Extent of disease affects the usefulness of fecal biomarkers in ulcerative colitis.

BACKGROUND: Fecal biomarkers are considered to be useful surrogate markers for endoscopic activity. Given the mechanisms of fecal biomarkers, we hypothesized that the extent of ulcerative colitis (UC; pancolitis, left-sided colitis, and proctitis) could affect the usefulness of fecal biomarkers for assessing endoscopic and clinical disease activity; however, few studies have evaluated the utility of fecal biomarkers in the disease extent of UC. METHODS: Fecal calprotectin, a fecal immunochemical test for hemoglobin, and fecal lactoferrin were used as fecal biomarkers. UC patients, who underwent colonoscopy within 30 days of the fecal biomarker test, participated in this observational study. Clinical and endoscopic disease activity was assessed using the Lichtiger Index and Mayo endoscopic subscore (MES), respectively. RESULTS: A total of 162 colonoscopies were performed on 133 UC patients. A correlation analysis between each biomarker and the MES for each disease-extent subgroup showed a decreased correlation in the proctitis compared with the other groups. With the exception of proctitis, it was possible to distinguish between MES 0 and MES ≥ 1 with high area-under-the-curve values for fecal calprotectin and fecal lactoferrin. The fecal immunochemical test for hemoglobin was superior at discriminating MES 0 for proctitis. CONCLUSIONS: For the practical application of fecal biomarkers for UC patients, it is necessary to consider disease extent before use. In particular, patients with proctitis exhibit a low correlation between stool biomarkers and endoscopic findings. The usefulness of these biomarkers for endoscopic remission is reduced, except for the fecal immunochemical test for hemoglobin.

MEFV Gene-Related Enterocolitis Account for Some Cases Diagnosed as Inflammatory Bowel Disease Unclassified.

BACKGROUND AND AIMS: Familial mediterranean fever (FMF), an autoinflammatory disease, is characterized by periodic fever and serositis. An MEFV gene mutation has been identified as the cause of FMF. Recently, patients with MEFV gene mutations and chronic gastrointestinal mucosal inflammation mimicking inflammatory bowel disease (IBD) have been reported. In this retrospective study, we analyzed the clinical characteristics of patients with IBD unclassified (IBDU) with MEFV gene mutations. METHODS: MEFV gene analysis was performed on 8 patients with IBDU among 710 patients with IBD who had been treated at Kyorin University Hospital from April 2016 to December 2018. Clinical manifestations, endoscopic findings, and serological markers were also analyzed. RESULTS: The average of the 8 patients with IBDU (3 men, 5 women) was 32.7 ± 6.4 years (range 26-76 years). Their symptoms comprised diarrhea (n = 8, 100%), hematochezia (n = 3, 37.5%), abdominal pain (n = 3, 37.5%), high fever (n = 2, 16.5%), and other periodic symptoms (n = 2, 16.5%). MEFV gene mutation was confirmed in 4/8 of these patients. Colonoscopy showed various mucosal lesions, rectal sparing, right side dominant colitis, pseudopolyposis, and granular protrusions. Colchicine was administered to 5 of the 8 patients (4 with and 1 without MEFV mutation) who were resistant to conventional treatment for ulcerative colitis. Clinical and endoscopic improvement was observed in all of 5 patients treated with colchicine. CONCLUSIONS: Some patients diagnosed as having IBDU have enterocolitis related to MEFV gene mutation and respond to colchicine therapy.

Akkermansia muciniphila in the small intestine improves liver fibrosis in a murine liver cirrhosis model.

Recent evidence indicates that liver cirrhosis (LC) is a reversible condition, but there is no established intervention against liver fibrosis. Although the gut microbiota is considered involved in the pathogenesis of LC, the underlying mechanisms remain unclear. Although the antibiotic, rifaximin (RFX), is effective for hepatic encephalopathy (HE) with LC, the impact of RFX on intestinal bacteria is unknown. We investigated the bacterial compositions along the GI tract under RFX treatment using a murine LC model. RFX improved liver fibrosis and hyperammonemia and altered the bacterial composition in the small intestine. The efficacy of RFX was associated with increases in specific bacterial genera, including Akkermansia. Administration of a commensal strain of Akkermansia muciniphila improved liver fibrosis and hyperammonemia with changing bacterial composition in the small intestine. This study proposed a new concept "small intestine-liver axis" in the pathophysiology of LC and oral A. muciniphila administration is a promising microbial intervention.

5-Aminosalicylic acid alters the gut microbiota and altered microbiota transmitted vertically to offspring have protective effects against colitis.

Although many therapeutic options are available for inflammatory bowel disease (IBD), 5-aminosalicylic acid (5-ASA) is still the key medication, particularly for ulcerative colitis (UC). However, the mechanism of action of 5-ASA remains unclear. The intestinal microbiota plays an important role in the pathophysiology of IBD, and we hypothesized that 5-ASA alters the intestinal microbiota, which promotes the anti-inflammatory effect of 5-ASA. Because intestinal inflammation affects the gut microbiota and 5-ASA can change the severity of inflammation, assessing the impact of inflammation and 5-ASA on the gut microbiota is not feasible in a clinical study of patients with UC. Therefore, we undertook a translational study to demonstrate a causal link between 5-ASA administration and alterations of the intestinal microbiota. Furthermore, by rigorously controlling environmental confounders and excluding the effect of 5-ASA itself with a vertical transmission model, we observed that the gut microbiota altered by 5-ASA affected host mucosal immunity and decreased susceptibility to dextran sulfate sodium-induce colitis. Although the potential intergenerational transmission of epigenetic changes needs to be considered in this study, these findings suggested that alterations in the intestinal microbiota induced by 5-ASA directed the host immune system towards an anti-inflammatory state, which underlies the mechanism of 5-ASA efficacy.