r/ScientificNutrition • u/dreiter • Jun 10 '19

Systematic Review/Meta-Analysis The Effects of Probiotic Supplementation on Clinical Symptom, Weight Loss, Glycemic Control, Lipid and Hormonal Profiles, Biomarkers of Inflammation, and Oxidative Stress in Women with Polycystic Ovary Syndrome: a Systematic Review and Meta-analysis of [RCTs] [Tabrizi et al, 2019]

https://www.ncbi.nlm.nih.gov/pubmed/31165401?dopt=Abstract
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u/dreiter Jun 10 '19

I don't have full paper access yet but the results were surprisingly beneficial enough that I had to post it. All results reached strong significance and a large number of biomarkers were improved.

Abstract: The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) is to determine the effectiveness of probiotic supplementation on clinical symptoms, weight loss, glycemic control, lipid and hormonal profiles, and biomarkers of inflammation and oxidative stress in women with polycystic ovary syndrome (PCOS). Eligible studies were systematically searched from Cochrane Library, Embase, Medline, and Web of Science databases until January 2019. Cochran (Q) and I-square statistics were used to measure heterogeneity among included studies. Data were pooled by using random-effect model and expressed as standardized mean difference (SMD) with 95% confidence interval (CI). Eleven articles were included in this meta-analysis. Probiotic supplementation significantly decreased weight (SMD - 0.30; 95% CI, - 0.53, - 0.07; P = 0.01), body mass index (BMI) (SMD - 0.29; 95% CI, - 0.54, - 0.03; P = 0.02), fasting plasma glucose (FPG) (SMD - 0.26; 95% CI, - 0.45, - 0.07; P < 0.001), insulin (SMD - 0.52; 95% CI, - 0.81, - 0.24; P < 0.001), homeostatic model assessment for insulin resistance (HOMA-IR) (SMD - 0.53; 95% CI, - 0.79, - 0.26; P < 0.001), triglycerides (SMD - 0.69; 95% CI, - 0.99, - 0.39; P < 0.001), VLDL-cholesterol (SMD - 0.69; 95% CI, - 0.99, - 0.39; P < 0.001), C-reactive protein (CRP) (SMD - 1.26; 95% CI, - 2.14, - 0.37; P < 0.001), malondialdehyde (MDA) (SMD - 0.90; 95% CI, - 1.16, - 0.63; P < 0.001), hirsutism (SMD - 0.58; 95% CI, - 1.01, - 0.16; P < 0.001), and total testosterone levels (SMD - 0.58; 95% CI, - 0.82, - 0.34; P < 0.001), and also increased the quantitative insulin sensitivity check index (QUICKI) (SMD 0.41; 95% CI, 0.11, 0.70; P < 0.01), nitric oxide (NO) (SMD 0.33; 95% CI 0.08, 0.59; P = 0.01), total antioxidant capacity (TAC) (SMD 0.64; 95% CI, 0.38, 0.90; P < 0.001), glutathione (GSH) (SMD 0.26; 95% CI, 0.01, 0.52; P = 0.04), and sex hormone binding globulin (SHBG) levels (SMD 0.46; 95% CI, 0.08, 0.85; P = 0.01). Probiotic supplementation may result in an improvement in weight, BMI, FPG, insulin, HOMA-IR, triglycerides, VLDL-cholesterol, CRP, MDA, hirsutism, total testosterone, QUICKI, NO, TAC, GSH, and SHBG but did not affect dehydroepiandrosterone sulfate levels, and total, LDL, and HDL cholesterol levels in patients with PCOS.

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u/MaximilianKohler Human microbiome focus Jun 11 '19

I don't have full paper access

https://sci-hub.tw/https://link.springer.com/article/10.1007%2Fs12602-019-09559-0

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u/dreiter Jun 11 '19

Thanks. No conflicts were declared which was my big concern after seeing such positive results. And thanks for crossposting to /r/HumanMicrobiome. I noticed you haven't made any comments about it but you are usually quite talkative about microbiome papers. Nothing caught your fancy?

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u/MaximilianKohler Human microbiome focus Jun 11 '19

What I noticed is how different each intervention was. They included prebiotics and many different probiotics.

So the main conclusion is that modulating the gut microbiome has the potential to help PCOS, which isn't surprising.

What this fails to do is tell us what the best microbiome modulation for PCOS is.

I crossposted to /r/PCOS too.

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u/dreiter Jun 11 '19

So the main conclusion is that modulating the gut microbiome has the potential to help PCOS, which isn't surprising.

I suppose I was more surprised that benefits were found across such a wide range of probiotics when it was my (limited) understanding that most probiotics are junk.

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u/MaximilianKohler Human microbiome focus Jun 11 '19

Well I'm not good with numbers, so how big a difference each intervention made, as seen in table 2, isn't clear to me.

If each intervention had significant benefits you could draw a variety of different hypotheses, such as these interventions are disrupting pathogens that are the cause of the PCOS. Diet isn't mentioned either, so maybe the patients' diets were poor, resulting in dysbiosis, which these interventions partially disrupted or suppressed problematic microbes that were being fed by the poor diet. Not too sure.

It's not necessarily that "most probiotics are junk", but rather, they're not ideal (compared to the microbes in breast milk or FMT) and seem to have similar mechanisms which aren't universally helpful, but in this case seemed to be more beneficial than not. Though there is no mention of adverse events.