Abstract: Objective To investigate the expression levels of serum Zonulin and soluble advanced glycation end product receptor (sRAGE) in patients with severe pneumonia and their correlation with intestinal flora. Method 80 patients with severe pneumonia admitted and diagnosed in Taizhou Jiangyan Hospital of Traditional Chinese Medicine from January 2019 to June 2022 were selected as the study group, in addition, 82 patients with common pneumonia were selected as the control group. General data of patients were collected; the serum levels of Zonulin and sRAGE were detected by ELISA; real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the number of intestinal flora; Pearson method was used to analyze the correlation between the levels of Zonulin, sRAGE and intestinal flora in patients with severe pneumonia.Divide patients into poor prognosis group(26 cases) and good prognosis group(54 cases) based on their survival within 28 days after discharge. Result The levels of Zonulin and sRAGE in the study group were obviously higher than those in the control group (t=14.293、12.033, P<0.05); The numbers of bifidobacterium, lactobacillus and rumen coccus in the study group were lower than those in the control group (t=9.139, 7.838, 5.130, P<0.05), and the numbers of enterococcus, Escherichia coli and staphylococcus in the study group were higher than those in the control group (t=3.397, 4.807, 3.960, P<0.05).; the levels of serum Zonulin and sRAGE were negatively correlated with the numbers of bifidobacteria, lactobacilli and rumen cocci (P<0.05), and positively correlated with the numbers of enterococci, staphylococci and Escherichia coli (P<0.05); Serum Zonulin and sRAGE levels in the poor prognosis group were significantly higher than those in the good prognosis group (t=6.910, 4.358, P<0.05). The number of bifidobacterium, lactobacillus and rumen cocci in the poor prognosis group was lower than that in the good prognosis group (t=4.368, 2.167, 3.197, P<0.05), and the number of enterococcus, staphylococcus and Escherichia coli in the poor prognosis group was higher than that in the good prognosis group (t=2.704, 3.489, 3.995, P<0.05). Conclusion The levels of serum Zonulin and sRAGE in patients with severe pneumonia are elevated, and there is a certain correlation between their levels and intestinal flora in patients with severe pneumonia.

Key words: Severe pneumonia, Zonulin, Soluble receptor for advanced glycation end products, Intestinal flora, Correlation