Gut microbiota and hepatocellular carcinoma

The intrahepatic bacterial metataxonomic signature of patients with hepatocellular carcinoma

Dysbiosis of the gut-liver axis increases the risk of bacterial and metabolite influx into the liver, which may contribute to the development of hepatocellular carcinoma (HCC). In this study, we compared the microbiomes in HCC tumors and adjacent tissues. We examined the HCC tumors and adjacent tissues from 19 patients diagnosed with HCC. We find that the liver tissues from HCC patients with capsule invasion presented higher alpha diversity at the genus level than those without. The bacterial compositions in liver tissues of HCC patients at stage II differed from those at stage I and Advanced, respectively. Metagenomic profiling revealed that order Actinomycetales was enriched in the HCC patients at advanced stages. Order Lactobacillales, family Veillonellaceae, genera Rhodobacter and Megasphaera are enriched in tumors of HCC patients, whereas genus Pseudochrobactrum is enriched in the adjacent tissues from HCC patients. An increased abundance of class Actinobacteria and order Actinomycetales is observed in the HCC patients with cirrhosis. In contrast, phylum Firmicutes, classes Clostridia and Betaproteobacteria, and order Clostridiales are enriched in those without cirrhosis. The presence of various types of bacterial 16S rRNAs in HCC tumors and adjacent tissues indicates the presence of various bacterial communities therein. Our study provides information about differentially abundant intrahepatic bacteria in patients with HCC. The differences found may support possible diagnostic and personalized therapeutic implications for HCC.

Brain-gut-liver axis: Chronic psychological stress promotes liver injury and fibrosis via gut in rats

Background

The effect of chronic psychological stress on hepatitis and liver fibrosis is concerned. However, its mechanism remains unclear. We investigated the effect and mechanism of chronic psychological stress in promoting liver injury and fibrosis through gut.

Methods

Sixty male SD rats were randomly assigned to 6 groups. Rat models of chronic psychological stress (4 weeks) and liver fibrosis (8 weeks) were established. The diversity of gut microbiota in intestinal feces, permeability of intestinal mucosa, pathologies of intestinal and liver tissues, collagen fibers, protein expressions of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor kappa β (NF-κβ), tumor necrosis factor α (TNF-α) and interleukin 1 (IL-1) in liver tissue, liver function and coagulation function in blood and lipopolysaccharide (LPS) in portal vein blood were detected and analyzed.

Results

The diversities and abundances of gut microbiota were significant differences in rats among each group. The pathological lesions of intestinal and liver tissues, decreased expression of occludin protein in intestinal mucosa, deposition of collagen fibers and increased protein expression of TLR4, MyD88, NF-κβ, TNF-α and IL-1 in liver tissue, increased LPS level in portal vein blood, and abnormalities of liver function and coagulation function, were observed in rats exposed to chronic psychological stress or liver fibrosis. There were significant differences with normal rats. When the dual intervention factors of chronic psychological stress and liver fibrosis were superimposed, the above indicators were further aggravated.

Conclusion

Chronic psychological stress promotes liver injury and fibrosis, depending on changes in the diversity of gut microbiota and increased intestinal permeability caused by psychological stress, LPS that enters liver and acts on TLR4, and active LPS-TLR4 pathway depend on MyD88. It demonstrates the possibility of existence of brain-gut-liver axis.

Segmental Distribution of Hepatocellular Carcinoma in Cirrhotic Livers

Background: To evaluate the segmental distribution of hepatocellular carcinoma (HCC) according to Couinaud’s anatomical division in cirrhotic patients. Methods: Between 2020 and 2021, a total of 322 HCC nodules were diagnosed in 217 cirrhotic patients who underwent computed tomography (CT) or magnetic resonance imaging (MRI) for the evaluation of suspicious nodules (>1 cm) detected during ultrasound surveillance. For each patient, the segmental position of the HCC nodule was recorded according to Couinaud’s description. The clinical data and nodule characteristics were collected. Results: A total of 234 (72.7%) HCC nodules were situated in the right lobe whereas 79 (24.5%) were detected in the left lobe (p < 0.0001) and only 9 nodules were in the caudate lobe (2.8%). HCC was most common in segment 8 (n = 88, 27.4%) and least common in segment 1 (n = 9, 2.8%). No significant differences were found in the frequencies of segmental or lobar involvement considering patient demographic and clinical characteristics, nodule dimension, or disease appearance. Conclusions: The intrahepatic distribution of HCC differs among Couinaud’s segments, with segment 8 being the most common location and segment 1 being the least common. The segmental distribution of tumour location was similar to the normal liver volume distribution, supporting a possible correlation between HCC location and the volume of hepatic segments and/or the volumetric distribution of the portal blood flow.