Proton Pump Inhibitors Increase the Susceptibility of Mice to Oral Infection with Enteropathogenic Bacteria.

BACKGROUND AND AIMS: Proton pump inhibitors (PPIs) are among the most frequently prescribed medications. Side effects including an increased risk of intestinal infections have been reported. It is assumed that PPIs can increase susceptibility to enteropathogens; however, the underlying mechanisms are unknown. Here in this study, we explored whether Lansoprazole (Laz), one of the PPIs, increases the susceptibility to enteropathogens, and further investigated the mechanism of it. METHODS: Mice were administered Laz intraperitoneally once daily and orally infected with Citrobacter rodentium (C. rodentium). The establishment of intestinal infection was assessed by histology and inflammatory cytokine expression levels measured by quantitative PCR. To test whether Laz changes the intestinal environment to influence the susceptibility, intestinal pH, microbiota, metabolites and immune cell distributions were evaluated via pH measurement, 16S rRNA gene sequencing, metabolome, and flow cytometry analyses after Laz administration. RESULTS: Colitis was induced with less C. rodentium in Laz-treated mice as compared with the controls. We found that increased numbers of C. rodentium could reach the cecum following Laz administration. Laz increased pH in the stomach but not in the intestines. It induced dysbiosis and changed the metabolite content of the small intestine. However, these changes did not lead to alterations of immune cell distribution. CONCLUSIONS: Laz raised susceptibility to C. rodentium as increased numbers of the pathogen reach the site of infection. Our results suggest that it was due to increased stomach pH which allowed more peroral enteropathogens to pass the stomach, but not because of changes of intestinal environment.

Indigo Naturalis Ameliorates Oxazolone-Induced Dermatitis but Aggravates Colitis by Changing the Composition of Gut Microflora.

BACKGROUND: Indigo naturalis (IND) is an herbal medicine that has been used as an anti-inflammatory agent to treat diseases including dermatitis and inflammatory bowel disease in China. However, the mechanism by which IND exerts its immunomodulatory effect is not well understood. METHODS: A murine model of dermatitis and inflammatory bowel disease, both induced by oxazolone (OXA), was treated with IND. The severity of dermatitis was evaluated based on ear thickness measurements and histological scoring. The severity of colitis was evaluated by measuring body weight, histological scoring, and endoscopic scoring. The expression of inflammatory cytokines in ear and colon tissue was evaluated using real-time PCR. 16S rRNA DNA sequencing of feces from OXA-induced colitis mice was performed before and after IND treatment. The effects of IND on OXA-induced colitis were also evaluated after depleting the gut flora with antibiotics to test whether alteration of the gut flora by IND influenced the course of intestinal inflammation in this model. RESULTS: IND treatment ameliorated OXA dermatitis with a reduction in IL-4 and eosinophil recruitment. However, OXA colitis was significantly aggravated in spite of a reduction in intestinal IL-13, a pivotal cytokine in the induction of the colitis. It was found that IND dramatically altered the gut flora and IND no longer exacerbated colitis when colitis was induced after gut flora depletion. CONCLUSIONS: Our data suggest that IND could modify the inflammatory immune response in multiple ways, either directly (i.e., modification of the allergic immune cell activity) or indirectly (i.e., alteration of commensal compositions).

Short-Term and Long-Term Outcomes of Infliximab and Tacrolimus Treatment for Moderate to Severe Ulcerative Colitis: Retrospective Observational Study.

BACKGROUND/AIMS: While some studies have shown that IFX and TAC exhibit similar efficacy against UC in the short-term, it is unclear which drug produces better long-term outcomes. In this study, we compared the long-term efficacy of IFX and TAC in patients with moderate to severe UC. METHODS: This retrospective study was conducted from 2009 to 2017. It included patients with no history of IFX or TAC treatment. We analyzed the clinical response and remission rates at 12 and 52 weeks, and colectomy-free and relapse-free survival were evaluated until the end of the study. RESULTS: At 12 weeks, 94.4% and 77.8% of the patients in the IFX group (n = 18) had demonstrated clinical responses and clinical remission, respectively, whereas 72.7% of the patients in the TAC group (n = 11) exhibited clinical responses and clinical remission. The clinical response, clinical remission, and colectomy-free rates did not differ significantly between the groups. At 52 weeks, clinical responses and clinical remission had been achieved in 76.5% and 70.6% of the patients both in the IFX group, respectively. In the TAC group, clinical responses and clinical remission were achieved in 50.0% of patients. Relapse-free and colectomy-free survival were estimated significantly better in IFX group evaluated by Kaplan-Meier curves. CONCLUSION: This study indicates that IFX and TAC produce similar short-term outcomes in UC patients, but IFX produces better long-term outcomes than TAC especially with avoidance of colectomy. Our data suggest that IFX therapy may be prioritized over TAC for the treatment of moderate to severe UC.