Human Microbiota and Liver Transplant
Condition: Intestinal Microbiota; Complication of Transplanted Liver; Acute Rejection of Liver Transplant; Infection
MeSH terms: Infections
Study type: Observational

Summary: 
      The microbiota represents the collections of microbial communities that colonize a host. In
      health, the microbiota protects against pathogens and maturation of the immune system. In
      return, the immune system determines the composition of the microbiota. Altered microbial
      composition (dysbiosis) has been correlated with a number of diseases in humans. The real
      role of the microbiota in transplant recipients is still unknown even though we suspect that
      it may be affected directly or indirectly by immunosuppressive drugs and antimicrobial
      prophylaxis taken by transplant patients, as well as by inflammatory process secondary to
      ischemia/reperfusion injury.

      A number of studies have investigated the impact of liver transplantation on the intestinal
      microbiota. In a recent analysis of stool flora (Microb Ecol 2013; 65: 781-791) in 12 liver
      transplant recipients, changes in the microbiota were correlated to post-transplant
      infections. The authors suggested that the shift to pathogenic strains of bacteria due to the
      use of prophylactic antibiotics may be contributing to post-transplant complications. In a
      larger study, Wu et al (Hepatobiliary Pancreat Dis Int 2012; 11: 40-50) demonstrated marked
      changes in the gut microbiota post-transplantation with an increase in Enterobacteriaceae and
      Enterococcus, and reduction in Eubacteria, Bifidobacterium and Lactobacillus species. These
      changes, however, resolved over time such that by 6 months, at times when bacterial
      prophylaxis ends and immunosuppression is reduced.

      A better characterization of the impact of post-transplant therapy on the human microbiota
      has the potential to improve our understanding of the infection process and translate into
      development of new therapeutic strategies.

      The main goal of this study is to characterize intestinal microbiota and confirm the same
      bacterial DNA in peripheral blood and portal lymph nodes in patients affected with end-stage
      chronic liver disease, and to analyze its evolution from the moment of inclusion in waiting
      list throughout the first year after liver transplantation. For each patient, a healthy
      CONTROL with a similar age (± 10 years) will be selected from the same family setting, in
      whom just one sample will be obtained during the enrollment phase.

      The second goal is to analyze the potential associations between microbiota flora and
      transplant outcomes during the same period.
    


Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adult liver transplant patients in Hospital Vall d´Hebron (Barcelona, Spain)
      
Biospecimen description: 
      Stool samples Portal nodes Periphereal blood
    
Keywords: Intestinal Microbiota; Liver Transplant; Acute Rejection; Infection