Different Metabolites of the Gastric Mucosa between Patients with Current Helicobacter pylori Infection, Past Infection, and No Infection History

Abstract

Helicobacter pylori (H. pylori) alters metabolism during the gastric carcinogenesis process. This study aimed to determine the metabolites in the gastric mucosa according to the status of the H. pylori infection. Patients who visited the outpatient clinic for a gastroscopy and H. pylori tests were included. Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) analysis was performed using gastric biopsied specimens from the corpus. Twenty-eight discriminative metabolites were found in the gastric mucosa of 10 patients with current H. pylori infection, in 15 with past infection, and in five with no infection history. The relative abundances (RAs) of amino acids and sugars/sugar alcohols were higher in patients with no infection history than in patients with current or past infection. The current infection group showed higher RAs of organic acids and lower RAs of fatty acids and lipids compared with the other groups. The RA of inosine was highest in the past infection group. Based on GC-TOF-MS analysis findings, metabolites differed not only between the infected and non-infected patients, but also between those with and without infection history. Amino acid and sugars/sugar alcohol metabolites decreased in patients with current or past infection, whereas fatty acid and lipid metabolites decreased only during current infection.

Keywords: Helicobacter pylori; gas chromatography; gastric mucosa; metabolites.

Figure 1

(A) Orthogonal partial least discriminant analysis score plots obtained from the GC-TOF-MS dataset of the gastric mucosa samples from three different groups. (B) Heat map analysis for the relative abundance of different metabolites (VIP > 1.0) derived from the GC-TOF-MS analysis. The colored squares (blue to red) indicate fold changes normalized by the average of each metabolite. * Significantly different metabolites among the three groups (CI, PI, and NI groups); p < 0.05 using one-way ANOVA.

Figure 2

(A) Heat map analysis for the relative abundance of different metabolites (VIP > 1.0) derived from the GC-TOF-MS analysis for the comparison between 26 patients without a history of gastric neoplasm and 4 patients with a history of gastric adenoma or cancer resection. (B) Heat map analysis for the comparison between 28 patients without duodenal ulcer scars and two patients with duodenal ulcer scars. The colored squares (blue to red) indicate the fold changes normalized by the average of each metabolite. * Significantly different metabolites among the two groups; p < 0.05 using the Student’s t-test.