Liver cirrhosis is the pathologic end stage of chronic liver disease. Increasing evidence suggests that gut flora is implicated in the pathogenesis of liver cirrhosis complications. The aim of this study was to characterize the fecal microbial communities in patients with liver cirrhosis in comparison with healthy individuals. We recruited 36 patients with liver cirrhosis and 24 healthy controls. The fecal microbial community was analyzed by way of 454 pyrosequencing of the 16S ribosomal RNA V3 region followed by real-time quantitative polymerase chain reaction. Community-wide changes of fecal microbiota in liver cirrhosis were observed compared with healthy controls. The proportion of phylum Bacteroidetes was significantly reduced (P 5 0.008), whereas Proteobacteria and Fusobacteria were highly enriched in the cirrhosis group (P 5 0.001 and 0.002, respectively). Enterobacteriaceae (P 5 0.001), Veillonellaceae (P 5 0.046), and Streptococcaceae (P 5 0.001) were prevalent in patients with cirrhosis at the family level. A positive correlation was observed between Child-Turcotte-Pugh (CTP) score and Streptococcaceae (R 5 0.386, P 5 0.02). Lachnospiraceae decreased significantly in patients with cirrhosis (P 5 0.004) and correlated negatively with CTP score (R 5 20.49, P 5 0.002). Using partial least square discriminate analysis, we identified 149 operational taxonomic units (OTUs) as key phylotypes that responded to cirrhosis, most of which were Lachnospiraceae (65 OTUs), Streptococcaceae (23 OTUs), and Veillonellaceae (21 OTUs). Conclusion: Fecal microbial communities are distinct in patients with cirrhosis compared with healthy individuals. The prevalence of potentially pathogenic bacteria, such as Enterobacteriaceae and Streptococcaceae, with the reduction of beneficial populations such as Lachnospiraceae in patients with cirrhosis may affect prognosis. (HEPATOLOGY 2011;54:562-572)

Background Coronavirus disease 2019 (COVID-19) is an emerging serious global health problem. Gastrointestinal symptoms are common in COVID-19 patients, and severe acute respiratory syndrome coronavirus 2 RNA has been detected in stool specimens. However, the relationship between the gut microbiome and disease remains to be established. Methods We conducted a cross-sectional study of 30 patients with COVID-19, 24 patients with influenza A(H1N1), and 30 matched healthy controls (HCs) to identify differences in the gut microbiota by 16S ribosomal RNA gene V3–V4 region sequencing. Results Compared with HCs, COVID-19 patients had significantly reduced bacterial diversity; a significantly higher relative abundance of opportunistic pathogens, such as Streptococcus, Rothia, Veillonella, and Actinomyces; and a lower relative abundance of beneficial symbionts. Five biomarkers showed high accuracy for distinguishing COVID-19 patients from HCs with an area under the curve (AUC) up to 0.89. Patients with H1N1 displayed lower diversity and different overall microbial composition compared with COVID-19 patients. Seven biomarkers were selected to distinguish the 2 cohorts (AUC = 0.94). Conclusions The gut microbial signature of patients with COVID-19 was different from that of H1N1 patients and HCs. Our study suggests the potential value of the gut microbiota as a diagnostic biomarker and therapeutic target for COVID-19, but further validation is needed.

To unravel the profile of intestinal microecological parameters in Chinese patients with asymptomatic carriage of hepatitis B virus (HBV), chronic hepatitis B, decompensated HBV cirrhosis, and health controls and to establish their correlation with liver disease progression, we performed quantitative PCR and immunological techniques to investigate fecal parameters, including population of fecal predominant bacteria and the abundance of some virulence genes derived from Escherichia coli, Bacteroides fragilis, Clostridium difficile, and Clostridium perfringens in fecal crude DNA and some immunological parameters in extracts of all fecal samples. Data analysis indicated that 16S rRNA gene copy numbers for Faecalibacterium prausnitzii, Enterococcus faecalis, Enterobacteriaceae, bifidobacteria, and lactic acid bacteria (Lactobacillus, Pediococcus, Leuconostoc, and Weissella) showed marked variation in the intestine of HBV cirrhotic patients. The Bifidobacteria/Enterobacteriaceae (B/E) ratio, which may indicate microbial colonization resistance of the bowel, was decreased significantly in turn from 1.15 ± 0.11 in healthy controls, 0.99 ± 0.09 in asymptomatic carriers, and 0.76 ± 0.08 in patients with chronic hepatitis B to 0.64 ± 0.09 in patients with decompensated HBV cirrhosis (for all, P < 0.01). This suggests that B/E ratio is useful for following the level of intestinal microecological disorder in the course of liver disease progression. The data for virulence gene abundance suggested increased diversity of virulence factors during liver disease progression. Fecal secretory IgA and tumor necrosis factor-α in decompensated HBV cirrhotic patients were present at higher levels than in other groups, which indicates that a complicated autoregulatory system tries to achieve a new intestinal microecological balance.

Figure 1 Changes of faecal microbial communities in different stages (acute, convalescence, postconvalescence) of patients with COVID-19 (n=30), compared with uninfected controls (n=30). (A) α-Diversity, illustrated by microbiota richness (Chao 1 index), was reduced in COVID-19 (p<0.01, Wilcoxon rank-sum test). Boxes represent the 25th-75th percentile of the distribution; the median is shown as a thick line in the middle of the box; whiskers extend to values with 1.5 times the difference between the 25th and 75th percentiles. ***P<0.001. (B) Principal coordinate analysis (PCoA) of Bray-Curtis distance analysis demonstrated that the overall microbial composition of patients with COVID-19 deviated from the uninfected controls (analysis of similarities, R = -0.201, p=0.001). (C) The same PCoA plot as (B), coloured by α-diversity measured by Chao 1 index.

This report describes an integrated study on identification of potential markers for gastric cancer in patients’ cancer tissues and sera based on: (i) genome-scale transcriptomic analyses of 80 paired gastric cancer/reference tissues and (ii) computational prediction of blood-secretory proteins supported by experimental validation. Our findings show that: (i) 715 and 150 genes exhibit significantly differential expressions in all cancers and early-stage cancers versus reference tissues, respectively; and a substantial percentage of the alteration is found to be influenced by age and/or by gender; (ii) 21 co-expressed gene clusters have been identified, some of which are specific to certain subtypes or stages of the cancer; (iii) the top-ranked gene signatures give better than 94% classification accuracy between cancer and the reference tissues, some of which are gender-specific; and (iv) 136 of the differentially expressed genes were predicted to have their proteins secreted into blood, 81 of which were detected experimentally in the sera of 13 validation samples and 29 found to have differential abundances in the sera of cancer patients versus controls. Overall, the novel information obtained in this study has led to identification of promising diagnostic markers for gastric cancer and can benefit further analyses of the key (early) abnormalities during its development.