Analysis Of Clinical Risk Factors For Early Abnormal Elevation Of Liver Enzymes After Bariatric Surgery And Characterization Of The Gut Microbiota Based On 16s Ribosomal DNA Amplicon Sequencing

Objective:More and more people with obesity are receiving bariatric surgery(BS).In clinical,we have observed the abnormal elevation of liver enzymes in some patients after BS in the early stage,which indicates the occurrence of transient liver injury.However,the reason for this phenomenon is still unclear.Therefore,we investigated the clinical risk factors for the early abnormal elevation of liver enzymes after BS.In addition,as gut microbiota has close communication with liver,forming the gut-liver axis,we explored the correlation and mechanism between liver injury and gut microflora in the early stage after BS from the perspective of gut microbiota.Methods:1.Clinical basic data before BS and postoperative follow-up data of 177 patients were collected for retrospective analysis.Two groups were divided into study group and control group according to whether Alanine transaminase(ALT)and/or Aspartate aminotransferase(AST)were increased and exceeded the clinical threshold(upper limit of normal value was 40U/L)in the early 1 month after BS.Logistic regression model was used to conduct statistical analysis on 15 related factors including gender,age,surgical method,anthropometric index and laboratory examination index,and independent risk factors were screened from them.2.Clinical data and preoperative feces of 32 patients with obesity undergoing BS were collected.To reduce the confounding bias of WC as an independent risk factor,32 patients were paired using propensity score matching(PSM).The DNA of microorganism samples was extracted and amplified,and then the library was constructed,and the sequencing data of each group of samples were processed and bioinformatics analyzed by Illumina Mi Seq sequencing platform.Results:1.Risk factors for abnormal elevation of liver enzymes in early post-BS were retrospective analyzed,and single factor logistic regression analysis showed that gender,BS approach,body mass index(BMI),and waist circumference(WC)had statistical differences between two groups(P<0.05).Multivariate logistic regression model was then included,and it was found that WC before BS was an independent risk factor(P<0.05);while gender,different BS types and BMI had no statistical differences between the two groups(P>0.05).According to receiver operating characteristic curve(ROC curve),the cut-off values of WC as an indicator for predicting abnormal elevation of ALT and AST after BS are 117.35 cm(sensitivity 0.75;specificity 0.62)and 113.65 cm(sensitivity 0.88;specificity 0.48),respectively.2.The gut microflora of the experimental group and the control group with abnormal elevation of ALT and AST in the early stage after BS were different in phylum,class,order,family and genus.However,there was no significant difference in the analysis results of Alpha and Beta diversity between groups.Conclusion:1.Temporary liver injury occurred in some patients with obesity in the early stage after BS.Preoperative WC was an independent risk factor for the occurrence of this phenomenon.Especially for patients with large WC and receiving bypass surgery,long-term liver-related follow-up is required after BS.2.The abnormal increase of liver enzymes in the early post-BS period may be related to the change of gut microflora.The preoperative pattern of gut microflora in patients with abnormally elevated liver enzymes was different from that in patients without elevated liver enzymes.