 In end-stage renal disease ESRD cardiovascular and infectious complications are common. The gut microbiome might play an important pathophysiological role. ESRD is hypothesized to be associated with profound alterations of gut microbiome and gut permeability. The investigators aim to test whether a multispecies probiotic mixture is able to revert the microbiome changes and decrease gut permeability. Furthermore the investigators aim to test whether this improvement in microbiome composition and gut permeability is also associated with improvements in endotoxemia, uremia and cardiovascular risk factors. 