Gut Bacteria and Their Hidden Viruses: A Surprising Discovery

In the microscopic universe of our gut, a complex ecosystem thrives. Among the inhabitants is the bacterium Desulfovibrio piger, found in both healthy individuals and those with inflammatory conditions. Scientists are intrigued by its role in our health.

Genomic Diversity and Megaplasmids

Researchers studied three strains of D. piger from healthy individuals and one from a person with ulcerative colitis. Their genomes revealed striking differences.

• FI11455: This strain boasted a larger genome, including a megaplasmid—a large piece of DNA.
• Gene Transfer: The megaplasmid contained a section similar to the main DNA of another strain, FI11311, suggesting horizontal gene transfer between bacterial DNA components.

Prophages: Hidden Viruses

Each strain harbored four to five prophages—viruses hidden within their DNA. These prophages were unique, with genes for:

• Replication
• Regulation
• Structural proteins

Some genes resembled Mu-like proteins, a type of virus.

Spontaneous Virus Release

The researchers induced virus release using mitomycin C and observed virus particles under a microscope. Surprisingly, they also noted spontaneous release of these viruses—a first for gut-associated Desulfovibrio bacteria.

Implications for Gut Health

This discovery suggests that these viruses can transfer genes between gut bacteria, potentially influencing the gut microbiome and overall health.