Influence of prophylactic probiotics and selective decontamination on bacterial translocation in patients undergoing pancreatic surgery: a randomized controlled trial

Synergistic immunomodulatory effect of synbiotics pre- and postoperative resection of pancreatic ductal adenocarcinoma: a randomized controlled study

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a highly immunosuppressive microenvironment. This single-blind, randomized study aimed to evaluate the synergistic immunomodulatory effects of synbiotics (probiotics and inulin prebiotics), as well as their impact on postoperative complications and outcomes, compared to the use of probiotics alone. Ninety patients diagnosed with PDAC were enrolled and randomly assigned into three groups: the placebo group, the probiotics group (receiving a mixture of ten strains of Lactobacillus, Bifidobacterium, and Streptococcus bacteria at a dose of 25 billion CFUs), and the synbiotics group (the same probiotics along with inulin prebiotics). The interventions were administered for 14 days before the surgery and continued for one month postoperatively. Tumor tissue infiltration of CD8 + T cells and the expression of IFN γ were assessed by immunohistochemistry (IHC). Inflammatory cytokines concentrations, including Il 1 B, IL 6, and IL 10, were evaluated as well by ELISA at various time points pre- and postoperative. Furthermore, patients were followed up after the surgery to assess postoperative short-term outcomes. Our results showed a significant elevation of CD8 + T cell proportion and IFN γ expression in the synbiotics group compared to the probiotics group (p = 0.049, p = 0.013, respectively). Inflammatory cytokines showed a significant gradual decrease in the synbiotics group compared to placebo and probiotics-treated groups (p = 0.000 for both). Administration of synbiotics and probiotics significantly decreased the rate of postoperative complications including anastomotic leakage, diarrhea, and abdominal distension (p = 0.032, p = 0.044, p = 0.042, respectively), with a remarkable reduction in bacteremia in the synbiotics group. These results revealed that this synbiotics formulation potentially enhances the immune response and reduces complications associated with surgery.Clinical trial identification: NCT06199752 (27-12-2023).

The Efficacy of Probiotics, Prebiotics, and Synbiotics in Patients Who Have Undergone Abdominal Operation, in Terms of Bowel Function Post-Operatively: A Network Meta-Analysis

BACKGROUND

Abdominal operations may lead to post-operative bowel dysfunction, while administration of probiotics, prebiotics and synbiotics may limit its manifestation. Τhe study aimed to assess the efficacy of probiotics, prebiotics and synbiotics in patients who undergone abdominal operation, in terms of bowel function post-operatively.

METHODS

PubMed, Scopus, Cochrane Central Register of Controlled Trials (Central), Embase, US Registry of clinical trials, and sources of grey literature were searched. The relative effect sizes were estimated, and we obtained the relative ranking of the interventions using cumulative ranking curves.

RESULTS

In total, 30 studies were included in the analysis. For the outcome of post-operative ileus, probiotics was superior to placebo/no intervention (relative risk, RR: 0.38; 95%CI: 0.14-0.98) with the highest SUCRA (surface under the cumulative ranking) value (92.1%). For time to first flatus, probiotics (MD: -0.47; 95%CI: -0.78 to -0.17) and synbiotics (MD: -0.53; 95%CI: -0.96 to -0.09) were superior to placebo/no intervention. For time to first defecation and for post-operative abdominal distension probiotics were superior to placebo/no intervention. For post-operative hospitalization days, synbiotics were superior to placebo/no intervention (MD: -3.07; 95%CI: -4.80 to -1.34).

CONCLUSIONS

Administration of probiotics in patients who had undergone abdominal surgery reduced the prevalence of post-operative ileus, time to first flatus, time to first defecation, and prevalence of post-operative abdominal distension. Synbiotics reduce time to first flatus and post-operative hospitalization days.

Probiotics or Synbiotics for Preventing Postoperative Infection in Hepatopancreatobiliary Cancer Patients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Postoperative infection of hepatopancreatobiliary cancer (HPBC) is a major cause of morbidity and mortality. Probiotics and synbiotics are potential prevention strategies, but evidence on the efficacy of probiotics or synbiotics in the prevention of postoperative infection for HPBC remains controversial. This study aimed to define the impact of probiotics or synbiotics on the incidence of postoperative infection in HPBC patients.

METHODS

A systematic search of the Cochrane Library, PubMed, Embase, and Web of Science databases was conducted from inception to February 2, 2021 to identify randomized controlled trials (RCTs) evaluating the efficacy of probiotics or synbiotics in HPBC. Data were pooled and expressed as the risk ratio (RR) and mean difference (MD) with 95% confidence intervals.

RESULTS

Eight RCTs involving 445 participants were included. Supplementation with probiotics or synbiotics significantly reduced the incidence of postoperative infection (RR 0.55) in HPBC patients, and both probiotics (RR 0.68) and synbiotics (RR 0.41) were effective in reducing the incidence of postoperative infection. In addition, probiotics or synbiotics can reduce duration of antibiotic use (MD -3.52) and length of hospital stay (MD -4.21).

CONCLUSION

Probiotics or synbiotics are effective strategies for the prevention of postoperative infection in HPBC patients.

Probiotics Evaluation in Oncological Surgery: A Systematic Review of 36 Randomized Controlled Trials Assessing 21 Diverse Formulations

BACKGROUND

Objectives were to evaluate probiotics safety and efficacy in oncological surgery.

METHODS

Systematic review methodology guided by Cochrane, PRISMA, SWiM, and CIOMS. Protocol registered on PROSPERO (CRD42018086168).

RESULTS

36 RCTs (on 3305 participants) and 6 nonrandomized/observational studies were included, mainly on digestive system cancers. There was evidence of a beneficial effect on preventing infections, with 70% of RCTs' (21/30) direction of effect favoring probiotics. However, five RCTs (17%) favored controls for infections, including one trial with RR 1.57 (95% CI: 0.79, 3.12). One RCT that changed (balanced) its antibiotics protocol after enrolling some participants had mortality risk RR 3.55 (95% CI: 0.77, 16.47; 7/64 vs. 2/65 deaths). The RCT identified with the most promising results overall administered an oral formulation of Lactobacillus acidophilus LA-5 + Lactobacillus plantarum + Bifidobacterium lactis BB-12 + Saccharomyces boulardii. Methodological quality appraisals revealed an overall substantial risk-of-bias, with only five RCTs judged as low risk-of-bias.

CONCLUSIONS

This large evidence synthesis found encouraging results from most formulations, though this was contrasted by potential harms from a few others, thus validating the literature that "probiotics" are not homogeneous microorganisms. Given microbiome developments and infections morbidity, further high-quality research is warranted using those promising probiotics identified herein.

Bacterial translocation in patients undergoing major gastrointestinal surgery and its role in postoperative sepsis

Bacteria of the human intestinal microflora have a dual role. They promote digestion and are part of a defense mechanism against pathogens. These bacteria could become potential pathogens under certain circumstances. The term “bacterial translocation” describes the passage of bacteria of the gastrointestinal tract through the intestinal mucosa barrier to mesenteric lymph nodes and other organs. In some cases, the passage of bacteria and endotoxins could result in blood stream infections and in multiple organ failure. Open elective abdominal surgery more frequently results in malfunction of the intestinal barrier and subsequent bacterial translocation and blood stream infections than laparoscopic surgery. Postoperative sepsis is a common finding in patients who have undergone non-elective abdominal surgeries, including trauma patients treated with laparotomy. Postoperative sepsis is an emerging issue, as it changes the treatment plan in surgical patients and prolongs hospital stay. The association between bacterial translocation and postoperative sepsis could provide novel treatment options.

Effects of Perioperative Probiotics and Synbiotics on Pancreaticoduodenectomy Patients: A Meta-Analysis of Randomized Controlled Trials

Post-pancreaticoduodenectomy infections cause mortality, morbidity, and prolonged antibiotic use. Probiotics or synbiotics may be advantageous for preventing postoperative infections, but their benefits on pancreaticoduodenectomy outcomes are controversial. This study evaluated the efficacy of probiotics and synbiotics in pancreaticoduodenectomy. The Embase, Web of Science, PubMed, and Cochrane Library databases were comprehensively searched for randomized controlled trials (RCTs) that evaluated the effects of probiotics or synbiotics on pancreaticoduodenectomy as of April 16, 2021. Outcomes included perioperative mortality, postoperative infectious complications, delayed gastric emptying, hospital stay length, and antibiotic-use duration. The results were reported as mean differences (MDs) and relative risks (RRs) with 95% confidence intervals (CI). Six RCTs involving 294 subjects were included. Probiotic or synbiotic supplementation did not reduce the perioperative mortality (RR, 0.34; 95% CI, 0.11, 1.03), but reduced the incidences of postoperative infection (RR, 0.49; 95% CI, 0.34, 0.70) and delayed gastric emptying (RR, 0.27; 95% CI, 0.09, 0.76) and also reduced the hospital stay length (MD, -7.87; 95% CI, -13.74, -1.99) and antibiotic-use duration (MD, -6.75; 95% CI, -9.58, -3.92) as compared to the controls. Probiotics or synbiotics can prevent infections, reduce delayed gastric emptying, and shorten the hospital stay and antibiotic-use durations in patients undergoing pancreaticoduodenectomy. These findings are clinically important for promoting recovery from pancreaticoduodenectomy, reducing the incidences of antibiotic resistance and iatrogenic infections, and reducing the medical burden.

The Roles of Lactobacillus Acidophilus and Pectin in Preventing Postoperative Sepsis and Intestinal Adaptation in a Rat Model of Short Bowel Syndrome

One of the primary causes of morbidity and mortality in those with short bowel syndrome (SBS) is sepsis, caused by bacterial translocation (BT). Since synbiotics can cease gut-related bacterial overgrowth, they may serve as a supportive dietary supplement-based strategy after gastrointestinal surgery. This study was conducted to determine the effects of Lactobacillus acidophilus and pectin on BT and gut adaptation after extensive small bowel resection in the rat. Forty rats were distributed in four groups. Group A suffered laparotomy, group B suffered gut transection and reanastomosis, SBS rats (group C) suffered 75% small gut resection, and finally, Group D suffered gut resection and treated with a synbiotic cocktail from day 7 before the surgery to day 14 after it. Intestinal structural changes and BT to mesenteric lymph nodes, liver, portal blood, and peripheral blood were detected on day 15 post-surgery. Treatment with a synbiotic cocktail led to a considerable reduction in bacterial translocation to liver and portal vein (degree II) compared with SBS untreated rats. Also, synbiotic administration significantly increased jejunum and ileum villus height and crypt depth, ileum villus width, and percentage of goblet cells in jejunum and ileum compared with SBS rats. In the rat model of short bowel syndrome, L. acidophilus, and pectin, as a potential synbiotic compound, could decrease the BT from the gut and improve the bowel adaptation.

Perioperative Probiotics or Synbiotics in Adults Undergoing Elective Abdominal Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To define the impact of perioperative treatment with probiotics or synbiotics on postoperative outcome in patients undergoing abdominal surgery.

BACKGROUND

Postoperative surgical infection accounts for a third of all cases of sepsis, and is a leading cause of morbidity and mortality. Probiotics, prebiotics, and synbiotics (preparations that combine probiotics and prebiotics) are nutritional adjuncts that are emerging as novel therapeutic modalities for preventing surgical infections. However, current evidence on their effects is conflicting.

METHODS

A comprehensive search of the PubMed, Embase, and WHO Global Index Medicus electronic databases was performed to identify randomized controlled trials evaluating probiotics or synbiotics in adult patients undergoing elective colorectal, upper gastrointestinal, transplant, or hepatopancreaticobiliary surgery. Bibliographies of studies were also searched. The primary outcome measure was incidence of postoperative infectious complications. Secondary outcomes included incidence of noninfectious complications, mortality, length of hospital stay, and any treatment-related adverse events. Quantitative pooling of the data was undertaken using a random effects model.

RESULTS

A total of 34 randomized controlled trials reporting on 2723 participants were included. In the intervention arm, 1354 patients received prebiotic or symbiotic preparations, whereas 1369 patients in the control arm received placebo or standard care. Perioperative administration of either probiotics or synbiotics significantly reduced the risk of infectious complications following abdominal surgery [relative risk (RR) 0.56; 95% confidence interval (CI) 0.46-0.69; P < 0.00001, n = 2723, I = 42%]. Synbiotics showed greater effect on postoperative infections compared with probiotics alone (synbiotics RR: 0.46; 95% CI: 0.33-0.66; P < 0.0001, n = 1399, I = 53% probiotics RR: 0.65; 95% CI: 0.53-0.80; P < 0.0001, n = 1324, I = 18%). Synbiotics but not probiotics also led to a reduction in total length of stay (synbiotics weighted mean difference: -3.89; 95% CI: -6.60 to -1.18 days; P = 0.005, n = 535, I = 91% probiotics RR: -0.65; 95% CI: -2.03-0.72; P = 0.35, n = 294, I = 65%). There were no significant differences in mortality (RR: 0.98; 95% CI: 0.54-1.80; P = 0.96, n = 1729, I = 0%) or noninfectious complications between the intervention and control groups. The preparations were well tolerated with no significant adverse events reported.

CONCLUSIONS

Probiotics and synbiotics are safe and effective nutritional adjuncts in reducing postoperative infective complications in elective abdominal surgery. The treatment effects are greatest with synbiotics.

A Systematic Review, Meta-Analysis, and Meta-Regression Evaluating the Efficacy and Mechanisms of Action of Probiotics and Synbiotics in the Prevention of Surgical Site Infections and Surgery-Related Complications

Intestinal microbiota play an important role in the pathogenesis of surgical site infections (SSIs) and other surgery-related complications (SRCs). Probiotics and synbiotics were found to lower the risk of surgical infections and other surgery-related adverse events. We systematically reviewed the approach based on the administration of probiotics and synbiotics to diminish SSIs/SRCs rates in patients undergoing various surgical treatments and to determine the mechanisms responsible for their effectiveness. A systematic literature search in PubMed/MEDLINE/Cochrane Central Register of Controlled Trials from the inception of databases to June 2018 for trials in patients undergoing surgery supplemented with pre/pro/synbiotics and randomized to the intervention versus placebo/no treatment and reporting on primarily: (i) putative mechanisms of probiotic/symbiotic action, and secondarily (ii) SSIs and SRCs outcomes. Random-effect model meta-analysis and meta-regression analysis of outcomes was done. Thirty-five trials comprising 3028 adult patients were included; interventions were probiotics (n = 16) and synbiotics (n = 19 trials). We found that C-reactive protein (CRP) and Interleukin-6 (IL-6) were significantly decreased (SMD: -0.40, 95% CI [-0.79, -0.02], p = 0.041; SMD: -0.41, 95% CI [-0.70, -0.02], p = 0.006, respectively) while concentration of acetic, butyric, and propionic acids were elevated in patients supplemented with probiotics (SMD: 1.78, 95% CI [0.80, 2.76], p = 0.0004; SMD: 0.67, 95% CI [0.37, -0.97], p = 0.00001; SMD: 0.46, 95% CI [0.18, 0.73], p = 0.001, respectively). Meta-analysis confirmed that pro- and synbiotics supplementation was associated with significant reduction in the incidence of SRCs including abdominal distention, diarrhea, pneumonia, sepsis, surgery site infection (including superficial incisional), and urinary tract infection, as well as the duration of antibiotic therapy, duration of postoperative pyrexia, time of fluid introduction, solid diet, and duration of hospital stay (p < 0.05). Probiotics and synbiotics administration counteract SSIs/SRCs via modulating gut-immune response and production of short chain fatty acids.

Pre-surgical Administration of Microbial Cell Preparation in Colorectal Cancer Patients: A Randomized Controlled Trial

INTRODUCTION

Disruption of normal gut function is a common side effect post abdominal surgery. It may result in reduced tolerance to oral nutrition and progress to postoperative ileus. Microbial cell preparation is beneficial as a pre-surgical nutritional supplement to aid in bowel recovery and promote the return of normal gut function following abdominal surgery. The aim of this study was to evaluate the efficacy of pre-surgical administration of microbial cell preparation in promoting the return of normal gut function.

METHOD

The study is a randomized, double-blind, placebo-controlled trial. In total, 40 patients were recruited. Patients were randomized to receive either microbial cell preparation (n = 20) or placebo (n = 20) for 7 days prior to elective surgery. The primary end point was the time to return of normal gut function, while the secondary end point was the duration of hospital stay.

RESULTS

The treatment group demonstrated significantly faster return of normal gut function with a median of 108.5 h (80-250 h) which was 48 h earlier than the placebo group at a median of 156.5 h (94-220 h), p = 0.022. The duration of hospital stay in the treatment group was also shorter at a median of 6.5 days (4-30 days), in comparison to the placebo group at 13 days (5-25 days), p = 0.012.

CONCLUSION

Pre-surgical administration of microbial cell preparation promotes the return of normal gut function in patients after colorectal cancer surgery, thus associated with faster recovery and shorter duration of hospital stay.

Effect of Perioperative Probiotics and Synbiotics on Postoperative Infections After Gastrointestinal Surgery: A Systematic Review With Meta-Analysis

BACKGROUND

Bacterial infection following gastrointestinal surgery remains a common morbidity. The aim of this study was to estimate the effect of the perioperative use of probiotics and synbiotics on postoperative infections.

MATERIALS AND METHODS

We searched PubMed, Embase, and the Cochrane Library to identify pertinent randomized controlled trials (RCTs). The primary outcome was postoperative infection rate. The secondary outcomes were length of hospital and intensive care unit (ICU) stay, length of antibiotic therapy, and mortality. The pooled outcomes were calculated using random effects models.

RESULTS

Twenty-eight RCTs involving 2511 patients were included in this systematic review. The incidence of infectious complications was lower among patients who received probiotics/synbiotics than among the controls (odds ratio [OR] = 0.35; 95% confidence interval [CI], 0.24-0.50), particularly regarding respiratory (OR = 0.44; 95% CI, 0.28-0.68), urinary tract (OR = 0.30; 95% CI, 0.16-0.55), and wound infections (OR = 0.58; 95% CI, 0.42-0.80). The lengths of hospital stay (mean difference [MD] = -3.20; 95% CI, -4.87 to -1.54) and duration of antibiotic therapy (MD = -3.40; 95% CI, -4.67 to -2.13) were shorter for patients who received probiotics/synbiotics than for controls. There were no significant differences in mortality (OR = 1.19; 95% CI, 0.52-2.74) or length of ICU stay (MD = -0.46; 95% CI, -1.07 to 0.14) between the compared groups.

CONCLUSION

Probiotics and synbiotics may prevent postoperative infections in patients undergoing gastrointestinal surgery. However, the results need to be interpreted with caution due to the risk of bias in the included studies and the potential publication bias.

Probiotics inhibit immune fluctuation in the intestinal mucous layer in rats

PURPOSE

Innate lymphocytes play a key role in maintaining the immune bowel barrier, which provides resistance to infection. However, the effects of probiotics on changes in the function of innate lymphocytes in the postoperative intestine remain known.

METHODS

Ninety-six male SD rats were divided into the blank group and the preoperative Lactobacillus intervention group, and parts of the ileum were sampled on days 0, 3, 5 and 7 after partial small bowel resection. Distal ileum samples were evaluated using immunohistochemistry to detect IL-5, IL-13, IL-17a and IL-22.

RESULTS

(1) There were more immune cells in the experimental group than in the blank group on day. (2) After the first 3 days, the levels of IL-22 and IL-5 (p = 0.024) were higher in the experimental group than in the blank group. From the third to the fifth day, the IL-5 and IL-22 levels were higher and the IL-13 and IL-17A levels were lower in the experimental group than in the blank group. From the fifth to the seventh day, the IL-5 and IL-13 levels were lower and the IL-22 and IL17A levels were higher in the experimental group than in the blank group.

CONCLUSIONS

Probiotics stabilize the fluctuation of the intestinal immune system postoperatively.

Probiotics and synbiotics for the prevention of postoperative infections following abdominal surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative infections, particularly surgical site infections (SSIs), cause significant morbidity and mortality. Probiotics or synbiotics are a potential prevention strategy.

AIM

To evaluate the efficacy of probiotics/synbiotics for reducing postoperative infection risk following abdominal surgery.

METHODS

We searched AMED, Central, CINAHL, Embase, Medline, and grey literature for randomized controlled trials of elective abdominal surgery patients administered probiotics or synbiotics compared to placebo or standard care. Primary outcome was SSIs. Secondary outcomes were adverse events, respiratory tract infections (RTIs), urinary tract infections (UTIs), combined infections, length of hospital stay, and mortality. Using random-effects meta-analyses, we estimated the relative risk (RR) or mean difference (MD) and 95% confidence interval (CI). Tests were performed for heterogeneity, subgroup and sensitivity analyses were conducted, and the overall evidence quality was graded.

FINDINGS

We identified 20 trials (N = 1374 participants) reporting postoperative infections. Probiotics/synbiotics reduced SSIs (RR: 0.63; 95% CI: 0.41-0.98; N = 15 studies), UTIs (RR: 0.29; 95% CI: 0.15-0.57; N = 11), and combined infections (RR: 0.49; 95% CI: 0.35-0.70; N = 18). There was no difference between groups for adverse events (RR: 0.89; 95% CI: 0.61-1.30; N = 6), RTIs (RR: 0.60; 95% CI: 0.36-1.00; N = 14), length of stay (MD: -1.19; 95% CI: -2.94 to 0.56; N = 12), or mortality (RR: 1.20; 95% CI: 0.58-2.48; N = 15).

CONCLUSION

Our review suggests that probiotics/synbiotics reduce SSIs and UTIs from abdominal surgeries compared to placebo or standard of care, without evidence of safety risk. Overall study quality was low, owing mostly to imprecision (few patients and events, or wide CIs); thus larger multi-centered trials are needed to further assess the certainty in this estimate.

The administration of probiotics and synbiotics in immune compromised adults: is it safe?

This study aimed to systematically evaluate safety of probiotics and synbiotics in immune compromised adults (≥18 years). Safety was analysed using the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification, thereby providing an update on previous reports using the most recent available clinical data (2008-2013). Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 57 clinical studies indicates that probiotic and/or synbiotic administration in immune compromised adults is safe with regard to the current evaluated probiotic strains, dosages and duration. Individuals were considered immune compromised if HIV-infected, critically ill, underwent surgery or had an organ- or an autoimmune disease. There were no major safety concerns in the study, as none of the serious adverse events (AE)s were related, or suspected to be related, to the probiotic or synbiotic product and the study products were well tolerated. Overall, AEs occurred less frequent in immune compromised subjects receiving probiotics and/or synbiotics compared to the control group. In addition, the results demonstrated a flaw in precise reporting and classification of AE in most studies. Furthermore, generalisability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes. We argue that standardised reporting on adverse events (CTCAE) in 'food' studies should be obligatory, thereby improving reliability of data and re-enforcing the safety profile of probiotics.

A comparative study of the use of selective digestive decontamination prophylaxis in living-donor liver transplant recipients

INTRODUCTION

Bacterial infections are major causes of early morbidity and mortality after liver transplantation. Selective digestive decontamination (SDD) can be used pre-operatively for living-donor liver transplant (LD-LT), but its role in this setting remains controversial.

METHODS

To evaluate this strategy, we retrospectively analyzed a cohort of consecutive LD-LTs performed in our center from March 2007 to February 2011 and compared the incidence and nature of early infectious complications, length of intensive care unit stay and hospitalization, antibiotic use, and emergence of resistant bacteria in patients with or without SDD prophylaxis.

RESULTS

Of 148 LD-LTs in the study period, 111 received SDD prophylaxis while 37 did not. In a multivariate model, the independent factors associated with an increased risk of early post-transplant infections were length of postoperative mechanical ventilation (for every additional day odds ratio [OR] = 2.37, 95% confidence interval [CI] 1.4-4.0; P = 0.002), and choledochojejunostomy (OR = 4.5, 95% CI 1.95-10.5; P < 0.001). Use of SDD did not affect the rate or distribution of infectious complications, duration of hospitalization, antibiotic use, or acquisition of resistant bacteria (OR = 3.52, 95% CI 0.43-15.17; P = 0.376).

CONCLUSION

In conclusion, the use of SDD prophylaxis in LD-LT was not beneficial and should be avoided, as it offers no advantage and could potentiate the emergence of multidrug-resistant organisms.

Selective decontamination of the digestive tract: the mechanism of action is control of gut overgrowth

PURPOSE

Gut overgrowth is the pathophysiological event in the critically ill requiring intensive care. In relation to the risk of developing a clinically important outcome, gut overgrowth is defined as ≥10(5) potential pathogens including 'abnormal' aerobic Gram-negative bacilli (AGNB), 'normal' bacteria and yeasts, per mL of digestive tract secretion. Surveillance samples of throat and gut are the only samples to detect overgrowth. Gut overgrowth is the crucial event which precedes both primary and secondary endogenous infection, and a risk factor for the development of de novo resistance. Selective decontamination of the digestive tract (SDD) is an antimicrobial prophylaxis designed to control overgrowth.

METHODS

There have been 65 randomised controlled trials of SDD in 15,000 patients over 25 years and 11 meta-analyses, which are reviewed.

RESULTS AND CONCLUSIONS

These trials demonstrate that the full SDD regimen using parenteral and enteral antimicrobials reduces lower airway infection by 72 %, blood stream infection by 37 %, and mortality by 29 %. Resistance is also controlled. Parenteral cefotaxime which reaches high salivary and biliary concentrations eradicates overgrowth of 'normal' bacteria such as Staphylococcus aureus in the throat. Enteral polyenes control 'normal' Candida species. Enteral polymyxin and tobramycin, eradicate, or prevent gut overgrowth of 'abnormal' AGNB. Enteral vancomycin controls overgrowth of 'abnormal' methicillin-resistant S. aureus. SDD controls overgrowth by achieving high antimicrobial concentrations effective against 'normal' and 'abnormal' potential pathogens rather than by selectivity.

Selective digestive tract decontamination in critically ill patients

INTRODUCTION

Selective decontamination of the digestive tract (SDD) has been proposed to prevent endogenous and exogenous infections and to reduce mortality in critically ill patients. Although the efficacy of SDD has been confirmed by randomized controlled trials (RCTs) and systematic reviews, SDD has been the subject of intense controversy, based mainly on an insufficient evidence of efficacy and on concerns about resistance.

AREAS COVERED

This article reviews the philosophy, the current evidence on the efficacy of SDD and the issue of emergence of resistance. All SDD RCTs were searched using Embase and Medline, with no restriction of language, gender or age. Personal archives were also explored, including abstracts from major scientific meetings; references in papers and published meta-analyses on SDD were crosschecked. Up-to-date evidence of the impact of SDD on carriage, infections and mortality is presented, and the efficacy of SDD in selected patient groups was investigated, along with the problem of the emergence of resistance.

EXPERT OPINION

SDD significantly reduces the number of infections of the lower respiratory tract and bloodstream, multiple organ failure and mortality. It also controls resistance, particularly when the full protocol of parenteral and enteral antimicrobials is used.

Potential risk factors for nonalcoholic steatohepatitis related to pancreatic secretions following pancreaticoduodenectomy

AIM: To identify risk factors for nonalcoholic steatohepatitis following pancreaticoduodenectomy, with a focus on factors related to pancreatic secretions.

METHODS: The medical records of 228 patients who had a pancreaticoduodenectomy over a 16-mo period were reviewed retrospectively. The 193 patients who did not have fatty liver disease preoperatively were included in the final analysis. Hepatic steatosis was diagnosed using the differences between splenic and hepatic attenuation and liver-to-spleen attenuation as measured by non-enhanced computed tomography.

RESULTS: Fifteen patients (7.8%) who showed postoperative hepatic fatty changes were assigned to Group A, and the remaining patients were assigned to Group B. Patient demographics, preoperative laboratory findings (including levels of C-peptide, glucagon, insulin and glucose tolerance test results), operation types, and final pathological findings did not differ significantly between the two groups; however, the frequency of pancreatic fistula (P = 0.020) and the method of pancreatic duct stenting (P = 0.005) showed significant differences between the groups. A multivariate analysis identified pancreatic fistula (HR = 3.332, P = 0.037) and external pancreatic duct stenting (HR = 4.530, P = 0.017) as independent risk factors for the development of postoperative steatohepatitis.

CONCLUSION: Pancreatic fistula and external pancreatic duct stenting were identified as independent risk factors for the development of steatohepatitis following pancreaticoduodenectomy.