Effects of melatonin on bacterial translocation in an experimental short bowel syndrome

Abstract

The most important reasons for morbidity and mortality in short bowel syndrome (SBS) are septic complications. There is no specific treatment to prevent bacterial translocation (BT) which causes these complications. Melatonin is proven to have positive effects on the gastrointestinal system. The aim of this study was to evaluate the effects of exogenously administered melatonin on BT in SBS. Fifty Sprague-Dawley rats were divided into six groups. In control groups, the rats underwent laparotomy (Group I, Control + saline, n = 5), (Group II, Control + Melatonin, n = 5, 20 mg/kg, IM). In Sham groups, the rats underwent ileal transection (Group III, Sham + Saline, n = 8), (Group IV, Sham + Melatonin, n = 8). In SBS groups, the rats underwent 75% small bowel resection (Group V, SBS + Saline, n = 12), (Group VI, SBS + Melatonin, n = 12). Histopathological and microbiological studies were performed at the 3rd postoperative day. No difference was detected in sites of BT and colony numbers between the various groups. BT was more common in SBS groups than sham groups. However, melatonin administered rats were observed to have decreased the BT rates as compared to their control groups. The number of Kupffer cells in the liver decreased in the ongoing surgery groups while melatonin administration, on the other hand, increased Kupffer cells. Sinusoids were observed to expand due to the surgical operation, while melatonin administration increased parenchymal areas in mesenteric lymph nodes (MLN). In SBS + Melatonin group, there were increased villus heights and total mucosal thickness than those of the control and sham groups. This study demonstrated that melatonin can ensure protection against BT in SBS as it contributes to the maintenance of immune defensive mechanisms and increases intestinal adaptive response.