Objective  To analyze the correlations between serum vasoactive intestinal peptide, endotoxin and intestinal flora imbalance in patients with rosacea.

  Methods  A total of 70 patients with rosacea were selected as rosacea group, and 70 healthy patients in the same period were selected as control group. The levels of endotoxin and vasoactive peptide were detected by gel method and immunohistochiistry, respectively. The distributions and quantities of Enterococcus, Escherichia coli, Enterococcus faecalis and Bifidobacterium in feces were compared between the two groups. Pearson correlation analysis was used to analyze the correlations between vasoactive intestinal peptide, endotoxin and the number of intestinal flora.

  Results  The levels of serum endotoxin and vasoactive intestinal peptide in the rosacea group were significantly higher than those in the control group (P < 0.05). The numbers of Enterococcus, Escherichia coli and Enterococcus faecalis in the rosacea group were significantly higher than those in the control group, and the number of Bifidobacteria and the ratio of Bifidobacteria to Enterobacteria (B/E value) were significantly lower than those in the control group (P < 0.05). The levels of serum endotoxin and vasoactive intestinal peptide increased significantly and gradually in mild, moderate and severe patients (P < 0.05). The levels of serum endotoxin and vasoactive intestinal peptide were positively correlated with the number of Enterococcus, Escherichia coli and Enterococcus faecalis in intestinal flora (P < 0.05), and negatively correlated with the number of Bifidobacterium (P < 0.05).

  Conclusion  High expressions of serum endotoxin and vasoactive intestinal peptide in patients with rosacea are closely related to the severity of rosacea and the imbalance of intestinal flora, and play certain roles in the occurrence and development of rosacea.