Saga University Kitagaki Laboratory

Kitagaki lab of National Saga University studies the role of sphingolipids in intestinal microbes and the epidermis.


Hiroshi Kitagaki, Ph. D.

Research themes
1 The role of sphingolipids in intestinal microbes

We have first elucidated that koji, which is the base for Japanese traditional fermented foods and drinks (sake, amazake, sake lees, miso, soy sauce, rice vinegar and kurozu) contains abundant glucosylceramide. Furthermore, we have elucidated that koji glycosykceramide improves intestinal microbial flora. Therefore, we have for the first time in the world elucidated that Japanese dietary fungus, KOJI Aspergillus is a prebiotic. These fundings are published in the following publications.

Japanese Traditional Dietary Fungus Koji Aspergillus oryzae Functions as a Prebiotic for Blautia Coccoides through Glycosylceramide.
SpringerPlus, 5, 1321 (2016)
Development of a quantitative method for the contents of glycosylceramide contained in Japanese foods brewed with koji and its application.
Chemical analysis of the sugar moiety of monohexosylceramide contained in koji, Japanese traditional rice fermented with Aspergillus.
Fermentation, 2016, 2(1), 2; doi:10.3390/fermentation2010002
Development of a quantitative method for the contents of glycosylceramide contained in Japanese foods brewed with koji and its application.
Journal of the Brewing Society of Japan, in press (2017)
Quantitation and structural determination of glucosylceramides contained in sake lees.
Journal of Oleo Science, 63, 1, 15-23 (2014)

Structural determination of glucosylceramides in the distillation remnants of shochu, the Japanese traditional liquor, and its production by Aspergillus kawachii.
Journal of Agricultural and Food Chemistry, 60 (46), 11473-82 (2012)

2 The role of sphingolipids and fermented products in the epidermis
We have first elucidated that sphingolipids (especially glycosylceramides) increases the expression of skin barrier and lipid repair genes in the epidermal keratinocytes.
We are now further studying the effect of related molecules on the skin health.

Glycosylceramides Purified from the Japanese Traditional Non-Pathogenic Fungus Aspergillus and Koji Increase the Expression of Genes Involved in Tight Junctions and Ceramide Delivery in Normal Human Epidermal Keratinocytes 
Miyuki Miyagawa, Ayami Fujikawa, Mayu Nagadome, Kanae Kohama, Takatoshi Ogami, Seiichi Kitamura, 北垣浩志
Fermentation 5(2) 43 - 43 2019年8月



Master course and Ph. D. courses from overseas are available.
For further details, contact the address below.



Activities of foreign students

Excellent student award, Kagoshima University
Excellent student award, Saga University
Honjo International scholarship
Medipolice scholarship
Outstanding Scientific Presentation in International Congress on Yeasts, 2012, IUBMB
Best paper Award, 1st Asia Future Conference

Key Scientific Article, Renewable Energy Global Innovations
Alltech Young Researcher Award Honorable Mention
Assistant professor, Southern Illinois University Carbondale, USA

Health benefits of koji

Japanese page


2021.6.21 updated html