〔Abstract〕 To explore the relationship between acne vulgaris and gut microbiota. Methods A total of 29 clinical cases diagnosed with moderate-to-severe acne vulgaris and 26 healthy individuals as control subjects were recruited. Fecal specimens were collected from all participants，and further analysis of gut microbial commu- nities was performed by leveraging high-throughput sequencing techniques that target the hypervariable regions of 16S rRNA genes. Results Associations between acne vulgaris and alterations in gut microbiota were identified. At the phylum level，the relative abundance of Bacteroidota exhibited a statistically significant elevation in the acne vulgaris cohort when compared with the healthy control group（P<0. 01）， while Cyanobacteria was signifi- cantly lower in the acne group（P<0. 01）. At the genus level，the top five different bacterial taxa in both groups were Bacteroides，Escherichia ⁃ Shigella，Klebsiella，Roseburia，and Parabacteroides. Among them，Bacteroides， Roseburia，and Parabacteroides were more abundant in acne patients. Linear discriminant analysis identified five biomarkers all belonging to the Bacteroidota phylum in the acne and control groups. These biomarkers belong to the phylum Bacteroidetes. Conclusion There are significant differences in the composition of intestinal microbiota be- tween acne patients and healthy people. Changes in the richness of specific bacterial genera may become new tar- gets for the diagnosis and treatment of acne.