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. nucleatum types taken from human colorectal tumors and from the mouths of people without cancer. Out of its several known subspecies, only one, called F. 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.
Q1: What is Gram-negative bacteria?
Gram-negative bacteria are classified by the color they turn after a chemical process called Gram staining is used on them. Gram-negative bacteria are enclosed in a protective capsule.
Source: A mouth bacteria has starring role in colorectal cancer, study finds
Last updated on August, 2026
→ UPSC Mains 2026 will be conducted on 21st, 22nd, 23rd, 29th and 30th August 2026.
→ Check out the latest UPSC Syllabus 2026 here.
→ UPSC Mains Admit Card 2026 is expected to be released in early August at upsc.gov.in or upsconline.nic.in
→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2026 for structured answer writing practice, expert evaluation, and exam-oriented feedback.
→ Go through the UPSC Mains Previous Year Papers to enhance your preparation.
→ Download UPSC Mains Essay Paper 2025, UPSC Mains GS Paper-I 2025, UPSC Mains GS Paper-II 2025, UPSC Mains GS Paper-III 2025, UPSC Mains GS Paper-IV 2025, UPSC Mains English (Compulsory) Paper 2025, UPSC Mains Hindi (Qualifying) Paper 2025 here.
→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.
→ UPSC Calendar 2027 has been released.
→ Also check Best UPSC Coaching in India







