A small study published online in the journal GUT suggests that certain types of mouth bacteria, some of which are found in gum disease, for example Granulicatella adjacens, are linked to the development of pancreatic cancer.

According to the authors, the findings could pave the way for new treatment approaches for pancreatic cancer, one of the hardest cancers to treat, by altering the balance of bacteria. Pancreatic cancer generally spreads rapidly with only one in twenty patients surviving longer than five years after their diagnosis.

The researchers conducted a study in which they compared bacteria found in the saliva of 10 pancreatic cancer patients whose cancer had not yet spread with 10 healthy people. The participants were matched for age and sex.

Their findings revealed that the two groups had substantial variations of bacterial colonies. The cancer group had 31 additional species and 25 fewer species in their saliva compared with that of the healthy group. To verify their results, the researchers conducted the same study on 28 new participants in each group.

In addition, they examined tissue samples from 28 patients with chronic inflammation of the pancreas (chronic pancreatitis), which is linked to an increased risk of developing pancreatic cancer, and discovered that among six suspicious species, two – Neisseria elongata and Streptococcus mitis – showed up substantially less often in the mouths of the cancer patients than in the healthy group, whilst levels of another species – Granulicatella adjacens – were substantially higher.

The findings accurately confirmed an 80% difference of the Neisseria elongata and Streptococcus mitis combination between healthy patients and those with cancer. The researchers also discovered similar differences in the prevalence of S mitis and Granulicatella adjacens between the chronic pancreatitis samples and healthy people’s saliva.

So far it is unclear if the presence of specific bacteria types are the cause or effect of pancreatic cancer, however, the findings are supported by earlier research, which showed that bacteria have an impact in the development of pancreatic diseases.

The researchers conclude by suggesting that levels of particular types of bacteria can potentially be utilized as a non-invasive and credible screen for pancreatic cancer, and that it could be a possible early detection method for a disease that displays no clear symptoms in its early stages.

Written by Petra Rattue