Antioxidative defense and gut microbial adaptation under pollution stress in Carassius gibelio from Bucharest Lakes

Fish are able to accumulate by ingestion various contaminants of aquatic environment,
with negative consequences on their intestine, being continuously threatened worldwide by heavy
metals, pesticides and antibiotics resulted from the human activities. Consequently, the health of
other species can be affected by eating the contaminated fish meat. In this context, our study aimed
to perform a comparison between the changes in intestine samples of Carassius gibelio individuals
collected from different artificial lakes in Bucharest (Romania), used by people for leisure and fishing.
The presence of various metals, pesticides and antibiotics in the gut of fish was assessed in order
to correlate their accumulation with changes of antioxidative enzymes activities and microbiome.
Our results showed that fish from Bucharest lakes designed for leisure (Chitila, Floreasca and Tei
lakes) have an increased level of oxidative stress in intestine tissue, revealed by affected antioxidant
enzymes activities and GSH levels, as well as the high degree of lipid peroxidation, compared to the
fish from protected environment (Vacaresti Lake). Some heavy metals (Fe, Ni and Pb) and pesticides
(aldrin and dieldrin) were in high amount in the gut of fish with modified antioxidative status. In
conclusion, our study could improve the knowledge regarding the current state of urban aquatic
pollution in order to impose several environmental health measures.