Probiotics suppress nonalcoholic steatohepatitis and carcinogenesis progression in hepatocyte-specific PTEN knockout mice.

Nonalcoholic fatty liver disease (NAFLD), a hepatic characteristic of metabolic syndrome, received significant attention in clinical settings. The multiple-hit theory is one of the proposed mechanisms of NAFLD, and gut dysbiosis is considered a hit. Thus, controlling gut microbiota is a potential target in the management of NAFLD, and probiotics can be used as a treatment agent for NAFLD. The current study aimed to investigate the efficacy of probiotics against nonalcoholic steatohepatitis in a hepatocyte-specific PTEN knockout mouse model that mimics the characteristics of human NAFLD. Probiotics were administered to male knockout mice for 8 or 40 weeks. Next, we assessed hepatic inflammation, fibrosis, carcinogenesis, and oxidative stress. Probiotics were found to reduce serum transaminase levels, NAFLD activity score, and the gene expression of pro-inflammatory cytokines. In addition, they decreased liver fibrosis grade, which was examined via Sirius red staining, gene expression of fibrotic markers, and hydroxyproline. Furthermore, probiotics suppressed the number of liver tumors, particular in HCC. Probiotics reduced oxidative stresses, including glutathione levels, and anti-oxidative stress marker, which may be an underlying mechanism for their beneficial effects. In conclusion, probiotics treatment had beneficial effects against NAFLD and carcinogenesis in hepatocyte-specific PTEN knockout mice.

Low prevalence of SARS-CoV-2 specific antibodies among endoscopists and their assistants in a university hospital in Tochigi prefecture-A single-center study.

Objectives: Gastrointestinal endoscopic procedures have a risk to transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through aerosols. Little information is available on the seroprevalence of SARS-CoV-2 antibodies among healthcare workers (HCWs) in endoscopy units. Thus, the seroprevalence was examined in HCWs who do and do not participate in gastrointestinal endoscopy. Methods: A total of 382 HCWs at Jichi Medical University Hospital were enrolled in this study through March 2021. Among 382 HCWs, 63 are in the endoscopy unit. Serum antibody levels against SARS-CoV-2 were determined by immunochromatography, chemiluminescent immunoassay (CLIA), electric CLIA (ECLIA), and chemiluminescence microparticle immunoassay (CMIA). HCWs in the endoscopy unit underwent testing up to three times. We defined antibody-positive as when at least one test was positive. Results: The seroprevalence of SARS-CoV-2 antibodies in 63 HCWs in the endoscopy unit was 0%-1.9%, 0%-1.7%, and 0%-1.7% during the first (Ap-May 2020), second (Jun-Nov 2020), and third intervals (Dec 2020-Mar 2021), respectively. This seroprevalence was comparable to that of other HCWs not involved with gastrointestinal endoscopy. Two HCWs in the endoscopy unit were positive for antibodies: one was ECLIA-positive and the another was CMIA-positive. The ECLIA-positive HCW was PCR negative and converted to negative for the second and third tests. Another HCW was CMIA-positive at all three evaluations and the titers were unchanged. No HCWs in the endoscopy unit contracted a SARS-CoV-2 infection. Conclusions: The seroprevalence of SARS-CoV-2 antibodies was low among HCWs in the endoscopy unit through March 2021 (UMIN000039997).

Double-balloon endoscopy facilitates efficient endoscopic resection of duodenal and jejunal polyps in patients with familial adenomatous polyposis.

BACKGROUND : Many patients with familial adenomatous polyposis (FAP) have adenomatous polyps of the duodenum and the jejunum. We aimed to elucidate the long-term outcomes after double-balloon endoscopy (DBE)-assisted endoscopic resection of duodenal and jejunal polyps in patients with FAP. METHODS : We retrospectively reviewed patients who underwent more than two sessions of endoscopic resection using DBE from August 2004 to July 2018. RESULTS : A total of 72 DBEs were performed in eight patients (median age 30 years, range 12-53; 1.4 DBE procedures/patient-year) during the study period, and 1237 polyps were resected. The median observation period was 77.5 months (range 8-167). There were 11 adverse events, including seven delayed bleeds and four episodes of acute pancreatitis. No delayed bleeding occurred after cold polypectomy. Although, in one patient, one endoscopically resected duodenal polyp was diagnosed as being intramucosal carcinoma, none of the patients developed an advanced duodenal or jejunal cancer during the study period. CONCLUSIONS : Endoscopic resection of duodenal and jejunal polyposis using DBE in patients with FAP can be performed safely, efficiently, and effectively.

TH1 cell-inducing Escherichia coli strain identified from the small intestinal mucosa of patients with Crohn's disease.

Dysbiotic microbiota contributes to the pathogenesis of Crohn's disease (CD) by regulating the immune system. Although pro-inflammatory microbes are probably enriched in the small intestinal (SI) mucosa, most studies have focused on fecal microbiota. This study aimed to examine jejunal and ileal mucosal specimens from patients with CD via double-balloon enteroscopy. Comparative microbiome analysis revealed that the microbiota composition of CD SI mucosa differs from that of non-CD controls, with an increased population of several families, including Enterobacteriaceae, Ruminococcaceae, and Bacteroidaceae. Upon anaerobic culturing of the CD SI mucosa, 80 bacterial strains were isolated, from which 9 strains representing 9 distinct species (Escherichia coli, Ruminococcus gnavus, Klebsiella pneumoniae, Erysipelatoclostridium ramosum, Bacteroides dorei, B. fragilis, B. uniformis, Parabacteroides distasonis, and Streptococcus pasteurianus) were selected on the basis of their significant association with CD. The colonization of germ-free (GF) mice with the 9 strains enhanced the accumulation of TH1 cells and, to a lesser extent, TH17 cells in the intestine, among which an E. coli strain displayed high potential to induce TH1 cells and intestinal inflammation in a strain-specific manner. The present results indicate that the CD SI mucosa harbors unique pro-inflammatory microbiota, including TH1 cell-inducing E. coli, which could be a potential therapeutic target.

Morphological and molecular-genetic characterization of Chloromyxum trilineatum n. sp. (Myxosporea: Bivalvulida) in the gall bladder of pale chub (Zacco platypus) in Japan.

The genus Chloromyxum (Myxozoa: Myxosporea: Bivalvulida) is defined as having ridged or smooth bivalvular myxospores containing four polar capsules, with/without caudal filaments. Currently containing more than 140 nominal species, this genus is reasonably speciose with myxospores of unique but heterogeneous morphology. Recent phylogenetic studies have demonstrated its polyphyletic nature. During our myxosporean survey of freshwater fish, a new coelozoic myxosporean species, Chloromyxum trilineatum n. sp., was detected in the gall bladder of the pale chub, Zacco platypus (Cypriniformes: Cyprinidae), which originated from central Japan. Spores were subspherical, measuring 8.5-9.1 (8.8) µm in length, 7.6-8.2 (8.0) µm in width, and 6.8-7.8 (7.4) µm in thickness (n = 20). The valvular surface was smooth and three or four distinct ridges ran parallel to the suture line. Four almost equal polar capsules, 2.9-3.8 (3.3) µm in length and 1.6-2.4 (2.0) µm in width, assembled at the apical part of the spores. The partial nucleotide sequence of the 18S ribosomal RNA gene, 2014 bp in length, was closest to that of morphologically distinct Chloromyxum ellipticum, infecting the gall bladder of grass carp (Ctenopharyngodon idella) in China with 96.99% (1673/1725) identity and three insertion/deletion (indel) sites, followed by Chloromyxum legeri, infecting the gall bladder of common carp (Cyprinus carpio) in the Czech Republic with 89.97% (1803/2004) identity and 14 indel sites. Other myxosporean species, including Chloromyxum spp. from the gall bladder or urinary system of freshwater and marine fish, were phylogenetically distant from the present species.

Enteromyxum leei (Myxosporea: Bivalvulida) as the cause of myxosporean emaciation disease of farmed olive flounders (Paralichthys olivaceus) and a turbot (Scophthalmus maximus) on Jeju Island, Korea.

A life-threatening emaciation disease of unknown cause(s) is affecting the farming of olive flounders (Paralichthys olivaceus) and turbots (Scophthalmus maximus) on Jeju Island, Korea. As this is one of the major industries in the region, it is of great concern to local farmers trying to develop successful and sustainable aquaculture. We examined 16 olive flounders and one turbot cultured at three farms located in the southern part of Jeju Island, which manifested moderate to severe emaciation such as thinning of the body with notable appearance of bony ridges of the skull on heads. Fresh mucosal scrapings of the intestinal mucosa contained many myxosporean vegetative stages at various developments but not fully grown spores. Histological examination of gastrointestinal and other visceral organs revealed striking changes in the intestinal mucosa such as detachment and loss of the epithelium due to intensive parasitism of the myxosporean vegetative stages, accompanied by considerable leukocyte infiltration in the lamina propria, and at the final stage villus atrophy with no epithelial lining. Specific polymerase chain reaction using a pair of primers targeting a fragment of the 18S ribosomal RNA gene (rDNA) of Enteromyxum leei, a known pathogen causing myxosporean emaciation disease in a variety of cultured fish in Mediterranean countries and Japan, amplified 433-bp products in almost all diseased fish samples, particularly the gastrointestinal tract. Nearly the whole length of the 18S rDNA, 1672-bp long excluding primer-aligning sequences, of the present Korean isolate was comparable to those of E. leei isolates from Japan and Europe, particularly those from the former region. Taking the heavy load of various developmental stages of E. leei in the gastrointestinal mucosa into account, we ascribe the emaciation disease of the fish examined in the present study to this well-known myxosporean species and not to another unknown pathogen(s).