Small intestinal bacterial overgrowth (SIBO) is characterized by changes in the number or species of small intestinal flora. Patients with liver cirrhosis often have intestinal congestion, edema, and delayed peristalsis and develop SIBO, which can further aggravate intestinal abnormalities. In patients with liver cirrhosis, SIBO can lead to significant adverse clinical outcomes, and since the increase in intestinal permeability may cause bacterial translocation into systemic circulation, SIBO is considered an important risk factor in the pathogenesis of liver cirrhosis, spontaneous bacterial peritonitis, and hepatic encephalopathy. Antibiotics, especially rifaximin, are the most effective therapies for SIBO, and in addition, studies are being conducted to investigate the efficacy of potential therapies such as prokinetic agents, probiotics, non-selective β-receptor blocker, and liver transplantation.

Objective:To explore the risk factors, clinical features, endoscopic characteristics and the efficacy of antiviral therapy in ulcerative colitis (UC) patients complicated with cytomegaloviremia (CMV) and Epstein-Barr (EB) viremia.Methods:From April 1, 2014 to January 31, 2019, at The Second Hospital of Hebei Medical University, a total of 320 UC patients hospitalized at the Department of Gastroenterology were enrolled. According to the pathogens, the patients were divided into four groups: complicated with CMV and EB viremia group ( n=35), only complicated with CMV viremia group ( n=33), only complicated with EB viremia group ( n=52) and without CMV and EB viremia group ( n=200). Clinical features and the efficacy of antiviral therapy of the patients were retrospectively analyzed. Multivariate logistic regression was used to analyze the risk factors of UC complicated with CMV and EB viremia. Kruskal-Wallis H test, Chi-square test and Fisher exact test were used for statistical analysis. Results:The proportion of patients of age>60 years old (42.86%, 15/35), the rate of glucocorticoid use (51.43%, 18/35) within three months before onset and the inefficacy rate of glucocorticoid treatment (22.86%, 8/35) of UC complicated with CMV and EB viremia group were all higher than those of UC without CMV and EB viremia group (14.00%, 28/200; 24.50%, 49/200; 1.00%, 2/200), and the differences were statistically significant ( χ2=17.062, 10.598 and 29.769; all P<0.01). However, there were no statistically significant differences between UC complicated with CMV and EB viremia group and UC without CMV and EB viremia group in gender, and treatment of 5-aminosalicylic acid (5-ASA), azathioprine and infliximab within three months before onset (all P>0.05). The proportion of patients with fever (54.29%, 19/35), abdominal pain (91.43%, 32/35), hematochezia (94.29%, 33/35), weight loss (28.57%, 10/35), severe disease activity (94.29%, 33/35), total colon involvement (91.43%, 32/35), serum albumin less than 30 g/L (71.43%, 25/35) and hemoglobin less than 100 g/L (48.57%, 17/35) of UC complicated with CMV and EB viremia group were all higher than those of UC without CMV and EB viremia group (13.50%, 27/200; 43.00%, 86/200; 44.00%, 88/200; 13.50%, 27/200; 38.00%, 76/200; 65.00%, 130/200; 18.00%, 36/200 and 18.50%, 37/200), and the differences were statistically significant ( χ2=31.475, 27.945, 32.930, 5.100 and 40.194, Fisher exact test, χ2=44.242 and 15.220, all P<0.01). However, there were no statistically significantl differences in clinical classification and disease course (all P>0.05). The incidence rates of deep ulcer (45.71%, 16/35), irregular ulcer (42.86%, 15/35) and longitudinal ulcer (8.53%, 3/35) under endoscopy of UC complicated with CMV and EB viremia group were significantly higher than those of UC without CMV and EB viremia group (1.50%, 3/200; 3.50%, 7/200 and 1.00%, 2/200), and the differences were statistically significant ( χ2=72.521 and 49.837, Fisher exact test, all P<0.01). The incidence rates of deep ulcer and irregular ulcer under endoscopy of UC complicated with CMV and EB viremia group were higher than those of UC only complicated with EB viremia group (15.38%, 8/52 and 11.54%, 6/52), and the differences were statistically significant ( χ2=9.663 and 11.206, P=0.002 and 0.001). The results of Multivariate Logistic regression analysis showed that severe disease activity, serum albumin level less than 30 g/L, and deep ulcer and irregular ulcer under endoscopy were risk factors of UC patients complicated with CMV and EB viremia (odds ratio=48.519, 44.352, 53.432 and 39.989, 95% confidence interval 9.057 to 587.669, 4.499 to 437.245, 3.302 to 864.670 and 3.418 to 467.910, all P<0.05). The improvement rate of antiviral therapy in UC complicated with CMV and EB viremia group (73.53%, 25/34) was significantly lower than those of UC only complicated with CMV group (96.88%, 31/32) and UC only complicated EB viremia group (95.65%, 44/46), and the differences were statistically significant ( χ2=6.989 and 6.310, P=0.008 and 0.012). Conclusions:UC patients with severe disease activity, serum albumin level less than 30 g/L, and deep ulcer and irregular ulcer under endoscopy are more likely to develop CMV and EB viremia. The more severe the disease, the worse the treatment response, so it is necessary to strengthen the screening to CMV and EB virus infection in UC patients.