title: The effect of synbiotics on acute radiation-induced diarrhea and its association with mucosal inflammatory and adaptive responses in rats.
abstract: BACKGROUND
  Previous clinical studies advocated that probiotics beneficially affect acute radiation-induced diarrhea. These encouraging results were attributed to the restoration of the intestinal flora; however, there is lack of evidence if and how probiotics influence the underlying pathophysiological mechanisms.
  
  
  OBJECTIVE
  The present study was conducted to investigate the potential supporting role of a synbiotic preparation (combination of pro- and pre-biotics) on experimentally-induced acute radiation diarrhea from the perspective of mucosal inflammation and histological injury.
  
  
  METHODS
  Ninety adult Wistar rats were randomly assigned into six groups. Group A (non-irradiated), group B (non-irradiated/synbiotic supplemented), group C (irradiated), and group D (irradiated/synbiotic supplemented) were followed up to a week after the beginning of the experiment. Group E (irradiated) and group F (irradiated/synbiotic supplemented) were followed up for four days. On the last day of the experiments tissues were harvested for structural and molecular assessments.
  
  
  RESULTS
  Synbiotic administration could not avert the occurrence of diarrhea, but significantly attenuated its severity. This effect was associated with the significant downregulation of neutrophil accumulation and lipid peroxidation during the acute phase. During the subacute phase, synbiotic treatment significantly improved both the histological profile and radiation mucositis. These mechanisms significantly contributed to the rehabilitation of the intestinal absorptive function as further indicated from the significantly reduced weight loss.
  
  
  CONCLUSIONS
  Given the optimization of the intestinal flora exerted by synbiotics, the resolution of diarrhea relies on the suppression of the "reactive" and the augmentation of "regenerative" components of acute radiation-induced intestinal response.
authors.affiliation: 1st Department of Propaedeutic Surgery, Hippokration Hospital, University of Athens School of Medicine, 114 Vasilissis Sofias Avenue, 11527, Athens, Greece. bill.spiropoulos@hotmail.com
authors.forename: Basileios G
authors.initials: BG
authors.lastname: Spyropoulos
authors.forename: George
authors.initials: G
authors.lastname: Theodoropoulos
authors.forename: Evangelos P
authors.initials: EP
authors.lastname: Misiakos
authors.forename: Christos N
authors.initials: CN
authors.lastname: Stoidis
authors.forename: Haralambos
authors.initials: H
authors.lastname: Zapatis
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Diamantopoulou
authors.forename: Chrisostomi
authors.initials: C
authors.lastname: Gialeli
authors.forename: Nikos K
authors.initials: NK
authors.lastname: Karamanos
authors.forename: Gabriel
authors.initials: G
authors.lastname: Karatzas
authors.forename: Anastasios
authors.initials: A
authors.lastname: Machairas
authors.forename: Constantinos
authors.initials: C
authors.lastname: Fotiadis
authors.forename: George C
authors.initials: GC
authors.lastname: Zografos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kelekis
authors.forename: Vasileios
authors.initials: V
authors.lastname: Kouloulias
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003967:Diarrhea / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D016002:Discriminant Analysis; D007413:Intestinal Mucosa / Q000473:pathology / Q000502:physiology; D008297:Male; D020556:Neutrophil Infiltration; D011833:Radiation Injuries, Experimental / Q000150:complications* / Q000276:immunology / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D058616:Synbiotics