The Study On Precise Diagnosis And Treatment Of Helicobacter Pylori Based On String-test And Changes Of Intestinal Flora Before And After Treatment

Objective:As the reduced eradication rate of Helicobacter pylori（H.pylori）,we introduced string-test and quantitative PCR（q PCR）for susceptibility-guided therapy innovatively.The practicality of string-test was evaluated.Additionally,to investigate the effect of multiple bismuth quadruple therapy on intestinal flora of patients with H.pylori infection.To assess the need for timely and precise treatment of patients with a history of prior H.pylori treatment from the perspective of intestinal flora changes.Methods:Subjects tested by ¹³C-urea breath test(¹³C-UBT)and string-q PCR were enrolled.Based on the results of string-q PCR,we calculated clarithromycin and levofloxacin resistance rates and gave ¹³C-UBT positive patients 14 days susceptibility guided bismuth quadruple therapy.In the empirical therapy group,we retrospectively analysed the treatment results of ¹³C-UBT positive patients also treated with bismuth quadruple at Shenzhen Luohu People’s Hospital from January 2021 to May 2022.The eradication rate was compared between susceptibility guided therapy and empirical therapy groups.Fecal samples were collected before and two months after treatment from treatment-naive patients and previously-treated patients with a history of prior H.pylori treatment.16S r DNA sequencing was used to investigate the difference of the effects between single and multiple use of bismuth quadruple therapy on intestinal flora.Results:The diagnosis of H.pylori infection using the string-q PCR had an overall concordance rate of 95.9%with the ¹³C-UBT results.Based on the results of string-q PCR,the clarithromycin and levofloxacin resistance rates were 26.1%and31.8%,respectively.The patients who were given 14 days susceptibility guided bismuth-based quadruple therapy achieved a high H.pylori eradication rate of 91.8%.Retrospective analysis of patient treatment data from January 2021 to May 2022available in the hospital database revealed an overall success rate of 82.3%for those who received empirical bismuth-based quadruple therapies.There was no statistically significant difference in the alpha and beta diversity of intestinal flora between treatment-naive and previously-treated patients before and after treatment.Before treatment,the dominant phyla of intestinal flora in both groups were Firmicutes,Bacteroidetes,Proteobacteria and Actinomycetes in sequence.Two months after treatment,the relative abundance of Bacteroides in the previously-treated group decreased,while the relative abundance of Firmicutes,Proteobacteria and Actinobacteria increased,and the relative abundance of Bacteroidetes was lower than that in the treatment-naive group.LEf Se analysis showed that the relative abundance of Collinsella,Alistipes,Ruminococcus＿torques＿group,and Megamonas in the treatment-naive group before treatment was significantly higher than that in the previously-treated group,and the relative abundance of Sarcina in the previously-treated group was significantly higher than that in the treatment-naive group（LDA>2）.Two months after treatment,the relative abundances of Paraprevotella,Ruminococcaceae＿UCG-002 and Subdoligranulum in the treatment-naive group were significantly higher than those in the previously-treated group,and the relative abundance of Pseudomonas in the previously-treated group was significantly higher than that in the treatment-naive group（LDA>2）.Conclusion:This study showed that the use of string-q PCR test to guide H.pylori eradication is a valuable and feasible approach for clinical practice to help improve H.pylori treatment success rate.Multiple use of bismuth quadruple therapy to eradicate H.pylori has little effect on the diversity of intestinal flora in patients,but it will lead to a decrease in the relative abundance of beneficial flora,and may lead to the growth of intestinal pathogenic flora.Figure 5 Table 11 Reference 61...