ABSTRACT
AIM: To investigate differences between gut microbiota diversity and composition of healthy pregnant women and women with pre-eclampsia (PE). METHODS AND RESULTS: This is a systematic review and meta-analysis of the literature, in which the terms "pre-eclampsia", "gastrointestinal microbiome" and "pregnant women" were used to search MEDLINE (PubMed), BVS (LILACS and others), Embase (Elsevier) and Cochrane Library, including observational studies and case-control that investigated changes in the gut microbiota during pregnancy. Six studies were included, with 479 pregnant women. A significantly lower gut microbiota alpha diversity measured as the Shannon index was found in pregnant women with PE in comparison with healthy controls (SMD: -0.47; 95 %IC: -0.77 to -0.18; P = 0.02; I2 = 0 %; three studies, 179 participants), while no significant differences were found in the relative abundance of Bacteroidetes, Firmicutes, Actinobacteria, and Proteobacteria, despite significant differences reported in the individual studies. CONCLUSION: Pregnant women with PE have lower gut microbiome diversity, however, there is insufficient evidence to determine whether there are changes in gut microbiota composition. SIGNIFICANCE AND IMPACT OF THE STUDY: The gut microbiota can be a new treatment target to try to prevent changes in maternal bacterial proportions, aiming to reduce complications during pregnancy.
Subject(s)
Gastrointestinal Microbiome , Pre-Eclampsia , Pregnancy , Humans , Female , Observational Studies as TopicABSTRACT
Among the main consequences of polycystic ovary syndrome (PCOS) are menstrual dysfunction, infertility, hyperandrogenism, insulin resistance, and weight gain; in aggravated cases, it can become a risk factor for the development of metabolic syndrome and cardiovascular disease. We hypothesized that green tea can be an option to complement the treatment of PCOS. Thus, this systematic review aims to evaluate the effects of green tea supplementation in women with PCOS. We searched for randomized controlled trials (RCTs) that evaluated women with PCOS who received green tea compared with placebo in electronic databases: MEDLINE via PubMed, EMBASE via Elsevier, Cochrane Library, LILACS via BVS, and Web of Science using the terms: "polycystic ovary syndrome," "green tea," "Camellia sinensis," "epigallocatechin gallate." The outcomes listed in the study protocol were body weight, fasting insulin, body mass index, body fat percentage, daily caloric intake, waist circumference, hip circumference, and waist/hip ratio. Four double-blind RCTs were included, with a total of 169 women: 85 in the green tea group and 84 in the placebo group. We found a significantly lower body weight (kg) for green tea group (mean difference, -2.80; 95% confidence interval, -5.25 to -0.35; P = .03; I² = 0%; 4 studies, 169 participants, very low-quality evidence). Green tea has potential positive effects for the reduction of weight, and future studies will be needed to confirm the estimated effect size; we reasonably expect this to be an option of adjuvant treatment in PCOS clinical management. Registration number: CRD42021226296.
