Data_Sheet_1_Effects of cadmium exposure on intestinal microflora of Cipangopaludina cathayensis.docx

As one of the most environmentally toxic heavy metals, cadmium (Cd) has attracted the attention of researchers globally. In particular, Guangxi, a province in southwestern China, has been subjected to severe Cd pollution due to geogenic processes and anthropogenic activities. Cd can be accumulated in aquatic animals and transferred to the human body through the food chain, with potential health risks. The aim of the present study was to explore the effects of waterborne Cd exposure (0.5 mg/L and 1.5 mg/L) on the intestinal microbiota of mudsnail, Cipangopaludina cathayensis, which is favored by farmers and consumers in Guangxi. Gut bacterial community composition was investigated using high-throughput sequencing of the V3–V4 segment of the bacterial 16S rRNA gene. Our results indicated that C. cathayensis could tolerate low Cd (0.5 mg/L) stress, while Cd exposure at high doses (1.5 mg/L) exerted considerable effects on microbiota composition. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes were the dominant phyla in the mudsnail gut microbiota. The relative abundances of Bacteroidetes increased significantly under high Cd exposure (H14) (p < 0.01), with no significant change in the low Cd exposure (L14) treatment. The dominant genera with significant differences in relative abundance were Pseudomonas, Cloacibacterium, Acinetobacter, Dechloromonas, and Rhodobacter. In addition, Cd exposure could significantly alter the pathways associated with metabolism, cellular processes, environmental information processing, genetic information processing, human diseases, and organismal systems. Notably, compared to the L14 treatment, some disease-related pathways were enriched, while some xenobiotic and organic compound biodegradation and metabolism pathways were significantly inhibited in the H14 group. Overall, Cd exposure profoundly influenced community structure and function of gut microbiota, which may in turn influence C. cathayensis gut homeostasis and health.

镉（Cd）作为一种对环境极具毒性的重金属，其研究引起了全球学者的广泛关注。特别是位于中国西南部的广西省，由于地质过程和人类活动的影响，遭受了严重的镉污染。镉能够在水生动物体内积累，并通过食物链传递至人体，从而产生潜在的健康风险。本研究旨在探讨水中镉暴露（0.5 mg/L和1.5 mg/L）对广西农民和消费者喜爱的螺蛳——中华圆田螺（Cipangopaludina cathayensis）肠道微生物群的影响。通过高通量测序技术对细菌16S rRNA基因的V3–V4片段进行测序，分析了肠道细菌群落组成。结果显示，中华圆田螺能够耐受低浓度镉（0.5 mg/L）的应激，而高剂量镉暴露（1.5 mg/L）则对微生物群组成产生了显著影响。在门水平上，变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）是螺蛳肠道微生物群中的主要门类。在高镉暴露（H14）条件下，拟杆菌门的相对丰度显著增加（p < 0.01），而在低镉暴露（L14）处理中则没有显著变化。相对丰度发生显著差异的优势菌属包括假单胞菌（Pseudomonas）、肠杆菌（Cloacibacterium）、不动杆菌（Acinetobacter）、脱氯菌（Dechloromonas）和红螺菌（Rhodobacter）。此外，镉暴露能够显著改变与代谢、细胞过程、环境信息处理、遗传信息处理、人类疾病和生物系统相关的途径。值得注意的是，与L14处理相比，某些疾病相关途径在H14组中得到了富集，而某些外源性和有机化合物生物降解及代谢途径在高镉暴露组中受到显著抑制。总体而言，镉暴露对肠道微生物群的群落结构和功能产生了深远影响，这可能会进一步影响中华圆田螺的肠道稳态和健康。