The Presence of Periodontal Pathogens in Gastric Cancer

Abstract

BackgroundThe microbiome is thought to play a role in the development of gastric cancer (GC). Several studies have put forward putatively carcinogenic species in addition to Helicobacter pylori, but are not in perfect alignment, possibly due to variable parameters in the experiments, including downstream processing. Meta-analyses have not been published so far, so there is lack in clinical guidance beyond H. pylori eradication therapy.MethodsHere, we analysed gastric mucosa samples from nine public data sets, including GC samples. Using both unsupervised and supervised learning, we defined fine grain bacterial networks of gastric mucosa and identified species associated with tumor status of samples.ResultsWe found anatomic locations and cohort regions among the possible factors leading to the observation of study specific gastric microbiomes. Despite this variability, the periodontal species Fusobacterium nucleatum, Parvimonas micra and Peptostreptococcus stomatis were found in association with tumor status in several datasets. The three species were predicted to be in interaction by ecological network analysis and also formed the intersection of tumor associated species between four GC data sets and five colorectal cancer (CRC) data sets we reanalyzed. We formulated a probiotic composition putatively competing with the GC pathogen spectrum, from correlation analysis in a large superset of gut samples (n=17,800) from clinical- and crowd-sourced studies.ImplicationsThe overlapping bacterial pathogen spectrum between two gastrointestinal tumor types, GC and CRC, has implications for etiology, treatment and prevention. In vitro testing results reported in literature suggest H. pylori eradication treatment should be efficient against the GC pathogen spectrum, yet the existence of an upstream periodontal reservoir is of concern. To address this, we propose longer term use of the formulated probiotics composition.

Association between bacteria other than Helicobacter pylori and the risk of gastric cancer

“…Although this bacterium has been identified as a commensal bacterium, it was reported that P. stomatis was associated with gastric tumors. 27 The relative abundance of Cutibacterium acnes, which is formally known as Propionibacterium acnes, was significantly higher in GC cases than in controls. In our previous study that reported an association between the relative abundance of gastric microbiota and GC risk, P. acnes was relatively highly abundant in GC cases.…”

“…Although this bacterium has been identified as a commensal bacterium, it was reported that P . stomatis was associated with gastric tumors 27 …”

Development of a rational framework for the therapeutic efficacy of fecal microbiota transplantation for calf diarrhea treatment

“…Notably, the establishment of FMT as a veterinary practice for the effective treatment of CD remains difficult due to safety concerns regarding the transmission of virulence factors [ 50 ]. It is also difficult to determine the potential for success from donors prior to FMT; however, a machine learning approach has provided some predictions of the microbial composition required in potential donors [ 51 ]. We identified Sporobacter as a potential biomarker for donor selection using RF classification and LEfSe analysis; Sporobacter was also positively correlated with the production of succinic acid in R-1-success, suggesting that it may play an important role in the interactions of microbiota and metabolites in potential donors.…”

The uninvited guests of our microbiome: Helicobacter pylori and Epstein-Barr virus and their role in gastric cancerogenesis

“…Attention was paid to several species of oral microbiota-Streptococcus anginosus, Peptostreptococcus stomatis, Parvimonas micra, Slackia exigua, and Dialister pneumosintes-they may play a key role in the development of the carcinogenesis process and could be used as noninvasive biomarkers to distinguish gastric cancer from superficial gastritis [42]. Other authors also note that the high level of periodontal pathogen colonization is associated with an increased risk of gastric precancerous lesions [43,44]. A very interesting study was conducted by Sun et al [45], which aimed to examine the characteristics of the oral microbiome in patients with gastric cancer and introduced screening tests for stomach cancer by using oral microbiome.…”