Perinatal outcomes of prenatal probiotic and prebiotic administration: an integrative review

Effect of probiotic administration during pregnancy on the functional diversity of the gut microbiota in healthy pregnant women

Our study aims to investigate the impact of probiotic consumption during pregnancy on gut microbiota functional diversity in healthy pregnant women. Thirty-two pregnant women were randomly assigned to two groups. The probiotic group (PG) consisted of pregnant women who consumed triple viable Bifidobacterium longum, Lactobacillus delbrueckii bulgaricus, and Streptococcus thermophilus tablets from the 32nd week of pregnancy until delivery. The functional profiles of the gut microbiota were predicted through high-throughput 16S rRNA sequencing results using PICRUSt software and referencing the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In the gut microbiota of the PG, the genera Blautia and Ruminococcus, as well as the species Subdoligranulum, showed significantly higher relative abundances compared to the control group (CG) (P < 0.05). At Level 1 of the KEGG signaling pathways, there was a significant reduction in the functional genes of the gut microbiota involved in Organismal Systems in the PG (P < 0.05). In Level 2 of the KEGG signaling pathways, there was a significant reduction in the functional genes of the gut microbiota involved in Infectious Disease in the PG (P < 0.05). In Level 3 of the KEGG signaling pathways, the PG exhibited a significant increase in the functional genes of the gut microbiota involved in ABC transporters, Oxidative phosphorylation, Folate biosynthesis, and Biotin metabolism (P < 0.05). The CG showed a significant increase in the functional genes related to Cysteine and methionine metabolism, Vitamin B6 metabolism, Tuberculosis, and Vibrio cholerae pathogenic cycle (P < 0.05). In conclusion, our findings suggest that probiotic supplementation during pregnancy has a significant impact on functional metabolism in healthy pregnant women.

IMPORTANCE

Probiotics are considered beneficial to human health. There is limited understanding of how probiotic consumption during pregnancy affects the functional diversity of the gut microbiota. The aim of our study is to investigate the impact of probiotic consumption during pregnancy on the functional diversity of the gut microbiota. Our findings suggest that probiotic supplementation during pregnancy has a significant impact on functional metabolism. This could potentially open up new avenues for preventing various pregnancy-related complications. This also provides new insights into the effects of probiotic consumption during pregnancy on the gut microbiota and offers a convenient method for exploring the potential mechanisms underlying the impact of probiotics on the gut microbiota of pregnant women.

Vaginal and Rectal microbiome changes following administration of a multi-species antenatal probiotic: A randomized control trial

The gut and vaginal microbiome undergo changes during pregnancy which may be protective or harmful to the birthing person. Probiotics have been found to cause protective changes to the gut and vaginal microbiomes, with the potential to improve perinatal outcomes. This randomized control trial compares the vaginal and rectal microbiomes before and after an antenatal probiotic or placebo intervention, with a diverse group of pregnant people and a special focus on racial disparities. The vaginal and rectal microbiomes reveal non-significant increased Lactobacillus in the probiotics group, with a greater increase in participants who identified as Black. Potential implications and future study are discussed.

The effects of probiotics administration during pregnancy on preeclampsia and associated maternal, fetal, and newborn outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to synthesize the available evidence on probiotic administration during pregnancy for the prevention of preeclampsia and its effects on related maternal, fetal, and newborn outcomes.

DATA SOURCES

Six databases were systematically searched for eligible studies, namely Ovid MEDLINE, Embase, CINAHL, Cochrane, Global Index Medicus, and the Maternity and Infant Care Database, from inception to August 2, 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that evaluated the effects of probiotic administration on women during any stage of pregnancy were eligible for inclusion.

METHODS

The protocol was registered with the International Prospective Register of Systematic Reviews under identifier CRD42023421613. Evaluating study eligibility, extracting data, assessing risk of bias (ROB-2 tool), and rating certainty (Grading of Recommendations, Assessment, Development and Evaluations) were conducted independently by 2 authors. The primary outcomes were incidence of preeclampsia, eclampsia, and maternal mortality. A meta-analysis was performed, and the results were reported as risk ratios with 95% confidence intervals.

RESULTS

A total of 29 trials (7735 pregnant women) met the eligibility criteria. There was heterogeneity across the trials in the population of enrolled women and the type of probiotic tested (20 different strains), although most used oral administration. Probiotics may make no difference to the risk of preeclampsia (risk ratio, 1.14; 95% confidence interval, 0.84-1.53; 11 trials; 2401 women; low certainty evidence), preterm birth at <37 weeks' gestation (risk ratio, 0.93; 95% confidence interval, 0.66-1.30; 18 trials, 4016 women; low certainty evidence), or gestational age at delivery (mean difference, -0.03 weeks [≈0.2 days]; 95% confidence interval, -0.16 to 0.10 weeks [≈ -1.1 to 0.7 days]; 13 trials, 2194 women; low certainty evidence). It is difficult to assess the effects of probiotics on other secondary outcomes because the evidence was of very low certainty, however, no benefits or harms were observed.

CONCLUSION

Limited evidence suggests that probiotic supplementation does not affect the risk for preeclampsia. Further high-quality trials are needed to definitively assess the benefits and possible harms of probiotic supplementation during pregnancy. There is also a lack of data from trials that included women who were undernourished or who experienced microbial dysbiosis and for whom probiotic supplementation might be useful.

Effects of Probiotic Supplementation on Inflammation and Oxidative Stress for Gestational Diabetes: A Meta-Analysis Study

BACKGROUND

Probiotic supplements may benefit to reduce inflammation and oxidative stress in patients with gestational diabetes, and this meta-analysis aims to explore the impact of probiotic supplementation on inflammation and oxidative stress for gestational diabetes.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched, and we included randomized controlled trials (RCTs) assessing the effect of a probiotic supplement on inflammation and oxidative stress in patients with gestational diabetes.

RESULTS

Five RCTs were finally included in the meta-analysis. Overall, compared with control intervention for gestational diabetes, probiotic supplementation intervention showed significantly reduced CRP (MD=-1.72; 95% CI=-2.54 to -0.90; P<0.0001), IL-6 (MD=-0.42; 95% CI=-0.66 to -0.18; P=0.0005) and MDA (MD=-0.88; 95% CI=-1.10 to -0.66; P<0.00001), increased NO (MD=2.42; 95% CI=0.80 to 4.04; P=0.003) and TAC (SMD=0.86; 95% CI=0.19 to 1.54; P=0.01), but showed no obvious impact on GSH (MD=13.73; 95% CI=-35.84 to 63.31; P=0.59).

CONCLUSIONS

Probiotic supplementation is effective to alleviate inflammation and oxidative stress for gestational diabetes.

Probiotic Supplement for the Prevention of Gestational Diabetes: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Probiotic supplements may have some potential in preventing gestational diabetes, and this meta-analysis aims to explore the efficacy of probiotic supplements to prevent gestational diabetes.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched, and we included randomized controlled trials (RCTs) assessing the effect of probiotic supplements on the incidence of gestational diabetes mellitus. Meta-analysis was performed using the fixed-effect or random-effect model as appropriate.

RESULTS

Six RCTs were finally included in the meta-analysis. Overall, compared with control intervention in pregnant women, probiotic supplementation intervention showed no obvious impact on the incidence of gestational diabetes (OR=0.68; 95% CI=0.39 to 1.20; P=0.18), fasting plasma glucose (SMD=-0.05; 95% CI=-0.29 to 0.19; P=0.69), 2 h-OGTT (SMD=-0.07; 95% CI=-0.27 to 0.13; P=0.47), gestational age (SMD=0.04; 95% CI=-0.14 to 0.21; P=0.69) or preeclampsia (OR=1.22; 95% CI=0.83 to 1.78; P=0.31).

CONCLUSIONS

Probiotic supplementation was confirmed to have no benefits for the prevention of gestational diabetes.

A randomized controlled trial of an oral probiotic to reduce antepartum group B Streptococcus colonization and gastrointestinal symptoms

BACKGROUND

Probiotics have been suggested as a strategy to reduce antenatal group B Streptococcus colonization. Although probiotics are known to improve gastrointestinal symptoms, this has not been studied during pregnancy.

OBJECTIVE

This study aimed to evaluate the efficacy of a probiotic to reduce: (1) standard-of-care antenatal group B Streptococcus colonization and colony counts and (2) gastrointestinal symptoms of pregnancy.

STUDY DESIGN

In a double-blind fashion, 109 healthy adult pregnant people were randomized to Florajen3 probiotic or placebo capsules once daily from 28 weeks' gestation until labor onset. Baseline vaginal and rectal study swabs for group B Streptococcus colony-forming units and microbiome analysis were collected at 28 and 36 weeks' gestation. Standard-of-care vaginal to rectal group B Streptococcus swabs were collected from all participants at 36 weeks' gestation and determined the need for intrapartum antibiotic prophylaxis. Data collection included solicitation of adverse events, demographic information, Antepartum Gastrointestinal Symptom Assessment score, yogurt ingestion, sexual activity, and vaginal cleaning practices.

RESULTS

A total of 83 participants completed the study to 36 weeks' gestation with no adverse events. Standard-of-care group B Streptococcus colonization was 20.4% in the control group and 15.4% in probiotic group participants (-5%; P=.73). The relative risk for positive standard-of-care vaginal-rectal group B Streptococcus colonization was 1.33 (95% confidence interval, 0.5-3.40) times higher in the control group than in the probiotic group (P=.55). There were no differences in median vaginal (P=.16) or rectal (P=.20) group B streptococcus colony-forming units at baseline or at 36 weeks (vaginal P>.999; rectal P=.56). Antepartum Gastrointestinal Symptom Assessment scores were similar at baseline (P=.19), but significantly decreased in probiotic group participants at 36 weeks (P=.02). No covariates significantly altered group B Streptococcus colonization. Significantly more Florajen3 bacteria components were recovered from the vaginal-rectal samples of probiotic group participants (32%; P=.04) compared with controls.

CONCLUSION

The findings of this study provided insufficient evidence for the clinical application of the Florajen3 probiotic intervention to reduce standard-of-care vaginal-rectal group B Streptococcus colonization. The prevalence of group B Streptococcus was lower than expected in the study population, and intervention adherence was poor. Probiotic bacteria colonization of the genitourinary tract occurred more in intervention group participants than in controls and significantly reduced gastrointestinal symptoms of pregnancy.

Supplementation of Probiotics in Pregnant Women Targeting Group B Streptococcus Colonization: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to determine if probiotic supplementation in pregnancy reduced maternal Group B streptococcus (GBS) recto-vaginal colonization in pregnant women at 35–37 weeks of gestation. Electronic databases (i.e., PubMed, MEDLINE, ClinicalTrials.gov, ScienceDirect, and the Cochrane Library) were searched from inception up to February 2022. We included RCTs assessing the effects of probiotic supplementation in pregnancy on GBS recto-vaginal colonization. The primary outcome was GBS-positive recto-vaginal cultures performed at 35–37 weeks of gestation. Secondarily, we evaluated obstetric and short-term neonatal outcomes. A total of 132 publications were identified; 9 full-length articles were reviewed to finally include 5 studies. Probiotic supplementation reduced vaginal GBS colonization: the GBS positive culture rate was estimated at 31.9% (96/301) in the intervention group compared to 38.6% (109/282) in the control group (OR = 0.62, 95% CI 0.40–0.94, I2 4.8%, p = 0.38). The treatment started after 30 weeks of gestation and was more effective in reducing GBS colonization (OR 0.41, 95% CI 0.21–0.78, I2 0%, p = 0.55). Probiotic administration during pregnancy, namely in the third trimester, was associated with a reduced GBS recto-vaginal colonization at 35–37 weeks and a safe perinatal profile. Whether this new strategy could reduce the exposition of pregnant women to significant doses of antibiotics in labor needs to be evaluated in other trials.

Gut Microbiome Changes in Gestational Diabetes

Gestational diabetes mellitus (GDM), one of the most common endocrine pathologies during pregnancy, is defined as any degree of glucose intolerance with onset or first discovery in the perinatal period. Physiological changes that occur in pregnant women can lead to inflammation, which promotes insulin resistance. In the general context of worldwide increasing obesity in young females of reproductive age, GDM follows the same ascending trend. Changes in the intestinal microbiome play a decisive role in obesity and the development of insulin resistance and chronic inflammation, especially in patients with type 2 diabetes mellitus (T2D). To date, various studies have also associated intestinal dysbiosis with metabolic changes in women with GDM. Although host metabolism in women with GDM has not been fully elucidated, it is of particular importance to analyze the available data and to discuss the actual knowledge regarding microbiome changes with potential impact on the health of pregnant women and newborns. We analyzed peer-reviewed journal articles available in online databases in order to summarize the most recent findings regarding how variations in diet and metabolic status of GDM patients can contribute to alteration of the gut microbiome, in the same way that changes of the gut microbiota can lead to GDM. The most frequently observed alteration in the microbiome of patients with GDM was either an increase of the Firmicutes phylum, respectively, or a decrease of the Bacteroidetes and Actinobacteria phyla. Gut dysbiosis was still present postpartum and can impact the development of the newborn, as shown in several studies. In the evolution of GDM, probiotic supplementation and regular physical activity have the strongest evidence of proper blood glucose control, favoring fetal development and a healthy outcome for the postpartum period. The current review aims to summarize and discuss the most recent findings regarding the correlation between GDM and dysbiosis, and current and future methods for prevention and treatment (lifestyle changes, pre- and probiotics administration). To conclude, by highlighting the role of the gut microbiota, one can change perspectives about the development and progression of GDM and open up new avenues for the development of innovative therapeutic targets in this disease.

Dietary factors that affect the risk of pre-eclampsia

Pre-eclampsia affects 3%–5% of pregnant women worldwide and is associated with a range of adverse maternal and fetal outcomes, including maternal and/or fetal death. It particularly affects those with chronic hypertension, pregestational diabetes mellitus or a family history of pre-eclampsia. Other than early delivery of the fetus, there is no cure for pre-eclampsia. Since diet or dietary supplements may affect the risk, we have carried out an up-to-date, narrative literature review to assess the relationship between nutrition and pre-eclampsia. Several nutrients and dietary factors previously believed to be implicated in the risk of pre-eclampsia have now been shown to have no effect on risk; these include vitamins C and E, magnesium, salt, ω-3 long-chain polyunsaturated fatty acids (fish oils) and zinc. Body mass index is proportionally correlated with pre-eclampsia risk, therefore women should aim for a healthy pre-pregnancy body weight and avoid excessive gestational and interpregnancy weight gain. The association between the risk and progression of the pathophysiology of pre-eclampsia may explain the apparent benefit of dietary modifications resulting from increased consumption of fruits and vegetables (≥400 g/day), plant-based foods and vegetable oils and a limited intake of foods high in fat, sugar and salt. Consuming a high-fibre diet (25–30 g/day) may attenuate dyslipidaemia and reduce blood pressure and inflammation. Other key nutrients that may mitigate the risk include increased calcium intake, a daily multivitamin/mineral supplement and an adequate vitamin D status. For those with a low selenium intake (such as those living in Europe), fish/seafood intake could be increased to improve selenium intake or selenium could be supplemented in the recommended multivitamin/mineral supplement. Milk-based probiotics have also been found to be beneficial in pregnant women at risk. Our recommendations are summarised in a table of guidance for women at particular risk of developing pre-eclampsia.

The Impact of Nutritional Supplementation During Pregnancy on the Incidence of Gestational Diabetes and Glycaemia Control

The nutritional state before and throughout pregnancy has a critical impact on the women's health and the baby's development and growth. The release of placental hormones during pregnancy induces/ increases maternal insulin resistance and promotes nutrition utilization by the fetus. Gestational Diabetes Mellitus (GDM) is the most common medical complication in pregnancy and is associated with significant maternal and fetal morbidity. Several studies have examined the effect of physical activity, healthy eating, and various food supplements on the risk of developing gestational diabetes (GDM) and related outcomes. Among those, Myo-Inositol supplementation has shown encouraging results in the prevention of GDM. Maternal vitamin D deficiency has been associated with an elevated risk of GDM, and supplementation can improve glucose haemostasis by lowering fasting blood glucose, HbA1c, and serum insulin concentration. Probiotics modulate the gut microbiota leading to an improved glucose and lipid metabolism, which is proposed to reduce the risk of GDM. We aim to review the strength and limitation of the current evidence for using some nutritional supplements either as single agents or in combinations on the risk of developing GDM and on glycaemic control.

Decrease in abundance of bacteria of the genus Bifidobacterium in gut microbiota may be related to pre-eclampsia progression in women from East China

Background

Pre-eclampsia (PE) can result in severe damage to maternal and fetal health. It has been reported that gut microbiota (GM) had important roles in regulating the metabolic and inflammatory responses of the mother. However, investigations on GM in PE are rare.

Objective

The objective of the present study was to investigate the changes of GM in PE and how to alter the GM composition in PE by dietary or dietary supplements.

Design

We analyzed the composition changes in GM as well as the relationship between bacteria of different genera and clinical indices by amplifying the V4 region of the 16S ribosomal RNA gene in 12 PE patients and eight healthy pregnant women in East China.

Results

In the PE group, the Observed Species Index was lower than that in the control group, indicating that the α-diversity of the microbiome in the PE group decreased. At phylum, family, and genus levels, the relative abundance of different bacteria in PE patients displayed substantial differences to those from healthy women. We noted a decreased abundance of bacteria of the phylum Actinobacteria (P = 0.042), decreased abundance of bacteria of the family Bifidobacteriaceae (P = 0.039), increased abundance of bacteria of the genus Blautia (P = 0.026) and Ruminococcus (P = 0.048), and decreased abundance of bacteria of the genus Bifidobacterium (P = 0.038). Among three enriched genera, bacteria of the genus Bifidobacterium showed a negative correlation with the systolic blood pressure (SBP), diastolic blood pressure (DBP), and dyslipidemia, which involved glucose metabolism, lipid metabolism, and the oxidative-phosphorylation pathway. The increased abundance of bacteria of the genera Blautia and Ruminococcus was positively correlated with obesity and dyslipidemia, which involved lipid metabolism, glycosyltransferases, biotin metabolism, and the oxidative-phosphorylation pathways. Moreover, women in the PE group ate more than women in the control group, so fetuses were more prone to overnutrition in the PE group.

Conclusion

There is a potential for GM dysbiosis in PE patients, and they could be prone to suffer from metabolic syndrome. We speculate that alterations in the abundance of bacteria of certain genera (e.g. increased abundance of Blautia and Ruminococcus, and decreased abundance of Bifidobacterium) were associated with PE development to some degree. Our data could help to monitor the health of pregnant women and may be helpful for preventing and assisting treatment of PE by increasing dietary fiber or probiotics supplement.

Probiotics for preventing gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a range of adverse pregnancy outcomes for mother and infant. The prevention of GDM using lifestyle interventions has proven difficult. The gut microbiome (the composite of bacteria present in the intestines) influences host inflammatory pathways, glucose and lipid metabolism and, in other settings, alteration of the gut microbiome has been shown to impact on these host responses. Probiotics are one way of altering the gut microbiome but little is known about their use in influencing the metabolic environment of pregnancy. This is an update of a review last published in 2014.

OBJECTIVES

To systematically assess the effects of probiotic supplements used either alone or in combination with pharmacological and non-pharmacological interventions on the prevention of GDM.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (20 March 2020), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and cluster-randomised trials comparing the use of probiotic supplementation with either placebo or diet for the prevention of the development of GDM. Cluster-randomised trials were eligible for inclusion but none were identified. Quasi-randomised and cross-over design studies were not eligible for inclusion in this review. Studies presented only as abstracts with no subsequent full report of study results were only included if study authors confirmed that data in the abstract came from the final analysis. Otherwise, the abstract was left awaiting classification.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed risk of bias of included studies. Data were checked for accuracy.

MAIN RESULTS

In this update, we included seven trials with 1647 participants. Two studies were in overweight and obese women, two in obese women and three did not exclude women based on their weight. All included studies compared probiotics with placebo. The included studies were at low risk of bias overall except for one study that had an unclear risk of bias. We excluded two studies, eight studies were ongoing and three studies are awaiting classification. Six included studies with 1440 participants evaluated the risk of GDM. It is uncertain if probiotics have any effect on the risk of GDM compared to placebo (mean risk ratio (RR) 0.80, 95% confidence interval (CI) 0.54 to 1.20; 6 studies, 1440 women; low-certainty evidence). The evidence was low certainty due to substantial heterogeneity and wide CIs that included both appreciable benefit and appreciable harm. Probiotics increase the risk of pre-eclampsia compared to placebo (RR 1.85, 95% CI 1.04 to 3.29; 4 studies, 955 women; high-certainty evidence) and may increase the risk of hypertensive disorders of pregnancy (RR 1.39, 95% CI 0.96 to 2.01, 4 studies, 955 women), although the CIs for hypertensive disorders of pregnancy also indicated probiotics may have no effect. There were few differences between groups for other primary outcomes. Probiotics make little to no difference in the risk of caesarean section (RR 1.00, 95% CI 0.86 to 1.17; 6 studies, 1520 women; high-certainty evidence), and probably make little to no difference in maternal weight gain during pregnancy (MD 0.30 kg, 95% CI -0.67 to 1.26; 4 studies, 853 women; moderate-certainty evidence). Probiotics probably make little to no difference in the incidence of large-for-gestational age infants (RR 0.99, 95% CI 0.72 to 1.36; 4 studies, 919 infants; moderate-certainty evidence) and may make little to no difference in neonatal adiposity (2 studies, 320 infants; data not pooled; low-certainty evidence). One study reported adiposity as fat mass (MD -0.04 kg, 95% CI -0.12 to 0.04), and one study reported adiposity as percentage fat (MD -0.10%, 95% CI -1.19 to 0.99). We do not know the effect of probiotics on perinatal mortality (RR 0.33, 95% CI 0.01 to 8.02; 3 studies, 709 infants; low-certainty evidence), a composite measure of neonatal morbidity (RR 0.69, 95% CI 0.36 to 1.35; 2 studies, 623 infants; low-certainty evidence), or neonatal hypoglycaemia (mean RR 1.15, 95% CI 0.69 to 1.92; 2 studies, 586 infants; low-certainty evidence). No included studies reported on perineal trauma, postnatal depression, maternal and infant development of diabetes or neurosensory disability.

AUTHORS' CONCLUSIONS

Low-certainty evidence from six trials has not clearly identified the effect of probiotics on the risk of GDM. However, high-certainty evidence suggests there is an increased risk of pre-eclampsia with probiotic administration. There were no other clear differences between probiotics and placebo among the other primary outcomes. The certainty of evidence for this review's primary outcomes ranged from low to high, with downgrading due to concerns about substantial heterogeneity between studies, wide CIs and low event rates. Given the risk of harm and little observed benefit, we urge caution in using probiotics during pregnancy. The apparent effect of probiotics on pre-eclampsia warrants particular consideration. Eight studies are currently ongoing, and we suggest that these studies take particular care in follow-up and examination of the effect on pre-eclampsia and hypertensive disorders of pregnancy. In addition, the underlying potential physiology of the relationship between probiotics and pre-eclampsia risk should be considered.

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.

Preterm Birth, Inflammation and Infection: New Alternative Strategies for their Prevention

BACKGROUND

Worldwide, the progress in reducing neonatal mortality has been very slow. The rate of preterm birth has increased over the last 20 years in low-income and middle-income countries. Its association with increased mortality and morbidity is based on experimental studies and neonatal outcomes from countries with socioeconomic differences, which have considered implementing alternative healthcare strategies to prevent and reduce preterm births.

METHODS

Currently, there is no widely effective strategy to prevent preterm birth. Pharmacological therapies are directed at inhibiting myometrial contractions to prolong parturition. Some drugs, medicinal plants and microorganisms possess myorelaxant, anti-inflammatory and immunomodulatory properties that have proved useful in preventing preterm birth associated with inflammation and infection.

RESULTS

This review focuses on the existing literature regarding the use of different drugs, medicinal plants, and microorganisms that show promising benefits for the prevention of preterm birth associated with inflammation and infection. New alternative strategies involving the use of PDE-4 inhibitors, medicinal plants and probiotics could have a great impact on improving prenatal and neonatal outcomes and give babies the best start in life, ensuring lifelong health benefits.

CONCLUSION

Despite promising results from well-documented cases, only a small number of these alternative strategies have been studied in clinical trials. The development of new drugs and the use of medicinal plants and probiotics for the treatment and/or prevention of preterm birth is an area of growing interest due to their potential therapeutic benefits in the field of gynecology and obstetrics.

Probiotics in pregnancy: protocol of a double-blind randomized controlled pilot trial for pregnant women with depression and anxiety (PIP pilot trial)

Background

Maternal prenatal depressive or anxiety symptoms are associated with adverse maternal and infant health outcomes. With prevalence rates of maternal prenatal depression and anxiety ranging between 10 and 20%, attempts to identify effective interventions to reduce symptoms are priority. There are indications that probiotics can reduce symptoms of maternal depression or anxiety. Probiotics ingested by the mother may thus offer a promising and accessible intervention to complement existing treatments.

Methods

The Probiotics in Pregnancy (PIP) pilot trial is a double-blind, placebo-controlled, randomized pilot trial. While one group orally consumes a probiotic mixture (Ecologic® Barrier; 2,5 × 109 colony forming units/g; 2 g; daily), the other group consumes a placebo, from between 26 and 30 weeks gestation until delivery. Subjects are randomly allocated (1:1) to the intervention or placebo group. Forty healthy pregnant women with symptoms of depression or anxiety and uncomplicated pregnancies at randomization will be included. The primary aim is to determine the feasibility and acceptability of a probiotic trial to reduce symptoms of maternal depression or anxiety in pregnancy. The secondary aim is to exploratorily compare the potential effect of probiotics, compared to placebo, on depressive and/or anxiety symptoms, maternal stress (i.e. reported/hair cortisol), maternal vaginal and intestinal microbiota, and by possibly affecting maternal mood and microbiota, maternal bonding to offspring, infant microbiota and infant crying.

Discussion

Results of this pilot trial will help determine whether or not to proceed with a full trial after the pilot trial, and if so, whether revisions should be made to the study protocol and procedures before conducting a full randomized controlled trial. Additionally, they are expected to provide insights into whether changes in psychological, behavioral and biological parameters can be attributed to the probiotic intervention.

Trial registration

Netherlands Trial Register, NTR6219. Registered on 28 February 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3389-1) contains supplementary material, which is available to authorized users.

Contextual risk factors impacting the colonization and development of the intestinal microbiota: Implications for children in low- and middle-income countries

Early adversities, such as poverty, maternal stress, and malnutrition, can affect the structure and functioning of the developing brain with implications for biological systems such as the intestinal microbiota. To date, most studies examining the impact of these risk factors on the development and functioning of the intestinal microbiota have primarily been conducted in high-income countries. However, arguably, children in low- and middle-income countries may be at increased risk given cumulative biological and psychosocial adversities during their development. Accumulating evidence in low- and middle-income countries has linked dysbiosis of the intestinal microbiota to child health outcomes such as stunting, malnutrition, and diarrheal diseases characterized by reduced microbial diversity and elevated pathogenic bacteria, which has implications for psychosocial outcomes. This review summarizes empirical findings that highlight the association between risk factors prevalent in low- and middle-income countries and the intestinal microbiota of children. Additionally, we briefly survey the current evidence regarding the effect of nutritional interventions on the microbial composition of children in low- and middle-income countries. We conclude that these empirical studies have the capacity to inform future research investigating the influence of preventive interventions on biological systems by targeting the predominant risk factors faced by children in low- and middle-income countries.

Through the Microbial Looking Glass: Premature Labor, Preeclampsia, and Gestational Diabetes: A Scoping Review

The influence of microbial factors on adverse perinatal outcomes has become the focal point of recent investigations, with particular interest in the role of the microbiome and probiotic interventions. The purpose of this scoping review was to identify and critique the most recent evidence about these factors as they relate to pregnancies complicated by preeclampsia (PEC), preterm birth (PTB), and gestational diabetes mellitus (GDM). Four databases (PubMed, EMBASE, Web of Science, and Cochrane) were searched for articles published in English in the last 10 years with the concepts of the microbiome, probiotics, and PEC, PTB, or GDM. Forty-nine articles were eligible for full-text review. Five articles were excluded, leaving 44 articles that met all the eligibility criteria. The relationships between the microbiome and the risk for PEC, PTB, and GDM are not fully elucidated, although probiotic interventions seem beneficial in decreasing PEC and GDM risk. Probiotic interventions targeting bacterial vaginosis and elimination of infection in women at risk for PTB appear to be beneficial. More research is needed to understand the contributions of the microbiome to adverse perinatal outcomes. Probiotic interventions appear to be effective in reducing risk for select outcomes.

Maternal probiotic supplementation for prevention of morbidity and mortality in preterm infants

BACKGROUND

Inflammation may contribute to preterm birth and to morbidity of preterm infants. Preterm infants are at risk for alterations in the normal protective microbiome. Oral probiotics administered directly to preterm infants have been shown to decrease the risk for severe necrotizing enterocolitis (NEC) as well as the risk of death, but there are safety concerns about administration of probiotics directly to preterm infants. Through decreasing maternal inflammation, probiotics may play a role in preventing preterm birth and/or decreasing the inflammatory milieu surrounding delivery of preterm infants, and may alter the microbiome of the preterm infant when given to mothers during pregnancy. Probiotics given to mothers after birth of preterm infants may effect infant bacterial colonization, which could potentially reduce the incidence of NEC.

OBJECTIVES

1. To compare the efficacy of maternal probiotic administration versus placebo or no intervention in mothers during pregnancy for the prevention of preterm birth and the prevention of morbidity and mortality of infants born preterm.2. To compare the efficacy of maternal probiotic administration versus placebo, no intervention, or neonatal probiotic administration in mothers of preterm infants after birth on the prevention of mortality and preterm infant morbidities such as NEC.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 2), MEDLINE via PubMed (1966 to 21 March 2017), Embase (1980 to 21 March 2017), and CINAHL (1982 to 21 March 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

We included randomized controlled trials in the review if they administered oral probiotics to pregnant mothers at risk for preterm birth, or to mothers of preterm infants after birth. Quasi-randomized trials were eligible for inclusion, but none were identified. Studies enrolling pregnant women needed to administer probiotics at < 36 weeks' gestation until the trimester of birth. Probiotics considered were of the genera Lactobacillus, Bifidobacterium or Saccharomyces.

DATA COLLECTION AND ANALYSIS

We used the standard methods of the Cochrane Collaboration and Cochrane Neonatal to determine the methodologic quality of studies, and for data collection and analysis.

MAIN RESULTS

We included 12 eligible trials with a total of 1450 mothers and 1204 known infants. Eleven trials administered probiotics to mothers during pregnancy and one trial administered probiotics to mothers after birth of their preterm infants. No studies compared maternal probiotic administration directly with neonatal administration. Included prenatal trials were highly variable in the indication for the trial, the gestational age and duration of administration of probiotics, as well as the dose and formulation of the probiotics. The pregnant women included in these trials were overall at low risk for preterm birth. In a meta-analysis of trial data, oral probiotic administration to pregnant women did not reduce the incidence of preterm birth < 37 weeks (typical risk ratio (RR) 0.92, 95% confidence interval (CI) 0.32 to 2.67; 4 studies, 518 mothers and 506 infants), < 34 weeks (typical risk difference (RD) 0.00, 95% CI -0.02 to 0.02; 2 studies, 287 mothers and infants), the incidence of infant mortality (typical RD 0.00, 95% CI -0.02 to 0.02; 2 studies, 309 mothers and 298 infants), or the gestational age at birth (mean difference (MD) 0.15, 95% CI -0.33 to 0.63; 2 studies, 209 mothers with 207 infants).One trial studied administration of probiotics to mothers after preterm birth and included 49 mothers and 58 infants. There were no significant differences in the risk of any NEC (RR 0.44, 95% CI 0.13 to 1.46; 1 study, 58 infants), surgery for NEC (RR 0.15, 95% CI 0.01 to 2.58; 1 study, 58 infants), death (RR 0.66, 95% CI 0.06 to 6.88; 1 study, 58 infants), and death or NEC (RR 0.53, 95% CI 0.19 to 1.49; 1 study, 58 infants). There was an improvement in time to reach 50% enteral feeds in infants whose mothers received probiotics, but the estimate is imprecise (MD -9.60 days, 95% CI -19.04 to -0.16 days; 58 infants). No other improvement in any neonatal outcomes were reported. The estimates were imprecise and do not exclude the possibility of meaningful harms or benefits from maternal probiotic administration. There were no cases of culture-proven sepsis with the probiotic organism. The GRADE quality of evidence was judged to be low to very low due to inconsistency and imprecision.

AUTHORS' CONCLUSIONS

There is insufficient evidence to conclude whether there is appreciable benefit or harm to neonates of either oral supplementation of probiotics administered to pregnant women at low risk for preterm birth or oral supplementation of probiotics to mothers of preterm infants after birth. Oral supplementation of probiotics to mothers of preterm infants after birth may decrease time to 50% enteral feeds, however, this estimate is extremely imprecise. More research is needed for post-natal administration of probiotics to mothers of preterm infants, as well as to pregnant mothers at high risk for preterm birth.

Gut microbiota in early life and its influence on health and disease: A position paper by the Malaysian Working Group on Gastrointestinal Health

The role of gut microbiota in early life and its impact on gut health and subsequent diseases remain unclear. There is a lack of research and awareness in this area, especially in the Asia-Pacific region, including Malaysia. This paper reports the position of a Malaysian Working Group on some key issues surrounding gut microbiota in early life and its role in gut health and diseases, as well as experts' stand on probiotics and prebiotics. The group reached a consensus that certain factors, including elective caesarean; premature deliveries; complementary feeding; use of antibiotics, prebiotics and/or probiotics; and exposure to the external environmental, have an impact on gut microbiota in early life. However, as evidence is lacking, especially from the Asia-Pacific region, further studies are needed to understand how gut microbiota in early life affects subsequent diseases, including allergy, inflammatory bowel disease, obesity and infantile colic. Lastly, although beneficial in acute diarrhoeal disease and probably allergic eczema, probiotics (and/or prebiotics) should be used cautiously in other gut dysbiotic conditions until more data are available.

Efficacy of probiotic supplement for gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Probiotic supplement might be beneficial for gestational diabetes mellitus. However, the results remained controversial. We conducted a systematic review and meta-analysis to explore the efficacy of probiotic supplement in gestational diabetes mellitus.

METHODS

PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of probiotic supplement in gestational diabetes mellitus were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome were fasting serum insulin and fasting plasma glucose. Meta-analysis was performed using the fixed-effect or random-effect model.

RESULTS

Six RCTs involving 830 patients were included in the meta-analysis. Overall, compared with control intervention in gestational diabetes mellitus, probiotic supplementation intervention was found to significantly reduce fasting serum insulin (Std. mean difference = -0.95; 95% CI = -1.73 to -0.17; p < .00001) and HOMA-IR (Std. mean difference = -1.12; 95% CI = -2.05 to -0.18; p = .02), but showed no substantial impact on fasting plasma glucose (Std. mean difference = -0.49; 95% CI = -1.05-0.08; p = .09), gestational age (Std. mean difference = 0.07; 95% CI = -0.20-0.34; p = .63), and gestational weight (Std. mean difference = -0.11; 95% CI = -0.38-0.16; p = .43).

CONCLUSIONS

Compared with control intervention in gestational diabetes mellitus, probiotic supplementation was found to significantly reduce insulin resistance (HOMA-IR) and fasting serum insulin, but had no substantial influence on fasting plasma glucose, gestational age and gestational weight.

Do bacteria shape our development? Crosstalk between intestinal microbiota and HPA axis

The human body contains as many bacteria in the intestine as the total number of human body cells. These bacteria have a central position in human health and disease, and would also play a role in the regulation of emotions, behavior, and even higher cognitive functions. The Hypothalamic-Pituitary-Adrenal axis (HPA axis) is a major physiological stress system that produces cortisol. This hormone is involved in responding to environmental stress and also shapes many aspects of brain development. Both the HPA axis and the intestinal microbiota show rapid and profound developmental changes during the first years of life. Early environmental disturbances can affect the development of both systems. Early adversity, for example, is known to lead to later unbalances in both, as well as to psychopathological behavior and emotions. The goal of this theoretical review is to summarize current knowledge on the developmental crosstalk between the intestinal microbiota and the HPA axis, providing a basis for understanding the development and bidirectional communication between these two essential systems in human functioning.

The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes

OBJECTIVE

This study was designed to evaluate the effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes among subjects with gestational diabetes (GDM).

METHODS

This randomized, double-blind, placebo-controlled clinical trial was done among 60 subjects with GDM who were not on oral hypoglycemic agents. Patients were randomly allocated to intake either probiotic capsule containing Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium bifidum (2 × 10⁹ CFU/g each) (n = 30) or placebo (n = 30) for six weeks.

RESULTS

Compared with the placebo, probiotic supplementation resulted in significant decreases in fasting plasma glucose (FPG) (-5.3 ± 6.7 vs. +0.03 ± 9.0 mg/dL, p = .01), serum high-sensitivity C-reactive protein (hs-CRP) (-2.2 ± 2.7 vs. +0.5 ± 2.4 μg/mL, p < .001), plasma malondialdehyde (MDA) concentrations (-0.1 ± 0.8 vs. +0.5 ± 1.5 μmol/L, p = .03) and MDA/TAC ratio (-0.0003 ± 0.0008 vs. +0.0009 ± 0.002, p = .004), and a significant increase in total antioxidant capacity (TAC) levels (+65.4 ± 103.3 vs. -37.2 ± 143.7 mmol/L, p = .002). Probiotic supplementation did not affect pregnancy outcomes.

CONCLUSIONS

Overall, probiotic supplementation among women with GDM for six weeks had beneficial effects on FPG, serum hs-CRP, plasma TAC, MDA and oxidative stress index, but did not affect pregnancy outcomes.

Obesity and overweight: Impact on maternal and milk microbiome and their role for infant health and nutrition

Obesity, particularly in infants, is becoming a significant public health problem that has reached "epidemic" status worldwide. Obese children have an increased risk of developing obesity-related diseases, such as metabolic syndromes and diabetes, as well as increased risk of mortality and adverse health outcomes later in life. Experimental data show that maternal obesity has negative effects on the offspring's health in the short and long term. Increasing evidence suggests a key role for microbiota in host metabolism and energy harvest, providing novel tools for obesity prevention and management. The maternal environment, including nutrition and microbes, influences the likelihood of developing childhood diseases, which may persist and be exacerbated in adulthood. Maternal obesity and weight gain also influence microbiota composition and activity during pregnancy and lactation. They affect microbial diversity in the gut and breast milk. Such microbial changes may be transferred to the offspring during delivery and also during lactation, affecting infant microbial colonisation and immune system maturation. Thus, an adequate nutritional and microbial environment during the peri-natal period may provide a window of opportunity to reduce the risk of obesity and overweight in our infants using targeted strategies aimed at modulating the microbiota during early life.

Maternal use of probiotics during pregnancy and effects on their offspring's health in an unselected population

Probiotics are used by women in the perinatal period and may improve balance of microbiota, with possible health benefits for both mother and baby. Characteristics and (health) behaviour patterns of mothers using probiotics during pregnancy, and health effects on their offspring, were investigated. Differences between mothers using probiotics during pregnancy and those who did not, were assessed. In total, 341 out of 2491 (13.7%) mothers reported use of probiotics during pregnancy. There were no significant differences in maternal features (gestation, age, ethnicity, education) between users and non-users. Logistic regression analyses showed that consumption of probiotics was significantly associated with use of homeopathic products [odds ratio (OR) 1.65, 95% confidence interval (CI) 1.17-2.33, p = 0.005], maternal history of smoking (OR 1.72, 95% CI 1.25-2.37, p = 0.001) and paternal history of smoking (OR 1.39, 95% CI 1.01-1.89, p = 0.05). Common disease symptoms during the first year of life in the offspring did not differ between both groups.

CONCLUSION

The use of probiotics or other health-related products without doctor's prescription during pregnancy might point to compensation for types of less favourable behaviour. Probiotic use during pregnancy does not seem to induce positive health effects in the offspring in an unselected population.

WHAT IS KNOWN

Aberrant microbiota compositions have been detected during critical periods when early programming occurs including pregnancy and early neonatal life. Probiotics modulate intestinal microbiota composition and are associated with positive health effects.

WHAT IS NEW

The use of probiotics or other health-related products without doctor's prescription during pregnancy is associated with and might point to compensation for types of less favourable behaviour. Probiotic use during pregnancy does not induce positive health effects in the offspring in this unselected population.

Immunomodulation of Lactobacillus reuteri CRL1324 on Group B Streptococcus Vaginal Colonization in a Murine Experimental Model

PROBLEM

Maternal Group B Streptococcus (GBS) colonization is a risk factor for infectious disease in newborns. One promising strategy is the modulation of vaginal defense to increase the host's ability to combat infection.

METHOD OF STUDY

The effect of intravaginal (i.va.) Lactobacillus reuteri CRL1324 inoculation on different immune cell populations, cytokines, and immunoglobulin isotypes in a murine model of GBS vaginal colonization was evaluated.

RESULTS

Seven i.va. inoculations of L. reuteri CRL1324 previous to GBS challenge showed an immunomodulatory effect on the cells and mediators of innate immunity, decreasing the number of neutrophils induced by the pathogen and increasing the activated macrophage population. Moreover, increases in B lymphocytes and IgA and IgG subclasses were observed in mice inoculated with L. reuteri CRL1324 and then challenged with GBS.

CONCLUSION

Lactobacillus reuteri CRL1324 shows a protective effect against GBS colonization that could be mediated by the modulation of the immune response.

Impact of probiotics in women with gestational diabetes mellitus on metabolic health: a randomized controlled trial

OBJECTIVE

Probiotics are live microorganisms that may confer health benefits on the host. Recent trials of probiotic use among healthy pregnant women demonstrate potential for improved glycemic control. The aim of this study was to investigate the effects of a probiotic capsule intervention on maternal metabolic parameters and pregnancy outcome among women with gestational diabetes.

STUDY DESIGN

This double-blind placebo-controlled randomized trial recruited pregnant women with a new diagnosis of gestational diabetes or impaired glucose tolerance following a 3-hour 100-g glucose tolerance test. Women were randomized to a daily probiotic (Lactobacillus salivarius UCC118) or placebo capsule from diagnosis until delivery. Fasting blood samples were collected at baseline and 4-6 weeks after capsule commencement for analysis of glucose, insulin, c-peptide, and lipids. The primary outcome was difference in fasting glucose postintervention, first analyzed on an intention-to-treat basis and followed by per-protocol analysis that excluded women commenced on pharmacological therapy (insulin or metformin). Secondary outcomes were changes in insulin, c-peptide, homeostasis model assessment and lipids, requirement for pharmacological therapy, and neonatal anthropometry.

RESULTS

Of 149 women recruited and randomized, there were no differences between the probiotic and placebo groups in postintervention fasting glucose (4.65 ± 0.49 vs 4.65 ± 0.53 mmol/L; P = 373), requirement for pharmacological therapy (17% vs 14%; P = .643), or birthweight (3.57 ± 0.64 vs 3.60 ± 0.57 kg; P = .845). Among 100 women managed with diet and exercise alone, fasting plasma glucose decreased significantly within both the probiotic (4.76 ± 0.45 to 4.57 ± 0.42 mmol/L; P < .001) and placebo (4.85 ± 0.58 to 4.58 ± 0.45 mmol/L; P < .001) groups, but the levels between groups did not differ (P = .316). The late gestation-related rise in total and low-density lipoprotein (LDL) cholesterol was attenuated in the probiotic vs the placebo group (+0.27 ± 0.48 vs +0.50 ± 0.52 mmol/L total cholesterol, P = .031; +0.08 ± 0.51 vs +0.31 ± 0.45 mmol/L LDL cholesterol, P = .011). No differences were noted between groups in other metabolic parameters or pregnancy outcome.

CONCLUSION

A probiotic capsule intervention among women with abnormal glucose tolerance had no impact on glycemic control. The observed attenuation of the normal pregnancy-induced rise in total and LDL cholesterol following probiotic treatment requires further investigation, particularly in this obstetric group at risk of future metabolic syndrome.