of probiotic supplementation on the vaginal microbiome and provide the effective evidences for clinical management of pregnant women.

METHODS

A total of 28 healthy pregnant women at 32 weeks of gestation were enrolled. The women were divided randomly to the probiotic group where they were prescribed with 2 g combined probiotics daily (13 cases) during the third trimester of pregnancy or to the control group (15 cases) on a voluntary basis. Their vaginal samples were taken for analyzing microbiome with the 16S rDNA amplicon sequencing of V4 region.

RESULTS

There was no significant difference on the clinical characteristics between the probiotic and control groups. The complexity of vaginal microbial network increased from 32 weeks of gestation to antepartum. Lactobacillus was the dominant microbiota. The probiotic supplementation had no obvious influence on the structure of the vaginal microbiome, whereas the relationships of some pivotal vaginal microbiota at the genus level changed in the probiotic group.

CONCLUSION

The vaginal microbiome varied during the third trimester of pregnancy. The features of the vaginal microbiota after probiotic supplementation had shifted and the interaction network had the tendency to be loose. The probiotic supplementation may be useful in regulating the interaction network of vaginal microbiome.

Probiotics and Probiotic-Derived Functional Factors-Mechanistic Insights Into Applications for Intestinal Homeostasis

Advances in our understanding of the contribution of the gut microbiota to human health and the correlation of dysbiosis with diseases, including chronic intestinal conditions such as inflammatory bowel disease (IBD), have driven mechanistic investigations of probiotics in intestinal homeostasis and potential clinical applications. Probiotics have been shown to promote intestinal health by maintaining and restoring epithelial function, ensuring mucosal immune homeostasis, and inhibiting pathogenic bacteria. Recent findings reveal an approach for defining previously unrecognized probiotic-derived soluble factors as potential mechanisms of probiotic action. This review focuses on the impact of probiotics and probiotic-derived functional factors, including probiotic products and metabolites by probiotics, on the cellular responses and signaling pathways involved in maintaining intestinal homeostasis. Although there is limited information regarding the translation of probiotic treatment outcomes from in vitro and animal studies to clinical applications, potential approaches for increasing the clinical efficacy of probiotics for IBD, such as those based on probiotic-derived factors, are highlighted in this review. In this era of precision medicine and targeted therapies, more basic, preclinical, and clinical evidence is needed to clarify the efficacy of probiotics in maintaining intestinal health and preventing and treating disease.

Neonatal intestinal dysbiosis

The initial colonization of the neonatal intestinal tract is influenced by delivery mode, feeding, the maternal microbiota, and a host of environmental factors. After birth, the composition of the infant's microbiota undergoes a series of significant changes particularly in the first weeks and months of life ultimately developing into a more stable and diverse adult-like population in childhood. Intestinal dysbiosis is an alteration in the intestinal microbiota associated with disease and appears to be common in neonates. The consequences of intestinal dysbiosis are uncertain, but strong circumstantial evidence and limited confirmations of causality suggest that dysbiosis early in life can influence the health of the infant acutely, as well as contribute to disease susceptibility later in life.