Hyperbaric oxygen therapy stimulates colonic stem cells and induces mucosal healing in patients with refractory ulcerative colitis: a prospective case series

BACKGROUND: Hyperbaric oxygen (HBO) is used as part of treatment in a variety of clinical conditions. Its use in the treatment of ulcerative colitis has been reported in few clinical reports. OBJECTIVE: We report the effect of HBO on refractory ulcerative colitis exploring one potential mechanism of action. DESIGN: A review of records of patients with refractory ulcerative colitis who received HBO was conducted. Clinical and histopathological scoring was utilised to evaluate the response to HBO therapy (HBOT). RESULTS: All patients manifested clinical improvement by the 40th cycle of HBOT. The median number of stool frequency dropped from seven motions/day (range=3–20) to 1/day (range=0.5–3), which was significant (z=−4.6, p<0.001). None of the patients manifested persistent blood passage after HBOT (z=−3.2, p=0.002). The severity index significantly improved after HBOT (z=−4.97, p<0.001). Histologically, a significant reduction of the scores of activity was recorded accompanied by a significant increase in the proliferating cell nuclear antigen labelling index of the CD44 cells of the colonic mucosa (p=0.001). CONCLUSIONS: HBOT is effective in the setting of refractory ulcerative colitis. The described protocol is necessary for successful treatment. HBOT stimulates colonic stem cells to promote healing.