Fusobacterium nucleatum

May 7, 2024

In a new study, a group of researchers has identified a distinct subtype of the Fusobacterium nucleatum that’s found in relatively greater quantities in colorectal cancer (CRC) tumours.

About Fusobacterium nucleatum:

Fusobacteria are Gram-negative anaerobic bacilli with species-specific reservoirs in the human mouth, gastrointestinal tract and elsewhere.
It has long been considered as an opportunistic pathogen given its frequent isolation and identification in anaerobic samples from patients with different infections.
Highlights of the research:
- The researchers first analyzed the genomes of F. nucleatumtypes taken from human colorectal tumors and from the mouths of people without cancer. Out of its several known subspecies, only one, called nucleatum animalis (or Fna), was routinely found in the tumor samples.
- Additional genetic analyses revealed that Fna could be divided even further, into two separate groups.
- While both groups were found in about equal proportions in the mouth, only one, dubbed Fna C2, was found in colorectal tumor samples in substantial numbers.
- Fna C2’s higher resistance to acid, which could allow it to potentially reach the intestines directly from the mouth, through the stomach.
- Fna C2 also had the ability to hide inside certain tumor cells, which could protect it from the immune system. And it was able to use nutrients found in the gastrointestinal tract, which are very different from those found in the mouth.