Why is it in the News?

In a recent study, researchers have discovered a unique subtype of Fusobacterium nucleatum that is more prevalent in colorectal cancer (CRC) tumours.

What is Fusobacterium nucleatum?

• Fusobacterium nucleatum is a species of bacteria commonly found in the human mouth and gastrointestinal tract.
• It is a Gram-negative anaerobic bacterium, meaning it does not require oxygen to survive.
• While it is a normal component of the oral microbiota, Fusobacterium nucleatum can also act as an opportunistic pathogen, potentially causing infections in various parts of the body.
• In recent research, specific subtypes of Fusobacterium nucleatum have been associated with colorectal cancer tumours, highlighting its potential role in certain diseases.
• It plays a role in periodontal disease and is often associated with various human diseases and infections, including preterm births.
• F. nucleatum can aggregate with other bacteria species in the oral cavity and is considered a key component of periodontal plaque due to its abundance.
• Detection of F. nucleatum typically involves surgical tissue retrieval, faecal tests, or blood tests in patients showing symptoms, and early detection is crucial for preventing further disease progression.

Highlights of the Recent Research:

• Researchers examined genomes of F. nucleatum types from colorectal tumour samples and individuals without cancer. Among its subspecies, only one, known as Fusobacterium nucleatum animalis (or Fna), was consistently found in tumour samples.
• Further genetic analysis divided Fna into two distinct groups, with only one group, Fna C2, being prevalent in colorectal tumours.
• Fna C2 showed higher acid resistance, potentially allowing it to travel from the mouth to the intestines via the stomach.
• Additionally, Fna C2 demonstrated the ability to hide within tumour cells, evade the immune system, and utilize nutrients found in the gastrointestinal tract.