BackgroundRecent metagenomic analyses have revealed dysbiosis of the gut microbiota of ulcerative colitis (UC) patients. However, the impacts of this dysbiosis are not fully understood, particularly at the strain level.ResultsWe perform whole-genome shotgun sequencing of fecal DNA extracts from 13 healthy donors and 16 UC and 8 Crohn’s disease (CD) patients. The microbiota of UC and CD patients is taxonomically and functionally divergent from that of healthy donors, with E. faecium being the most differentially abundant species between the two microbial communities. Transplantation of feces from UC or CD patients into Il10−/− mice promotes pathological inflammation and cytokine expression in the mouse colon, although distinct cytokine expression profiles are observed between UC and CD. Unlike isolates derived from healthy donors, E. faecium isolates from the feces of UC patients, along with E. faecium strain ATCC 19434, promotes colitis and colonic cytokine expression. Inflammatory E. faecium strains, including ATCC 19434 and a UC-derived strain, cluster separately from commercially available probiotic strains based on whole-genome shotgun sequencing analysis. The presence of E. faecium in fecal samples is associated with large disease extent and the need for multiple medications in UC patients.ConclusionsE. faecium strains derived from UC patients display an inflammatory genotype that causes colitis.
A man in his 60s visited our hospital because of a pancreatic head tumor. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) revealed that the tumor consisted of a neuroendocrine carcinoma (NEC) and adenocarcinoma, including signet-ring cell carcinoma, and that the ratio of these components was approximately 50:50. Therefore, he was diagnosed with mixed adenoneuroendocrine carcinoma (MANEC). Because of liver and lymph node metastases, systemic chemotherapy was initiated using a regimen for the NEC component based on an increase in neuron-specific enolase (NSE). Although the patient achieved stable disease after two chemotherapy cycles, the tumor increased in size after three cycles, which was associated with a gradual increase in carcinoembryonic antigen and a decrease in NSE level. An EUS-FNA reexamination revealed that the adenocarcinoma component accounted for 90 % of the tumor. Thus, an adenocarcinoma chemotherapy regimen was started, and a slight reduction in tumor size was observed. Here, we report an extremely rare and remarkable case of MANEC of the pancreas that demonstrates the effectiveness of EUS-FNA for helping to decide the chemotherapy regimen.
Overuse of antibiotic drugs alters the composition of gut microbiota and has detrimental effects on the host. In our study, we investigated association of gut flora and antibiotics in the prognosis of patients with liver cancer who have undergone chemotherapy by analyzing two independent clinical studies. We retrospectively subanalyzed a previously reported randomized controlled trial (RCT) on hepatic arterial infusion chemotherapy in patients with hepatocellular carcinoma (HCC) to investigate the association between use of antibiotics and prognosis. In the other study, we prospectively determined the abundance of specific bacterial genus in patients with HCC by sequencing 16S ribosomal RNA and assessed its association with survival. Subanalysis of the RCT data showed that, of 26 types of antibiotics used, administration of carbapenem before or during chemotherapy was associated with poor progression‐free survival (PFS) and overall survival (OS) of patients with HCC (carbapenem + vs. −; median PFS, 78 days vs. 154 days, p = 0.0053; median OS, 177 days vs. 475 days, p = 0.0003). Multivariate analysis revealed that antianaerobic drug use is an independent predictor of poor prognosis. In the prospective study, the abundance of Blautia in fecal microbiota correlated positively with both PFS and OS of patients with HCC who underwent chemotherapy. Use of antibiotics targeting anaerobes is associated with a poor prognosis in patients with HCC who have undergone chemotherapy, whereas the intestinal anaerobic bacteria, Blautia is associated with a good prognosis. These findings might indicate the need for caution regarding overuse of broad‐spectrum antibiotics targeting anaerobes in patients with HCC.
Tocilizumab, an anti-human interleukin 6 receptor (IL-6R) monoclonal antibody, is widely used to treat rheumatoid arthritis (RA) and is expected to exhibit clinical efficacy when used to treat other autoimmune diseases. However, a risk of opportunistic infection is occasionally recognized. A 54-year-old woman had received an oral corticosteroid and methotrexate to treat RA. Despite receiving these treatments, she received additional treatment with tocilizumab due to poor control of the disease activity. She presented at our hospital with a high fever and epigastralgia 19 days after receiving this treatment. A laboratory evaluation revealed liver injury and cytomegalovirus (CMV) viremia. Abdominal ultrasonography and computed tomography (CT) revealed hepatosplenomegaly, but no ascites. Upper gastrointestinal endoscopy revealed gastric erosions induced by CMV, which were confirmed immunohistochemically. Hence, we diagnosed the patient with CMV reactivation-induced acute hepatitis and gastric erosions under tocilizumab treatment. She received an anti-cytomegalovirus drug, ganciclovir, for 14 days due to her viremia and impaired general condition, which was suggestive of a severe infection. Her general condition subsequently improved, the liver function test results normalized, and the gastric erosions disappeared. In conclusion, although tocilizumab is very useful for treating certain autoimmune and inflammatory diseases, and will be prescribed more widely in the future, associated CMV infections must be closely monitored, as these can be lethal.
<b><i>Introduction:</i></b> Gut microbiota alterations cause inflammation in patients with ulcerative colitis (UC). Fecal microbiota transplantation (FMT) enables manipulating the microbiota’s composition, but the mechanisms underlying colonization of the posttransplantation microbiota are poorly understood. <b><i>Methods:</i></b> In this open-label, nonrandomized study, the FMT efficacy and changes in the gut microbiota were evaluated in 8 UC patients with mild-to-moderately active endoscopic colonic lesions. Compositional changes in the fecal and mucosal microbiotas between donors and recipients were examined via 16S rRNA-based sequencing. To investigate the effects of oral corticosteroids on microbiota colonization, FMT was performed in germ-free prednisolone (PSL)-administered mice to examine the factors determining colonization. <b><i>Results:</i></b> Four UC patients achieved clinical remission (CR) after FMT, and 3 also achieved endoscopic remission. The fecal microbiotas of the CR patients changed similar to those of the donors after FMT. The mucin-coding gene, <i>MUC2</i>, was less expressed in the colons of the PSL-dependent patients than in the PSL-free patients. In the mice, PSL treatment decreased the fecal mucin production and altered the posttransplantation fecal microbiota composition. Adding either exogenous mucin or the mucin secretagogue, rebamipide, partially alleviated the PSL-induced dysbiosis of the gut microbiota. Administering rebamipide with FMT from healthy donors relieved inflammation in mice with <i>Enterococcus faecium</i>-induced colitis. <b><i>Conclusion:</i></b> Colonic mucin controlled the gut microbiota composition, and oral corticosteroid treatment modified the gut microbiota partly by reducing the colonic mucin.
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