biostudies-literatureWu QYouth project of the Natural Science Foundation of Hubei ProvinceHubei Province Excellent Young and Middle aged Science and Technology Innovation Team ProjectNational Natural Science Foundation of ChinaHuangshi Science and Technology Innovation Team ProjectNational Nature Science Foundation of ChinaHubei Province Excellent Young and Middle-aged Science and Technology Innovation Team ProjectResearch project funded by China Three Gorges CorporationChina Three Gorges Corporation527https://www.ebi.ac.uk/biostudies/studies/S-EPMC11280922biostudies-literatureUnknown12(7)Microcystin-LR (MCLR) poses a significant threat to aquatic ecosystems and public health. This study investigated the protective effects of the probiotic <i>Lactobacillus rhamnosus</i> against MCLR-induced developmental toxicity in zebrafish larvae. Zebrafish larvae were exposed to various concentrations of MCLR (0, 0.9, 1.8, and 3.6 mg/L) with or without <i>L. rhamnosus</i> from 72 to 168 h post-fertilization (hpf). Probiotic supplementation significantly improved survival, hatching, and growth rates and reduced malformation rates in MCLR-exposed larvae. <i>L. rhamnosus</i> alleviated MCLR-induced oxidative stress by reducing reactive oxygen species (ROS) levels and enhancing glutathione (GSH) content and catalase (CAT) activity. Probiotics also mitigated MCLR-induced lipid metabolism disorders by regulating key metabolites (triglycerides, cholesterol, bile acids, and free fatty acids) and gene expression (<i>ppara</i>, <i>pparb</i>, <i>srebp1</i>, and <i>nr1h4</i>). Moreover, 16S rRNA sequencing revealed that <i>L. rhamnosus</i> modulated the gut microbiome structure and diversity in MCLR-exposed larvae, promoting beneficial genera like <i>Shewanella</i> and <i>Enterobacter</i> and inhibiting potential pathogens like <i>Vibrio</i>. Significant correlations were found between gut microbiota composition and host antioxidant and lipid metabolism parameters. These findings suggest that <i>L. rhamnosus</i> exerts protective effects against MCLR toxicity in zebrafish larvae by alleviating oxidative stress, regulating lipid metabolism, and modulating the gut microbiome, providing insights into probiotic-based strategies for mitigating MCLR toxicity in aquatic organisms.ToxicsProbiotics Alleviate Microcystin-LR-Induced Developmental Toxicity in Zebrafish Larvae.PMC11280922CXPT20230000072021CFB2430799253T202202832201388Liu XLiu HHou JYang ZGong AZhu YWu QfalseProbiotics Alleviate Microcystin-LR-Induced Developmental Toxicity in Zebrafish Larvae.Microcystin-LR (MCLR) poses a significant threat to aquatic ecosystems and public health. This study investigated the protective effects of the probiotic <i>Lactobacillus rhamnosus</i> against MCLR-induced developmental toxicity in zebrafish larvae. Zebrafish larvae were exposed to various concentrations of MCLR (0, 0.9, 1.8, and 3.6 mg/L) with or without <i>L. rhamnosus</i> from 72 to 168 h post-fertilization (hpf). Probiotic supplementation significantly improved survival, hatching, and growth rates and reduced malformation rates in MCLR-exposed larvae. <i>L. rhamnosus</i> alleviated MCLR-induced oxidative stress by reducing reactive oxygen species (ROS) levels and enhancing glutathione (GSH) content and catalase (CAT) activity. Probiotics also mitigated MCLR-induced lipid metabolism disorders by regulating key metabolites (triglycerides, cholesterol, bile acids, and free fatty acids) and gene expression (<i>ppara</i>, <i>pparb</i>, <i>srebp1</i>, and <i>nr1h4</i>). Moreover, 16S rRNA sequencing revealed that <i>L. rhamnosus</i> modulated the gut microbiome structure and diversity in MCLR-exposed larvae, promoting beneficial genera like <i>Shewanella</i> and <i>Enterobacter</i> and inhibiting potential pathogens like <i>Vibrio</i>. Significant correlations were found between gut microbiota composition and host antioxidant and lipid metabolism parameters. These findings suggest that <i>L. rhamnosus</i> exerts protective effects against MCLR toxicity in zebrafish larvae by alleviating oxidative stress, regulating lipid metabolism, and modulating the gut microbiome, providing insights into probiotic-based strategies for mitigating MCLR toxicity in aquatic organisms.2024-01-01T00:00:00Z2024 Jul2025-08-27T03:10:58.942Z2025-08-27T03:10:58.942ZS-EPMC112809223905817910.3390/toxics12070527