Sequential Changes in the Mesenteric Lymph Node Microbiome and Immune Response during Cirrhosis Induction in Rats

• Published in: mSystems Vol. 4; no. 1
• Main Authors: Santiago, Alba, Sanchez, Elisabet, Clark, Allison, Pozuelo, Marta, Calvo, Miguel, Yañez, Francisca, Sarrabayrouse, Guillaume, Perea, Lidia, Vidal, Silvia, Gallardo, Alberto, Guarner, Carlos, Soriano, German, Manichanh, Chaysavanh
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.01.2019
• Subjects: Animal models; Ascites; Ascitic fluid; Bacteria; Bacterial infections; bacterial translocation; Blood; Candidatus Arthromitus; Carbon tetrachloride; CCL4 protein; Cirrhosis; cirrhosis complication; Cytokines; decompensated cirrhosis; Digestive system; Escherichia; Fecal microflora; Feces; Filamentous bacteria; Gastroenterology; Gastrointestinal tract; Host-Microbe Biology; Hypertension; Immune response; Immune system; Inflammation; Intestinal microflora; Intestine; Laboratory animals; Liver; Liver cirrhosis; Lymph nodes; Lymphatic system; Medical prognosis; Microbiomes; Microbiota; Permeability; proinflammatory response; Research Article; Rodents; Tumor necrosis factor-TNF; Variance analysis; Spain; bacterial translocation; cirrhosis complication; proinflammatory response; decompensated cirrhosis
• ISSN: 2379-5077; 2379-5077
• DOI: 10.1128/mSystems.00278-18

Whether the interaction between the gut microbiota and the immune response influences the evolution of cirrhosis is poorly understood. We aimed to investigate modifications of the microbiome and the immune response during the progression of cirrhosis. Rats were treated with carbon tetrachloride (CCl ) to induce cirrhosis. We then assessed microbiome load and composition in stool, ileocecal contents (ICCs), mesenteric lymph nodes (MLNs), blood, and ascitic fluids (AFs) at 6, 8, and 10 weeks or ascites production and measured cytokine production in MLNs and blood. The microbiome of MLN, blood, and AF showed a distinct composition compared to that of stool and ICCs. ( ) were found associated with the appearance of a decompensated state of cirrhosis. Microbial load increased and showed a positive correlation with the relative abundance of pathobionts in the MLN of decompensated rats. Among several genera, and " Arthromitus" positively correlated with elevated levels of systemic proinflammatory cytokines. " Arthromitus," a segmented filamentous bacteria, was detected in ICC, MLN, and AF samples, suggesting a possible translocation from the gut to the AF through the lymphatic system, whereas was detected in ICC, MLN, AF, and blood, suggesting a possible translocation from the gut to the AF through the bloodstream. In the present study, we demonstrate that microbiome changes in distinct intestinal sites are associated with microbial shifts in the MLNs as well as an increase in cytokine production, providing further evidence of the role the gut-liver-immunity axis plays in the progression of cirrhosis. Cirrhosis severity in patients was previously shown to be associated with progressive changes in the fecal microbiome in a longitudinal setting. Recent evidence shows that bacterial translocation from the gut to the extraintestinal sites could play a major role in poor disease outcome and patient survival. However, the underlying mechanisms involving the microbiota in the disease progression are not well understood. Here, using an animal model of cirrhosis in a longitudinal and multibody sites setting, we showed the presence of a distinct composition of the microbiome in mesenteric lymph nodes, blood, and ascitic fluid compared to that in feces and ileocecal content, suggesting compartmentalization of the gut microbiome. We also demonstrate that microbiome changes in intestinal sites are associated with shifts in specific microbial groups in the mesenteric lymph nodes as well as an increase in systemic cytokine production, linking inflammation to decompensated cirrhosis in the gut-liver-immunity axis.