Increased Abundance of Clostridium and Fusobacterium in Gastric Microbiota of Patients with Gastric Cancer in Taiwan

Abstract

Helicobacter pylori is recognised as a main risk factor for gastric cancer. However, approximately half of the patients with gastritis are negative for H. pylori infection, and the abundance of H. pylori decreases in patients with cancer. In the current study, we profiled gastric epithelium-associated bacterial species in patients with gastritis, intestinal metaplasia, and gastric cancer to identify additional potential pathogenic bacteria. The overall composition of the microbiota was similar between the patients with gastritis and those with intestinal metaplasia. H. pylori was present in half of the non-cancer group, and the dominant bacterial species in the H. pylori-negative patients were Burkholderia, Enterobacter, and Leclercia. The abundance of those bacteria was similar between the cancer and non-cancer groups, whereas the frequency and abundance of H. pylori were significantly lower in the cancer group. Instead, Clostridium, Fusobacterium, and Lactobacillus species were frequently abundant in patients with gastric cancer, demonstrating a gastric cancer-specific bacterial signature. A receiver operating characteristic curve analysis showed that Clostridium colicanis and Fusobacterium nucleatum exhibited a diagnostic ability for gastric cancer. Our findings indicate that the gastric microenvironment is frequently colonised by Clostridium and Fusobacterium in patients with gastric cancer.

Gastric mucosal microbiota in a Mongolian population with gastric cancer and precursor conditions

“…Among the remaining cases, Fusobacterium , Parvimonas , and Streptococcus genera were enriched in GC group. In previous studies, Parvimonas and Streptococcus genera were enriched among GC patients, including inner Mongolia where the population is mixture of Mongolian and Chinese population . In our current study, Lactobacillus track closely with both cancer and IM with no cancer, but less so with atrophy.…”

Other Helicobacters and the gastric microbiome

“…There was also a co‐exclusion relationship demonstrated between H. pylori and Campylobacter concisus which has been previously hypothesized as part of the potential mechanism through which H. pylori exerts a protective effect in inflammatory bowel disease . An increased abundance of Fusobacterium , alongside increased abundance of Clostridium and Lactobacillus species, was also demonstrated in patients with GC from Taiwan . The various studies reaffirm the previous findings that the gastric microbiome shifts based on H. pylori status and also disease progression but also based on different study populations which will be affected by environmental exposures and influences.…”

“…Lactobacillus species, was also demonstrated in patients with GC from Taiwan. 43 The various studies reaffirm the previous findings that the gastric microbiome shifts based on H. pylori status and also disease progression but also based on different study populations which will be affected by environmental exposures and influences. Therefore, it is currently not possible to define a GC dysbiotic signature based on bacterial diversity further emphasizing that detailing functional implications of dysbiosis, which is dysbiosis in its own right, may actually provide a more useful consistent biomarker.…”

“…Other smaller studies detailing the GC microbiome also confirmed a reduction in H. pylori abundance in GC tissue alongside a concomitant increase in other bacterial species . The Castano‐Rodriguez study did not show the reduction in α‐diversity seen in other studies but showed that H. pylori ‐positive patients had higher species richness and serological status was a significant on diversity and composition suggesting the composition of the gastric microbiome is shaped by the immune response .…”

Fecal microbiota transplantation in cancer management: Current status and perspectives

“…Carcinogenesis of gastric cancers is associated with H. pylori and some oral microbiota including Fn , Parvimonas micra and Peptostreptococcus stomatis . Significant enrichment of Peptostreptococcus stomatis , Parvimonas micra , Streptococcus anginosus , Dialister pneumosintes , Slackia exigua, Clostridium colicanis and Fn and depletion of Helicobacterium was observed in gastric cancer, and alterations in bacterial diversity and abundance in patients with gastric cancer revealed a dysbiotic microbial community with prediction potential . Recently, incremental data has demonstrated that eradication treatment for H. pylori could reduce the risk of gastric cancer .…”