Gut origin of sepsis: a prospective study investigating associations between bacterial translocation, gastric microflora, and septic morbidity

Aims-To investigate the "gut origin of sepsis" hypothesis. Methods-Prospective controlled study of 279 surgical patients in which cult ures of nasogastric aspirates were compared with those obtained from mesent eric lymph nodes taken at laparotomy and the organisms cultured from subseq uent septic complications. Bacterial translocation was confirmed if positiv e cultures were obtained from mesenteric lymph nodes. Postoperative sepsis was defined as any positive culture in the postoperative period. Bacterial species obtained in gastric microflora, mesenteric lymph nodes, and postope rative septic complications were compared. Results-Only 85/279 patients (31%) had a sterile nasogastric aspirate; the most frequently identified organism was Candida spp. (54%) and the most com mon enteric organism cultured was E coli (20%). Multiple organisms were iso lated in 39% and occurred more frequently in patients aged over 70 years, t hose undergoing nonelective surgery and in those requiring proximal gastroi ntestinal surgery. Postoperative sepsis was more common in these patients. Bacterial translocation occurred in 21% and was significantly more frequent in those with multiple organisms in their nasogastric aspirates. E coli wa s the commonest organism isolated from the lymph node specimens (48%) and s eptic foci (53%). Fungal translocation did not occur. An identical genus wa s identified in the nasogastric aspirate and the septic focus in 30% of pat ients, in the nasogastric aspirate and the lymph node in 31%, and in the ly mph node and a postoperative septic focus in 45%. Conclusions-Proximal gut colonisation is associated with both increased bac terial translocation and septic morbidity. The commonality of organisms ide ntified supports the gut origin of sepsis hypothesis.