Acquisition, transmission and strain diversity of human gut-colonizing crAss-like phages

Area of Science:

• Microbiology
• Virology
• Human Microbiome

Background:

• CrAss-like phages are prevalent double-stranded DNA viruses in the human gut microbiome.
• Understanding their acquisition and transmission is crucial for microbiome research.

Purpose of the Study:

• To investigate crAss-like phage acquisition, transmission, and strain diversity in mother-infant pairs.
• To evaluate crAss-like phage transmission through fecal microbiota transplantation (FMT).

Main Methods:

• Analysis of gut metagenomic data from mother-infant pairs.
• Tracking crAss-like phage clades and specific strains.
• Assessment of phage genomes and protein variations.
• Evaluation of FMT samples for phage acquisition.

Main Results:

• CrAss-like phages are rare at birth but prevalent by one month in infants.
• Vertical transmission from mother to infant is suggested by near-identical genomes.
• Infant crAss-like phage strain diversity increases over time.
• Putative tail fiber proteins show high strain variation, suggesting evolutionary importance.
• Prototypical crAssphage (p-crAssphage) can be acquired via FMT.

Conclusions:

• CrAss-like phages colonize the infant gut postnatally, with mothers as a likely source.
• Strain diversity, particularly in tail fiber proteins, is a key feature of crAss-like phages.
• Fecal microbiota transplantation is a viable route for crAss-like phage acquisition.