Abstract: Gut microbiota plays vital roles in human health and has become one of the emerging topics in environmental toxicology research worldwide. Since the gut and gut microbial system are usually the first contact point when most pollutants enter living organisms, it is likely these pollutants would pass through the gut microbiota (as a barrier) and cause potential adverse effects. There has been increasing global concern about the potential impact of environmental pollutants on the gut microbiota and their interaction with the host's health, and it is noteworthy. This paper indicated that: (1) The interference of different pollutants (e.g., pharmaceuticals and personal care products, medical drugs, heavy metals, pesticides, emerging chemicals, air pollutants and POPs) on the abundance and diversity of gut microbiota has been the current research focus, and these pollutants can change the gut and gut microbial system. (2) Disturbance of beneficial gut microbiota (e.g., Bacteroidetes, Firmicutes, Lactobacillus and Bifidobacteria) is the key pathway of toxicity since these beneficial microbiotas can interact with each other and participate in various physiological processes of the host such as the regulation of nutrient digestion and immune system responses, modulation of endocrine system and activities of neurons. (3) Exposure to environmental pollutants can affect the structure and metabolic activities of gut microbiotas, which would damage the functions and undermine the integrity of gut barrier, further disturbing a series of physiological and biochemical processes and ultimately affecting the health of the host. The gut and gut microbial system has been recognized as a new end point by environmental toxicologists, therefore, it is of great importance for in-depth study of the toxic effects and mechanisms of pollutants.