Exposure to microplastics induces digestive blockage, microbiota dysbiosis and stimulates immune response in the gut of guppy (Poecilia reticulata)

Microplastics (MPs) are environmental pollutants and have the potential to cause varying degrees of aquatic toxicity. The activity of digestive enzymes (Trypsin, Chymotrypsin, Amylase and Lipase) in guppy decreased with the increase of microplastic concentrations. At the phylum level, the abundance of Proteobacteria and Acinetobacter decreased significantly. In addition, high throughput sequencing of the 16S rRNA gene revealed a significant change in the richness and diversity of microbiota in the gut of MP-treated guppy. Moreover, it was observed that MPs evaluated the levels of immune response in the gut, indicating that inflammation occurred after MPs exposure. PICRUSt analysis revealed that MPs maybe have an inhibitory effect on metabolism of guppy. Our findings suggest that MPs could induce microbiota dysbiosis and digestive blockage, while elevate immune response in the gut of juvenile guppy.