Del Piano Filomena, Mateu Baptiste, Coretti Lorena, Borrelli Luca, Piccolo Giovanni, Addeo Nicola Francesco, Esposito Sergio, Mercogliano Raffaelina, Turco Luigia, Meli Rosaria, Lembo Francesca, Ferrante Maria Carmela
Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, 80137 Naples, Italy.
Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy; Task Force on Microbiome Studies, University of Naples Federico II, 80131 Naples, Italy.
Sci Total Environ. 2024 Dec 20;957:177857. doi: 10.1016/j.scitotenv.2024.177857. Epub 2024 Dec 3.
Microplastics (MPs) are a threat of growing concern for living organisms as they exist in all ecosystems. The bidirectional communication between the gut, its microbiota, and the liver, has been conceptualized as gut-liver axis and may be influenced by environmental factors. MPs can cause intestinal and hepatic injuries, but there is still limited research exploring their impact on gut-liver axis. The aim of this study was to assess the effects of MP ingestion on gut-liver axis balance in gilthead seabream (Sparus aurata) fed with a diet enriched with polystyrene (PS)-MPs (0, 25, or 250 mg/kg b.w./day) for 21 days. PS-MPs affected the composition of gut microbiota, enhancing the evenness of gut microbial species. We also observed the impoverishment of core microbiota, suggesting reduced stability and permanence of microbiota members. Furthermore, PS-MPs reduced predominant bacteria in the gut of gilthead seabreams, increasing low-abundance species, including potential harmful taxa. On the other hand, PS-MPs increased the gene expression of immune and inflammatory mediators (i.e., TLR2, TLR5, and COX-2) in the liver. PS-MP exposure also increased serum triglycerides and bile acids (BAs) without modifying cholesterol. Moreover, the hepatic BA metabolism was impacted by PS-MPs which increased the expression of genes involved in primary BA kinetic (i.e., CYP27A1 and LXRa), which in turn can modulate intestinal microbial community. Indeed, PICRUSt2 mapping of BA-related functions predicted the increase of factors involved in BA metabolism. Specifically, K01442 (choloylglycine hydrolase) and K00076 (7α-hydroxysteroid dehydrogenase) were augmented by PS-MPs, suggesting a possible adaptation or co-evolution of gut microbiota to the modified hepatic BA metabolism. Thus, the obtained results showed that ingested PS-MPs impact the gut microbiota architecture and functions, the hepatic innate immunity, and the BA metabolism, suggesting the involvement of the gut-liver axis in MP-induced toxicity.
微塑料（MPs）存在于所有生态系统中，对生物构成了日益严重的威胁。肠道、其微生物群和肝脏之间的双向交流已被概念化为肠-肝轴，并且可能受到环境因素的影响。微塑料会导致肠道和肝脏损伤，但关于它们对肠-肝轴影响的研究仍然有限。本研究的目的是评估摄入微塑料对金头鲷（Sparus aurata）肠-肝轴平衡的影响，这些金头鲷喂食富含聚苯乙烯（PS）-微塑料（0、25或250毫克/千克体重/天）的饲料21天。聚苯乙烯微塑料影响了肠道微生物群的组成，提高了肠道微生物物种的均匀度。我们还观察到核心微生物群的贫乏，这表明微生物群成员的稳定性和持久性降低。此外，聚苯乙烯微塑料减少了金头鲷肠道中的优势细菌，增加了低丰度物种，包括潜在的有害分类群。另一方面，聚苯乙烯微塑料增加了肝脏中免疫和炎症介质（即TLR2、TLR5和COX-2）的基因表达。接触聚苯乙烯微塑料还增加了血清甘油三酯和胆汁酸（BAs），而胆固醇没有改变。此外，聚苯乙烯微塑料影响了肝脏胆汁酸代谢，增加了参与初级胆汁酸动力学的基因（即CYP27A1和LXRa）的表达，这反过来又可以调节肠道微生物群落。事实上，胆汁酸相关功能的PICRUSt2图谱预测了参与胆汁酸代谢的因子的增加。具体而言，聚苯乙烯微塑料增加了K01442（胆酰甘氨酸水解酶）和K00076（7α-羟基类固醇脱氢酶），这表明肠道微生物群可能对改变的肝脏胆汁酸代谢进行了适应或共同进化。因此，获得的结果表明，摄入的聚苯乙烯微塑料会影响肠道微生物群的结构和功能、肝脏先天免疫和胆汁酸代谢，表明肠-肝轴参与了微塑料诱导的毒性作用。
