The combined exposure of polystyrene microplastics and high-fat feeding affects the intestinal pathology damage and microbiome in zebrafish.

The pervasive utilization of plastics and their integration into ecosystems has resulted in significant environmental issues, particularly the pollution of microplastics (MPs). In aquaculture, high-fat feed (HFD) is frequently employed to enhance the energy intake and economic fish production. This study utilized zebrafish as a model organism to investigate the impact of concurrent exposure to HFD and MPs on fish intestinal pathology damage and intestinal microbiome. The experimental design involved the division of zebrafish into two groups: one receiving a normal diet (ND) and the other receiving HFD. The zebrafish were exposed to a control group, as well as polystyrene (PS) MPs of varying sizes (5 and 50 µm). Histopathological examination revealed that the combination of 5 µm MPs and HFD resulted in the most significant damage to the zebrafish intestinal tract. Furthermore, gut microbiome assays indicated that exposure to MPs and HFD altered the composition of the gut microbiome. This study demonstrates that in aquaculture, the issue of HFD must be considered alongside concerns about MPs contamination, as both factors appear to have a combined effect on the intestinal pathology damage and intestinal microbiome. The findings of this research offer valuable insights for the improvement of fish farming practices.

Combined effects of high-fat diet and polystyrene microplastic exposure on microplastic bioaccumulation and lipid metabolism in zebrafish.

Extensive use of microplastics (MPs) threatens the safety of aquatic environments and hydrobionts. Increasing the weight of economic fish through high-fat diet (HFD) to increase production is common in aquaculture. However, little is known about the combined effects of MPs and HFD in fish. The aim of this study was to investigate the relationship between adiposity and MP bioaccumulation in fish. Using zebrafish as a vertebrate model, the content of polystyrene (PS) MPs in zebrafish tissues exposed to 5 and 50 µm of 1000 µg/L PS MPs was detected via confocal Raman spectroscopy in normal diet (ND) and HFD. The content of PS MPs in HFD group was significantly higher than that in ND group. The levels of hepatic lipids were significantly elevated in zebrafish subjected to HFD treatment, and this effect was aggravated by exposure to 5 µm PS MPs, and even caused liver injury. Transcriptomic analysis revealed that exposure to PS MPs interferes with hepatic lipid metabolism and energy homeostasis in zebrafish. These results suggests that in addition to controlling the use and performing proper recycling of plastic products in our daily life, we should not blindly increase the weight of fish through HFD. This aids protect the quality of economic fish and prevent MPs from being consumed by humans through the food chain. This study explored the interaction between fish feed culture and environmental pollutants to provide important reference for fish culture.