The 'normalization' of germ-free guineapigs with host-specific caecal microflora

Area of Science:

• Microbiology
• Gastroenterology
• Animal Science

Background:

• Germ-free animal models are crucial for studying host-microbiota interactions.
• Establishing a normal gut microbiota is essential for host health and development.
• Understanding the source of gut microbiota is key to successful colonization.

Purpose of the Study:

• To evaluate the efficacy of mouse-derived cecal microflora (mCRF) versus guinea pig-derived cecal microflora (gpCRF) in normalizing germ-free guinea pigs.
• To compare the impact of different microbial sources on key intestinal parameters and colonization resistance.
• To determine the suitability of mouse and guinea pig flora for establishing a healthy gut microbiome in guinea pigs.

Main Methods:

• Germ-free guinea pigs were colonized with either mCRF or gpCRF.
• A conventionally raised group served as controls.
• Key parameters assessed included body weight, colonization resistance (CR) to Escherichia coli, relative cecal weight (RCW), fecal beta-aspartylglycine, cecal volatile fatty acids, and fecal bile acids.
• A separate group involved co-housing mCRF-colonized guinea pigs with gpCRF-colonized guinea pigs.

Main Results:

• mCRF colonization resulted in significantly different CR and RCW values compared to controls, indicating mouse flora's unsuitability for guinea pigs.
• gpCRF colonization led to CR and RCW values comparable to controls, demonstrating the suitability of guinea pig flora.
• Co-housing mCRF guinea pigs with gpCRF guinea pigs improved CR and RCW, normalizing them to control levels.

Conclusions:

• Guinea pig-derived cecal flora (gpCRF) is effective in normalizing germ-free guinea pigs.
• Mouse-derived cecal microflora (mCRF) is not suitable for establishing a normal gut microbiome in guinea pigs.
• Co-housing can facilitate the successful normalization of gut microbiota in guinea pigs colonized with heterologous flora.