Please cite this article in press as: Giorgio V, et al. Intestinal permeability is increased in children with non-alcoholic fatty liver disease, and correlates with liver disease severity. Dig Liver Dis (2014), http://dx.doi.org/10.1016/j.dld.2014.02.010 ARTICLE IN PRESS G Model YDLD-2587; No. of Pages 5 Digestive and Liver Disease xxx (2014) xxx–xxx Contents lists available at ScienceDirect Digestive and Liver Disease jou rnal h om epage: www.elsevier.com/locate/dld Liver, Pancreas and Biliary Tract Intestinal permeability is increased in children with non-alcoholic fatty liver disease, and correlates with liver disease severity Valentina Giorgio a,1 , Luca Miele b,c,1 , Luigi Principessa d , Francesca Ferretti a , Maria Pia Villa d , Valentina Negro d , Antonio Grieco b , Anna Alisi a , Valerio Nobili a,∗ a Hepato-metabolic Disease Unit, Bambino Gesù Children Hospital, Rome, Italy b Clinical Division of Internal Medicine, Gastroenterology and Liver Unit, Complesso Integrato Columbus Hospital, Catholic University of Rome, Italy c Institute of Internal Medicine, Catholic University of Rome, Italy d Pediatric Unit, Sant’Andrea University Hospital, Rome, Italy a r t i c l e i n f o Article history: Received 8 December 2013 Accepted 12 February 2014 Available online xxx Keywords: Intestinal permeability Lactulose/mannitol ratio Lipopolysaccharides Non-alcoholic fatty liver disease Non-alcoholic steatohepatitis a b s t r a c t Background: Increased intestinal permeability seems to play a major role in non-alcoholic liver disease development and progression. Aim: To investigate the prevalence of altered intestinal permeability in children with non-alcoholic fatty liver disease, and to study its potential association with the stage of liver disease. Methods: We performed a case–control study examining intestinal permeability in children using the lactulose–mannitol bowel permeability test. Results: Overall, 39 consecutive patients (30 males, median age 12 years) and 21 controls (14 males, median age 11.8 years) were included. The lactulose/mannitol ratio resulted impaired in 12/39 patients (31%) and none of the controls. Intestinal permeability was higher in children with non-alcoholic fatty liver disease (lactulose/mannitol ratios: 0.038 ± 0.037 vs. 0.008 ± 0.007, p < 0.05). Within the non- alcoholic fatty liver disease group, intestinal permeability was increased in children with steatohepatitis compared to those with steatosis only (0.05 ± 0.04 vs. 0.03 vs. 0.03, p < 0.05). Pathological lactu- lose/mannitol ratio correlated with portal inflammation (p = 0.02), fibrosis (p = 0.0002), and ballooning of hepatocytes (p = 0.003). Blood lipopolysaccharides levels were higher in children with steatohepatitis (2.27 ± 0.68 vs. 2.80 ± 0.35, p < 0.05). Conclusions: Intestinal permeability is increased in children with non-alcoholic fatty liver disease, and correlates with the severity of the disease. © 2014 Published by Elsevier Ltd on behalf of Editrice Gastroenterologica Italiana S.r.l. 1. Introduction Non-alcoholic fatty liver disease (NAFLD) is nowadays one of the most common chronic liver diseases, both in adults and chil- dren. The disease ranges from simple fat accumulation in the liver (steatosis) to inflammation and fibrosis, i.e. non-alcoholic steato- hepatitis (NASH). The progression of NAFLD to the more severe form, NASH, is linked to both genetic and environmental fac- tors [1]. Plenty of research focused on the interaction between the liver and the gut, since the so-called gut-liver axis appears ∗ Corresponding author at: Hepatometabolic Unit, Bambino Gesù Children Hos- pital, Piazza Sant’Onofrio 4, 00165 Rome, Italy. Tel.: +39 06 68592243; fax: +39 06 68593889. E-mail address: nobili66@yahoo.it (V. Nobili). 1 These two authors equally contributed to this manuscript. to play a major role among the factors leading to disease pro- gression [2,3]. In vitro and animal models of NAFLD showed that alteration of gut microbiota and increased intestinal permeability augment the exposure of the liver to gut-derived bacterial prod- ucts, such as lipopolysaccharides (LPS). Increased serum levels of LPS and other intestinal bacterial products determine endotoxemia, especially in the portal system and the liver. Endotoxemia stimu- lates innate immune receptors, namely Toll-like receptors (TLR), which activate signalling pathways involved in liver inflamma- tion and fibrogenesis [4]. Miele et al. [5] demonstrated that also in humans NAFLD is associated with increased intestinal perme- ability and small intestinal bacterial overgrowth (SIBO), and that these intestinal factors are associated with the severity of hepatic steatosis. Specifically, a progressive disruption of the tight junc- tions (TJ) was demonstrated in NAFLD patients, a process that might explain the contribution of intestinal products to liver disease progression. http://dx.doi.org/10.1016/j.dld.2014.02.010 1590-8658/© 2014 Published by Elsevier Ltd on behalf of Editrice Gastroenterologica Italiana S.r.l.