Gut microbiota has been shown to play critical roles in host health. The present study was to determine the toxicological effects of microcystin-LR (MCLR) on gut microbial community and metabolites using 16S rDNA sequencing and gas chromatography-mass spectrometry (GC-MS). MCLR was administered to BALB/c mice by gavage for eight weeks. Results of the microbial alpha-diversity (Sobs, Chao1, ACE and Shannon indexes) decreased in MCLR-treated group versus controls. Phylum Candidatus Saccharibacteria decreased significantly in MCLR-treated group versus controls. Correspondingly, more than thirties genera in relative abundance decreased, especially short chain fatty acid (SCFA)-producing bacteria (e.g., Alistipes and Ruminococcus). These results indicated that the gut microbial community structure was remarkably changed by MCLR. Furthermore, concentrations of SCFAs were significantly decreased after MCLR exposure (P < 0.01), where butyrate decreased as high as 4.9-fold. Consequently, sub-chronic exposure to MCLR could not only alter the microbial composition but metabolites. This study offered novel insights into the toxic mechanism of MCs from gut microbiota, and facilitated further clarification of risks to human health from MCs exposure.

肠道菌群已显示在宿主健康中起关键作用。本研究旨在使用16S rDNA测序和气相色谱-质谱法（GC-MS）确定微囊藻毒素-LR（MCLR）对肠道微生物群落和代谢产物的毒理作用。通过强饲法将MCLR给予BALB / c小鼠八周。与对照组相比，MCLR治疗组的微生物α多样性结果（Sobs，Chao1，ACE和Shannon指数）降低。与对照组相比，MCLR治疗组的白假丝酵母菌明显减少。相应地，超过在相对丰度三十年代属下降，尤其是短链脂肪酸（SCFA）产生的细菌（例如，Alistipes和瘤胃球菌属）。这些结果表明，MCLR显着改变了肠道微生物群落结构。此外，MCLR暴露后 ，SCFA的浓度显着降低（P <0.01），其中丁酸的降低高达4.9倍。因此，亚慢性暴露于MCLR不仅会改变微生物组成，而且会改变代谢产物。这项研究为肠道微生物群中MC的毒性机理提供了新颖的见解，并有助于进一步阐明MC暴露对人体健康的危害。