Microbiota-Influenced Toxicological Responses in Caenorhabditis elegans Exposed to Strawberry and Menthol E-Liquids

Electronic nicotine delivery systems are marketed as safer than cigarettes, but their flavoring agents may be toxic. We evaluated reproductive effects of menthol- and strawberry-flavored e-liquids in <i>Caenorhabditis elegans</i> using wild-type and chemosensory-defective mutants ( <i>ocr-2 ; osm-9 ; ocr-1 ; trpa-1</i> ). L4-stage worms were exposed to flavored e-liquids on peptone-free media with <i>Escherichia coli</i> or natural microbiota ( <i>Lelliottia amnigena</i> , <i>Stenotrophomonas indicatrix</i> , <i>Comamonas piscis</i> ). Flavored exposure reduced brood size; menthol delayed egg-laying. Microbiota mitigated effects in most strains except <i>ocr-2 ; osm-9 ; ocr-1</i> with strawberry. Findings show flavored e-liquids harm reproduction, and microbiota may protect against flavor-induced toxicity.