These Tiny Beings Called Gut Bacteria Show Us Great Possibilities.

What do you all want to learn at our Faculty of Pharmacy?

I hope you will decide to apply after you have a clear answer to that question.

In this column, as an example of the research conducted at our university,

I will introduce "gut bacteria," a subject I have been studying for a long time.

Please use this as a reference for deciding your future path.

As of November 2021

Our intestines are home to hundreds of species and 100 trillion bacteria, and this community of gut bacteria is called the gut microbiota. The symbiotic relationship between the gut microbiota and humans began with the history of humankind. It is believed that in exchange for humans providing a home for the bacteria in their intestines, the bacteria came to play a role in helping us maintain our health.

Over the past decade or so, analysis technology for the gut environment has advanced rapidly. It has become possible to determine what kinds of bacteria are in the gut, what metabolites they produce, and whether those metabolites are harmful or harmless. We have learned that gut bacteria are deeply involved in various physiological functions, including human immune function. If the gut environment is healthy, various diseases can be prevented. Conversely, it has been suggested that if the gut environment is disrupted by lifestyle habits or other factors, it can lead to the onset or worsening of diseases.

For example, diet has a major impact on the gut environment. If you eat only easily digestible foods, most of the nutrients are absorbed in the small intestine, and the bacteria in the large intestine do not receive enough nutrients. This reduces the variety of bacteria and changes the composition of the microbiota. To maintain a healthy gut environment, it is important to consume plenty of indigestible substances like dietary fiber.

Based on research findings that have clarified the effects of these gut bacteria on human physiological functions and the causal relationship between gut bacteria and diseases, we aim to develop new approaches for disease prevention and therapeutic drugs that utilize gut bacteria. In fact, data from previous research suggests that specific gut bacteria or their metabolites may be able to control diseases.

At the Keio University Faculty of Pharmacy, we have launched the "Physis Project," which aims to conduct drug discovery research to combat COVID-19 and to gain knowledge to suppress the progression to severe illness. I am also a member of this project, and my research activities here also focus on the gut microbiota.

Various lifestyle habits have been cited as risk factors for developing severe COVID-19. For example, obesity. Obesity can lead to a breakdown of the intestinal barrier function, a condition known as "leaky gut," which allows bacterial components and metabolites to circulate throughout the body, leading to a state where inflammation is easily triggered. It is believed that if a virus enters the body in this state, it is more likely to trigger a cytokine storm, a highly lethal immune response. We are currently conducting research based on the idea that the gut microbiota may be able to contribute to suppressing such severe outcomes.

"Tiny, invisible microorganisms can improve barren soil environments." These were the words of my homeroom teacher, who was an English teacher, and they are what inspired me to pursue my current research. Perhaps because it came from a teacher outside my field of specialty, it left a strong impression on me, and I became vaguely interested in the power of microorganisms. My interest in microorganisms continued after entering university, and I chose pathogenic microorganisms as my research theme. In truth, I had also long been interested in gut bacteria, but at the time, methods for analyzing the gut environment, a higher-order complex system, had not been established, so I was unable to venture into it. Amidst this, analysis technology for the gut environment has made great strides over the past decade, and I am now finally able to approach gut bacteria as an extension of my previous research.

When I entered university, I chose to do so with the goal of studying microorganisms. What are you all thinking of studying at university now? Please do not choose the Keio Faculty of Pharmacy based solely on its name or rankings. I want you to decide to apply after learning what you can study at the Keio Faculty of Pharmacy and clarifying for yourself what you want to learn. And I truly hope that people who will not lose their desire to gain new knowledge after enrolling, and who can maintain an attitude of thinking for themselves and exploring, will come to the Keio Faculty of Pharmacy.