Mapping Crohn's Disease Pathogenesis with Mycobacterium paratuberculosis: A Hijacking by a Stealth Pathogen

Area of Science:

• Gastroenterology
• Microbiology
• Immunology

Background:

• Mycobacterium avium ssp. paratuberculosis (MAP) is a suspected cause of Crohn's disease (CD), sharing pathological similarities with Johne's disease (JD) in ruminants.
• The development of CD is thought to involve MAP infection, gut dysbiosis, and dietary factors, necessitating a comprehensive understanding for effective treatment.

Purpose of the Study:

• To review the potential role of MAP in Crohn's disease pathogenesis.
• To explore how MAP's known pathogenesis in cattle and other human mycobacterial infections inform our understanding of CD.
• To discuss the challenges and implications for diagnostic testing of MAP in CD patients.

Main Methods:

• Review of existing literature on MAP, JD, CD, and mycobacterial infections.
• Analysis of pathological and clinical similarities between JD and CD.
• Examination of current diagnostic methodologies for MAP detection in CD.

Main Results:

• Current diagnostic tests (PCR, DNA sequencing, culture) have been inconclusive in establishing a definitive link between MAP and CD.
• Microscopy and histopathology offer insights into in situ mycobacterial activity and disease manifestations like granulomas.
• Understanding MAP's pathogenesis in cattle and other human mycobacterial infections provides a framework for its potential role in CD.

Conclusions:

• Improved and accurate detection methods for MAP are essential to confirm an infectious etiology for CD.
• Isolation, identification, and cultivation of MAP from human gut tissue would strengthen causal relationship evidence.
• Tailoring combination therapies (antibiotics, FMT, diet) to MAP's activity requires robust microbiological evidence of its presence and influence.