Five Days Periodic Fasting Elevates Levels of Longevity Related Christensenella and Sirtuin Expression in Humans.

Periodic fasting (PF) is an increasingly popular approach that assists in the management of metabolic and inflammatory diseases as well as in preventing mechanisms involved in aging. However, little is known about the effects of fasting on gut microbiota and its impact on the epigenetic regulation of metabolically relevant enzymes, especially sirtuins (SIRTs). We analyzed the effect of periodic fasting on the human gut microbiota, SIRTs expression, and mitochondrial content in 51 males and females. The participants fasted under supervision for five consecutive days following the Buchinger fasting guidelines. Ketogenesis, selected mRNAs, miRNAs, mitochondrial (mt) DNA, and gut composition were analyzed before and after PF. PF triggered a significant switch in metabolism, as indicated by the increase in ß-hydroxybutyrate (BHB) and pyruvate dehydrogenase kinase isoform 4 (PDK4) expression in the capillary blood. MtDNA, SIRT1, SIRT3, and miRlet7b-5p expression in blood cells were elevated, whereas SIRT6 and miR125b-5p were not affected. Following fasting, gut microbiota diversity increased, and a statistically significant correlation between SIRT1 gene expression and the abundance of Prevotella and Lactobacillus was detected. The abundance of longevity related Christensenella species increased after fasting and inversely correlated with age as well as body mass index (BMI). Thus, this represents the first study that showing that fasting not only changes the composition of the gut microbiota, making it more diverse, but also affects SIRT expression in humans.

[Peritoneal dialysis in patients with polycystic kidney disease]. / Peritonealdialyse bei Patienten mit Polyzystischer Nierendegeneration.

In Austria, patients with end-stage renal disease caused by polycystic kidney disease are less frequently treated with peritoneal dialysis (PD) than patients with noncystic renal diseases (6% versus 8%). In contrast, the United States renal data system reports that more than one fifth of patients with polycystic kidney disease choose PD as their initial form of renal replacement therapy. The reasons for this difference are unknown. Extrarenal manifestations of the disease, such as diverticulosis, development of hernias or vascular aneurysms, may theoretically promote the occurrence of complications typically related to PD. However, studies undertaken to clarify these questions did not find any difference in the rates of peritonitis caused by diverticulosis or Gram-negative bacteria, and no differences were seen with respect to vascular complications. Nevertheless, in comparison with the general population, patients with polycystic kidney disease are more likely to develop hernias, and the incidence of herniation may be further increased by PD. In conclusion, patients with polycystic kidney disease who also have abdominal complaints such as meteorism and discomfort, or lumbago resulting from the markedly enlarged kidneys, should not be actively advised to have PD treatment. The same is true for patients with recurrent hernias. However, the technical survival, quality of dialysis, duration of therapy and rates of complications in PD are comparable in patients with cystic or noncystic kidney disease, and therefore all patients with polycystic kidney disease who do not have abdominal complaints or history of recurrent hernias should be informed that PD is an adequate form of renal replacement therapy, equally effective as hemodialysis.