Hsu Lab · Department of Biological Sciences · Virginia Tech
The viruses that shape the gut microbiome
Trillions of bacteria live in the human gut, and so do bacteriophages — viruses that infect bacteria. We work out what these phages do to gut bacterial communities, and we engineer them into precision therapeutics.
what we do, In plain terms
Precise. Most interventions act on the gut microbiome broadly. Phages often infect with species to strain-level specificity, so it can target individual bacteria while leaving the rest of the community alone.
Prevalent. Phages are a native part of the gut, present in enormous numbers. What they do to bacterial communities is still largely uncharacterized and represents an area of opportunity for study.
Programmable. A phage can carry genetic cargo, introducing this material to resident gut bacteria during the infection process and turning them into tiny microbial factories.
What we work on
01
How phages shape the gut microbiome
Viruses that infect bacteria are a large, mostly uncharted part of the gut. We are working out what they do there.
02
Phages as precision tools inside the gut
Antibiotics and probiotics affect the whole gut at once. Phages can be aimed at one kind of bacterium and used to change what it does.
03
Biomaterials for women’s health
We are applying materials science to menstrual products, an area with little development.
Recent work
Prophage-encoding engineered bacteria enable prophylactic lytic phage therapy for enteric infection in micePhage therapy is conventionally applied after bacterial infection, which is especially difficult for treating enteric infections. In this work we engineer a non-pathogenic bacteria to act as a carrier for a lytic phage, spontaneously producing this antibacterial agent to protect against later bacterial infection.
Nature Microbiology · 2026
Bacteriophage-mediated cell lysis externalizes a metabolically valuable nutrient to broadly modulate bacterial communitiesBacteria often produce nutrients that it doesn’t intend on sharing. In communities that often benefit from sharing of metabolites, we show that bacterial lysis by phage is one mechanism by which typically intracellular materials can be released to the extracellular medium.
The ISME Journal · 2026
Sustained in situ protein production and release in the mammalian gut by an engineered bacteriophageOral delivery of protein drugs is challenging because they are readily degraded in the stomach. Here we show that lytic phages can be genetically programmed to produce proteins so that when they establish intestinal persistence that is typical of gut phages, these encoded therapeutic proteins can be produced directly in the intestinal mucosa.
Nature Biotechnology · 2026
A bacteriophage-conditional mouse model reveals the impact of phages within a conventionally colonized gut microbiotaIts challenging to characterize how phages impact host-associated bacterial communities because they have extensive ties to gut microbiomes. Here, we develop a simple strategy to deplete the phage community from the gut microbiota and show that these phages can be reintroduced to reconstitute this community in vivo.
Cell Host & Microbe · 2025
The lab
People
The lab, December 2025