<p>This study aimed to analyze the dynamic changes in gut microbiota during high-fat diet (HFD)-induced obesity in mice, investigate the transmissibility of obesity-associated inflammation via fecal microbiota transplantation (FMT), and identify key bacterial genera linked to inflammation. In experiment 1, 8 control group mice and 12 obese group mice were fed a normal diet (ND) and a HFD, respectively, and fecal samples were collected from six mice in each group at weeks 4, 8, and 12. The results showed that long-term HFD (12&#xa0;weeks) significantly reduced the diversity and richness of the gut microbiota (<i>p</i> &lt; 0.05). HFD significantly affected the composition of the gut microbiota during the experimental period, with an increase in the relative abundance of harmful bacteria genera such as <i>Escherichia-Shigella</i> and <i>Proteus</i> (<i>p</i> &lt; 0.05). In experiment 2, the transmissibility of obesity-associated inflammation was validated through a fecal FMT experiment. The results indicated that the intestinal microbiota of obese mice increased the inflammation level of recipient mice (<i>p </i>&lt; 0.05), and the composition of the intestinal microbiota in the obese recipient group was significantly affected by that in the obese donor group. Furthermore, correlation analysis revealed that the relative abundances of <i>Proteus</i> and <i>Escherichia-Shigella</i> were positively correlated with the levels of inflammatory factors in the serum and ileal tissue (<i>p</i> &lt; 0.05), suggesting that these two bacterial genera may serve as potential pro-inflammatory biomarkers. This study revealed the dynamic changes in the gut microbiota during HFD-induced obesity, confirmed the critical role of the gut microbiota in the transmission of inflammation, and provided a new theoretical basis for the intervention of obesity-related diseases.</p>