A simple oral rinse may lead to early detection of gastric cancer, according to new findings presented recently at ASCO’s Annual Meeting 2024 in Chicago, USA, and simultaneously published in Gastroenterology.

In the new study, researchers analysed bacteria samples from the mouths of 98 patients scheduled to undergo endoscopy – 30 of whom were known to have gastric cancer, 30 of whom had premalignant gastric conditions, and 38 of whom were healthy controls. 

The researchers found distinct differences between the oral microbiomes of the controls compared with patients with gastric cancer and premalignant conditions. They also discovered little difference between the samples collected from the patients with gastric cancer and those with premalignant conditions, suggesting that changes in the microbiome may occur as soon as the stomach environment begins to undergo changes that can eventually develop into cancer.

The findings indicated that oral bacteria alone could serve as biomarkers for the risk of gastric cancer. After conducting their research, the researchers developed a model of the 13 bacterial genera representing the most significant differences between controls and the gastric cancer and premalignant conditions groups.

The researchers plan to conduct larger studies involving multiple institutions to ensure that their findings are generalisable to a wider population.