Although the production of polychlorinated biphenyl 77 (PCB77) has already been banned globally, PCB77 is still used for a wide range of commercial purposes. Previous evidence has demonstrated that the PCB77 administration should be responsible for the gut microbiota variations and the host health risk. However, the host disorders and bacterial functions involved in PCB77 exposure remain largely unknown. Few studies have been performed to illuminate the correlation between the bacterial functions and disorders. Furthermore, it is urgently needed to find specific strains as potential biomarkers to monitor PCB77 pollution and associated disorders. This study was designed to investigate the effects of PCB77 on gut microbiota and induced disorders in female mice. Obtained results indicated that PCB77 exposure induced gut microbiota dysbiosis, obesity, hyperlipidemia, hepatic lipid accumulation, and liver injury in mice. Functional prediction based on the phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) algorithm showed that exposure to PCB77 weakened the bacterial functions relating to lipid and energy metabolism, and immune system disease. Experimental findings were consistent with the result of the PICRUSt functional prediction. Importantly, three PCB77-associated bacterial taxa were screened out as potential biomarkers for the assessment of PCB77 pollution. This study provides previously unknown knowledge linking PCB77 administration, gut microbiota functional profile and lipid abnormalities, which is of important clinical significance for therapies treating PCB77-associated diseases.