Clinical outcomes of patients with remitting ulcerative colitis after discontinuation of indigo naturalis.

Indigo naturalis is an effective treatment for ulcerative colitis. However, long-term use of indigo naturalis causes adverse events, such as pulmonary hypertension. The natural history of patients with ulcerative colitis who discontinued indigo naturalis after induction therapy is unknown. Moreover, the clinical features of patients who relapsed within 52 weeks after the discontinuation of indigo naturalis are unclear. This study aimed to assess the clinical outcomes of patients with ulcerative colitis after discontinuation of indigo naturalis and to identify potential markers responsible for relapse. This single-center retrospective study investigated the follow-up of 72 patients who achieved a clinical response 8 weeks after indigo naturalis treatment. We observed relapse in patients with ulcerative colitis after the discontinuation of indigo naturalis. We analyzed the factors predicting long-term outcomes after discontinuation of indigo naturalis. Relapse was observed in 24%, 57%, and 71% of patients at 8, 26, and 52 weeks, respectively. There were no predictive markers in patients who relapsed within 52 weeks after the discontinuation of indigo naturalis. The ulcerative colitis relapse rate after indigo naturalis discontinuation was high. Follow-up treatment is required after the discontinuation of indigo naturalis in patients with ulcerative colitis.

D-amino Acids Ameliorate Experimental Colitis and Cholangitis by Inhibiting Growth of Proteobacteria: Potential Therapeutic Role in Inflammatory Bowel Disease.

BACKGROUND & AIMS: D-amino acids, the chiral counterparts of protein L-amino acids, were primarily produced and utilized by microbes, including those in the human gut. However, little was known about how orally administered or microbe-derived D-amino acids affected the gut microbial community or gut disease progression. METHODS: The ratio of D- to L-amino acids was analyzed in feces and blood from patients with ulcerative colitis (UC) and healthy controls. Also, composition of microbe was analyzed from patients with UC. Mice were treated with D-amino acid in dextran sulfate sodium colitis model and liver cholangitis model. RESULTS: The ratio of D- to L-amino acids was lower in the feces of patients with UC than that of healthy controls. Supplementation of D-amino acids ameliorated UC-related experimental colitis and liver cholangitis by inhibiting growth of Proteobacteria. Addition of D-alanine, a major building block for bacterial cell wall formation, to culture medium inhibited expression of the ftsZ gene required for cell fission in the Proteobacteria Escherichia coli and Klebsiella pneumoniae, thereby inhibiting growth. Overexpression of ftsZ restored growth of E. coli even when D-alanine was present. We found that D-alanine not only inhibited invasion of pathological K. pneumoniae into the host via pore formation in intestinal epithelial cells but also inhibited growth of E. coli and generation of antibiotic-resistant strains. CONCLUSIONS: D-amino acids might have potential for use in novel therapeutic approaches targeting Proteobacteria-associated dysbiosis and antibiotic-resistant bacterial diseases by means of their effects on the intestinal microbiota community.

Development of an Indigo Naturalis Suppository for Topical Induction Therapy in Patients with Ulcerative Colitis.

BACKGROUND: Indigo naturalis (IN) consists of ligands for the aryl hydrocarbon receptor and exhibits anti-inflammatory effects. Previously, we demonstrated that an 8-week treatment with oral IN is effective in inducing a clinical response in patients with ulcerative colitis (UC). Some UC patients with proctitis are refractory to topical mesalamine or corticosteroids and therefore require an alternative topical treatment. OBJECTIVES: We aimed to prospectively evaluate the safety and efficacy of IN suppositories in UC patients. METHOD: We performed an open-label, single-center, prospective pilot study from February 2018 to October 2018. A total of 10 patients with active UC, who had moderate to severe inflammation from the rectum to the sigmoid colon, were enrolled. The patients received a daily dose of 50 mg IN suppository for 4 weeks. The primary endpoint was safety at week 4. RESULTS: Although 1 patient experienced anal pain, no serious adverse events were observed. At week 4, the rates of clinical remission and mucosal healing were 30 and 40%, respectively. Mayo rectal bleeding subscores significantly improved after treatment (1.80 ± 0.13 vs. 0.90 ± 0.28; p = 0.009). Approximately 80% of the patients with a baseline Mayo endoscopic subscore in the rectum (r-MES) of 2 achieved mucosal healing, but those with a baseline r-MES of 3 did not. CONCLUSIONS: We found that 4 weeks of IN suppository can be tolerated by UC patients, but its efficacy was limited by the severity of the disease. Further investigation will be needed in order to confirm the optimum dose of IN suppository for patients with UC.