Lead is an environmental toxicant that has toxicity effect to the health of aquatic organisms. Gut microbiota has been reported to be closely related to human health. The aim of this study was to investigate the effects of lead exposure on the composition of gut microbiota. The composition of gut microbiota alteration was detected by 16S rRNA gene sequencing, following a 42-day exposure of lead (1 mg/L). The results showed that compared with the normal control group, the carp of lead group showed severe intestinal tissues injury and decreased Zona Occludens 1 (ZO-1) and occludin expression. The production of LPS in serum was increased by the treatment of lead exposure. Our results showed gut bacterial diversity in lead-treated common carp was lower than the control group. At the phylum level, the abundance of Bacteroidetes (LPS producing bacteria) and Fusobacteria in lead-treated carp were much higher than the control carp. And the abundance of Actinobacteria decreased by lead exposure. At the genus level, we found the abundance of Bacteroides (LPS producing bacteria) and Plesiomonas (an important pathogenic bacteria), increased significantly by lead exposure. And the abundance of Akkermansia, a critical probiotics, was markedly inhibited by lead exposure. In conclusion, this study indicated exposure of carp to lead causes gut microbiota alterations and intestinal structural integrity destruction.

铅是对水生生物健康具有毒性作用的环境毒物。据报道肠道菌群与人类健康密切相关。这项研究的目的是调查铅暴露对肠道菌群组成的影响。铅（1 mg / L）暴露42天后，通过16S rRNA基因测序检测肠道菌群改变的组成。结果表明，铅组the鱼与正常对照组相比，肠道组织受到严重损伤，Zona Occludens 1（ZO-1）和occludin表达降低。铅暴露可增加血清中LPS的产生。我们的结果表明，铅处理的鲤鱼的肠道细菌多样性低于对照组。在门的水平上，拟杆菌数量丰富铅处理的鲤鱼中的细菌（LPS产生细菌）和梭菌比对照鲤鱼高得多。铅暴露会降低放线菌的丰度。在属的水平，我们发现丰杆菌（LPS的细菌）和邻单胞菌（一种重要病原菌），由铅暴露显著上升。铅暴露可显着抑制关键益生菌Akkermansia的含量。总之，这项研究表明鲤鱼接触铅会导致肠道菌群改变和肠道结构完整性破坏。