The impact of the anti-diabetic drug metformin on the intestinal microbiome of larval brown trout (Salmo trutta f. fario)

The anti-diabetic pharmaceutical metformin is frequently analysed in the aquatic environment. Its impact on the fish microbiome is studied to get a deeper knowledge about the consequence of the metformin presence in river systems. Gut microbiome analyses were performed on larval brown trout with metformin including environmental concentrations. Therefore, the fish were exposed to metformin in concentrations of 0, 1, 10, 100, and 1000 µg/L. Especially, the lower metformin concentrations were measured in river waters containing percentages of conditioned wastewater from municipal wastewater treatment plants.