Protective Effects of Dietary Curcumin Against Heavy Metal-Induced Gut Dysbiosis, Oxidative Stress, and Intestinal Damage in Zebrafish (Danio Rerio)

Abstract

Aquatic species are negatively impacted by heavy metal contamination in aquatic ecosystems because it damages intestinal tissues, disrupts gut microbiota, and causes oxidative stress. The current work examines how dietary curcumin protects intestinal health and gut microbiota in zebrafish (Danio rerio) exposed to water contaminated by heavymetals. To reduce toxicity and improve aquatic health, it is crucial to comprehend how environmental contaminants affect host–microbiota interactions and to find efficient and sustainable natural remedies. Physicochemical analyses of contaminated water samples showed high concentrations of heavy metals such as cadmium, copper, manganese, and chromium, as well as chemical oxygen demand (COD) and total suspended solids (TSS). Under these experimental conditions, zebrafish were fed feed enriched with curcumin. Colony forming unit (CFU) analysis was used to measure the gut microbial burden, and oxidative stress indicators such as total protein, reduced glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) were evaluated. A histopathological study was performed to assess intestinal structural changes.Significant microbial dysbiosis, decreased protein content, decreased SOD and GSH activity, and elevated MDA levels, all of which indicate increased oxidative stress and lipid peroxidation,were the results of heavy metal exposure. Severe intestinal damage, including villi ulceration, epithelial detachment, inflammatory infiltration, goblet cell hyperplasia, and muscle necrosis, was found. Curcumin administration reduced these effects by lowering oxidative damage, boosting antioxidant defenses, reducing microbial burden, and restoring gut architecture. Dietary curcumin shows strong protective potential against oxidative stress and intestinal toxicity caused by heavy metals.