image: Djenet Bousbaine - winner of the 2025 NOSTER & Science Microbiome Prize
Credit: Djenet Bousbaine
For her work to illuminate how the immune system responds to the beneficial skin microbiome, Djenet Bousbaine is the winner of the 2025 NOSTER & Science Microbiome Prize.
Bousbaine’s work reveals a surprisingly sophisticated immune response that could be harnessed for the development of innovative, needle-free vaccination strategies.
“I am delighted that 2025 attracted a diverse and exciting roster of entries for the NOSTER & Science Microbiome Prize,” said Caroline Ash, senior editor at Science. “It’s wonderful to see the range of expertise displayed by our prize winners this year.”
While the immune system is known for launching rapid, targeted defenses against harmful pathogens, it also mounts surprisingly complex responses to the beneficial microbes that peacefully colonize our bodies.
Previous research has shown that immune responses to the microbiome are widespread and highly specific, similar to those elicited by pathogens. Yet, unlike typical immune responses to pathogens, these interactions with commensals occur without inflammation and across intact physical barriers like the skin.
In this prize-winning essay, Bousbaine discuss her work that explored how the immune system responds to Staphylococcus epidermidis, a common and beneficial skin microbe, finding that it triggers not only wound-healing T cells, but also robust, antigen-specific B cell responses.
This phenomenon was also observed in non-human primates and humans, suggesting evolutionary conservation. Bousbane and her colleagues identified the cell-wall attached protein accumulation associated protein (Aap) as a key antigen targeted by B cells during colonization with S. epidermidis.
Building on this, the team investigated whether this natural, preemptive immune response could be repurposed for vaccination. By inserting a harmless piece of tetanus toxin into the Aap protein, the researchers engineered S. epidermidis to display a foreign antigen, which when applied to the skin, triggered a strong, systemic antibody response in mice that protected them against a lethal dose of tetanus toxin.
“Our immune system is constantly monitoring and responding to the harmless bacteria that naturally live on our skin,” said Bousbaine. “Our work shows that we can leverage this type of immunity to create powerful topical vaccines.”
“Now in its sixth year, this prize represents our global commitment to advancing microbiome research for the benefit all people,” said Kohey Kitao, CEO of NOSTER Inc. “We are proud to support young scientists whose insights may one day lead to innovative microbiome based therapeutics that offer real world solutions for safe and sustainable healthcare worldwide.”
Ayele Argaw-Denboba is a finalist for the NOSTER & Science Microbiome Prize for his essay “The gut microbiome-germline axis: does a prospective father’s gut microbiota matter.” In his essay, Argaw-Denboba discusses how a father's gut microbiota can affect the health of his offspring by influencing his germline cells at the molecular level.
Mohammad Arifuzzaman is also a finalist for his essay “Illuminating microbial dark matter: dietary alterations uncover microbial regulation of immunity and metabolism.” This work explores how diet and gut microbes interact to shape immune responses through specific bile acid metabolites, offering new insight into how gut microbiota influence health and disease.