Toshifumi Ohkusa

Toshifumi Ohkusa IPC

Department of Microbiota Research, Juntendo University Graduate School of Medicine, Tokyo, Japan

Short Biography

1986 - 2001      Research Associate and Instructor at First Department of Internal Medicine, Tokyo Medical and Dental University
2001 - 2004      Assistant Professor at Department of Gastroenterology, Juntendo University
2005 - 2008   Associate Professor at Department of Gastroenterology, Juntendo University School of Medicine
2008-2019    Professor at Department of Gastroenterology and Hepatology, The Jikei University Kashiwa Hospital
2019 - present  Special Professor at Department of Microbiota Research, Juntendo University Graduate School of Medicine  

Current research: 
Gut Microbiota, Ulcerative Colitis, DSS Colitis, Colorectal Cancer, Fusobacterium, Helicobacter pylori


1) Okayasu I, Hatakeyama S, Yamada M, Ohkusa T, Inagaki Y, Nakaya R: A novel method in the induction of reliable experimental acute and chronic ulcerative colitis in mice.  Gastroenterology  1990;98: 694-702.

2) Yamada M, Ohkusa T, Okayasu I: Occurence of dysplasia and adenocarcinoma after chronic ulcerative colitis in hamsters induced by dextran sulfate sodium.  Gut 1992;33: 1521- 1527.

3) Okayasu I, Ohkusa T, Kajiura K, Kanno J, Sakamoto S: Promotion of colorectal neoplasia in experimental murine ulcerative colitis.  Gut 1996; 39:87-92.

4) Ohkusa T, Takashimizu I, Fujiki K, Suzuki S, Shimoi K, Horiuchi T, Sakurazawa S, Ariake K, Ishii K, Kumagai J, Tanizawa T: Disappearance of hyperplastic polyps in the stomach after eradication of Helicobacter pylori - A randomized, controlled trial. Ann Int Med 1998;129: 712-715.

5) Ohkusa T, Fujiki K, Takashimizu I, Kumagai J, Tanizawa T, Eishi Y, Yokoyama T, Watanabe M: Improvement in atrophic gastritis and intestinal metaplasia in patients in whom Helicobacter pylori was eradicated.  Ann Intern Med  2001;134: 380-386.

6) Ohkusa T, Okayasu I, Ogihara T, Morita K, Ogawa M, Sato N: Induction of experimental ulcerative colitis by Fusobacterium varium isolated from colonic mucosa of patients with ulcerative colitis. Gut 2003;52:79-83.

7) Ohkusa T, Kato K, Terao S, Chiba T, Mabe K, Murakami K, Mizokami Y, Sugiyama T, Yanaka A, Takeuchi Y, Yamato S, Yokoyama T, Okayasu I, Watanabe S, Tajiri H, Sato N. Newly Developed Antibiotic Combination Therapy for Ulcerative Colitis: A Double-Blind Placebo-Controlled Multicenter Trial.  Am J Gastroenterol. 2010;105:1820-9.

8) Kato K, Ohkusa T, Terao S, Chiba T, Murakami K, Yanaka A, Uehara T, Ishii Y, Soma M, Tajiri H. Adjunct antibiotic combination therapy for steroid-refractory or -dependent ulcerative colitis: an open-label multicentre study. Aliment Pharmacol Ther. 2014;39:949-56.

9) Ohkusa T, Koido S. Intestinal microbiota and ulcerative colitis. J Infect Chemother. 2015;21:761-8.

10) Shibahara-Sone H, Gomi A, Iino T, Kano M, Nonaka C, Watanabe O, Miyazaki K, Ohkusa T. Living cells of probiotic Bifidobacterium bifidum YIT 10347 detected on gastric mucosa in humans. Benef Microbes. 2016;7:319-26.