Since the widespread usage of plastic materials and inadequate handling of plastic debris, nanoplastics (NPs) and microplastics (MPs) have become global hazards. Recent studies prove that NPs/MPs can induce various toxicities in organisms, with these adverse effects closely related to gut microbiota changes. This review thoroughly summarized the interactions between NPs/MPs and gut microbiota in various hosts, speculated on the potential factors affecting these interactions, and outlined the impacts on hosts' health caused by NPs/MPs exposure and gut microbiota dysbiosis. Firstly, different characteristics and conditions of NPs/MPs often led to complicated hazardous effects on gut microbiota. Alterations of gut microbiota composition at the phylum level were complex, while changes at the genus level exhibited a pattern of increased pathogens and decreased probiotics. Generally, the smaller size, the rougher surface, the longer shape, the higher concentration, and the longer exposure of NPs/MPs induced more severe damage to gut microbiota. Then, different adaptation and tolerance degrees of gut microbiota to NPs/MPs exposure might contribute to gut microbiota dysbiosis. Furthermore, NPs/MPs could be carriers of other hazards to generally exert more severe damage on gut microbiota. In summary, both pristine and contaminated NPs/MPs posed severe threats to hosts through inducing gut microbiota dysbiosis.
Keywords: Nanoplastics; gut microbiota; hazards; host health; microplastics.