The University of Tokyo

Using silkworms to research how bacteria attached to pollen causes hay fever

Yuan Hu

First-year Master's degree student, Graduate School of Pharmaceutical Science

Yuan Hu

In her laboratory, she is the only woman in a sea of men. “Sometimes I want to talk about girly things, but I can't,” she laments.

Many people suffer from cedar pollen allergies at the start of every spring. A variant of hay fever, the affliction's cause is believed to be proteins embedded in the pollen that become antigens and cause an allergic reaction in one's body. However, a new theory on what causes hay fever was formulated by Yuan, then a 4th-year undergraduate student in the School of Pharmaceutical Sciences' Laboratory of Microbiology. Her experiments showed that bacteria attached to pollen grains were highly pathogenic and negatively affect their host organism. This research set the stage for a new story to be told in the field of microbiology.

“One day, a silkworm that I had injected with cedar pollen died. When I looked into the reason why, I discovered that the cause of death was infection by bacillus bacteria that had been attached to the pollen. We generally use anti-allergy medication to treat hay fever at present, but this incident made me realize that perhaps antibacterial drugs would be effective instead.”

The silkworm's internal organs, brain and transparent blood are all contained in its white body that is about the size of a person's little finger. Yuan says that silkworms are used not only in sericulture (making silk); these small insects are also highly valued as laboratory animals. One reason for their superior status in the scientific world is the fact that they are easy to raise, which keeps costs down. Also, they do not pose as much of an ethical problem when used in experiments as mice or other mammals would.

“I used to not like any insects at all, but I now make an exception for silkworms. By taking care of them in the laboratory, I've grown fond of them and come to think that they are cute…”

Yuan's discovery and hard work have not gone unnoticed. She was listed as the first author of an academic paper covering her research findings while she was still an undergraduate student. This paper was published in an international scientific journal and introduced at an academic conference. Yuan was also bestowed with the President's Grand Award, one of the University of Tokyo President's Awards which are given to outstanding students every year. However, despite all of these accolades for her research, she is not aiming to be a hay fever specialist. With her award decorating the space across from the piano in her room, she is currently forging ahead to take on a new challenge: the bacterium Pseudomonas aeruginosa.

“Pseudomonas aeruginosa is a green pus that forms on open wounds. This bacterium is receiving a lot of attention right now since it is causing infections that spread within hospitals. I have always wanted to join an organization like the WHO and work on public health issues by researching these different kinds of bacteria. I still have a long way to go in my studies to reach that point. In the future, though, I want to put the knowledge about microbiology that I gained from the University to good use while going to different places around the world.”

Yuan buys a new lab coat every year; she is now on her third one. Watch for when the prestigious grime from her accumulated experience in experiments has covered her seventh coat. That will be the sign that this talented lady from the prefecture of Ehime is leaping forward into the world of public health!

Q&A Extras

Do you have hay fever?

“Fortunately, no.”


What part of the silkworm do you inject the pollen into?

“The back, where the major blood vessel is.”


How would you describe your character?

“I think I'm a stubborn-headed type.”


What club activities did you participate in during your undergraduate years?

“I was in the English Speaking Society, called E.S.S. for short. We won at two of the four big annual club tournaments.”


What does being “tough” mean to you?

“I think it describes someone who carries something out to the end once they decide they're going to do it.”

Yuan Hu

Yuan before UTokyo

She wore glasses in high school.