Fig. 3

Differentially abundant metabolites and functions in the intestine. (A) (D) A volcano plot of the positive and negative ion modes is shown. The abscissa represents the logarithm (log2) value, which represents the quantitative difference in multiple metabolites between the two samples; the y-axis represents the -log10 of the P value. (B) (E) An OPLS-DA score map in the positive and negative ion modes is shown; the abscissa represents the decomposition degree of the first main component, and the ordinate represents the decomposition degree of the second main component. (C) (F) The OPLS-DA permutation test diagram in the positive and negative ion modes is shown. If this diagram meets any of the following criteria, the results are reliable and effective: (1) the intersection between the regression line and the ordinate of the point is less than 0, and (2) all blue Q2 points are lower than the original blue Q2 point on the far right. (G) In the multifunctional difference test chart, the left bar chart represents the mean level of each product in different groups, the middle chart shows the 95% confidence interval with an error line, and the right chart shows the P value of the difference in the levels of the product between the two groups. (H) In the differential enrichment score plot, the horizontal axis represents the DA score, where DA score = (number of substances with increased levels - number of substances with decreased levels)/total number of differentially regulated substances in the pathway. The vertical axis represents the metabolic pathway, and the columns on the left and right represent the pathways inhibited and activated, respectively, in the ESCC group. The size of the top column represents the number of enriched differentially abundant metabolites in the pathway. (I) A line chart of the N-acetyl-L-phenylalanine content is shown; the abscissa is the tumor stage, and the ordinate is the content. (J) The receiver operating characteristic curve is shown; the abscissa represents 1-specificity, and the ordinate represents specificity