New Study Reveals Hidden Stomach Bacteria Could Raise Gastric Cancer Risk

New Delhi: A study from the University of Birmingham published in the Helicobacter journal has provided new insights into how Helicobacter pylori and other stomach bacteria may work together to trigger gastric adenocarcinoma, a major cause of cancer-related deaths.

Researchers used advanced imaging techniques to examine stomach tissue samples from patients with chronic gastritis and its precancerous stage, gastric intestinal metaplasia.

Using RNA in situ hybridization combined with immunohistochemistry, the team distinguished between H. pylori—which was found only in the gastric glands—and other bacteria that invaded the lamina propria, the supportive tissue beneath the stomach lining. This invasion was seen in 67% of H. pylori-positive chronic gastritis cases and 80% of H. pylori-positive intestinal metaplasia cases.

"Our data reveal that non-H. pylori bacteria aren’t just bystanders—they actually invade the lamina propria in the presence of H. pylori. Thus, we propose that H. pylori facilitates opportunistic invasion of the lamina propria by transiting microbes," said the researchers.

The study also found that the amount of non-H. pylori bacteria increases as the condition worsens from chronic gastritis to intestinal metaplasia, possibly due to the development of intestinal-like niches in the stomach.

Eradicating H. pylori with antibiotics can lower the risk of cancer if caught early, but once precancerous changes occur, such treatments become less effective—often described as reaching the “point of no return.”

Dr Amanda Rossiter-Pearson, the study’s corresponding author, commented:

“We are excited about the potential of this observation to open a new avenue of research in the prevention of stomach cancer. It is possible that a simple antibiotic treatment could be administered to treat these bacteria. However, there is a lot more work to do.

“We must first determine the identity of these bacteria and understand how the presence of these bacteria in the precancerous condition impacts on the patient’s risk of developing stomach cancer.”

Dr Talisia Quallo, Research Programme Manager at Cancer Research UK, added:

“Stomach cancer has limited treatment options and poor survival rates. Better approaches are needed to find it earlier, and offer treatment when it is more likely to be successful.

“This research is showing us that the most common type of bacteria linked to stomach cancer, Helicobacter pylori, may work alongside other bacteria to drive a precursor condition to stomach cancer. Much more research is needed to understand how this interaction works, and what could be done to stop it, but from this research we can explore new ways to detect who will go on to develop stomach cancer.”

In their concluding remarks, the research team stated:

“In conclusion, we have observed that invasive bacteria are associated with H. pylori infection in the early and middle stages of Correa’s carcinogenic cascade and therefore represent an attractive target for microbiome-based interventions in the prevention, diagnosis, and management of GAC.”

These findings pave the way for new strategies that target both H. pylori and the secondary bacteria that may accelerate cancer progression. Future research will aim to understand the mechanisms behind this bacterial synergy and how disrupting it might lower the risk of gastric cancer, offering hope for improved diagnostics and treatments.