Department of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133 Milano, Italy.
Teagasc Food Research Centre, Moorepark, P61 C996 Cork, Ireland.
Biomolecules. 2022 May 31;12(6):767. doi: 10.3390/biom12060767.
Sex steroids, derived mainly from gonads, can shape microbiota composition; however, the impact of gonadectomy and sex on steroid production in the gut (i.e., gut steroids), and its interaction with microbiota composition, needs to be clarified. In this study, steroid environment and gut steroidogenesis were analysed by liquid chromatography tandem mass spectrometry and expression analyses. Gut microbiota composition as branched- and short-chain fatty acids were determined by 16S rRNA gene sequence analysis and gas chromatography flame ionisation detection, respectively. Here, we first demonstrated that levels of pregnenolone (PREG), progesterone (PROG), and isoallopregnanolone (ISOALLO) were higher in the female rat colon, whereas the level of testosterone (T) was higher in males. Sexual dimorphism on gut steroidogenesis is also reported after gonadectomy. Sex, and more significantly, gonadectomy, affects microbiota composition. We noted that a number of taxa and inferred metabolic pathways were associated with gut steroids, such as positive associations between with T, dihydroprogesterone (DHP), and allopregnanolone (ALLO), whereas negative associations were noted between and T, ALLO, PREG, ISOALLO, DHP, and PROG. In conclusion, this study highlights the novel sex-specific association between microbiota and gut steroids with possible relevance for the gut-brain axis.
性激素主要来源于性腺，可以影响微生物群落的组成；然而，性腺切除术和性别对肠道中类固醇的产生（即肠道类固醇）及其与微生物群落组成的相互作用的影响仍需阐明。在这项研究中，我们通过液相色谱串联质谱和表达分析来分析类固醇环境和肠道类固醇生成。通过 16S rRNA 基因序列分析和气相色谱火焰离子化检测分别确定了微生物群落组成的分支和短链脂肪酸。在这里，我们首次证明了孕烯醇酮（PREG）、孕酮（PROG）和异孕烯醇酮（ISOALLO）的水平在雌性大鼠结肠中较高，而雄性大鼠中睾丸酮（T）的水平较高。性腺切除术后也报告了肠道类固醇生成的性别二态性。性别，更重要的是，性腺切除术，影响微生物群落的组成。我们注意到，许多分类群和推断的代谢途径与肠道类固醇有关，例如 T、二氢孕酮（DHP）和异孕烯醇酮（ALLO）与 之间呈正相关，而 T、ALLO、PREG、ISOALLO、DHP 和 PROG 与 之间呈负相关。总之，这项研究强调了微生物群和肠道类固醇之间存在新的性别特异性关联，这可能与肠道-大脑轴有关。
