Balancing Act: Exploring the Gut Microbiota-Brown Adipose Tissue Axis in PCOS Pathogenesis and Therapeutic Frontiers.

Polycystic ovary syndrome (PCOS) is a prevalent reproductive, endocrine, and metabolic disease that affects 5-18% of women worldwide, with a rising incidence. Hyperandrogenemia and insulin resistance are two key pathophysiological factors that contribute to PCOS, both of which contribute to a variety of health issues such as menstrual irregularities, obesity, dysfunctional glucose and lipid homeostasis, infertility, mental disorders, and cardiovascular and cerebrovascular diseases. Despite ongoing studies, the origin and pathogenesis of PCOS remain elusive; there is also a clinical need for simpler, more effective, longer lasting, and more comprehensive treatments for women with PCOS. The gut-fat axis, a critical regulatory route for metabolism, endocrine function, and immune response, has received considerable interest in recent years in the research of the etiology and treatment of metabolic illnesses such as type 2 diabetes mellitus and non-alcoholic fatty liver disease. The latest research in PCOS has revealed significant alterations in the homogeneity and phylogenetic diversity of the gut microbiota. Animal research using fecal microbiota transplantation has confirmed the importance of gut microbiota in regulating insulin sensitivity and sex hormone balance in PCOS. Furthermore, studies have shown a decrease in the volume and/or activity of brown adipose tissue (BAT) in PCOS patients, a change that alters adipokine release, leading to insulin resistance and hyperandrogenemia, aggravating PCOS progression. Given the function of BAT in increasing energy expenditure and alleviating metabolic parameters, efforts to activate BAT or induce browning of white adipose tissue have emerged as possible treatments for PCOS. Recent research has suggested that the gut microbiota can influence BAT creation and activity via metabolites such as short-chain fatty acids and bile acids, as well as the gut-brain axis. Cold exposure, healthy dieting, metformin, bariatric surgery, glucagon-like peptide 1 receptor agonists and melatonin have all been shown in basic and clinical studies to modulate BAT activity by influencing the gut microbiota, demonstrating significant clinical potential. However, more studies into the regulation mechanisms of the gut-BAT axis are required to produce more effective, comfortable, and safe tailored therapeutics for PCOS.

Li Y ，Fang Y ，Wang H ，Zhang H ... -  《-》

Electroacupuncture improves metabolic and ovarian function in a rat model of polycystic ovary syndrome by decreasing white adipose tissue, increasing brown adipose tissue, and modulating the gut microbiota.

Zhang F ，Ma T ，Tong X ，Liu Y ，Cui P ，Xu X ，Shi J ，Hu W ，Lu W ，Pei Z ，Xu M ，Li X ，Xu C ，Feng Y ... -  《-》

Evaluating the therapeutic potential of moxibustion on polycystic ovary syndrome: a rat model study on gut microbiota and metabolite interaction.

Polycystic ovary syndrome (PCOS) is a common systemic disorder related to endocrine disorders, affecting the fertility of women of childbearing age. It is associated with glucose and lipid metabolism disorders, altered gut microbiota, and insulin resistance. Modern treatments like pioglitazone, metformin, and spironolactone target specific symptoms of PCOS, while in Chinese medicine, moxibustion is a common treatment. This study explores moxibustion's impact on PCOS by establishing a dehydroepiandrosterone (DHEA)-induced PCOS rat model. Thirty-six specific pathogen-free female Sprague-Dawley rats were divided into four groups: a normal control group (CTRL), a PCOS model group (PCOS), a moxibustion treatment group (MBT), and a metformin treatment group (MET). The MBT rats received moxibustion, and the MET rats underwent metformin gavage for two weeks. We evaluated ovarian tissue changes, serum testosterone, fasting blood glucose (FBG), and fasting insulin levels. Additionally, we calculated the insulin sensitivity index (ISI) and the homeostasis model assessment of insulin resistance index (HOMA-IR). We used 16S rDNA sequencing for assessing the gut microbiota, 1H NMR spectroscopy for evaluating metabolic changes, and Spearman correlation analysis for investigating the associations between metabolites and gut microbiota composition. The results indicate that moxibustion therapy significantly ameliorated ovarian dysfunction and insulin resistance in DHEA-induced PCOS rats. We observed marked differences in the composition of gut microbiota and the spectrum of fecal metabolic products between CTRL and PCOS rats. Intriguingly, following moxibustion intervention, these differences were largely diminished, demonstrating the regulatory effect of moxibustion on gut microbiota. Specifically, moxibustion altered the gut microbiota by increasing the abundance of UCG-005 and Turicibacter, as well as decreasing the abundance of Desulfovibrio. Concurrently, we also noted that moxibustion promoted an increase in levels of short-chain fatty acids (including acetate, propionate, and butyrate) associated with the gut microbiota of PCOS rats, further emphasizing its positive impact on gut microbes. Additionally, moxibustion also exhibited effects in lowering FBG, testosterone, and fasting insulin levels, which are key biochemical indicators associated with PCOS and insulin resistance. Therefore, these findings suggest that moxibustion could alleviate DHEA-induced PCOS by regulating metabolic levels, restoring balance in gut microbiota, and modulating interactions between gut microbiota and host metabolites.

Lin Y ，Zeng H ，Lin J ，Peng Y ，Que X ，Wang L ，Chen L ，Bai N ... -  《Frontiers in Cellular and Infection Microbiology》

Effects of gut microbiota on omega-3-mediated ovary and metabolic benefits in polycystic ovary syndrome mice.

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder that frequently exhibits low-grade inflammation, pro-oxidant activity, and gut dysbiosis. PCOS has become one of the leading causes of female infertility worldwide. Recently, omega-3 polyunsaturated fatty acids (PUFAs) have been proven to benefit metabolic disorders in PCOS patients. However, its roles in the regulation of metabolic and endocrinal balances in PCOS pathophysiology are not clear. In the present study, we aimed to explore how omega-3 PUFAs alleviate ovarian dysfunction and insulin resistance in mice with dehydroepiandrosterone (DHEA)-induced PCOS by modulating the gut microbiota. We induced PCOS in female mice by injecting them with DHEA and then treated them with omega-3 PUFAs. 16S ribosomal DNA (rDNA) amplicon sequencing, fecal microbiota transplantation (FMT) and antibiotic treatment were used to evaluate the role of microbiota in the regulation of ovarian functions and insulin resistance (IR) by omega-3 PUFAs. To further investigate the mechanism of gut microbiota on omega-3-mediated ovarian and metabolic protective effects, inflammatory and oxidative stress markers in ovaries and thermogenic markers in subcutaneous and brown adipose tissues were investigated. We found that oral supplementation with omega-3 PUFAs ameliorates the PCOS phenotype. 16S rDNA analysis revealed that omega-3 PUFA treatment increased the abundance of beneficial bacteria in the gut, thereby alleviating DHEA-induced gut dysbiosis. Antibiotic treatment and FMT experiments further demonstrated that the mechanisms underlying omega-3 benefits likely involve direct effects on the ovary to inhibit inflammatory cytokines such as IL-1β, TNF-α and IL-18. In addition, the gut microbiota played a key role in the improvement of adipose tissue morphology and function by decreasing multilocular cells and thermogenic markers such as Ucp1, Pgc1a, Cited and Cox8b within the subcutaneous adipose tissues. These findings indicate that omega-3 PUFAs ameliorate androgen-induced gut microbiota dysbiosis. The gut microbiota plays a key role in the regulation of omega-3-mediated IR protective effects in polycystic ovary syndrome mice. Moreover, omega-3 PUFA-regulated improvements in the ovarian dysfunction associated with PCOS likely involve direct effects on the ovary to inhibit inflammation. Our findings suggest that omega-3 supplementation may be a promising therapeutic approach for the treatment of PCOS by modulating gut microbiota and alleviating ovarian dysfunction and insulin resistance.

Zhang H ，Zheng L ，Li C ，Jing J ，Li Z ，Sun S ，Xue T ，Zhang K ，Xue M ，Cao C ，Ouyang L ，Qian Z ，Xu R ，He Z ，Ma R ，Chen L ，Yao B ... -  《Journal of Ovarian Research》

White-brown adipose tissue interplay in polycystic ovary syndrome: Therapeutic avenues.

Abbasi K ，Zarezadeh R ，Valizadeh A ，Mehdizadeh A ，Hamishehkar H ，Nouri M ，Darabi M ... -  《-》