Detection and identification of bacterial DNA in serum from patients with acute pancreatitis

The role of gut microbiota and bacterial translocation in the pathogenesis and management of type 2 diabetes mellitus: Mechanisms, impacts, and dietary therapeutic strategies

PURPOSE OF REVIEW

The influence of gut microbiota on Type 2 Diabetes Mellitus (T2DM) is an emerging area of research. This review investigates the relationship between gut microbiota dysbiosis, bacterial translocation, and T2DM. It aims to elucidate how microbial imbalances contribute to the progression of T2DM through bacterial translocation and to evaluate dietary and therapeutic strategies to manage these effects.

RECENT FINDINGS

Recent studies highlight that dysbiosis in T2DM patients often leads to increased systemic inflammation, impaired glucose metabolism, and disrupted gut barrier integrity. These disruptions promote elevated levels of harmful bacterial components, such as lipopolysaccharides, in the bloodstream. This, in turn, is linked to worsening insulin resistance and metabolic dysfunction. Advances in molecular methods and biomarkers have provided deeper insights into bacterial translocation and its impact on diabetes. Dietary interventions, including nutraceutical agents, high-fiber and low-glycemic index diets, as well as the use of probiotics and prebiotics, have shown promise in restoring gut health and mitigating bacterial translocation.

CONCLUSION

Maintaining a balanced gut microbiota and intestinal barrier integrity is crucial for managing T2DM. Therapeutic strategies, including dietary modifications and nutraceuticals, have demonstrated potential in reducing bacterial translocation and systemic inflammation. Continued research is needed to refine these approaches and explore novel treatment modalities for improving metabolic health in T2DM patients.

Construction and validation of a rat model of acute necrotizing pancreatitis-associated intestinal injury

Acute pancreatitis (AP) is an acute inflammatory reaction of the pancreatic tissue, which involves auto-digestion, edema, hemorrhage, and necrosis. AP can be categorized into mild, moderately severe, and severe AP, with severe pancreatitis also referred to as acute necrotizing pancreatitis (ANP). ANP is characterized by the accumulation of necrotic material in the peritoneal cavity. This can result in intestinal injury. However, the mechanism of ANP-associated intestinal injury remains unclear. We established an ANP-associated intestinal injury rat model (ANP-IR model) by injecting pancreatitis-associated ascites fluid (PAAF) and necrotic pancreatic tissue at various proportions into the triangular area formed by the left renal artery and ureter. The feasibility of the ANP-IR model was verified by comparing the similar changes in indicators of intestinal inflammation and barrier function between the two rat models. In addition, we detected changes in apoptosis levels and YAP protein expression in the ileal tissues of rats in each group and validated them in vitro in rat epithelial crypt cells (IEC-6) to further explore the potential injury mechanisms of ANP-associated intestinal injury. We also collected clinical data from patients with ANP to validate the effects of PAAF and pancreatic necrosis on intestinal injury. Our findings offer a theoretical basis for restricting the buildup of peritoneal necrosis in individuals with ANP, thus promoting the restoration of intestinal function and enhancing treatment efficacy. The use of the ANP-IR model in further studies can help us better understand the mechanism and treatment of ANP-associated intestinal injury.NEW & NOTEWORTHY We constructed a rat model of acute necrotizing pancreatitis-associated intestinal injury and verified its feasibility. In addition, we identified the mechanism by which necrotic pancreatic tissue and pancreatitis-associated ascites fluid (PAAF) cause intestinal injury through the HIPPO signaling pathway.

Endoscopic and surgical treatment of necrotizing pancreatitis-a comparison of short- and long-term outcome

BACKGROUND

Acute necrotizing pancreatitis is still related to high morbidity and mortality rates. Minimal-invasive treatment options, such as endoscopic necrosectomy, may decrease peri-interventional morbidity and mortality. This study aims to compare the initial operative with endoscopic treatment on long-term parameters, such as endocrine and exocrine functionality, as well as mortality and recurrence rates.

METHODS

We included 114 patients, of whom 69 were treated with initial endoscopy and 45 by initial surgery. Both groups were further assessed for peri-interventional and long-term parameters.

RESULTS

In the post-interventional phase, patients in the group of initial surgical treatment (IST) showed significantly higher rates of renal insufficiency (p < 0.001) and dependency on invasive ventilation (p < 0.001). The in-house mortality was higher in the surgical group, with 22% vs. 10.1% in the group of patients following initial endoscopic treatment (IET; p = 0.077). In long-term follow-up, the overall mortality was 45% for IST and 31.3% for IET (p = 0.156). The overall in-hospital stay and intensive care unit (ICU) stay were significantly shorter after IET (p < 0.001). In long-term follow-up, the prevalence of endocrine insufficiency was 50% after IST and 61.7% after IET (p = 0.281). 57.1% of the patients following IST and 16.4% of the patients following IET had persistent exocrine insufficiency at that point (p =  < 0.001). 8.9% of the IET and 27.6% of the IST patients showed recurrence of acute pancreatitis (p = 0.023) in the long-term phase.

CONCLUSION

In our cohort, an endoscopic step-up approach led to a reduced in-hospital stay and peri-interventional morbidity. The endocrine function appeared comparable in both groups, whereas the exocrine insufficiency seemed to recover in the endoscopic group in the long-term phase. These findings advocate for a preference for endoscopic treatment of acute necrotizing pancreatitis whenever feasible.

Identification and characterization of pancreatic infections in severe and critical acute pancreatitis patients using 16S rRNA gene next generation sequencing

Objectives

This study aimed to identify the bacterial composition in the pancreatic fluid of severe and critical acute pancreatitis (SAP and CAP) patients.

Methods

A total of 78 pancreatic fluid samples were collected from 56 SAP and CAP patients and analyze using aerobic culture and 16S rRNA gene next-generation sequencing. The clinical data of the patients were obtained from the electronic medical records.

Results

Among the total 78 samples, 16S rRNA gene NGS identified a total of 660 bacterial taxa, belonging to 216 species in 123 genera. The dominant aerobic bacteria included Klebsiella pneumoniae, Acinetobacter baumannii, and Enterococcus faecium, while the dominant anaerobic bacteria included Bacteroides, Dialister invisus, and Olsenella uli. As compared to aerobic culturing, 95.96% (95/99) of the aerobic cultured bacteria were detected using the 16S rRNA gene NGS.

Conclusion

The pancreatic infections in SAP and CAP patients might originate not only from the gut but also from the oral cavity and airways as well as related environments. Dynamic analysis of bacterial profile and abundance showed that some bacteria with low abundance might become the main pathogenic bacteria. There were no significant differences in the bacterial diversity between SAP and CAP.

Systemic injury caused by taurocholate-induced severe acute pancreatitis in rats

Systemic injury plays a central role in severe acute pancreatitis (SAP). Retrograde biliopancreatic duct infusion of sodium taurocholate (NaT) is commonly used to establish SAP animal models. To better characterize the systemic injury in this model, SAP was induced in Sprague-Dawley rats by NaT administration (3.5 or 5%), followed by sacrifice at 3, 6, 9, 12, 24, 48 and 72 h. Normal saline was used as a control in Sham-operated rats. The mortality rate, ascites volume, and serum and ascitic fluid amylase and lipase activities were assessed. Multiple organ dysfunction, including dysfunction of the pancreas, lung, ileum, liver, and kidney, was investigated using hematoxylin and eosin staining. The interleukin (IL)-1β, IL-6, and tumor necrosis factor-α levels in the ascitic fluid, serum, and ileum tissues were evaluated using an enzyme-linked immunosorbent assay (ELISA). Tight junction proteins, zonula occludens-1 (ZO-1) and occludin, in ileum tissues were studied using immunofluorescence. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE) and urea levels were measured using an automatic biochemical analyzer. The results of the present study indicated that both 3.5 and 5% NaT could induce a stable elevation of pancreatitis indices, with histopathological injury of the pancreas, lungs and ileum (5% NaT). The ascitic fluid levels of IL-6 and IL-1β were increased in the 5% NaT group. ALT and AST levels increased temporarily and recovered in 72 h, without a significant increase in CRE and urea levels or apparent hepatic and renal pathological injury. In conclusion, rats with NaT-induced SAP have characteristics of necrotizing hemorrhagic pancreatitis with multiple organ injuries, including inflammatory lung injury, ischemic intestinal injury and slight liver and kidney injuries.

Significant Succession of Intestinal Bacterial Community and Function During the Initial 72 Hours of Acute Pancreatitis in Rats

Acute pancreatitis (AP) is followed by structural and functional changes in the intestine, resulting from microbiome dysbiosis. However, it remains unclear how gut microbiome changes within the initial 72h of onset. In this study, severe acute pancreatitis (SAP), mild acute pancreatitis (MAP), and sham operation (SO) were replicated in rat models. 16S ribosomal RNA gene sequencing was used to explore the gut bacteria community. The predicted Cluster of Orthologous Genes (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways were associated with the 16S rRNA profiles. Compared to the SO group, significant community succession was found during the initial 72h in AP group. At 72 h after AP induction, the Firmicutes/Bacteroidetes (F/B) ratios were significantly different, with the highest ratio in SAP group and the lowest in MAP group. Lactobacillus was the most abundant genus, but it nearly disappeared in SAP rats at 72 h. Clostridiaceae 1 and Clostridium sensu stricto 1 were significantly enriched in AP group. Bacteroidales S24-7 and Bacteroidales S24-7 group norank were enriched in MAP group, while Collinsella, Morganella, and Blautia were enriched in SAP group. Lactobacillus was significantly correlated with nine COGs. Nine COGs showed significant differences between AP group and SO group. Moreover, four COGs showed significant differences between the MAP and SAP groups. KEGG Level_3 pathways propanoate metabolism (Ko00640) in AP group was significantly higher than that in SO group. The aspartate‒ammonia ligase and four KEGG orthology terms of the AP group were lower than that in the SO group, respectively. All these results suggest that the intestinal bacterial community structure and function was changed during the initial 72h in AP rats. The intestinal F/B ratio and the relative abundance of Lactobacillus could be potential markers for early diagnosis of MAP and SAP. The genus Clostridium sensu stricto 1 was the most enriched genus in AP, and may be an important marker for AP.

Preventing Bacterial Translocation in Patients with Leaky Gut Syndrome: Nutrition and Pharmacological Treatment Options

Leaky gut syndrome is a medical condition characterized by intestinal hyperpermeability. Since the intestinal barrier is one of the essential components maintaining homeostasis along the gastrointestinal tract, loss of its integrity due to changes in bacterial composition, decreased expression levels of tight junction proteins, and increased concentration of pro-inflammatory cytokines may lead to intestinal hyperpermeability followed by the development of gastrointestinal and non-gastrointestinal diseases. Translocation of microorganisms and their toxic metabolites beyond the gastrointestinal tract is one of the fallouts of the leaky gut syndrome. The presence of intestinal bacteria in sterile tissues and distant organs may cause damage due to chronic inflammation and progression of disorders, including inflammatory bowel diseases, liver cirrhosis, and acute pancreatitis. Currently, there are no medical guidelines for the treatment or prevention of bacterial translocation in patients with the leaky gut syndrome; however, several studies suggest that dietary intervention can improve barrier function and restrict bacteria invasion. This review contains current literature data concerning the influence of diet, dietary supplements, probiotics, and drugs on intestinal permeability and bacterial translocation.

Blood Bacteria-Free DNA in Septic Mice Enhances LPS-Induced Inflammation in Mice through Macrophage Response

Although bacteria-free DNA in blood during systemic infection is mainly derived from bacterial death, translocation of the DNA from the gut into the blood circulation (gut translocation) is also possible. Hence, several mouse models with experiments on macrophages were conducted to explore the sources, influences, and impacts of bacteria-free DNA in sepsis. First, bacteria-free DNA and bacteriome in blood were demonstrated in cecal ligation and puncture (CLP) sepsis mice. Second, administration of bacterial lysate (a source of bacterial DNA) in dextran sulfate solution (DSS)-induced mucositis mice elevated blood bacteria-free DNA without bacteremia supported gut translocation of free DNA. The absence of blood bacteria-free DNA in DSS mice without bacterial lysate implies an impact of the abundance of bacterial DNA in intestinal contents on the translocation of free DNA. Third, higher serum cytokines in mice after injection of combined bacterial DNA with lipopolysaccharide (LPS), when compared to LPS injection alone, supported an influence of blood bacteria-free DNA on systemic inflammation. The synergistic effects of free DNA and LPS on macrophage pro-inflammatory responses, as indicated by supernatant cytokines (TNF-α, IL-6, and IL-10), pro-inflammatory genes (NFκB, iNOS, and IL-1β), and profound energy alteration (enhanced glycolysis with reduced mitochondrial functions), which was neutralized by TLR-9 inhibition (chloroquine), were demonstrated. In conclusion, the presence of bacteria-free DNA in sepsis mice is partly due to gut translocation of bacteria-free DNA into the systemic circulation, which would enhance sepsis severity. Inhibition of the responses against bacterial DNA by TLR-9 inhibition could attenuate LPS-DNA synergy in macrophages and might help improve sepsis hyper-inflammation in some situations.

Parabacteroides produces acetate to alleviate heparanase-exacerbated acute pancreatitis through reducing neutrophil infiltration

BACKGROUND

The endoglycosidase heparanase which degrades heparan sulfate proteoglycans, exerts a pro-inflammatory mediator in various inflammatory disorders. However, the function and underlying mechanism of heparanase in acute pancreatitis remain poorly understood. Here, we investigated the interplay between heparanase and the gut microbiota in the development of acute pancreatitis.

METHODS

Acute pancreatitis was induced in wild-type and heparanase-transgenic mice by administration of caerulein. The differences in gut microbiota were analyzed by 16S ribosomal RNA sequencing. Antibiotic cocktail experiment, fecal microbiota transplantation, and cohousing experiments were used to assess the role of gut microbiota.

RESULTS

As compared with wild-type mice, acute pancreatitis was exacerbated in heparanase-transgenic mice. Moreover, the gut microbiota differed between heparanase-transgenic and wild-type mice. Heparanase exacerbated acute pancreatitis in a gut microbiota-dependent manner. Specially, the commensal Parabacteroides contributed most to distinguish the differences between wild-type and heparanase-transgenic mice. Administration of Parabacteroides alleviated acute pancreatitis in wild-type and heparanase-transgenic mice. In addition, Parabacteroides produced acetate to alleviate heparanase-exacerbated acute pancreatitis through reducing neutrophil infiltration.

CONCLUSIONS

The gut-pancreas axis played an important role in the development of acute pancreatitis and the acetate produced by Parabacteroides may be beneficial for acute pancreatitis treatment. Video abstract.

Microbiome changes associated with acute and chronic pancreatitis: A systematic review

BACKGROUND

Altered intestinal microbiota has been reported in pancreatic disorders, however, it remains unclear whether these changes alter the course of disease in patients with acute (AP) and chronic pancreatitis (CP), or whether these disease states alter the environment to enable pathogenic microbial composition changes to occur. We undertook a systematic review to characterize the gut microbiome in pancreatitis patients.

METHODS

MEDLINE and EMBASE were searched for studies on microbiota in pancreatitis published from January 1, 2000 to June 5, 2020. Animal studies, reviews, case reports, and non-English articles were excluded. A frequency analysis was performed for outcomes reported in ≥2 studies and studies were analyzed for risk of bias and quality of evidence.

RESULTS

22 papers met inclusion criteria; 15 included AP, 7 included CP. No studies were appropriately designed to assess whether alterations in the gut microbiome exacerbate pancreatitis or develop as a result of pancreatitis. We did identify several patterns of microbiome changes that are associated with pancreatitis. The gut microbiome demonstrated decreased alpha diversity in 3/3 A P studies and 3/3 C P studies. Beta diversity analysis revealed differences in bacterial community composition in the gut microbiome in 2/2 A P studies and 3/3 C P studies. Functionally, gut microbiome changes were associated with infectious pathways in AP and CP. Several studies suffered from high risk of bias and inadequate quality.

CONCLUSIONS

Detecting differences in microbial composition associated with AP and CP may represent a diagnostic tool. Appropriately controlled longitudinal studies are needed to determine whether microbiome changes are causative or reactive in pancreatitis.

Early Weight-Based Aggressive vs. Non-Aggressive Goal-Directed Fluid Resuscitation in the Early Phase of Acute Pancreatitis: An Open-Label Multicenter Randomized Controlled Trial (The WATERFALL Trial), Design, and Rationale

Treatment options are limited for acute pancreatitis (AP). Early aggressive fluid resuscitation (AFR) has been widely considered beneficial because of theoretical improvement in end-organ perfusion, including the pancreas and gut, with pancreatic necrosis and bacterial translocation as consequences of ischemia. There is scarce direct evidence for its association to improved outcomes. Furthermore, it has been described that AFR may be associated with poor outcomes in severe AP. WATERFALL is an investigator-initiated international multicenter open-label randomized controlled trial comparing AFR vs. moderate fluid resuscitation (MFR) in AP. The main outcome variable will be the incidence of moderate to severe AP (a clinically relevant outcome that has been validated). Aggressive fluid resuscitation will consist in lactated Ringer solution (LR) 20-mL/kg bolus (administered over 2 h) followed by LR 3 mL/kg per hour. Patients randomized to MFR will receive an LR bolus 10 mL/kg in case of hypovolemia or no bolus in patients with normal volemia, followed by LR 1.5 mL/kg per hour. The patients will be assessed at 3 (±1), 12 (±4), 24 (±4), 48 (±4), and 72 (±4) h from recruitment, and fluid resuscitation will be adjusted to the patient's clinical and analytical status according to a protocol. Based on a prospective multicenter study, the incidence of moderate to severe AP is 35%. Sample sizes of 372 patients per group (overall 744) achieve 80% power to detect a difference in the incidence of moderate to severe AP of 10%, at a significance level (α) of 0.05 using a two-sided z-test, assuming a 10% dropout rate. These results assume that three sequential tests are made using the O'Brien-Fleming spending function to determine the test boundaries.

Effects of Short-Peptide-Based Enteral Nutrition on the Intestinal Microcirculation and Mucosal Barrier in Mice with Severe Acute Pancreatitis

SCOPE

Short-peptide-based enteral nutrition (SPEN) is absorbed more efficiently in patients with severe acute pancreatitis (SAP). More importantly, SPEN decreases SAP-induced enterogenous infection risk. This study aims to investigate whether SPEN alleviates intestinal bacterial translocation in mice with SAP, and the underlying mechanisms.

METHODS AND RESULTS

The SAP model is established after pre-treatment with SPEN or intact-protein-based enteral nutrition. Although there is no improvement in pancreas injury, as evaluated through Hematoxylin-Eosin staining or serum amylase, SPEN obviously attenuates intestinal bacterial translocation after SAP. To unveil the mechanisms, it is found that the intestinal mechanical barrier destroyed by SAP is significantly relieved by SPEN, which presents with recovered ZO-1 expression, mucus layer, and goblet cell function. Additionally, SPEN alleviates local CCR6/CCL20 induced CD11c+ dendritic cell infiltration, systemic immunosuppression, and inhibits the secretion of luminal secretory immunoglobulin A. Possibly responsible for SAP-induced mucosal dysfunctions, destroyed intestinal mucosal microcirculation and local hypoxia are largely improved in SAP+SPEN group.

CONCLUSION

SPEN can improve downregulated intestinal mucosal microcirculation secondary to SAP, which may be responsible for mucosal inflammation relief, maintenance of the mechanical barrier and mucosal immunity, the correction of systemic immunosuppression, and play a protective role in defending commensal bacterial translocation after SAP.

Bacterial translocation in acute pancreatitis

Bacterial translocation is a phenomenon in which live bacteria or their products cross the intestinal barrier to other organs or the circulatory system. Gut translocation of bacteria has been reported in both animal models, and clinical trials often accompany acute pancreatitis and are believed to be linked to patient outcome, especially in severe acute pancreatitis. Therefore, the mechanisms of intestinal bacterial translocation in acute pancreatitis have become a topic of interest in recent years. This review discusses Bacterial translocation in acute pancreatitis, identifies possible mechanisms of action, and provides an overview of the methods used to detect Bacterial translocation in acute pancreatitis. This review also highlights areas that require further research.

Potential of cell-free DNA as a screening marker for parasite infections in dog

Parasitic infections are common in stray dogs and accurate knowledge of parasite communities in dogs would provide insight into the epidemiology of parasitic diseases. In this study, we used Illumina sequencing technology to evaluate cell-free DNA (cfDNA) as a marker for screening of parasitic infections in dogs. Plasma samples from 14 stray dogs captured in Bangladesh were used in the experiments. An average of 2.3 million reads was obtained for each sample. BLASTn analysis identified 150 reads with high similarity with parasites from 19 different genera. In particular, we detected sequences of Babesia spp. in five dogs; consistent with this, a previous study using conventional PCR showed that four of these dogs were positive for B. gibsoni. Several reads with similarity to Leishmania and filarial nematodes were also identified. These findings indicate that cfDNA in blood can be a potential screening marker for identifying parasite diversity in dogs.

Effect of intestinal epithelial autophagy on bacterial translocation in severe acute pancreatitis

BACKGROUND AND OBJECTIVE

We examined the impact of autophagy activation on bacterial translocation (BT) and tight junction (TJ) proteins in the intestinal mucosa of patients with severe acute pancreatitis (SAP).

METHODS

Thirty-one SAP patients were divided into two groups, BT(+) and BT(-), according to the presence of BT in the blood, as detected by 16S rDNA sequencing. Eight healthy individuals were included in the control group. Serum endotoxin levels were measured by ELISA. Colonic mucosal tissue was obtained by endoscopy, and the TJ proteins and phosphatidylethanolamine-conjugated microtubule-associated protein light chain 3 (LC3-II) were analyzed using immunofluorescence and Western blotting.

RESULTS

The expression of LC3II in patients with SAP was higher than that observed in healthy controls. Patients who tested positive for the presence of BT had a higher level of claudins-2 (CL-2) and a lower level of occludin and Zonula occluden-1 (ZO-1) than BT(-) patients. Moreover, the levels of LC3II in BT(-) patients was higher than that found in BT(+) patients, and occludin and ZO-1 were positively correlated with LC3II.

CONCLUSIONS

Autophagy activation in the intestinal epithelial cells of patients with SAP and its effects on BT may act through enhancing para-cellular TJs.

The intestinal barrier: a fundamental role in health and disease

The gastrointestinal mucosa constitutes a critical barrier where millions of microbes and environmental antigens come in close contact with the host immune system. Intestinal barrier defects have been associated with a broad range of diseases and therefore denote a new therapeutic target. Areas covered: This review is based on an extensive literature search in PubMed of how the intestinal barrier contributes to health and as a trigger for disease. It discusses the anatomy of the intestinal barrier and explains the available methods to evaluate its function. Also reviewed is the importance of diet and lifestyle factors on intestinal barrier function, and three prototypes of chronic diseases (inflammatory bowel disease, celiac disease and nonalcoholic fatty liver disease) that have been linked to barrier defects are discussed. Expert commentary: The intestinal barrier has been investigated by various methods, but correlation of results across studies is difficult, representing a major shortcoming in the field. New upcoming techniques and research on the effect of barrier-restoring therapeutics may improve our current understanding of the gut barrier, and provide a step forward towards personalised medicine.

Impact of gut microbiota on the fly's germ line

Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation.

The gut microbiota can play various roles in the host's physiology, but is not known to influence the germ line. Here, Elgart et al. show that certain extracellular gut bacteria can affect oogenesis and embryo development in the fruit fly.

Serum bacterial DNA detection in patients with cholangitis after Kasai procedure

BACKGROUND

The aim of this study was to investigate the detectability of bacterial DNA (bactDNA) and associated clinical factors in patients with cholangitis after the Kasai procedure through the identification of bactDNA in blood.

METHODS

A cross-sectional study of 110 patients who had undergone the Kasai procedure was carried out. A total of 77 patients had cholangitis and 33 did not. Blood samples were obtained on admission or on follow up at the outpatient visit. bactDNA was analyzed using a polymerase chain reaction-based method, DNA nucleotide sequencing, for identification of bacterial species.

RESULTS

Rate of bactDNA positivity was higher using the 16SrDNA method than the culture method (58.4% vs 14.3%, P < 0.0001), and more patients with cholangitis were positive for bactDNA compared with the patients without cholangitis (58.4% vs 39.4%, P = 0.095). Bacteria identified on blood 16SrDNA primarily consisted of opportunistic pathogens derived from the gut, including Escherichia coli, Klebsiella pneumoniae, Shigella fexneri, and Enterobacteriaceae bacterium. Treatment with probiotics or antibiotics showed a trend toward reduced prevalence of bactDNA. Pediatric end-stage liver disease score, procalcitonin, C-reactive protein, and heart rate were all significantly associated with the presence of bactDNA.

CONCLUSION

bactDNA is frequently detected in patients with cholangitis after the Kasai procedure compared with those without cholangitis (and controls), and the bacteria are similar to those in the gut, suggesting that it is useful as an early diagnostic tool for cholangitis and other infections (registration number in Chinese Clinical Trial Registry ChiCTR-ECC-13003759).

Gut failure in critical care: old school versus new school

The concept of bacterial translocation and gut-origin sepsis as causes of systemic infectious complications and multiple organ deficiency syndrome in surgical and critically ill patients has been a recurring issue over the last decades attracting the scientific interest. Although gastrointestinal dysfunction seemingly arises frequently in intensive care unit patients, it is usually underdiagnosed or underestimated, because the pathophysiology involved is incompletely understood and its exact clinical relevance still remains controversial with an unknown yet probably adverse impact on the patients' outcome. The purpose of this review is to define gut-origin sepsis and related terms, to describe the mechanisms leading to gut-derived complications, and to illustrate the therapeutic options to prevent or limit these untoward processes.

Translocation of gut flora and its role in sepsis

Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and the internal organs. Sometimes instead of bacteria, inflammatory compounds are responsible for clinical symptoms as in systemic inflammatory response syndrome (SIRS). The difference between sepsis and SIRS is that pathogenic bacteria are isolated from patients with sepsis but not with those of SIRS. Bacterial translocation occurs more frequently in patients with intestinal obstruction and in immunocompromised patients and is the cause of subsequent sepsis. Factors that can trigger bacterial translocation from the gut are host immune deficiencies and immunosuppression, disturbances in normal ecological balance of gut, mucosal barrier permeability, obstructive jaundice, stress, etc. Bacterial translocation occurs through the transcellular and the paracellular pathways and can be measured both directly by culture of mesenteric lymph nodes and indirectly by using labeled bacteria, peripheral blood culture, detection of microbial DNA or endotoxin and urinary excretion of non-metabolisable sugars. Bacterial translocation may be a normal phenomenon occurring on frequent basis in healthy individuals without any deleterious consequences. But when the immune system is challenged extensively, it breaks down and results in septic complications at different sites away from the main focus. The factors released from the gut and carried in the mesenteric lymphatics but not in the portal blood are enough to cause multi-organ failure. Thus, bacterial translocation may be a promoter of sepsis but not the initiator. This paper reviews literature on the translocation of gut flora and its role in causing sepsis.

Meta-analysis of gut barrier dysfunction in patients with acute pancreatitis

BACKGROUND

The gut is implicated in the pathogenesis of acute pancreatitis but there is discrepancy between individual studies regarding the prevalence of gut barrier dysfunction in patients with acute pancreatitis. The aim of this study was to determine the prevalence of gut barrier dysfunction in acute pancreatitis, the effect of different co-variables, and changes in gut barrier function associated with the use of various therapeutic modalities.

METHODS

A literature search was performed using PRISMA and MOOSE guidelines. Summary estimates were presented as pooled prevalence of gut barrier dysfunction and the associated 95 per cent c.i.

RESULTS

A total of 44 prospective clinical studies were included in the systematic review, of which 18 studies were subjected to meta-analysis. The pooled prevalence of gut barrier dysfunction was 59 (95 per cent c.i. 48 to 70) per cent; the prevalence was not significantly affected by disease severity, timing of assessment after hospital admission or type of test used, but showed a statistically significant association with age. Overall, nine of 13 randomized clinical trials reported a significant improvement in gut barrier function following intervention compared with the control group, but only three of six studies that used standard enteral nutrition reported a statistically significant improvement in gut barrier function after intervention.

CONCLUSION

Gut barrier dysfunction is present in three of five patients with acute pancreatitis, and the prevalence is affected by patient age but not by disease severity. Clinical studies are needed to evaluate the effect of enteral nutrition on gut function in acute pancreatitis.

CD64 expression is increased in patients with severe acute pancreatitis: clinical significance

BACKGROUND/AIMS

Upregulated CD64 expression on neutrophils is the most useful marker for acute bacterial infections and systemic inflammation. However, it is unknown whether CD64 is involved in the pathogenesis of acute pancreatitis (AP). This study was designed to determine whether CD64 is implicated in severe acute pancreatitis (SAP), and thus, is a suitable marker for SAP.

METHODS

SAP was induced in rats with an intraperitoneal injection of L-arginine. CD64 expression in the rat pancreas was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry. Additionally, the CD64 mRNA expression in peripheral blood leukocytes from 21 patients with mild acute pancreatitis (MAP) and 10 patients with SAP was investigated at the time of admission and during remission by qRT-PCR.

RESULTS

CD64 mRNA and protein expression in the pancreas was significantly higher in rats with SAP, compared to the controls. The CD64 expression was higher in the patients with SAP than in the patients with MAP. During remission, CD64 mRNA decreased in both the MAP and SAP patients. The area under the curve of CD64 expression for the detection of SAP was superior to both the Ranson and the Acute Physiology and Chronic Health Evaluation II scores.

CONCLUSIONS

The CD64 level was significantly increased in correlation with the disease severity in SAP and may act as a useful marker for predicting the development of SAP.

Bacteremia in patients with acute pancreatitis as revealed by 16S ribosomal RNA gene-based techniques*

OBJECTIVES

To define the characteristic of bacteremia in patients with acute pancreatitis and determine its possible association with the disease severity.

DESIGN

A prospective controlled study.

SETTING

ICU of Jinling Hospital, China.

PATIENTS

A total of 48 patients with mild or severe acute pancreatitis were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples of peripheral blood were collected from the patients at 4 or 5 and 9 or 10 days after acute pancreatitis was definitely diagnosed. Resulting DNA from the blood was analyzed using denaturing gradient gel electrophoresis, and separated fragments were sequenced for identification of bacterial species. Bacterial DNA was detected in peripheral blood from 68.8% of patients with acute pancreatitis, and more than half (60.4%) of the patients encountered polymicrobial flora. Translocated bacteria in patients with acute pancreatitis were primarily constituted of opportunistic pathogens derived from the gut, including Escherichia coli, Shigella flexneri, Enterobacteriaceae bacterium, Acinetobacter lwoffii, Bacillus coagulans, and Enterococcus faecium. The species of circulating bacteria shifted remarkably among the patients with different severity. The presence of the bacteremia correlated positively with the Acute Physiology and Chronic Health Evaluation-II scores of patients with acute pancreatitis (r = 0.7918, p < 0.0001).

CONCLUSIONS

This study provides a detailed description on the prevalence of bacteremia and characteristic of bacterial species in patients with acute pancreatitis. We demonstrate an association between the bacteremia and the disease severity, which enables us to better understand a potential role of bacterial translocation in the pathogenesis of septic complication in acute pancreatitis.

Complete genes may pass from food to human blood

Our bloodstream is considered to be an environment well separated from the outside world and the digestive tract. According to the standard paradigm large macromolecules consumed with food cannot pass directly to the circulatory system. During digestion proteins and DNA are thought to be degraded into small constituents, amino acids and nucleic acids, respectively, and then absorbed by a complex active process and distributed to various parts of the body through the circulation system. Here, based on the analysis of over 1000 human samples from four independent studies, we report evidence that meal-derived DNA fragments which are large enough to carry complete genes can avoid degradation and through an unknown mechanism enter the human circulation system. In one of the blood samples the relative concentration of plant DNA is higher than the human DNA. The plant DNA concentration shows a surprisingly precise log-normal distribution in the plasma samples while non-plasma (cord blood) control sample was found to be free of plant DNA.

Implications of culture positivity in acute pancreatitis: does the source matter?

BACKGROUND AND AIMS

Sepsis is an important complication and cause of morbidity and mortality in acute pancreatitis (AP). The source of sepsis may be infected pancreatic and peripancreatic collections and/or necrosis or extrapancreatic including infections in the bloodstream or respiratory and urinary tracts. We studied the implications of the source of sepsis on various outcome parameters in AP like persistent organ failure (POF), length of hospital (LOH) stay, and mortality.

METHODS

A retrospective analysis of culture reports of AP patients was done, and the outcome parameters were recorded.

RESULTS

Three hundred fifty-seven patients (229 M; age: 40.3 ± 14.04 years) of AP who had detailed culture reports were included. Eighty-four (23.5%) patients had pancreatic (or peripancreatic) source (group 1), 52 (14.6%) patients had other (extrapancreatic) sources (group 2), 20 (5.6%) patients were noted to have positive cultures from sources, which were both pancreatic and extrapancreatic (combined) sources (group 3), while 201 patients had sterile cultures. POF was seen in 147 (48%) patients (group 1: 67.8%; group 2: 65%; group 3: 90%; group 4: 34% [P < 0.001]). The mean LOH stay was 22.1 ± 20.26 days (group 1: 30.2 ± 20.64 days; group 2: 26.4 ± 26.82 days; group 3: 47.3 ± 32.60 days; group 4: 15.2 ± 11.34 days [P < 0.001]). Seventy (19.7%) patients succumbed to their illness (group 1 [22.9%]; group 2 [36.5%]; group 3 [40%]; group 4 [12%] [P < 0.001]).

CONCLUSIONS

POF and LOH stay were more common in patients with combined pancreatic and extrapancreatic sources of sepsis. Mortality was significantly higher in patients with sepsis (groups 1, 2, 3) compared with sterile groups.

Pathological bacterial translocation in cirrhosis: pathophysiology, diagnosis and clinical implications

Bacterial translocation (BT) is defined by the passage of viable indigenous bacteria from the intestinal lumen to mesenteric lymph nodes (MLNs) and other territories, and its diagnostic criteria rely on the isolation of viable bacteria in MLNs. Small intestinal overgrowth, increased intestinal permeability and immunological alterations are the main factors involved in its pathogenesis. BT is obviously difficult to identify in patients with cirrhosis, and alternative methods have been proposed instead. Bacterial DNA detection and species identification in serum or ascitic fluid has been proposed as a reliable marker of BT. Bacterial products, such as endotoxin, or bacterial DNA can translocate to extra-intestinal sites and promote an immunological response similar to that produced by viable bacteria. Therefore, pathological BT plays an important role in the pathogenesis of the complications of cirrhosis, not only in infections, but by exerting a profound inflammatory state and exacerbating the haemodynamic derangement. This may promote in turn the development of hepatorenal syndrome, hepatic encephalopathy and other portal hypertension-related complications. Therapeutic approaches for the prevention of BT in experimental and human cirrhosis are summarized. Finally, new investigations are needed to better understand the pathogenesis and consequences of translocation by viable bacteria (able to grow in culture), or non-viable BT (detection of bacterial fragments with negative culture) and open new therapeutic avenues in patients with cirrhosis.

TREM-1 Promotes Pancreatitis-Associated Intestinal Barrier Dysfunction

Severe acute pancreatitis (SAP) can cause intestinal barrier dysfunction (IBD), which significantly increases the disease severity and risk of mortality. We hypothesized that the innate immunity- and inflammatory-related protein-triggering receptor expressed on myeloid cells-1 (TREM-1) contributes to this complication of SAP. Thus, we investigated the effect of TREM-1 pathway modulation on a rat model of pancreatitis-associated IBD. In this study we sought to clarify the role of TREM-1 in the pathophysiology of intestinal barrier dysfunction in SAP. Specifically, we evaluated levels of serum TREM-1 and membrane-bound TREM-1 in the intestine and pancreas from an animal model of experimentally induced SAP. TREM-1 pathway blockade by LP17 treatment may suppress pancreatitis-associated IBD and ameliorate the damage to the intestinal mucosa barrier.

Bacterial DNA promotes proliferation of rat pancreatic stellate cells thorough toll-like receptor 9: potential mechanisms for bacterially induced fibrosis

OBJECTIVES

We hoped to clarify the possible role of CpG DNA as a trigger factor for overt pancreatic inflammation of pancreatic stellate cells (PSCs).

METHODS

Pancreatic stellate cells were isolated from the male Lewis rat. The expression of Toll-like receptor 9 (TLR9) messenger RNA and protein were evaluated by reverse transcription-polymerase chain reaction and immunofluorescent cytochemistry. Internalization of CpG DNA was analyzed by confocal laser scanning microscopy. Pancreatic stellate cells were incubated with CpG DNA, and then cell proliferation and migration were assessed.

RESULTS

Constitutive expression of TLR9 occurs at the messenger RNA and protein levels. After several minutes of CpG DNA administration, CpG DNA was observed on the cell membrane surface and in the cytoplasm and found to be translocating into the perinucleus of PSCs. Pancreatic stellate cells migrated and proliferated in dose- and time-dependent manners in response to simulation by CpG DNA. Proliferation of PSCs was observed 3 hours after administration (earlier than platelet-derived growth factor-induced proliferation), suggesting that PSCs respond readily to provide innate immunity. Endosomal acidification inhibitors attenuated CpG DNA-induced signaling, leading to suppression of DNA synthesis by PSCs.

CONCLUSIONS

Our findings demonstrate that bacterial DNA promotes migration and proliferation of PSCs and suggest that bacterial DNA can initiate and sustain pancreatic inflammation and fibrosis by means of TLR9.

Citrobacter freundii infection after acute necrotizing pancreatitis in a patient with a pancreatic pseudocyst: a case report

Introduction

Infections are the most frequent and severe complications of acute necrotizing pancreatitis with a mortality rate of up to 80 percent. Although experimental and clinical studies suggest that the microbiologic source of pancreatic infection could be enteric, information in this regard is controversial.

Case presentation

We describe a Citrobacter freundii isolation by endoscopy ultrasound fine needle aspiration in a 80-year-old Caucasian man with pancreatic pseudocyst after acute necrotizing pancreatitis.

Conclusion

Our case report confirms that this organism can be recovered in patients with a pancreatic pseudocyst. On-site cytology feedback was crucial to the successful outcome of this case as immediate interpretation of the fine needle aspiration sample directed the appropriate cultures and, ultimately, the curative therapy. To the best of our knowledge, this is the first reported case of isolated pancreatic C. freundii diagnosed by endoscopy ultrasound fine needle aspiration.

Gut Microbiota in Health and Disease

Gut microbiota is an assortment of microorganisms inhabiting the length and width of the mammalian gastrointestinal tract. The composition of this microbial community is host specific, evolving throughout an individual's lifetime and susceptible to both exogenous and endogenous modifications. Recent renewed interest in the structure and function of this “organ” has illuminated its central position in health and disease. The microbiota is intimately involved in numerous aspects of normal host physiology, from nutritional status to behavior and stress response. Additionally, they can be a central or a contributing cause of many diseases, affecting both near and far organ systems. The overall balance in the composition of the gut microbial community, as well as the presence or absence of key species capable of effecting specific responses, is important in ensuring homeostasis or lack thereof at the intestinal mucosa and beyond. The mechanisms through which microbiota exerts its beneficial or detrimental influences remain largely undefined, but include elaboration of signaling molecules and recognition of bacterial epitopes by both intestinal epithelial and mucosal immune cells. The advances in modeling and analysis of gut microbiota will further our knowledge of their role in health and disease, allowing customization of existing and future therapeutic and prophylactic modalities.

Early infection of peripancreatic tissue in mild acute pancreatitis: report of a case

Mild acute pancreatitis (AP) is rarely complicated by infection, and the value of prophylactic antibiotics is questionable. We report a case of mild AP complicated by infection, which developed within 1 week after the onset. A 66-year-old woman was referred to our hospital where a diagnosis of mild AP was made, based on laboratory data and computed tomography (CT) findings. She was managed conservatively with fluid resuscitation, intravenous antibiotics, and protease inhibitor. Her general condition improved initially, but a high fever redeveloped on hospital day 3. On hospital day 7, a repeat CT scan showed a peripancreatic fluid collection with gas, indicating peripancreatic abscess. A drainage operation was performed, and the organism cultured from the abscess was Escherichia coli. Her postoperative course was uneventful. We report this case to stress that infection may develop even in mild AP, and even in the early phase.

Role of triggering receptor expressed on myeloid cells-1 in experimental severe acute pancreatitis

BACKGROUND/PURPOSE

Triggering receptor expressed on myeloid cells-1 (TREM-1) is a regulator of immunity and an amplifier of inflammatory signaling. The aim was to clarify the role of TREM-1 in the pathophysiology of experimental severe acute pancreatitis (SAP).

METHODS

SAP was induced by retrograde injection of 3 and 20% sodium deoxycholate (DCA) into the biliopancreatic ducts in rats (DCA pancreatitis). Soluble TREM-1 levels in serum, ascitic fluid, pancreas, liver and kidney were determined with an established available enzyme-linked immunosorbent assay (ELISA) kit. To clarify the source of soluble TREM-1 in serum and ascitic fluid, peritoneal macrophage depletion was done. Moreover, the effect of blockade of TREM-1 pathway was examined using LP17 (a synthetic TREM-1 inhibitor).

RESULTS

Soluble TREM-1 levels in serum and ascitic fluid were higher in SAP. Membrane-bound TREM-1 protein was increased in pancreas, liver and kidney in SAP. Peritoneal macrophage depletion resulted in the reduction of soluble TREM-1 levels in serum and ascitic fluid. Pretreatment with LP17 improved the hepatic and renal dysfunction (serum aspartate aminotransferase and blood urea nitrogen levels) in SAP.

CONCLUSIONS

TREM-1 may act as an important mediator for inflammation and organ injury in SAP. TREM-1 may be a potential therapeutic target for the development of SAP and associated organ dysfunction.

Cytokine association with bacterial DNA in serum of patients with inflammatory bowel disease

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) involves the interaction between genetic susceptibility, mucosal immunity, and intestinal bacteria. Bacterial translocation is a common event in these patients and plays an important role in the perpetuation of chronic intestinal inflammation. Blood microbiological cultures, however, are frequently negative. The aim was to evaluate the presence of bacterial DNA (bactDNA) and the associated cytokine response in patients with IBD.

METHODS

Fifteen healthy donors, 29 patients with ulcerative colitis (UC), and 33 patients with Crohn's disease (CD) were studied. The presence of bactDNA was pursued by PCR followed by nucleotide sequencing analysis. Microbiological cultures were carried out among all controls and patients. Cytokine serum levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

BactDNA was detected in 14 out of 33 patients with CD (42.4%) and in 15 out of 29 patients with UC (51.7%). BactDNA translocation was present in 7 out of 21 (33%) and in 10 out of 15 (34%) patients with CD and UC in remission, respectively. None of healthy controls showed bactDNA in serum. A statistically significant increase in all Th1-derived cytokines in CD but not in UC patients with the presence of bactDNA was observed in comparison with patients without bactDNA and controls.

CONCLUSIONS

BactDNA is present in IBD patients, irrespective of their disease activity. This fact is associated with a marked Th1-driven immune reaction in CD patients, even in those in remission. Whether bactDNA is inducing or is favored by an increased inflammatory scenario in these patients remains under discussion.

Advancement of intestinal function disorders in severe acute pancreatitis

Recent studies indicate that increased intestinal permeability and changes of intestinal mucosal immune function are very common in patients with severe acute pancreatitis (SAP). And they may be the main reasons for bacterial and endotoxin translocation, which are associated with secondary infection and multiorgan dysfunction syndrome in SAP. However, the accurate mechanism underlying the abnormality of intestinal mucosal immune dysfunction is not clarified, which deserves further study.

Increased levels of soluble triggering receptor expressed on myeloid cells-1 in patients with acute pancreatitis

OBJECTIVE

To determine the contribution of triggering receptor expressed on myeloid cells (TREM)-1 in acute pancreatitis (AP).

DESIGN

Prospective study.

SETTING

General intensive care unit at Kobe University Hospital.

PATIENTS

Forty-eight patients with AP and seven patients as control.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured serum concentrations of soluble TREM-1 (sTREM-1) at the time of admission by enzyme-linked immunoadsorbent assay. Serum sTREM-1 levels increased significantly in AP (63 +/- 11 pg/mL) and correlated with Ranson score (R = .628, p < .001) and Acute Physiology and Chronic Health Evaluation II score (R = .504, p < .001). Serum TREM-1 levels were higher in patients with early organ dysfunction (which occurred within 7 days after onset) than those without early organ dysfunction (101 +/- 19 vs. 25 +/- 4 pg/mL, p < .001). Incidences of early organ dysfunction in patients whose serum sTREM-1 levels were < or = 40 and > 40 pg/mL were 17% and 83%, respectively (p < .001). The usefulness of serum sTREM-1 in detecting early organ dysfunction was superior to that of C-reactive protein, interleukin-6, interleukin-8, Ranson score, and Acute Physiology and Chronic Health Evaluation II score. Serum sTREM-1 levels decreased with resolution of early organ dysfunction.

CONCLUSIONS

Serum sTREM-1 levels were significantly increased and correlated with disease severity and early organ dysfunction in patients with AP. Serum sTREM-1 level may be a useful marker for early organ dysfunction in AP.

Alterations in intestinal microbial flora and human disease

PURPOSE OF REVIEW

To highlight the evidence supporting the role of altered commensal gut flora in human disease. While the contribution of the indigenous gut microbial community is widely recognized, only recently has there been evidence pointing to indigenous flora in disease.

RECENT FINDINGS

This review discusses recent evidence pointing to the role of altered commensal gut flora in such common conditions as irritable bowel syndrome and inflammatory bowel disease. Recent studies document the intricate relationship between the vast population of microbes that live in our gut and the human host. Since increased intestinal permeability and immune activation are consequences of an altered host-gut microbial relationship, what are the clinical effects of this shift in relationship?

SUMMARY

We focus on the example of an abnormal expansion of gut microbial flora into the small bowel or small intestinal bacterial overgrowth and discuss the effects of bacterial overgrowth on the human host in acute pancreatitis, bacterial gastroenteritis, irritable bowel syndrome, inflammatory bowel disease, hepatic encephalopathy, and fibromyalgia and burn injury. The identification of the underlying role of altered commensal gut microbiota in these and other human diseases could lead to novel diagnostic and therapeutic strategies that would improve clinical outcome.

Prevention of infection following severe acute pancreatitis

PURPOSE OF REVIEW

This review highlights recently reported strategies aimed at quantifying severity of illness earlier in the course of acute pancreatitis and at preventing secondary infection in pancreatic necrosis.

RECENT FINDINGS

New and improved scoring models appear to suggest that the optimal interventional window is between 24 and 72 h of the onset of severe acute pancreatitis. Prospective randomized clinical trials in which patients with severe acute pancreatitis were treated with broad-spectrum antimicrobial regimens as prophylaxis, however, have demonstrated no benefit in terms of preventing late infection in pancreatic necrosis. In contrast, early enteral nutrition with various formulas and supplements, including probiotics, may confer a clinical advantage in terms of morbidity and mortality.

SUMMARY

Continuing to advocate antimicrobial prophylaxis in severe acute pancreatitis is not reasonable, in view of the evidence now available from two large clinical trials. Current guidelines should be revised because of the potential harm to gastrointestinal ecology associated with long-term antibiotic treatment. A suitable alternative way to prevent bacterial overgrowth and secondary infection is lacking, however.

Early nasogastric enteral nutrition for severe acute pancreatitis: a systematic review

AIM

To evaluate the effectiveness and safety of early nasogastric enteral nutrition (NGEN) for patients with severe acute pancreatitis (SAP).

METHODS

We searched Cochrane Central Register of Controlled Trials (Issue 2, 2006), Pub-Medline (1966-2006), and references from relevant articles. We included randomized controlled trials (RCTs) only, which reported the mortality of SAP patients at least. Two reviewers assessed the quality of each trial and collected data independently. The Cochrane Collaboration's RevMan 4.2.9 software was used for statistical analysis.

RESULTS

Three RCTs were included, involving 131 patients. The baselines of each trial were comparable. Meta-analysis showed no significant differences in mortality rate of SAP patients between nasogastric and conventional routes (RR = 0.76, 95% CI = 0.37 and 1.55, P = 0.45), and in other outcomes, including time of hospital stay (weighted mean difference = -5.87, 95% CI = -20.58 and 8.84, P = 0.43), complication rate of infection (RR = 1.41, 95% CI = 0.62 and 3.23, P = 0.41) or multiple organ deficiency syndrome (RR = 0.97, 95% CI = 0.27 and 3.47, P = 0.97), rate of admission to ICU (RR = 1.00, 95% CI = 0.48 and 2.09, P = 0.99) or conversion to surgery (RR = 0.66, 95% CI = 0.12 and 3.69, P = 0.64), as well as recurrence of re-feeding pain and adverse events associated with nutrition.

CONCLUSION

Early NGEN is a breakthrough in the management of SAP. Based on current studies, early NGEN appears effective and safe. Since the available evidence is poor in quantity, it is hard to make an accurate evaluation of the role of early NGEN in SAP. Before recommendation to clinical practice, further high qualified, large scale, randomized controlled trials are needed.

Review article: bacterial translocation in the critically ill--evidence and methods of prevention

BACKGROUND

Delayed sepsis, systemic inflammatory response syndrome (SIRS) and multiorgan failure remain major causes of morbidity and mortality on intensive care units. One factor thought to be important in the aetiology of SIRS is failure of the intestinal barrier resulting in bacterial translocation and subsequent sepsis.

AIM

This review summarizes the current knowledge about bacterial translocation and methods to prevent it.

METHODS

Relevant studies during 1966-2006 were identified from a literature search. Factors, which detrimentally affect intestinal barrier function, are discussed, as are methods that may attenuate bacterial translocation in the critically ill patient.

RESULTS

Methodological problems in confirming bacterial translocation have restricted investigations to patients undergoing laparotomy. There are only limited data available relating to specific interventions that might preserve intestinal barrier function or limit bacterial translocation in the intensive care setting. These can be categorized broadly into pre-epithelial, epithelial and post-epithelial interventions.

CONCLUSIONS

A better understanding of factors that influence translocation could result in the implementation of interventions which contribute to improved patient outcomes. Glutamine supplementation, targeted nutritional intervention, maintaining splanchnic flow, the judicious use of antibiotics and directed selective gut decontamination regimens hold some promise of limiting bacterial translocation. Further research is required.

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.

Bacterial translocation: overview of mechanisms and clinical impact

Bacterial translocation (BT) is a phenomenon in which live bacteria or its products cross the intestinal barrier. Gut translocation of bacteria has been shown in both animal and human studies. BT and its complications have been shown clearly to occur in animal models, but its existence and importance in humans has been difficult to ascertain. We review the mechanisms of BT and its clinical impact based on the current literature.

Direct detection of Cardiobacterium hominis in serum from a patient with infective endocarditis by broad-range bacterial PCR

Bacterial DNA was detected directly in the serum of a patient with endocarditis by broad-range 16S rRNA PCR followed by sequencing and analysis of the results by the BLAST search. Using these methods, Cardiobacterium hominis was identified in 2 days from the date of serum collection. The microorganism was also isolated and identified using conventional methods (bacterial culture and biochemical tests) 17 days from the date of sample collection. This is the first report showing the direct detection of C. hominis in a patient's serum using molecular-based methods, emphasizing their potential usefulness as additional and rapid diagnostic tools for the detection and identification of fastidious bacteria.