Stomach microbiota composition varies between patients with non-atrophic gastritis and patients with intestinal type of gastric cancer

Abstract

We aimed to characterize microbiota of the gastric mucosa as it progress to intestinal type of cancer. Study included five patients each of non-atrophic gastritis (NAG), intestinal metaplasia (IM) and intestinal-type gastric cancer (GC). Gastric tissue was obtained and DNA extracted for microbiota analyses using the microarray G3 PhyloChip. Bacterial diversity ranged from 8 to 57, and steadily decreased from NAG to IM to GC (p = 0.004). A significant microbiota difference was observed between NAG and GC based on Unifrac-presence/absence and weighted-Unifrac-abundance metrics of 283 taxa (p < 0.05). HC-AN analyses based on presence/absence of 238 taxa revealed that GC and NAG grouped apart, whereas IM overlapped with both. An ordinated analyses based on weighted-Unifrac distance given abundance of 44 taxa showing significance across categories revealed significant microbiota separation between NAG and GC. This study is the first to show a gradual shift in gastric microbiota profile from NAG to IM to GC.

Gastric microbiota and carcinogenesis: the role of non-Helicobacter pylori bacteria - A systematic review

“…However, bacteria belonging to the Actinomycetales order were also present and correlated significantly with both conditions (p < 0.01) (25). It is surprising that previous studies on gastric cancer and chronic atrophic gastritis failed to detect these bacteria (20,22,24). The significance of this atypical microbiota colonization remains to be studied.…”

“…Klebsiella pneumoniae and Acinetobacter baumannii are two notable exceptions, as they belong to the phylum Proteobacteria, although they tend to increase with gastric carcinogenesis (19). It is intriguing that one study found that Streptococcus sinensis was associated with a decreasing trend from premalignant lesions to gastric cancer (22), whereas another study reported that its family, Streptococacceae, was increased in gastric cancer compared with intestinal metaplasia and chronic gastritis (20).…”

“…In addition, although significant differences in bacterial diversity were noted between non-atrophic gastritis and gastric cancer (p = 0.004) but not between intestinal metaplasia and any other group, a decreasing trend from non-atrophic gastritis to intestinal metaplasia to gastric cancer was observed (22).…”

“…From the 12 OTU with the most significant p-values (as selected by the authors), 10 displayed a clear decreasing trend from non-atrophic gastritis to intestinal metaplasia to gastric cancer (2 TM7, 2 Porphyromonas spp, 1 Neisseria spp, 1 Haemophilus spp, 1 Bulleidia spp, Prevotella pallens, Streptococcus sinensis and Bergeriella denitrificans), while 2 revealed an increasing trend (Lactobacillus coleohominis and Lachnospiraceae) (22).…”

“…It is interesting to note that, globally, there is a decrease in bacteria belonging to the phyla Proteobacteria (Neisseria spp [22], Haemophilus spp [22], Bergeriella denitrificans [22], Epsilonproteobacteria [20] and Helicobacteriaceae [20]) and Bacteroidetes (Porphyromonas spp [22] and Prevotella pallens [22]), whereas bacteria belonging to the phyla Firmicutes are either increased (Streptococacceae [20], Lachnospiraceae [22] and Lactobacillus coleohominis [22]) or decreased (Streptococcus sinensis [22]). Klebsiella pneumoniae and Acinetobacter baumannii are two notable exceptions, as they belong to the phylum Proteobacteria, although they tend to increase with gastric carcinogenesis (19).…”