Effect of probiotics and synbiotics on selected anthropometric and biochemical measures in women with polycystic ovary syndrome: a systematic review and meta-analysis

The effects of prebiotic, probiotic or synbiotic supplementation on overweight/obesity indicators: an umbrella review of the trials' meta-analyses

Background

There is controversial data on the effects of prebiotic, probiotic, or synbiotic supplementations on overweight/obesity indicators. Thus, we aimed to clarify this role of biotics through an umbrella review of the trials' meta-analyses.

Methods

All meta-analyses of the clinical trials conducted on the impact of biotics on overweight/obesity indicators in general populations, pregnant women, and infants published until June 2023 in PubMed, Web of Sciences, Scopus, Embase, and Cochrane Library web databases included. The meta-analysis of observational and systematic review studies without meta-analysis were excluded. We reported the results by implementing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart. The Assessment of Multiple Systematic Reviews-2 (AMSTAR2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological quality and quality of evidence.

Results

Overall, 97 meta-analysis studies were included. Most studies were conducted on the effect of probiotics in both genders. Consumption of prebiotic: 8-66 g/day, probiotic: 104 -1.35×1015 colony-forming unit (CFU)/day, and synbiotic: 106-1.5×1011 CFU/day and 0.5-300 g/day for 2 to 104 weeks showed a favorable effect on the overweight/obesity indicators. Moreover, an inverse association was observed between biotics consumption and overweight/obesity risk in adults in most of the studies. Biotics did not show any beneficial effect on weight and body mass index (BMI) in pregnant women by 6.6×105-1010 CFU/day of probiotics during 1-25 weeks and 1×109-112.5×109 CFU/capsule of synbiotics during 4-8 weeks. The effect of biotics on weight and BMI in infants is predominantly non-significant. Prebiotics and probiotics used in infancy were from 0.15 to 0.8 g/dL and 2×106-6×109 CFU/day for 2-24 weeks, respectively.

Conclusion

It seems biotics consumption can result in favorable impacts on some anthropometric indices of overweight/obesity (body weight, BMI, waist circumference) in the general population, without any significant effects on birth weight or weight gain during pregnancy and infancy. So, it is recommended to intake the biotics as complementary medications for reducing anthropometric indices of overweight/obese adults. However, more well-designed trials are needed to elucidate the anti-obesity effects of specific strains of probiotics.

Inulin-type fructans with different degrees of polymerization improve insulin resistance, metabolic parameters, and hormonal status in overweight and obese women with polycystic ovary syndrome: A randomized double-blind, placebo-controlled clinical trial

Polycystic ovary syndrome (PCOS) is associated with reproductive disorders and adverse cardiometabolic risk factors that can negatively impact the general health of women. Inulin-type fructans (ITFs) are proposed to beneficially affect risk factors associated with metabolic disorders. Whether ITFs can help with the management of PCOS by modifying insulin resistance (IR) and androgen levels has not yet been explored. The aim of this study was to investigate the effects of ITFs with different degrees of polymerization on insulin resistance, blood lipids, anthropometric measures, and hormonal status in overweight and obese women with PCOS. In a randomized double-blind placebo-controlled trial, seventy-five women with PCOS aged 18-40 years old were randomly assigned to receive 10 g/day of high-performance inulin (HPI) or oligofructose-enriched inulin (OEI) or maltodextrin for 12 weeks. Biochemical and clinical outcomes were measured at baseline and after the intervention. Participants in the HPI and OEI groups experienced improvements in waist circumference, total testosterone, free androgen index, sex hormone-binding globulin, and triglycerides compared to the placebo group. Also, the number of women with irregular menses or oligomenorrhoea decreased significantly in both ITF groups. Participants in the HPI group reported lower body mass, fasting insulin, and HOMA-IR, as well as a higher quantitative insulin sensitivity check index. ITF supplementation, especially with long-chain ITFs, when given for 12 weeks may improve metabolic outcomes, androgen status and clinical manifestations in women with PCOS.

Association of probiotic ingestion with serum sex steroid hormones among pre- and postmenopausal women from the NHANES, 2013-2016

BACKGROUND

Sex hormone-related diseases, encompassing a wide range of conditions from reproductive disorders to certain cancers, pose significant health challenges worldwide. Recent scientific investigations have highlighted the intricate interplay between the gut microbiome and sex hormone regulation, indicating the potential for microbiota-targeted interventions in the management of such diseases. Although individual studies have elucidated the influence of the gut microbiome on sex hormones, a comprehensive cross-sectional examination of the population-wide prevalence of probiotic intake and its correlation with sex hormones is still lacking.

OBJECTIVES

This study aimed to evaluate the association of probiotic ingestion with sex hormones in pre- and post-menopausal women.

METHODS

We conducted an observational cohort study comprising a nationally representative sample of adults who participated in the National Health and Nutrition Examination Survey between 2013 and 2016. Probiotic ingestion was considered when a subject reported yogurt or probiotic supplement consumption during the 24-h dietary recall or during the Dietary Supplement Use 30-Day questionnaire. A survey-weighted generalized linear model was used to analyze the association between probiotic intake and female/male sex hormones. To reduce selection bias, we used propensity score matching (PSM).

RESULTS

This study included 2,699 women, with 537 of them consuming yogurt and/or dietary supplements containing probiotics, while the remaining 2,162 women did not consume any probiotics. The findings indicated that there were associations between probiotic intake and sex hormone levels in premenopausal and postmenopausal women. For premenopausal women, probiotic intake was positively associated with estradiol (E2) levels. On the contrary, in postmenopausal women, probiotic intake was inversely associated with total testosterone (TT) levels.

CONCLUSIONS

This study indicated that probiotic consumption was associated with higher E2 level in premenopausal women and lower TT level in postmenopausal women. Probiotic intake might be a sensible strategy for preventing sex hormone-related diseases.

The role of probiotic supplementation in inflammatory biomarkers in adults: an umbrella meta-analysis of randomized controlled trials

OBJECTIVE

Despite the increasing evidence for probiotics' anti-inflammatory effects, the results of meta-analyses remain inconsistent. The present umbrella meta-analysis aimed to investigate the effects of probiotic supplementation on inflammatory biomarkers.

METHODS

We performed a wide-ranging systematic search in several databases, including PubMed, Web of Science, Scopus, EMBASE, and Google Scholar up to April 2023. The overall effect sizes were calculated using effect size (ES) values and their corresponding confidence intervals (CI).

RESULTS

Out of a total of 580 related articles, 39 studies were qualified for inclusion in the analysis. The results of the analysis revealed a significant reduction of C-reactive protein (CRP) (ES = -1.02; 95% CI: -1.23, -0.80, p < 0.001; I2: 94.1%, p < 0.001), TNF-α (ES = -0.35; 95% CI: -0.50, -0.20, p < 0.001; I2: 75.6%, p < 0.001), and interleukin-6 (IL-6) levels (ES = -0.36; 95% CI: -0.59, -0.13, p = 0.002; I2: 85.6%, p < 0.001), following probiotic supplementation.

CONCLUSION

Probiotic supplementation significantly reduced serum concentrations of TNF-a, CRP, and IL-6. Thus, probiotic supplementation can be considered adjuvant therapy to alleviate inflammation in various inflammatory conditions.

The effects of pro-, pre-, and synbiotics supplementation on polycystic ovary syndrome: an umbrella review of meta-analyses of randomized controlled trials

Background

Synbiotics, refer to a combination of probiotics and prebiotics in a form of synergism that beneficially affect the host's health by alternating the composition and/or function of the gut microbiota. Numerous meta-analyses of randomized clinical trials have proven that pro, pre-, and synbiotics supplementation has health outcomes in women with polycystic ovary syndrome (PCOS). However, the strength and quality of this evidence in aggregate have not yet been synthesized in great detail.

Methods

PubMed, Scopus, Web of Sciences, and Google Scholar were searched up to March 2023. We pooled the mean difference and its 95% confidence interval (CI) by applying a random-effects model.

Results

Overall, nine meta-analyses including a total of 12 trials were identified. The results of the present study indicated that probiotic supplementation significantly reduced the homeostatic model assessment for insulin resistance (HOMA-IR; WMD: -0.29, 95% CI: -0.57 to -0.02, p = 0.03, n = 4; moderate certainty) and fasting glucose concentration (FGC; WMD: -7.5 mg/dL, 95% CI: -13.60 to -0.51, p = 0.03; n = 4; low certainty). Moreover, synbiotic supplementation had beneficial effects on glycemic control, lipid profile, and hormonal parameters, but the certainty of the evidence was rated as low to very low. However, supplementation with pro-/synbiotics did not affect inflammation and oxidative stress in women with PCOS. Furthermore, waist/hip circumference, fasting glucose concentration, lipid profile, dehydroepiandrosterone sulfate, high-sensitivity C-reactive protein, and hirsutism score were significantly reduced after prebiotics supplementation with low certainty of evidence.

Conclusion

Although pro-, pre-, and synbiotics supplementation had beneficial effects on some PCOS-related outcomes, the certainty of the evidence was rated as low to very low. Therefore, further well-designed RCTs might help to confirm our findings in women with PCOS.

Alleviation of Limosilactobacillus reuteri in polycystic ovary syndrome protects against circadian dysrhythmia-induced dyslipidemia via capric acid and GALR1 signaling

Knowledge gaps that limit the development of therapies for polycystic ovary syndrome (PCOS) concern various environmental factors that impact clinical characteristics. Circadian dysrhythmia contributes to glycometabolic and reproductive hallmarks of PCOS. Here, we illustrated the amelioration of Limosilactobacillus reuteri (L. reuteri) on biorhythm disorder-ignited dyslipidemia of PCOS via a microbiota-metabolite-liver axis. A rat model of long-term (8 weeks) darkness treatment was used to mimic circadian dysrhythmia-induced PCOS. Hepatic transcriptomics certified by in vitro experiments demonstrated that increased hepatic galanin receptor 1 (GALR1) due to darkness exposure functioned as a critical upstream factor in the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway to suppress nuclear receptors subfamily 1, group D, member 1 (NR1D1) and promoted sterol regulatory element binding protein 1 (SREBP1), inducing lipid accumulation in the liver. Further investigations figured out a restructured microbiome-metabolome network following L. reuteri administration to protect darkness rats against dyslipidemia. Notably, L. reuteri intervention resulted in the decrease of Clostridium sensu stricto 1 and Ruminococcaceae UCG-010 as well as gut microbiota-derived metabolite capric acid, which could further inhibit GALR1-NR1D1-SREBP1 pathway in the liver. In addition, GALR antagonist M40 reproduced similar ameliorative effects as L. reuteri to protect against dyslipidemia. While exogenous treatment of capric acid restrained the protective effects of L. reuteri in circadian disruption-induced PCOS through inhibiting GALR1-dependent hepatic lipid metabolism. These findings purport that L. reuteri could serve for circadian disruption-associated dyslipidemia. Manipulation of L. reuteri-capric acid-GALR1 axis paves way for clinical therapeutic strategies to prevent biorhythm disorder-ignited dyslipidemia in PCOS women.

Efficacy and safety of gastrointestinal microbiome supplementation for allergic rhinitis: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Allergic rhinitis (AR) is a non-infective chronic inflammatory disease of nasal mucosa.

PURPOSE

To evaluate the efficacy and safety of gastrointestinal microbiome supplementation (GMS) for patients with allergic rhinitis (AR), concerning improvement on symptoms and signs, laboratory outcomes, quality of life, and medication scores.

METHODS

Five English databases were searched up to Dec 12th, 2022. Probiotics, prebiotics, and synbiotics were main therapies or adjuvants in experimental groups. Systematic reviews and meta-analyses were conducted based on the Cochrane systematic review method by using RevMan 5.4 Software, with meta-influence analyses, subgroup-analyses, meta-regression, and publication bias performed for exploration of heterogeneity by Stata V.14. Trial sequential analyses were performed by TSA 0.9, and quality of the results was accessed through the GRADE-pro GDT.

RESULTS

Finally, extracted from 53 articles, 65 RCTs involving 3,634 participants with sound worldwide representativeness were included. Primary results showed better improvement in GMS groups on TNSS (WMD=1.05, P for WMD=0.004, 95%CI:0.34 to 1.76), overall nasal condition (WMD=1.25, P for WMD<0.001, 95%CI:0.90 to 1.61), overall quality of life (WMD=6.16, P for WMD<0.001, 95%CI:4.92 to 7.40) and medication score (WMD=0.42, P for WMD=0.42, 95%CI:-0.06 to 0.90).However, GMS groups were inferior than the controls concerning reduction on serum total IgE (WMD=-1.81) and ratios of serum Th1/Th2 (WMD=-1.06). Meta-regressions suggested significant (p<0.05) variations of the effects in some comparisons. In addition, results of sub-group analyses firstly revealed potential influence between final results and the variables above. Instantly after intervention, the GRADE levels of evidence were sound, including "High ⨁⨁⨁⨁" in 10, "Moderate ⨁⨁⨁◯" in 33, and "Low ⨁⨁◯◯" in nine comparisons. However, overall certainties decreased obviously during follow-ups.

CONCLUSION

Overall, our pooled results firstly revealed that GMS yielded acceptable benefits for patients with AR compared with controls with sound certainties, after balancing the benefits and harms.

The effects of probiotics, prebiotics, and synbiotics on polycystic ovarian syndrome: an overview of systematic reviews

Introduction

Accumulating evidence has highlighted the critical role of the gut microbiota and its potential action as a regulator of metabolic disorders including insulin resistance, obesity, and systemic inflammation in polycystic ovarian syndrome (PCOS). Microbiota-modulating interventions, such as probiotics, prebiotics, and synbiotics, could be effective in PCOS management.

Methods

We conducted an overview of systematic reviews (SRs) and meta-analyses to summarize reviews regarding the effectiveness of probiotics/prebiotics/synbiotics on the management of PCOS through a systematic literature search in PubMed, Web of Science, and Scopus databases until September 2021.

Results

Eight SRs and meta-analyses were included in this study. Our overview confirmed that probiotic supplementation had a potentially beneficial effect on some PCOS-related parameters including body mass index (BMI), fasting plasma glucose (FPG), and lipid profiles. Evidence shows that synbiotics in comparison with probiotics were less effective on these parameters. The methodological quality of SRs was assessed using the AMSTAR-2 assessment tool and was determined as high for four SRs, low for two SRs, and critically low for one SR. Due to limited evidence and high heterogeneity of the studies, it remains difficult to identify optimal probiotics strains, prebiotics types, length of duration, and doses.

Discussion

Future clinical trials with higher quality are recommended to clarify the efficacy of probiotics/prebiotics/synbiotics on the management of PCOS and provide more accurate evidence.

An overview on effects of micronutrients and macronutrients interventions in management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the common endocrinopathies among women. Changing dietary behaviors for PCOS management has been an important research focus during the last decades. This review has discussed current evidence and clinical trial studies relating to the impact of macronutrients and micronutrients in the management of different clinical feature of PCOS. The possible relationship between the quality and quantity of micronutrients and macronutrients and PCOS as well as the necessity to manage PCOS as a complex condition highlights the importance of diet-related interventions. The growing number of clinical trials related to the effect of micronutrients (zinc, chromium, selenium, vitamin D, inositol, and vitamin E) and macronutrients interventions (manipulation of fat, carbohydrate, protein, and MedDiet, Calorie restriction, Low Glycemic Diet) have been demonstrated to be practical approaches for managing clinical and biochemical features of PCOS, however the potential benefit of micronutrient and macronutrient approaches could be different from one by one, particularly in different phenotypes of PCOS. To achieve optimum outcomes, providing information regarding safety and the best dose selection of micronutrients and macronutrients is necessary. Hence, to better understand the approaches' risk/benefit in women with PCOS, future trials with a large sample size are recommended.

Effects of nutrition on metabolic and endocrine outcomes in women with polycystic ovary syndrome: an umbrella review of meta-analyses of randomized controlled trials

CONTEXT

Numerous meta-analyses have been conducted on the effects of nutritional interventions on various health outcomes in women with polycystic ovary syndrome (PCOS). However, the strength of the evidence and its clinical significance are unclear.

OBJECTIVE

This umbrella review aimed to summarize the effects of nutritional interventions on women with PCOS and assess the strength of the evidence.

DATA SOURCES

PubMed, Scopus, and Web of Science were searched from inception until March 17, 2021.

DATA EXTRACTION

Meta-analyses of randomized clinical trials (RCTs) that examined the impact of dietary modifications or supplementations on women with PCOS were selected. Data extraction, quality assessments of the meta-analyses, and evaluation of the strength of the evidence were conducted independently by 2 investigators and confirmed by a third.

DATA ANALYSIS

Twenty-eight RCT meta-analyses were included, reporting 40 different outcomes. Lower carbohydrate, Dietary Approaches to Stop Hypertension, or lower glycemic index/load diets in women with PCOS significantly improved some anthropometric and metabolic characteristics (with very low to low certainty). Probiotics/synbiotics reduced fasting plasma glucose, fasting insulin (FI), and homeostasis model assessment-estimated insulin resistance (HOMA-IR) (with moderate to high certainty). Curcumin supplementation decreased fasting plasma glucose, FI, and HOMA-IR (with moderate certainty). Fish oil supplementation decreased FI and HOMA-IR, and omega-3 reduced triglycerides (with moderate certainty). There were also improvements in FI after taking vitamin D or inositol supplements (with moderate certainty). Supplementation with fish oil increased adiponectin (with high certainty), and probiotics/synbiotics reduced total testosterone (with moderate certainty). In subfertile women with PCOS, inositol increased the ovulation rates (with moderate certainty).

CONCLUSION

There was no high-certainty evidence that diets alone in women with PCOS improved health or reproductive outcomes. Supplementation with vitamin D, probiotics/synbiotics, omega-3, inositol, and curcumin showed favorable effects on some metabolic outcomes. Probiotics/synbiotics possibly reduces total testosterone, and inositol stimulates ovulation in women with PCOS.

REGISTRATION

PROSPERO registration no. CRD42021251496.

Role of probiotics/synbiotic supplementation in glycemic control: A critical umbrella review of meta-analyses of randomized controlled trials

The evidence regarding the beneficial effects of probiotics/synbiotic supplementation have been revealed by several meta-analyses, however some of these studies have fielded inconsistent results and a conclusion has yet to be reached. Therefore, the aim of present umbrella meta-analyses was to assess relevant evidence and elucidate the efficacy of probiotics/synbiotic supplementation in glycemic control. A comprehensive search in four databases (Cochrane library, PubMed, Web of science and Scopus) was performed to collect relevant studies up to August 2022, the pooled effects were measured with the use of random/fix-effect model depends on the heterogeneity. A total of 47 eligible meta-analyses involving 47,720 participants were identified to evaluate the pooled effects. The overall results showed that probiotics/synbiotic supplementation delivered significant decreases in fast plasma glucose (ES = -0.408, 95% CI: -0.518, -0.298; P < 0.001; I2 = 82.996, P < 0.001), fast plasma insulin (ES = -1.165, 95% CI: -1.454, -0.876; P < 0.001; I2 = 89.629, P < 0.001), homeostasis model assessment of insulin resistance (ES = -0.539, 95% CI: -0.624, -0.454; P < 0.001; I2 = 56.716, P < 0.001), and glycosylated hemoglobin (ES = -0.186, 95% CI: -0.270, -0.102; P < 0.001; I2 = 59.647, P = 0.001). Subgroup analysis showed that patients with impaired glucose homeostasis might benefit the most from probiotics/synbiotic supplementation. In conclusion, current umbrella meta-analysis strongly supporting the beneficial health effects of probiotics/synbiotic supplementation in glycemic control.

Effects of inulin-type fructans with different degrees of polymerization on inflammation, oxidative stress and endothelial dysfunction in women with polycystic ovary syndrome: A randomized, double-blind, placebo-controlled trial

OBJECTIVE

Polycystic ovary syndrome (PCOS) is associated with several cardiovascular risk factors. Prebiotics were proposed to beneficially affect risk factors associated with metabolic disorders. The aim of this study was to investigate and compare the effects of inulin-type fructans (ITFs), as well-studied prebiotics, with different degrees of polymerization, on markers of inflammation, oxidative stress and endothelial dysfunction in PCOS patients.

DESIGN

A randomized, double-blind, placebo-controlled trial.

PATIENTS

Seventy-five PCOS women were randomly assigned to receive 10 g/day of either high-performance inulin (HPI) or oligofructose-enriched inulin (OEI) or placebo for 12 weeks.

MEASUREMENTS

Biochemical indices and blood pressure levelswere assessed before and after the intervention.

RESULTS

In the intent-to-treat analysis, high-sensitive C-reactive protein (hs-CRP) decreased in HPI and OEI groups, over the 12 weeks, and the changes were significant in the HPI group, compared to placebo (changes from baseline in the HPI group: -0.11 vs. placebo group: 0.004 mg/L [conversion factor to SI units (nmol/L): 9/5238]; p = .007). Serum levels of nitric oxide (NO) increased, and endothelin-1 and total oxidant status decreased in HPI and OEI groups, at the end of the trial; however, these changes were not significantly compared to placebo (p = .07, .36 and .22, respectively). No differences in systolic and diastolic blood pressure were found. Per-protocol analysis (n = 68) yielded consistent results for all endpoints, with the exception that the significant effect of ITFs on serum hs-CRP levels in the unadjusted ITT analysis became nonsignificant in the per-protocol analysis (p = .06).

CONCLUSION

A 12-week supplementation with long-chain ITFs had favourable effects on inflammatory status among PCOS patients.

Probiotic therapy, a novel and efficient adjuvant approach to improve glycemic status: An umbrella meta-analysis

BACKGROUND

Probiotics exert several promoting effects on the glycemic status, however, the results of meta-analyses are inconsistent. we conducted an umbrella meta-analysis, across existing systematic reviews and meta-analyses of clinical trials to determine the definite effects of supplementation with probiotics on glycemic indices.

METHODS

A comprehensive systematic search of PubMed/Medline, Scopus, EMBASE, and Web of Science was carried out till August 2021. The random-effects model was employed to conduct meta-analysis. Meta-analysis studies of randomized clinical trials examining the impacts of probiotics supplementation on glycemic indices were qualified in the current umbrella meta-analysis.

RESULTS

48 articles out of 693 in the literature search qualified for inclusion in the umbrella meta-analysis. Pooled effects of probiotics on fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and insulin levels were reported in articles 45, 21, 35, and 33, respectively. The analysis indicated a significant decrease of FPG (ES= -0.51 mg/dL; 95% CI: -0.63, -0.38, p < 0.001), HbA1c (ES = -0.32 mg/dL; 95% CI: -0.44, -0.20, p < 0.001), HOMA-IR (ES= -0.56; 95% CI: -0.66, -0.47, p < 0.001), and insulin levels (ES= -1.09 IU/mL; 95% CI: -1.37, -0.81, p = 0.006) by probiotics supplementation.

CONCLUSION

Probiotics have amending effects on FPG, HbA1c, HOMA-IR, and insulin levels. A < 8-week period of probiotic supplementation in the moderate dosages (10⁸ or 10⁹ CFU) is an efficacious approach in improving glycemic parameters. Overall, probiotics could be recommended as an adjuvant anti-hyperglycemic agent.

Anti-obesity properties of probiotics; a considerable medical nutrition intervention: Findings from an umbrella meta-analysis

Although several studies have indicated that consumption of probiotics is effective in the treatment of obesity, the results in this regard have yielded controversial findings. The current umbrella meta-analysis was performed to evaluate the effects of probiotics supplementation on obesity indices in adults. Scopus, PubMed, Web of Science, Embase and Google Scholar were searched for relevant studies published till November 2021. Meta-analysis was conducted using the random-effects model. Sensitivity and subgroup analyses were performed. In total, 29 meta-analyses with 14,366 participants, including 112, 78, and 38 unique trials for body mass index (BMI), body weight (BW), and waist circumference (WC), were included in the study, respectively. The findings demonstrated that the probiotics supplementation was significantly effective on decreasing of BMI (ES = -0.21; 95% CI: -0.30, -0.13, p < 0.001; I² = 83.0%, p < 0.001), BW (ES = -0.38, 95% CI: -0.60, -0.16; p < 0.001; I² = 81.8%, p < 0.001), and WC (ES = -0.60; 95% CI: -0.89, -0.31; p < 0.001; I² = 89.1%, p < 0.001). Greater effects on BW were observed when intervention duration was >8 weeks and on obese individuals. BMI was also greatly modified in participants with metabolic syndrome and when intervention duration lasted for ≥12 weeks. The methodological quality (AMSTAR2) was moderate in 83%, low in 10%, and critically low in 7% of included studies. The current umbrella meta-analysis indicated that supplementation of probiotics in adults led to a meaningful reduction in BW, BMI, and WC. Therefore, our findings strongly recommend supplementation with probiotics as a potent intervention in the management of obesity.

A narrative review of the role of gastrointestinal dysbiosis in the pathogenesis of polycystic ovary syndrome

Diet-induced gastrointestinal dysbiosis has been hypothesized to play a significant role in stimulating an increase in gastrointestinal permeability and activating systemic inflammation in women with polycystic ovary syndrome (PCOS). We reviewed the current proof-of-concept studies on the proposed mechanism of dysbiosis in the pathogenesis of PCOS. A literature search was performed to identify articles on changes in the intestinal microbiome (dysbiosis) and increased intestinal mucosal permeability involving lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), and zonulin. We also searched for systematic reviews and meta-analyses that synthesized the results of studies on the therapeutic effects of prebiotics, probiotics, or synbiotics in women with PCOS. Our search was confined to human studies between 2012 and 2021 using the PubMed, Scopus, and Cochrane databases. Thirty-one studies met the inclusion criteria (14 microbiota, 1 LPS, 1 LPS-BP, 1 LPS and LPS-BP, 5 zonulin, 9 systematic reviews). Our analysis revealed that most studies reported reduced alpha diversity and dysbiosis in women with PCOS. Preliminary studies suggest that LPS, LPS-BP, and zonulin may be involved in the pathophysiology of increased intestinal permeability. Treatment of PCOS with prebiotics, probiotics, and synbiotics appears to have a range of beneficial effects on metabolic and biochemical profiles. This review highlights the need for continued research into the pathophysiological mechanisms of dysbiosis and the clinical efficacy of prebiotics, probiotics, and synbiotics in women with PCOS.

Effects of Synbiotic Supplementation and Lifestyle Modifications on Women With Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age.

OBJECTIVE

This study was designed to evaluate effects of lifestyle modifications and synbiotic supplementation on PCOS.

DESIGN

A randomized (1:1) double-blind, placebo-controlled trial.

SETTING

Academic hospital.

PATIENTS OR OTHER PARTICIPANTS

Overweight and obese women with PCOS were identified according to the Rotterdam criteria. Evaluations were performed at baseline and repeated after 3 months of treatment.

INTERVENTION

Lifestyle modifications in combination with synbiotic supplementation or placebo.

MAIN OUTCOME MEASURES

Change in body mass index (BMI) and testosterone level.

RESULTS

In the placebo group, a 5% decrease in BMI was accompanied by significant decreases of the waist, hip, and thigh circumferences. The synbiotic group experienced an 8% decrease in BMI, which was significantly greater than that in the control group (P = 0.03) and was accompanied by decreases in the waist, hip, and thigh circumferences. Testosterone did not decrease significantly in the placebo group (decrease of 6%), whereas in the synbiotic group it decreased by 32% (P < 0.0001). The decrease of testosterone was significantly greater in the synbiotic group than in the placebo group (P = 0.016).

CONCLUSIONS

Synbiotic supplementation potentiated effects of lifestyle modifications on weight loss and led to significant reduction of serum testosterone.

Effects of probiotics, prebiotics, and synbiotics on polycystic ovary syndrome: a systematic review and meta-analysis

This meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effects of probiotics, prebiotics, and synbiotics on insulin resistance (IR), lipid profiles, anthropometric indices, and C-reactive protein (CRP) level for polycystic ovary syndrome (PCOS). We searched 8 databases from their inception until 1st October, 2020. The effect sizes were expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Subgroup analyses were undertaken for further identification of effects of probiotics, prebiotics, and synbiotics, based on the following aspects: (1) type of intervention (probiotics, prebiotics, or synbiotics); (2) study duration (≥ 12 weeks or < 12 weeks); (3) number of probiotic strains (multi strains or single strain); (4) probiotic dose (≥ 2 × 10⁸ colony-forming units [CFU] or < 2 × 10⁸ CFU). A total of 17 eligible RCTs with 1049 participants were included. Results showed that probiotic, prebiotic, and synbiotic intake decreased fasting plasma glucose (SMD, -1.35; 95% CI, -2.22 to -0.49; p = 0.002), fasting insulin (SMD, -0.68; 95% CI, -1.08 to -0.27; p = 0.001), homeostatic model of assessment for IR (SMD, -0.73; 95% CI, -1.15 to -0.31; p = 0.001), triglycerides (SMD, -0.85; 95% CI, -1.59 to -0.11; p = 0.024), total cholesterol (SMD, -1.09; 95% CI, -1.98 to -0.21; p = 0.015), low-density lipoprotein cholesterol (SMD, -0.84; 95% CI, -1.64 to -0.03; p = 0.041), very-low-density lipoprotein cholesterol (SMD, -0.44; 95% CI, -0.70 to -0.18; p = 0.001), and increased quantitative insulin sensitivity check index (SMD, 2.00; 95% CI, - 0.79 to 3.22; p = 0.001). However, probiotic, prebiotic, and synbiotic supplements did not affect anthropometric indices, high-density lipoprotein cholesterol, and CRP levels. Subgroup analysis showed that probiotic or prebiotic might be the optimal choice for ameliorating IR or lipid profiles, respectively. Additionally, the effect was positively related to courses and therapeutical dose. Overall, the meta-analysis demonstrates that probiotic, prebiotic, or synbiotic administration is an effective and safe intervention for modifying IR and lipid profiles.

Efficacy of synbiotic interventions on blood pressure: a systematic review and meta-analysis of clinical trials

PURPOSE

The present systematic review and meta-analysis aimed to evaluate the effect of synbiotic interventions on blood pressure levels in adults.

METHODS

A systematic literature search was conducted in the databases of MEDLINE, Scopus, Web of Science, and Cochrane through March 2020 to identify all randomized control trials (RCTs) investigating the effects of synbiotic interventions on blood pressure parameter, including systolic (SBP) and diastolic blood pressure (DBP). Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale was used to assess the certainty of evaluated outcomes and determine the strength of recommendations.

RESULTS

Eleven RCTs were included in the meta-analysis. Synbiotic interventions significantly reduced SBP (-3.02 mmHg; 95% CI: -4.84, -1.21; I² = 55%) without changing DBP levels (-0.57 mmHg; 95% CI: -1.78, 0.64; I² = 50%). Subgroup analyses revealed that the SBP-lowering effects of synbiotic interventions were more pronounced wherein trials were longer (≥12 weeks), synbiotic interventions were administrated as a supplement, and participants were younger (<50 years old). Also, a significant improvement in both SBP and DBP levels was evident in subgroups with a lower (<30 kg/m²) body mass index.

CONCLUSIONS

Synbiotic interventions may significantly improve SBP levels in adults.

Probiotics as a Complementary Therapy for Management of Obesity: A Systematic Review

Background

Considering the observed role of probiotics in modulating gut microbiome, probiotics are discussed to be one potential complementary therapy for obesity management in recent years. The aim of the present study was to systematically review the meta-analyses of controlled trials and investigate the effects of probiotics on obesity.

Methods

A comprehensive search was conducted on PubMed, Web of Science, and Cochrane Library web databases up to May 2020. Inclusion criteria were meta-analyses of controlled trials which evaluated the impact of probiotics on obesity in English language. Meta-analyses done on pregnant women, children, animal studies, or the effect of prebiotics on anthropometric indices were excluded.

Results

Within 325 recorded studies, 20 studies met the inclusion criteria consisting of 16676 overweight/obese adults with different underlying disorders such as nonalcoholic fatty liver disease (NAFLD), or polycystic ovary syndrome (PCOS). The length of intervention varied from 2 to 26 weeks. Results of meta-analyses have shown a moderate effect of probiotics on body weight in overweight/obese adults: from −0.526 kg/m² (95% CI: −0.810, −0.247) to −0.25 kg/m² (95% CI: −0.33, −0.17). Body mass index (BMI) was changed from −1.46 kg/m² (95% CI: −2.44, −0.48) to −1.08 kg/m² (95% CI: −2.05, −0.11) in NAFLD. Probiotics could reduce BMI from −0.36 kg/m² (95% CI: −0.74, 0.02) to −0.29 kg/m² (95% CI: −0.54, −0.03) in patients with PCOS.

Conclusion

It seems that the probiotic products could have beneficial effects as an adjunct therapy for care and management of obesity when used in high dose. However, due to heterogeneity of included studies, it is required to confirm our results by more meta-analyses of clinical trials.

Effects of Cangfu Daotan Decoction on obese polycystic ovary syndrome and its mechanism

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders affecting women of reproductive age. Cangfu Daotan Decoction (CFDTT) is one of the prescriptions in the stagnation of obesity-type PCOS. Our previous study showed that CFDTT treatment of obese PCOS was correlated with organic anion transporting polypeptides (OATPs).

METHODS

Here, we studied the effects of CFDTT on obese PCOS and its underlying mechanism. We built an obese PCOS rat model and treated the rats with CFDTT. Then, we detected the serum levels of TCHO, TG, LDL-c, HDL-c, luteinizing hormone (LH), follicle stimulating growth hormone (FSH), testosterone (T), estradiol (E2), IL-1β, IL-6, and TNF-α in each group and adopted RT-PCR, western blotting and immunohistochemical staining to investigate the effects of CFDTT treatment on the expression of OATP2B1 and OATP3A1 in ovarian and uterine tissues. In addition, we compared the pregnancy outcomes of each group.

RESULTS

We found that CFDTT decreased the serum levels of TCHO, TG, LDL-c, LH, T, IL-1β, IL-6, and TNF-α and increased the levels of HDL-c, FSH and E2 in a dose-dependent manner. CFDTT could induce the expression of OATP2B1 and OATP3A1 in ovarian and uterine tissues. Moreover, CFDTT could improve pregnancy outcomes.

CONCLUSION

These data suggested that the therapeutic mechanism of Cangfu Daotan Decoction on PCOS may be correlated with regulating lipid metabolism, sex hormone secretion and the inflammatory response and increasing OATP2B1 and OATP3A1 expression. Cangfu Daotan Decoction can be developed as a PCOS treatment drug.

Improvement of glucose metabolism in pregnant women through probiotic supplementation depends on gestational diabetes status: meta-analysis

The aim of this study was to assess the effects of probiotic and synbiotic supplementation on glucose metabolism in pregnant women using data from randomized controlled trials. Furthermore, this meta-analysis examines whether the observed effects depend on the presence or absence of gestational diabetes mellitus (GDM), and if the effect is dependent on the type of supplement used (probiotic or synbiotic). We performed a literature search of databases (Medline, Scopus, Web of Knowledge, and Cochrane Library) and identified all relevant randomized controlled trials (RCTs) published prior to May 2019. We compared the effects of probiotic supplementation with the administration of placebos in pregnant women with and without GDM. The systematic review and meta-analysis protocol were registered in the International Prospective Register of Systematic Reviews as number CRD 42019111467. 1119 study participants from 15 selected studies were included. The participants in four studies did not have GDM (being recruited to the study before week 20 of pregnancy) and the participants in the rest of the studies were diagnosed with GDM between weeks 24 and 28 of gestation. The meta-analysis showed that supplementation lowers serum glucose, insulin levels, and HOMA-IR index, but only in pregnant women with GDM. Moreover, both probiotics and synbiotics lower serum insulin level and HOMA-IR index, but the glucose lowering effect is specific only to probiotics and not synbiotics. Probiotic supplementation may improve glucose metabolism in pregnant women with GDM. There is a need for more RCT studies with larger groups to better estimate this effect.

The effect of synbiotics supplementation on anthropometric indicators and lipid profiles in women with polycystic ovary syndrome: a randomized controlled trial

Background

Different therapies have been suggested for polycystic ovary syndrome (PCOS), but changes in lifestyle and diet have been considered. Diet and dietary factors can be very effective in modifying the disease. The positive effects of probiotic and synbiotics supplementation on improving lipid profiles and anthropometric indices have been examined in various diseases. This study was conducted to evaluate the effects of synbiotics supplementation on lipid and anthropometric profiles in infertile women with PCOS.

Methods

PCOS patients aged 19–37 years old were randomized to receive either synbiotics supplement (n = 50) or placebo (n = 49) for 12 weeks.

Results

Consumption of synbiotics compared to the placebo, resulted in a significant decrease in Low-density lipoprotein cholesterol (LDL) value (Change Mean Difference (CMD): 4.66, 95%CI: 0.20, 9.13) and a significant increase in high-density lipoprotein cholesterol (HDL) (CMD: 1.80, 95%CI: 0.34, 3.26). Although we failed to find a significant effect of synbiotics consumption on total cholesterol (TC) and triglyceride (TG) levels. We did not find differences in anthropometric indices between groups.

Conclusions

Overall, 12 weeks of synbiotics supplementation among PCOS women resulted in beneficial effects on LDL and HDL, although it is not yet clear how much our findings are clinically significant and more clinical studies with larger sample sizes are still needed.

Trial registration

Iranian Registry of clinical Trial, IRCT.ir, ID: IRCT2014110515536N2. Registered on 19 December 2015.

Graphical abstract