ABSTRACT
Background/Aims@#The gut microbiota regulates intestinal immune homeostasis through host-microbiota interactions. Multiple factors affect the gut microbiota, including age, sex, diet, and use of drugs. In addition, information on gut microbiota differs depending on the samples.The aim of this study is to investigate whether changes in cecal microbiota depend on aging. @*Methods@#Gut microbiota in cecal contents of 6-, 31-, and 74-week-old and 2-year-old male Fischer-344 rats (corresponding to 5-, 30-, 60-, and 80-year-old humans in terms of age) were analyzed using 16S ribosomal RNA metagenome sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) based on the Kyoto Encyclopedia of Genes and Genomes orthology.Moreover, short-chain fatty acid (SCFA) level in cecum and inflammation related factors were measured using real-time quantitative polymerase chain reaction and enzyme linked immunosorbent assay. @*Results@#Alpha and beta diversity did not change significantly with age. At the family level, Lachnospiraceae and Ruminococcaceae, which produce SCFAs, showed significant change in 31-week-old rats: Lachnospiraceae significantly increased at 31 weeks of age, compared to other age groups, while Ruminococcaceae decreased. Butyrate levels in cecum were significantly increased in 31-week-old rats, and the expression of inflammation related genes was increased followed aging. Especially, EU622775_s and EU622773_s, which were highly abundance species in 31-week-old rats, showed significant relationship with butyrate concentration. Enzymes required for producing butyrate—acetyl-CoA transferase, butyryl-CoA dehydrogenase, and butyrate kinase—were not predicted by PICRUSt. @*Conclusions@#Major bacterial taxa in the cecal lumen, such as Lachnospiraceae, well-known SCFAs-producing family, changed in 31-week-old rats.Moreover, unknown species EU622775_s and EU622773_s showed strong association with cecal butyrate level at 31 weeks of age.
ABSTRACT
Background/Aims@#Favorable outcomes of potassium-competitive acid blocker (PCAB)-containing eradication therapy have been reported. In fact, tegoprazan, a recently developed PCAB, was presumed to show good eradication efficacy even for resistant Helicobacter pylori. We aimed to investigate the anti-H. pylori efficacy of tegoprazan compared with that of vonoprazan. @*Methods@#A total of 220 resistant clinical H. pylori isolates were utilized. The anti-H. pylori efficacy of PCABs was determined by evaluating the minimum inhibitory concentrations (MICs) of clarithromycin, fluoroquinolone, metronidazole, and amoxicillin in combination with vonoprazan or tegoprazan by the agar dilution method. The impact of the mutations responsible for resistance development, such as 23S rRNA, gyrA, rdxA, frxA, and pbp1 mutations, was also analyzed. @*Results@#H. pylori growth was significantly inhibited in a medium containing 1 μg/mL clarithromy-cin with tegoprazan (128 μg/mL). The MICs of clarithromycin (46.3%), fluoroquinolone (46.7%), metronidazole (55.6%), and amoxicillin (34.5%) against resistant H. pylori isolates improved after tegoprazan administration. Tegoprazan demonstrated more frequent susceptibility acquisitionwith metronidazole than with vonoprazan (20.6% vs 4.7%, p=0.014). However, there were nosignificant differences depending on the mutational status of each antimicrobial agent. @*Conclusions@#Tegoprazan administration may improve the susceptibility of antimicrobial-resistant H. pylori, independent of acid suppression.