Critical evaluation of diagnosing bacterial overgrowth in the proximal small intestine.

BACKGROUND: Clinical small bowel bacterial overgrowth (SBBO) syndrome can be objectified by bacterial overgrowth tests. As direct culture of jejunal aspirates has disadvantages, noninvasive tests such as breath tests (BTs) are used. Major drawback of lactulose BT might be rapid lactulose transit to the colon. We evaluated diagnosing bacterial overgrowth using experimental and standard BT, and culture and molecular-based methods. STUDY: Bacterial overgrowth was analyzed in 11 controls and 15 SBBO predisposed subjects. During experimental breath testing, an occlusive balloon limited lactulose to the small intestine. Jejunal fluid was analyzed using culture and molecular-based methods. Bacterial overgrowth was diagnosed on the basis of 20 ppm hydrogen or methane increase above baseline within 90 minutes or more than 10 CFU/mL excluding lactobacilli and streptococci and furthermore using all published definitions. RESULTS: Experimental and standard BT showed no changes in timing of hydrogen excretion between controls and SBBO subjects. Using standard BT, 3/11 controls and 8/15 SBBO subjects were bacterial overgrowth positive. Total counts showed no significant differences between controls and SBBO subjects using culture and molecular-based methods. Bacterial overgrowth was diagnosed in 0/9 controls and 4/12 SBBO subjects using culture-based methods. Other definitions used in literature revealed no significant differences between controls and SBBO subjects. CONCLUSIONS: In a small group of subjects, the experimental BT did not improve the ability of lactulose BT to diagnose bacterial overgrowth. Culturing showed less bacterial overgrowth in controls compared with BT. Remarkably, current diagnostic criteria do not seem to be accurate in discriminating between SBBO subjects and controls.

Timing of surgical intervention in necrotizing pancreatitis.

OBJECTIVE: To determine the effect of timing of surgical intervention for necrotizing pancreatitis. DESIGN: Retrospective study of 53 patients and a systematic review. SETTING: A tertiary referral center. Main Outcome Measure Mortality. RESULTS: Median timing of the intervention was 28 days. Eighty-three percent of patients had infected necrosis and 55% had preoperative organ failure. The mortality rate was 36%. Sixteen patients were operated on within 14 days of initial admission, 11 patients from day 15 to 29, and 26 patients on day 30 or later. This latter group received preoperative antibiotics for a longer period (P < .001), and Candida species and antibiotic-resistant organisms were more often cultured from the pancreatic or peripancreatic necrosis in these patients (P = .02). The 30-day group also had the lowest mortality (8% vs 75% in the 1 to 14-days group and 45% in the 15 to 29-days group, P < .001); this difference persisted when outcome was stratified for preoperative organ failure. During the second half of the study, necrosectomy was further postponed (43 vs 20 days, P = .06) and mortality decreased (22% vs 47%, P = .09). We also reviewed 11 studies with a total of 1136 patients. Median surgical patient volume was 8.3 patients per year (range, 5.3-15.6), median timing of surgical intervention was 26 days (range, 3-31), and median mortality was 25% (range, 6%-56%). We observed a significant correlation between timing of intervention and mortality (R = - 0.603; 95% confidence interval, - 2.10 to - 0.02; P = .05). CONCLUSION: Postponing necrosectomy until 30 days after initial hospital admission is associated with decreased mortality, prolonged use of antibiotics, and increased incidence of Candida species and antibiotic-resistant organisms.

Modification of intestinal flora with multispecies probiotics reduces bacterial translocation and improves clinical course in a rat model of acute pancreatitis.

BACKGROUND: Infection of pancreatic necrosis by gut bacteria is a major cause of morbidity and mortality in patients with severe acute pancreatitis. Use of prophylactic antibiotics remains controversial. The aim of this experiment was assess if modification of intestinal flora with specifically designed multispecies probiotics reduces bacterial translocation or improves outcome in a rat model of acute pancreatitis. METHODS: Male Sprague-Dawley rats were allocated into 3 groups: (1) controls (sham-operated, no treatment), (2) pancreatitis and placebo, and (3) pancreatitis and probiotics. Acute pancreatitis was induced by intraductal glycodeoxycholate and intravenous cerulein infusion. Daily probiotics or placebo was administered intragastrically from 5 days prior until 7 days after induction of pancreatitis. Tissue and fluid samples were collected for microbiologic and quantitative real-time PCR analysis of bacterial translocation. RESULTS: Probiotics reduced duodenal bacterial overgrowth of potential pathogens (Log(10) colony-forming units [CFU]/g 5.0 +/- 0.7 [placebo] vs 3.5 +/- 0.3 CFU/g [probiotics], P < .05), resulting in reduced bacterial translocation to extraintestinal sites, including the pancreas (5.38 +/- 1.0 CFU/g [placebo] vs 3.1 +/- 0.5 CFU/g [probiotics], P < .05). Accordingly, health scores were better and late phase mortality was reduced: 27% (4/15, placebo) versus 0% (0/13, probiotics), respectively, P < .05. CONCLUSIONS: This experiment supports the hypothesis that modification of intestinal flora with multispecies probiotics results in reduced bacterial translocation, morbidity, and mortality in the course of experimental acute pancreatitis.

Effects of subtotal colectomy on bacterial translocation during experimental acute pancreatitis.

OBJECTIVES: The colon is considered a major source of bacteria causing infection of pancreatic necrosis in acute pancreatitis (AP). Subtotal colectomy before AP in rats reduces mortality, but its role in affecting small bowel flora, bacterial translocation, and infection of pancreatic necrosis is unknown. Our aim was to study these phenomena in rats with AP. METHODS: Fifty rats, allocated in 4 groups, underwent 2 laparotomies: group 1, sham laparotomy and saline biliopancreatic duct infusion; group 2, subtotal colectomy and saline infusion; group 3, sham laparotomy and AP (ductal infusion of glycodeoxycholic acid and intravenous cerulein); group 4, subtotal colectomy and AP. Seventy-two hours later, samples were collected for microbiological analysis. RESULTS: Subtotal colectomy caused small bowel bacterial overgrowth with gram-positive cocci (group 1 versus group 2, duodenum: P = 0.030, ileum: P = 0.029). Bacterial counts of gram-negative rods/anaerobes in the duodenum and ileum and pancreatic bacterial counts of rats with colectomy and AP were significantly higher than in rats with AP only (group 3 versus group 4, duodenum: P = 0.040, ileum: P = 0.029, pancreas: P = 0.017). Duodenal bacterial overgrowth and pancreatic infection correlate significantly (r = 0.45, P = 0.004). CONCLUSIONS: Subtotal colectomy induces small bowel bacterial overgrowth, which is associated with increased bacterial translocation to the pancreas.