Gut microbiota contribution to hepatocellular carcinoma manifestation in non-alcoholic steatohepatitis

Recently, the gut microbiota has been recognized as an obvious active player in addition to liver steatosis/steatohepatitis in the pathophysiological mechanisms of the development of hepatocellular carcinoma (HCC), even in the absence of cirrhosis. Evidence from clinical and experimental studies shows the association of specific changes in the gut microbiome and the direct contribution to maintaining liver inflammation and/or cancerogenesis in nonalcoholic fatty liver disease-induced HCC. The composition of the gut microbiota differs significantly in obese and lean individuals, especially in the abundance of pro-inflammatory lipopolysaccharide-producing phyla, and, after establishing steatohepatitis, it undergoes minor changes during the progression of the disease toward advanced fibrosis. Experimental studies proved that the microbiota of obese subjects can induce steatohepatitis in normally fed mice. On the contrary, the transplantation of healthy microbiota to obese mice relieves steatosis. However, further studies are needed to confirm these findings and the mechanisms involved. In this review, we have evaluated well-documented clinical and experimental research on the role of the gut microbiota in the manifestation and promotion of HCC in nonalcoholic steatohepatitis (NASH). Furthermore, a literature review of microbiota alterations and consequences of dysbiosis for the promotion of NASH-induced HCC was performed, and the advantages and limitations of the microbiota as an early marker of the diagnosis of HCC were discussed.     

Gastrectomy impact on the gut microbiome in patients with gastric cancer: A comprehensive review

Gastric cancer is one of the most common malignancies worldwide and gastrectomy remains the only potentially curative treatment option for this disease. However, the surgery leads to significant physiological and anatomical changes in the gastrointestinal (GI) tract including loss of the gastric barrier, an increase in oxygenation levels in the distal gut, and biliary diversion after gastrectomy. These changes in the GI tract influence the composition of the gut microbiome and thus, host health. Gastrectomy-induced dysbiosis is characterized by increased abundance of typical oral cavity bacteria, an increase in aero-tolerant bacteria (aerobes/facultative anaerobes), and increased abundance of bile acid-transforming bacteria. Furthermore, this dysbiosis is linked to intestinal inflammation, small intestinal bacterial overgrowth, various GI symptoms, and an increased risk of colorectal cancer.     

Mucosa-associated lymphoid tissue lymphoma simulating Crohn’s disease:A case report

BACKGROUND Differential diagnosis between extranodal marginal zone lymphoma of mucosaassociated lymphoid tissue and inflammatory bowel disease is mainly based on histopathologic evaluation of intestinal biopsies,although there is no single definitive diagnostic investigation and that circumstance can lead to misdiagnosis in particular cases.Herein we present a rare,ulcerative form of marginal zone lymphoma which mimics the Crohn’s disease(CD)of upper digestive tract.CASE SUMMARY A 50-year-old man was presented with recurrent episodes of malaise and melena also weight loss.Enteroscopy of the small bowel demonstrated an ulcer in the jejunum.Microscopically,biopsies showed lymphoplasmacytic infiltrate.Diagnosis of CD was made.Primary treatment consisted of prednisone and azathioprine and was followed by azathioprine 100 mg per day with good clinical response in the following 2 years until relapse.At this time the results of endoscopic biopsies derived from proximal wall of stomach revealed Helicobacter pylori-negative marginal zone lymphoma of the gastric fundus.Immunophenotyping confirmed atypical CD20-positive cell population.Based on these biopsies,marginal zone lymphoma of mucosa-associated lymphoid tissue was diagnosed.Unfortunately,the contact with the patient was lost until one year later he was hospitalized with nausea,vomiting and severe pain because of gastrointestinal perforation.Four months later after laparotomy,the patient was treated with a course of chemotherapy.Complete remission was observed following 6 cycles of treatment.CONCLUSION This case report highlights the clinical relevance of knowledge and awareness of marginal zone lymphoma simulating CD.