Clinical significance of translocation

Proton-Pump Inhibitors and Risk of Bloodstream Infection without an Identifiable Source: a Hospital-Based Case-Control Study

The association between proton-pump inhibitor (PPI) use and systemic infections caused by bacterial translocation is unclear. This study aimed to investigate whether patients receiving PPI therapy have a higher risk of bloodstream infections (BSI) without an identifiable source of infection. We conducted a hospital-based case-control study which enrolled all patients aged 20 years and older who were hospitalized in Ichinomiya Nishi Hospital with BSI confirmed by two sets of positive blood cultures in 2019. Patient data were collected from medical records, and the bacterial translocation-type (BT-type) BSI group was defined as patients with BSI without an identifiable source of infection, whereas those with a BSI from an identifiable source were assigned to the control group based on the diagnostic criteria for each infectious disease. Data from 309 patients, including 66 cases and 243 controls, were analyzed. Compared with PPI non-users, PPI users had a 2.4-fold higher risk of developing BT-type BSI after controlling for potential confounders (adjusted odds ratio: 2.41, 95% confidence interval: 1.29-4.51, P = 0.006). In conclusion, PPI use is associated with a higher risk of BSI without an identifiable source; therefore, PPI use might increase the risk of BSI secondary to bacterial translocation.

Association between preoperative systemic immune inflammation index and postoperative sepsis in patients with intestinal obstruction: A retrospective observational cohort study

BACKGROUND

Sepsis is a severe complication that results in increased morbidity and mortality after intestinal obstruction surgery. This study examined the role of preoperative systemic immune inflammation index (SII) for postoperative sepsis in intestinal obstruction patients.

METHODS

Data on patients who underwent intestinal obstruction surgery were collected. SII was determined and separated into two groups (≤1792.19 and >1792.19) according to the optimal cut-off value of SII for postoperative sepsis. The odds ratio (OR) is calculated for the correlation between SII and postoperative sepsis. Additional analyses were used to estimate the robustness of SII.

RESULTS

A total of 371 intestinal obstruction patients undergoing surgery were included in the final cohort, and 60 (16.17%) patients developed postoperative sepsis. Patients with an SII ＞1792.19 had a significantly higher risk for developing postoperative sepsis after multivariable adjustment [adjusted odds ratio = 2.12, 95% confidence interval: [1.02-4.40]]. The analysis of interaction showed no correlation between the preoperative SII and postoperative sepsis regarding age, hypertension, American Society of Anesthesiologists classification, blood loss, albumin, hemoglobin, creatinine, and leukocyte (all interactions p > .05). In subgroup analysis, all statistically significant subgroups showed that SII was a risk factor for postoperative sepsis (all p < .05). The analyses of subgroups and interactions revealed that the interaction effect of a preoperative SII ＞1792.19 and postoperative sepsis remained significant. A sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

A preoperative SII ＞ 1792.19 was a risk factor for postoperative sepsis in patients undergoing intestinal obstruction surgery.

Direct-from-Blood Detection of Pathogens: a Review of Technology and Challenges

Blood cultures have been the staple of clinical microbiology laboratories for well over half a century, but gaps remain in our ability to identify the causative agent in patients presenting with signs and symptoms of sepsis. Molecular technologies have revolutionized the clinical microbiology laboratory in many areas but have yet to present a viable alternative to blood cultures. There has been a recent surge of interest in utilizing novel approaches to address this challenge. In this minireview, I discuss whether molecular tools will finally give us the answers we need and the practical challenges of incorporating them into the diagnostic algorithm.

L-FABP and NGAL are novel biomarkers for detection of abdominal injury and hemorrhagic shock

INTRODUCTION

Delayed diagnosis of abdominal injuries and hemorrhagic shock leads to secondary complications and high late mortality in severely traumatized patients. The liver fatty acid-binding protein (L-FABP) is expressed in intestine, liver and kidney; the neutrophil gelatinase-associated lipocalin (NGAL) in colon and kidney. We hypothesized that l-FABP is an early biomarker for abdominal injury and hemorrhagic shock and that l-FABP and NGAL are specific markers for detection of liver and/or kidney injuries.

PATIENTS AND METHODS

Traumatized patients with an age ≥18 years and an abdominal injury (AIS_abd≥2), independently from Injury Severity Score (ISS), were prospectively included from 04/2018 to 05/2021. 68 patients had an abdominal injury ("Abd") and 10 patients had an abdominal injury with hemorrhagic shock ("HS Abd"). 41 patients without abdominal injury and hemorrhagic shock but with an ISS ≥ 25 ("noAbd") were included as control group. Four abdominal subgroups with isolated organ injuries were defined. Plasma l-FABP and NGAL levels were measured at admission (ER) and up to two days post-trauma.

RESULTS

All patient groups had a median ISS≥25. In ER, median l-FABP levels were significantly higher in "HS Abd" group (1209.2 ng/ml [IQR=575.2-1780.3]) compared to "noAbd" group (36.4 ng/ml [IQR=14.8-88.5]), and to "Abd" group (41.4 ng/ml [IQR=18.0-235.5]), p<0.001. In matched-pair-analysis l-FABP levels in the group "Abd" were significantly higher (108.3 ng/ml [IQR=31.4-540.9]) compared to "noAbd" (26.4 ng/ml [IQR=15.5-88.8]), p = 0.0016. l-FABP correlated significantly with clinical parameters of hemorrhagic shock; the optimal cut-off level of l-FABP for detection was 334.3 ng/ml (sensitivity: 90%, specificity: 78%). Median l-FABP-levels were significantly higher in patients with isolated liver or kidney injuries and correlated significantly with AST, ALT and creatinine value. Median NGAL levels in the ER were significantly higher in "HS Abd" group (115.9 ng/ml [IQR=90.6-163.8]) compared to "noAbd" group (58.5 ng/ml [IQR=41.0-89.6],p<0.001) and "Abd" group (70.5 ng/ml [IQR=53.3-115.5], p<0.05). The group "Abd" showed significant higher median NGAL levels compared to "noAbd", p = 0.019. NGAL levels correlated significantly with clinical parameters of hemorrhagic shock.

CONCLUSION

L-FABP and NGAL are novel biomarkers for detection of abdominal trauma and hemorrhagic shock. l-FABP may be a useful and promising parameter in diagnosis of liver and kidney injuries, NGAL failed to achieve the same.

Prolonged lipopolysaccharide-induced illness elevates glucagon-like peptide-1 and suppresses peptide YY: A human-randomized cross-over trial

Severe systemic inflammation is associated with nausea, loss of appetite, and delayed gastric emptying, which increases hospitalization admission length and mortality rate. There is a lack of human controlled studies exploring gastric emptying rates and underlying mechanisms during inflammatory conditions. We aimed to investigate if systemic inflammation in young men delays gastro-intestinal transit times, lowers motility, and affects gastrointestinal hormone secretion. This substudy of a randomized crossover trial investigated eight healthy young men on two separate occasions; (I) following an overnight fast (healthy conditions/HC) and (II) fasting and bedrest combined with two lipopolysaccharide (LPS) injections of 1 ng kg-1 following an overnight fast and 0.5 ng kg-1 following another 24 h (systemic inflammation/SI). A standardized protein beverage and a SmartPill capsule (a wireless gastrointestinal monitoring system) were swallowed during each occasion. Whole gut transit time was comparable between HC and SI. SI decreased gastric mean pressure peak amplitude (p = 0.04) and increased pH rise across the pylorus and small bowel pH (p = 0.02) compared with HC. Glucagon-like peptide-1 was elevated during SI compared with HC (p = 0.04). Peptide YY was lower during SI compared with HC (p = 0.007). Prolonged LPS exposure combined with fasting and bedrest elevated glucagon-like peptide 1 concentrations, which may play a role for the nausea and loss of appetite typically associated with SI.

Pathologic Inflammation in Malnutrition Is Driven by Proinflammatory Intestinal Microbiota, Large Intestine Barrier Dysfunction, and Translocation of Bacterial Lipopolysaccharide

Acute malnutrition, or wasting, is implicated in over half of all deaths in children under five and increases risk of infectious disease. Studies in humans and preclinical models have demonstrated that malnutrition is linked to an immature intestinal microbiota characterized by increased prevalence of Enterobacteriaceae. Observational studies in children with moderate acute malnutrition (MAM) have also observed heightened systemic inflammation and increased circulating bacterial lipopolysaccharides (LPS; endotoxin). However, the mechanisms that underpin the systemic inflammatory state and endotoxemia, and their pathophysiological consequences, remain uncertain. Understanding these pathophysiological mechanisms is necessary to design targeted treatments that will improve the unacceptable rate of failure or relapse that plague current approaches. Here we use a mouse model of MAM to investigate the mechanisms that promote inflammation in the malnourished host. We found that mice with MAM exhibited increased systemic inflammation at baseline, increased translocation of bacteria and bacterial LPS, and an exaggerated response to inflammatory stimuli. An exaggerated response to bacterial LPS was associated with increased acute weight loss. Remarkably, intestinal inflammation and barrier dysfunction was found in the cecum and colon. The cecum showed a dysbiotic microbiota with expansion of Gammaproteobacteria and some Firmicutes, and contraction of Bacteroidetes. These changes were paralleled by an increase in fecal LPS bioactivity. The inflammatory phenotype and weight loss was modulated by oral administration of non-absorbable antibiotics that altered the proportion of cecal Gammaproteobacteria. We propose that the heightened inflammation of acute malnutrition is the result of changes in the intestinal microbiota, intestinal barrier dysfunction in the cecum and colon, and increased systemic exposure to LPS.

Gut Microbiota Interact With the Brain Through Systemic Chronic Inflammation: Implications on Neuroinflammation, Neurodegeneration, and Aging

It has been noticed in recent years that the unfavorable effects of the gut microbiota could exhaust host vigor and life, yet knowledge and theory are just beginning to be established. Increasing documentation suggests that the microbiota-gut-brain axis not only impacts brain cognition and psychiatric symptoms but also precipitates neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). How the blood-brain barrier (BBB), a machinery protecting the central nervous system (CNS) from the systemic circulation, allows the risky factors derived from the gut to be translocated into the brain seems paradoxical. For the unique anatomical, histological, and immunological properties underpinning its permeable dynamics, the BBB has been regarded as a biomarker associated with neural pathogenesis. The BBB permeability of mice and rats caused by GM dysbiosis raises the question of how the GM and its metabolites change BBB permeability and causes the brain pathophysiology of neuroinflammation and neurodegeneration (NF&ND) and brain aging, a pivotal multidisciplinary field tightly associated with immune and chronic systemic inflammation. If not all, gut microbiota-induced systemic chronic inflammation (GM-SCI) mainly refers to excessive gut inflammation caused by gut mucosal immunity dysregulation, which is often influenced by dietary components and age, is produced at the interface of the intestinal barrier (IB) or exacerbated after IB disruption, initiates various common chronic diseases along its dispersal routes, and eventually impairs BBB integrity to cause NF&ND and brain aging. To illustrate the immune roles of the BBB in pathophysiology affected by inflammatory or "leaky" IB resulting from GM and their metabolites, we reviewed the selected publications, including the role of the BBB as the immune barrier, systemic chronic inflammation and inflammation influences on BBB permeability, NF&ND, and brain aging. To add depth to the bridging role of systemic chronic inflammation, a plausible mechanism indispensable for BBB corruption was highlighted; namely, BBB maintenance cues are affected by inflammatory cytokines, which may help to understand how GM and its metabolites play a major role in NF&ND and aging.

Efficacy and Safety of Faecal Microbiota Transplantation for Acute Pancreatitis: A Randomised, Controlled Study

Aims: We investigated whether faecal microbiota transplantation (FMT) decreases intra-abdominal pressure (IAP) and improves gastrointestinal (GI) dysfunction and infectious complications in acute pancreatitis (AP). Methods: In this first randomised, single-blind, parallel-group, controlled study, we recruited and enrolled consecutive patients with AP complicated with GI dysfunction. Eligible participants were randomly assigned to receive faecal transplant (n = 30) or normal saline (n = 30) via a nasoduodenal tube once and then again 2 days later. The primary endpoint was the rate of IAP decline; secondary endpoints were GI function, infectious complications, organ failure, hospital stay and mortality. Analyses were based on intention to treat. Results: We enrolled 60 participants and randomly assigned them to the FMT (n = 30) or control (n = 30) group. Baseline characteristics and disease severity were similar for both groups. IAP decreased significantly 1 week after intervention in both groups, with no difference in the IAP decline rate between FMT and Control group [0.1 (-0.6, 0.5) vs. 0.2 (-0.2, 0.6); P = 0.27]. Normal gastrointestinal failure (GIF) scores were achieved in 12 (40%) patients in the FMT group and 14 (47%) in the control group, with no significant difference (P = 0.60). However, D-lactate was significantly elevated in the FMT group compared to the control group, as calculated by the rate of decline [-0.3 (-3.7, 0.8) vs. 0.4 (-1.1, 0.9); P = 0.01]. Infectious complications occurred in 15 (50%) and 16 (53.33%) patients in the FMT and control groups, respectively (P = 0.80). However, interleukin-6 (IL-6) was significantly elevated in the FMT group compared to the control group, as calculated by the rate of decline [0.4 (-3.6, 0.9) vs. 0.8 (-1.7, 1.0); P = 0.03]. One participant experienced transient nausea immediately after FMT, but no serious adverse events were attributed to FMT. Conclusion: FMT had no obvious effect on IAP and infectious complications in AP patients, though GI barrier indictors might be adversely affected. Further multi-centre studies are needed to confirm our findings. The study was registered at https://clinicaltrials.gov (NCT02318134).

[Nasointestinal intubation in the treatment of acute adhesive small bowel obstruction]

Proximal gastrointestinal decompression is essential in the treatment of acute adhesive small bowel obstruction. Improvement of endoscopic methods, surgical instruments and radiological methods of control makes it possible to timely assess lavage and intra-intestinal therapy. The review presents current views on upper gastrointestinal decompression and other options for the treatment of adhesive small bowel obstruction.

Environmental, Metabolic, and Inflammatory Factors Converge in the Pathogenesis of Moderate Acute Malnutrition in Children: An Observational Cohort Study

Acute malnutrition affects more than 50 million children worldwide. These children are at an increased risk of morbidity and mortality from infectious disease. However, the pathogenesis of acute malnutrition and mechanisms underlying the increased risk and poor outcomes from infection are not well understood. Our objective was to identify differences in inflammation and inflammatory responses between children with moderate acute malnutrition (MAM) and healthy controls (HCs), and search for environmental, pathophysiological, and metabolic factors that may influence this response. Sixteen children with MAM and 16 HCs aged 18-36 months were studied in Nairobi, Kenya. None of the children had symptoms of an infectious disease (fever, diarrhea, or cough) in the 2 weeks before enrollment and sample collection. Demographic and health data were provided by their primary caregivers. Blood samples were collected to measure various biomarkers and the response to an inflammatory stimulus. Children with MAM were more frequently from households with contaminated water, crowding, and unstable income sources. They also had increases in basal inflammation, circulating bacterial lipopolysaccharide (LPS), markers of intestinal damage, and an exaggerated whole blood inflammatory response to LPS. Metabolic changes in children with MAM led to increased plasma levels of long-chain fatty acids, which were found to contribute to the pro-inflammatory state. These exploratory findings suggest convergence of multiple factors to promote dysregulated inflammatory responses and prompt several mechanistic hypotheses that can be pursued to better understand the pathogenesis of MAM.

Correlation between Multidrug-Resistant Bacteria Colonization and Bloodstream Infections in Children with Hematolymphoid Malignancies at a Tertiary Cancer Center in India

Background Bloodstream infections with drug-resistant bacteria are associated with a higher morbidity and mortality. Based on previous studies in our institution demonstrating a rising incidence of multidrug resistant organism (MDR) bacteria in bloodstream infections (BSI) and high prevalence of enteric colonization with MDR, the “de-escalation” strategy for empirical antibiotics was adopted in the management of febrile neutropenia in children with hematolymphoid malignancies and MDR colonization. An audit was carried out to determine whether surveillance rectal swabs correlated with blood cultures in febrile neutropenia.

Methods Patient data from January 2015 to July 2016 was examined. Rectal swabs of children with hematolymphoid malignancies were obtained at presentation. Blood cultures were taken during febrile neutropenia. Data were analyzed using SPSS version 24.0. The significance level was set at p < 0.05.

Results Most patients (62.1%) with confirmed BSI were colonized with either extended-spectrum β-lactamase producing organisms (ESBLO) (31.9%) or MDR (30.2%). Majority 116 (62.7%) developed BSI caused by either MDR or ESBLO. In contrast, only 12 (10.6%) patients colonized by sensitive bacteria, developed BSI caused by either MDR or ESBLO. These differences were statistically significant (p < 0.001). Thus, the baseline rectal swab had a sensitivity and a specificity of 90.6% and 59.4%, respectively, in predicting BSI with either MDR or ESBLO.

Conclusions We conclude that high prevalence of MDR colonization at presentation significantly results in MDR BSI, which further results in a significant increase in intensive care unit admissions and mortality. This would justify the use of a “de-escalation” antibiotic policy. Whether such a strategy has been successful in impacting outcomes, would need further study.

Evaluation of a Nasoenteral Feeding Tube With Balloon to Facilitate Placement

BACKGROUND

Enteral feeding is essential for critically ill, head trauma, and burn patients who are unable to swallow.

OBJECTIVE

To evaluate a new nasoenteral feeding tube with distal tip balloon designed to facilitate post-pyloric migration and avoid misplacement in the trachea.

METHODS

A case series was conducted in 50 critically ill patients aged 19 to 89 years receiving mechanical ventilation and requiring enteral nutrition in a teaching hospital. Patients received a soft, flexible, kink-resistant nasoenteral feeding tube with a balloon near the distal tip to enhance postpyloric migration by peristalsis. The feeding tube was inserted with a novel thread technique to reduce posterior nasopharyngeal trauma and tube misplacement. Pulse oximetry provided early detection of misplacement into the trachea. Placement was verified by abdominal radiography performed shortly after the procedure and repeated within 24 hours if needed.

RESULTS

Postpyloric placement was achieved at 30 minutes in 24% of patients and by the following morning in 70% of patients. Tracheal intubation occurred in 1 patient but was recognized and corrected without injury. No tube occlusion from kinking occurred.

CONCLUSIONS

Early gastric or postpyloric feeding can be provided with this novel feeding tube. Its use facilitates quick bedside recognition of accidental misplacement in the trachea, reducing the chance of pneumothorax. The tip balloon reduces deeper placement into a lung and promotes distal migration into the small intestine. The design prevents occlusion from kinking, which is common with conventional feeding tubes. Nurses easily adopted the tube and insertion technique.

Autotaxin loss accelerates intestinal inflammation by suppressing TLR4-mediated immune responses

Autotaxin (ATX) converts lysophosphatidylcholine and sphingosyl-phosphorylcholine into lysophosphatidic acid and sphingosine 1-phosphate, respectively. Despite the pivotal function of ATX in lipid metabolism, mechanisms by which ATX regulates immune and inflammatory disorders remain elusive. Here, using myeloid cell lineage-restricted Atx knockout mice, we show that Atx deficiency disrupts membrane microdomains and lipid rafts, resulting in the inhibition of Toll-like receptor 4 (TLR4) complex formation and the suppression of adaptor recruitment, thereby inhibiting TLR4-mediated responses in macrophages. Accordingly, TLR4-induced innate immune functions, including phagocytosis and iNOS expression, are attenuated in Atx-deficient macrophages. Consequently, Atx^-/- mice exhibit a higher bacterial prevalence in the intestinal mucosa compared to controls. When combined with global Il10^-/- mice, which show spontaneous colitis due to the translocation of luminal commensal microbes into the mucosa, myeloid cell lineage-restricted Atx knockout accelerates colitis development compared to control littermates. Collectively, our data reveal that Atx deficiency compromises innate immune responses, thereby promoting microbe-associated gut inflammation.

Microbiome signatures in neonatal central line associated bloodstream infections

Neonates are at high risk for central line associated bloodstream infections (CLABSI). Biofilm formation is universal on indwelling catheters but why some biofilms seed the bloodstream to cause CLABSI is not clearly understood. With the objective to test the hypothesis that catheter biofilm microbiome in neonates with CLABSI differs than those without infection, we prospectively enrolled neonates (n = 30) with infected and uninfected indwelling central catheters. Catheters were collected at the time of removal, along with blood samples and skin swabs at the catheter insertion sites. Microbiomes of catheter biofilms, skin swabs and blood were evaluated by profiling the V4 region of the bacterial 16S rRNA gene using Illumina MiSeq sequencing platform. The microbial DNA load was higher from catheter biofilms of CLABSI patients without differences in alpha diversity when compared to that of the non-CLABSI neonates. Proteus and unclassified Staphylococcaceae were more abundant in infected catheter biofilms while Bradyrhizobium, Cloacibacterium, and Sphingomonas were more abundant in the uninfected catheters. A blood microbiome was detected in uninfected samples. The blood microbiome in CLABSI neonates clustered separately from the uninfected blood samples in beta diversity plots. We found that the microbiome signature in catheter biofilm and blood of neonates with CLABSI is different than the microbiomes of non-CLABSI neonates.

Is I-FABP not only a marker for the detection abdominal injury but also of hemorrhagic shock in severely injured trauma patients?

Background

Hemorrhagic shock can lead to intestinal damage with subsequent hyperinflammation and multiple organ dysfunction syndrome (MODS). The intestinal fatty acid-binding protein (I-FABP) is solely expressed in the intestine and is released extracellulary after tissue damage. This study evaluates the validity of I-FABP as an early biomarker to detect hemorrhagic shock and abdominal injury.

Patients and methods

Severely injured patients with an Injury Severity Score (ISS) ≥ 16 points and an age ≥ 18 years, admitted from January 2010 to December 2016, were included. Overall, 26 patients retrospectively presented with hemorrhagic shock to the emergency room (ER): 8 patients without abdominal injury ("HS noAbd") and 18 patients with abdominal injury ("HS Abd"). Furthermore, 16 severely injured patients without hemorrhagic shock and without abdominal injury ("noHS noAbd") were retrospectively selected as controls. Plasma I-FABP levels were measured at admission to the ER and up to 3 days posttraumatic (d1-d3).

Results

Median I-FABP levels were significantly higher in the "HS Abd" group compared with the "HS noAbd" group (28,637.0 pg/ml [IQR = 6372.4-55,550.0] vs. 7292.3 pg/ml [IQR = 1282.5-11,159.5], p < 0.05). Furthermore, I-FABP levels of both hemorrhagic shock groups were significantly higher compared with the "noHS noAbd" group (844.4 pg/ml [IQR = 530.0-1432.9], p < 0.05). The time course of I-FABP levels showed a peak on the day of admission with a subsequent decline in the post-traumatic course. Furthermore, significant correlations between I-FABP levels and clinical parameters of hemorrhagic shock, such as hemoglobin, lactate value, systolic blood pressure (SBP), and shock index, were found.The optimal cut-off level of I-FABP for detection of hemorrhagic shock was 1761.9 pg/ml with a sensitivity of 85% and a specificity of 81%.

Conclusion

This study confirmed our previous observation that I-FABP might be used as a suitable early biomarker for the detection of abdominal injuries in general. In addition, I-FABP may also be a useful and a promising parameter in the diagnosis of hemorrhagic shock, because of reflecting low intestinal perfusion.

Are Probiotic Really Safe for Humans?

Probiotic bacteria have been used as a health-promoting factor for a very long time. Nowadays, products containing probiotic bacteria are becoming more and more popular on the market. The term probiotics refers to the products belonging to the following groups: probiotic drugs (medicinal products – live biotherapeutic products for human use), medical devices, probiotic foods (e.g. foods, food ingredients, dietary supplements or food for special medical purposes), directly fed microorganisms (for animal use) and designer probiotics (genetically modified probiotics). Safety assessment of bacterial strains used as probiotics should be carefully studied. Even though probiotic bacteria have the generally recognized as safe (GRAS status), there are several reports about side effects triggered by the presence of these organisms. Microorganisms used as probiotics may cause systemic infections, stimulate the immune system, disturb metabolism and participate in horizontal gene transfer.

Detection of endotoxin in plasma of hospitalized diarrheic calves

OBJECTIVES

To investigate whether lipopolysaccharide (LPS) is present in plasma of calves with naturally occurring diarrhea. The second objective was to determine whether plasma [LPS] correlates with clinical, hematological, biochemical, and acid-base variables, and whether [LPS] differs between surviving and nonsurviving diarrheic calves.

DESIGN

Prospective observational study (January 2012-May 2014).

SETTING

Veterinary teaching hospital.

ANIMALS

Thirty-four calves <28 days old admitted for diagnosis and treatment of diarrhea and 30 healthy control calves.

MEASUREMENTS AND MAIN RESULTS

Admission demographics, physical examination, blood gas, biochemistry analysis, and outcome data were recorded. Plasma concentration of LPS was determined using a bovine LPS ELISA assay. Plasma [LPS] was detected in both healthy and diarrheic calves. Plasma [LPS] was significantly higher in diarrheic than healthy calves (median: 0.99 ng/mL; Interquartile range (IQR): 0.068, vs 0.88 ng/mL; 0.065 ng/mL, respectively; P < 0.001). Plasma [LPS] was higher in nonsurviving (1.04 ng/mL; 0.07 ng/mL) than in surviving calves (0.98 ng/mL; 0.022 ng/mL; P < 0.001). Plasma [LPS] was higher in beef (1.07 ng/mL; 0.182 ng/mL) than in dairy diarrheic calves (0.99 ng/mL; 0.022 ng/mL; P < 0.001). In diarrheic calves, plasma [LPS] correlated with [l-lactate] (r² = 0.496; P = 0.002); hypoglycemia (r² = -0.453; P = 0.007); increased unmeasured strong ions (r² = 0.332; P = 0.050), [Mg²⁺ ] (r² = 0.475; P = 0.004), and [phosphate] (r² = 0.468; P = 0.005), and increased aspartate aminotransferase activity (r² = 0.348; P = 0.003).

CONCLUSIONS

This study highlights a potential role of LPS in the pathogenesis of metabolic derangements such as hyperlactatemia, hypoglycemia, and increased concentration of unmeasured strong anions in diarrheic calves. Further investigation evaluating the effect of LPS on l-lactate and glucose metabolism in diarrheic calves is warranted.

Physiological Effects of Dietary Amino Acids on Gut Health and Functions of Swine

Gut health has significant implications for swine overall health status and nutrient utilization, due to its various functions including digestion and absorption of nutrients, secretion of mucins and immunoglobulins, and selective barrier protection against harmful antigens and pathogens. Both the basic anatomical structure of the gut (such as epithelial cells) and its luminal microbiota play important roles for maintaining gut health and functions. The interactions between epithelial cells and luminal microbiota have significant impact on host nutrition and health through the metabolism of dietary components. Amino acids, which are major nutrients for pigs, are not only obligatory for maintaining the intestinal mucosal mass and integrity, but also for supporting the growth of microorganisms in the gut. Dietary amino acids are the major fuel of the small intestinal mucosa. Particularly, glutamate, glutamine, and aspartate are the major oxidative fuel of the intestine. Emerging evidence shows that arginine activates the mTOR signaling pathway in the small intestine. Utilization of glycine by the small intestinal mucosa to synthesize glutathione is a very important physiological pathway, and the role of glycine as a powerful cytoprotectant has also been recognized. The major end products of methionine and cysteine metabolism are glutathione, homocysteine and taurine, which play important roles in the intestinal immune and anti-oxidative responses. Threonine is highly utilized by the gut and is particularly important for mucin synthesis and maintenance of gut barrier integrity. Moreover, either a deficiency or an excess of dietary threonine can reduce the synthesis of intestinal mucosal proteins and mucins in young pigs. Various new functions of amino acids on gut health and functions have been discovered in recent years. Thus, this review is to provide some up-to-date knowledge for industry application of dietary amino acids in order to enhance swine gut health and functions, and also it is to provide a comprehensive reference for further scientific research in this regard.

Burn injury alters the intestinal microbiome's taxonomic composition and functional gene expression

Burn patients have a high risk of sepsis-related mortality even after surviving the initial injury. Immunosuppression increases the risk of sepsis after burn injury, as does the disruption of the intestinal epithelial barrier, which allows the translocation of bacteria and bacterial products into the circulation. The integrity of the intestinal epithelial barrier is largely maintained by the intestinal microbiota. Burn injury has been reported to result in significant changes in the intestinal microbiome composition. In this mouse study, we confirm these taxonomic differences in a full-thickness scald injury model using CF-1 mice. For the first time, we also address alterations in functional gene expression of the intestinal microbiota after burn injury to assess the microbiome's physiological capabilities for overgrowth and pathogenic invasion: 38 pathways were differentially abundant between the sham and burn injury mice, including bacterial invasion of epithelial cells and gap- and adherens junction pathways.

Gastrointestinal Colonization of Candida Albicans Increases Serum (1→3)-β-D-Glucan, without Candidemia, and Worsens Cecal Ligation and Puncture Sepsis in Murine Model

The role of intestinal Candida albicans in bacterial sepsis, in the absence of candidemia, was investigated in murine models. Live C albicans or normal saline solution (NSS) was administered orally once, followed by 5 days of daily oral antibiotic-mixtures (ATB). Cecal ligation and puncture (CLP) was then performed to induce sepsis.Fecal Candida was detected by culture only in models with Candida administration. Oral Candida administration with/without ATB enhanced gut-pathogenic bacteria as determined by microbiome analysis. Despite negative candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida preconditioning models than in CLP-controls (NSS-preconditioning) at 6 and/or 18 h post-CLP. Blood bacterial burdens were not increased with Candida administration.Additionally, CLP with high-dose Candida (10 colony forming units) induced higher levels of fecal Candida, serum BG, serum IL-6, and mortality than the lowest dose (100 colony forming units). Interestingly, fluconazole attenuated fecal Candida and improved survival in mice with live-Candida administration, but not in the CLP-controls. Heat-killed Candida preparations or their supernatants reduced bone marrow-derived macrophage killing activity in vitro but enhanced cytokine production.In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis severity, perhaps through cytokine storm induction and/or decreased macrophage killing activity. These observations suggest that further investigation of the potential role of intestinal fungal burdens in sepsis is warranted.

Role of lipoproteins and proprotein convertase subtilisin/kexin type 9 in endotoxin clearance in sepsis

PURPOSE OF REVIEW

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition is a recent high-impact cardiovascular intervention aimed at reducing low-density lipoprotein (LDL) cholesterol levels. Notably, pathogen lipids are also carried in lipoprotein particles and are cleared by hepatocyte LDL receptors. Therefore, the role of PCSK9 in sepsis is reviewed.

RECENT FINDINGS

Endogenous PCSK9 decreases clearance of LDL cholesterol by decreasing the number of LDL receptors on hepatocytes. Similarly, PCSK9 decreases clearance of pathogen lipids, such as endotoxin, carried in LDL. Pathogen lipids, such as lipopolysaccharide (LPS) from gram-negative organisms or lipoteichoic acid from gram-positive organisms, are carried in high-density lipoprotein, LDL, and very low-density lipoprotein particles. Transfer proteins that handle pathogen lipids (e.g., LPS binding protein) are homologous to transfer proteins that handle cholesterol (e.g., phospholipid transfer protein, cholesterol ester transfer protein). Reduction in PCSK9 function results in increased LPS clearance, a decreased inflammatory response, and improved clinical outcomes in mice. PCSK9 inhibition improves survival in septic mice. Similarly, humans who carry loss-of-function variants of the PCSK9 gene have increased survival in sepsis.

SUMMARY

PCSK9 inhibition may be a useful strategy to increase pathogen lipid clearance in the treatment of patients with sepsis.

Interactions of Gut Microbiota, Endotoxemia, Immune Function, and Diet in Exertional Heatstroke

Exertional heatstroke (EHS) is a medical emergency that cannot be predicted, requires immediate whole-body cooling to reduce elevated internal body temperature, and is influenced by numerous host and environmental factors. Widely accepted predisposing factors (PDF) include prolonged or intense exercise, lack of heat acclimatization, sleep deprivation, dehydration, diet, alcohol abuse, drug use, chronic inflammation, febrile illness, older age, and nonsteroidal anti-inflammatory drug use. The present review links these factors to the human intestinal microbiota (IM) and diet, which previously have not been appreciated as PDF. This review also describes plausible mechanisms by which these PDF lead to EHS: endotoxemia resulting from elevated plasma lipopolysaccharide (i.e., a structural component of the outer membrane of Gram-negative bacteria) and tissue injury from oxygen free radicals. We propose that recognizing the lifestyle and host factors which are influenced by intestine-microbial interactions, and modifying habitual dietary patterns to alter the IM ecosystem, will encourage efficient immune function, optimize the intestinal epithelial barrier, and reduce EHS morbidity and mortality.

Fecal Microbiota Transplant Restores Mucosal Integrity in a Murine Model of Burn Injury

The gut microbiome is a community of commensal organisms that are known to play a role in nutrient production as well as gut homeostasis. The composition of the gut flora can be affected by many factors; however, the impact of burn injury on the microbiome is not fully known. Here, we hypothesized that burn-induced changes to the microbiome would impact overall colon health. After scald-burn injury, cecal samples were analyzed for aerobic and anaerobic colony forming units, bacterial community, and butyrate levels. In addition, colon and total intestinal permeabilities were determined. These parameters were further determined in a germ-reduced murine model. Following both burn injury and germ reduction, we observed decreases in aerobic and anaerobic bacteria, increased colon permeability and no change to small intestinal permeability. After burn injury, we further observed a significant decrease in the butyrate producing bacteria R. Gnavus, C. Eutactus, and Roseburia species as well as decreases in colonic butyrate. Finally, in mice that underwent burn followed by fecal microbiota transplant, bacteria levels and mucosal integrity were restored. Altogether our data demonstrate that burn injury can alter the microbiome leading to decreased butyrate levels and increased colon permeability. Of interest, fecal microbiota transplant treatment was able to ameliorate the burn-induced changes in colon permeability. Thus, fecal transplantation may represent a novel therapy in restoring colon health after burn injury.

Oral administration of live- or heat-killed Candida albicans worsened cecal ligation and puncture sepsis in a murine model possibly due to an increased serum (1→3)-β-D-glucan

Candida albicans is the most common fungus in the human intestinal microbiota but not in mice. To make a murine sepsis model more closely resemble human sepsis and to explore the role of intestinal C. albicans, in the absence of candidemia, in bacterial sepsis, live- or heat-killed C. albicans was orally administered to mice at 3h prior to cecal ligation and puncture (CLP). A higher mortality rate of CLP was demonstrated with Candida-administration (live- or heat-killed) prior to CLP. Fecal Candida presented only in experiments with live-Candida administration. Despite the absence of candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida-administration than CLP-controls (normal saline administration) at 6h and/or 18h post-CLP. Interestingly, fluconazole attenuated the fecal Candida burden and improved survival in mice with live-Candida administration, but not CLP-control. Microbiota analysis revealed increased Bacteroides spp. and reduced Lactobacillus spp. in feces after Candida administration. Additionally, synergy in the elicitation of cytokine production from bone marrow-derived macrophages, in vitro, was demonstrated by co-exposure to heat-killed E. coli and BG. In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis-severity, perhaps through enhanced cytokine elicitation induced by synergistic responses to molecules from gut-derived bacteria and fungi. Conversely, reducing intestinal fungal burdens decreased serum BG and attenuated sepsis in our model.

Patients with chronic kidney disease have abnormal upper gastro-intestinal tract digestive function: A study of uremic enteropathy

BACKGROUND AND AIM

Chronic kidney disease (CKD) affects gastrointestinal (GI) function and results in numerous adaptive and maladaptive responses. Disruption of the colonic microbiome and its attendant consequences-the loss of gut barrier integrity and increased generation of uremic toxins-has become well-recognized. However, less attention has been paid to characterizing the mechanisms behind dysfunction of the upper GI tract, largely owing to the difficulty of studying small bowel function in vivo. This present study was designed to comprehensively describe upper GI function in those with advanced renal impairment.

METHODS

Thirty-five non-diabetic subjects (12 CKD stage 4/5 patients, 23 healthy controls) underwent detailed GI magnetic resonance imaging (MRI) in both fasted and fed states. Upper GI function was assessed by quantification of gastric emptying and intra-luminal small bowel water. Characterization of hydration and cardiovascular status was performed at baseline. Gut barrier integrity was assessed using serum endotoxin level.

RESULTS

Chronic kidney disease was associated with dysmotility (gastric half-emptying time 96 ± 32 vs 74 ± 27 min, P = 0.04) and reduced fasting and post-prandial small bowel water (36 ± 22 mL vs 78 ± 42 mL, P < 0.001), reflecting abnormal digestive secretion, and absorption. This was related to the degree of endotoxemia (r = -0.60, P = 0.04) and poorer symptom scores, but not to disease severity, arterial stiffness or hydration status.

CONCLUSION

Chronic kidney disease adversely affects digestive function. Abnormalities in digestive secretion and absorption may potentially have a broad impact in the prevention and treatment of both CKD and its complications. Further study is required to assess the factors that contribute to this dysfunction in a wider CKD population.

Prebiotics: A Novel Approach to Treat Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the fatal malignancies and is considered as the third leading cause of death. Mutations, genetic modifications, dietary aflatoxins, or impairments in the regulation of oncogenic pathways may bring about liver cancer. An effective barrier against hepatotoxins is offered by gut-liver axis as a change in gut permeability and expanded translocation of lipopolysaccharides triggers the activation of Toll-like receptors which stimulate the process of hepatocarcinogenesis. Prebiotics, nondigestible oligosaccharides, have a pivotal role to play when it comes to inducing an antitumor effect. A healthy gut flora balance is imperative to downregulation of inflammatory cytokines and reducing lipopolysaccharides induced endotoxemia, thus inducing the antitumor effect.

Cocaine Hepatotoxicity and Its Potentiation by Lipopolysaccharide: Treatment and Gender Effects

This study was conducted to investigate the effect of a 7-day treatment as well as the influence of gender on cocaine hepatotoxicity (CH). Lipopolysaccharide (LPS) potentiation of CH was also investigated. Male and female CF-1 mice were orally administered 20 mg/kg body weight cocaine hydrochloride once daily for 7 days. Four hours after the last cocaine administration, the mice were administered 12 × 106 EU LPS (or equal volume of sterile saline) intraperitoneally. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were evaluated as indices of liver injury. Blood and liver glutathione (GSH), glutathione reductase (GRx), and catalase (CAT) activities were also determined to investigate the oxidation stress induced by the treatment. Plasma ALT and AST concentrations were elevated in all males receiving cocaine alone or cocaine + LPS. Furthermore, blood GSH and CAT were decreased and GRx activity was elevated in the same males. Histological analysis revealed a high degree of focal necrosis in the male cocaine group, and severe necrosis in the male cocaine + LPS group. Unlike males, females showed no effect of either cocaine alone or cocaine + LPS treatments. These results indicate that gender plays a significant role in CH and its potentiation by LPS and lengthening the administration by two treatments increased the severity of cocaine + LPS hepatotoxicity dramatically in male mice.

Influence of Gender on Cocaine Hepatotoxicity in CF-1 Mice

Gender is known to play a role in the bioavailability, metabolism, and lethality of many toxic substances. This study was conducted to investigate the influence of gender on cocaine hepatotoxicity (CH) and lipopolysaccharide (LPS) potentiation of CH. Male and female CF-1 mice were orally administered 20 mg/kg body weight cocaine hydrochloride once daily for 7 days. Four hours after the last cocaine administration, the mice were administered 12 × 106 EU LPS (or equal volume of sterile saline) intraperitoneally. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were evaluated as indices of liver injury. Blood and liver glutathione (GSH), glutathione reductase (GRx), and catalase (CAT) activities were also determined to investigate the extent of oxidative stress induced by the treatments. Serum ALT and AST concentrations were elevated in all males receiving cocaine alone or cocaine + LPS. Furthermore, blood GSH and CAT were decreased and GRx activity was elevated in these same animals. Histological analysis revealed a high degree of hepatic focal necrosis in the male cocaine group, and severe hemorrhagic necrosis in the male cocaine + LPS group. Unlike males, females showed no damage resulting from cocaine or cocaine + LPS exposure, whereas testosterone-supplemented ovariectomized females displayed histological and biochemical profiles statistically similar to males. The results demonstrate that the extent of CH or LPS-potentiated CH is influenced by gender and sex hormones, particularly testosterone.

Heat stroke

Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling.

Association of increased rate of condemnation of broiler carcasses due to hepatic abnormalities with immunosuppressive diseases in the broiler chicken industry in Saskatchewan

The objective of this study was to identify the causative agents of hepatitis observed in broiler chickens at processing. Livers of chickens from 16 broiler farms in Saskatchewan with gross lesions of hepatitis were collected at processing. In addition to routine bacterial isolation and histopathological examination, serologic studies for infectious bursal disease virus (IBDV) and Chicken anaemia virus (CAV), calculation of the ratio of the weight of the bursa of Fabricius (BF) to body weight (BBW), and histopathological examination of the BF were done. Of the 264 livers with gross lesions, 83% had multifocal to coalescing necrotizing hepatitis, 16% had perihepatitis, and 1% had hemorrhages. No definitive causative microorganisms were isolated from the hepatic lesions; however, no significant bacterial isolations were made. Bursal atrophy, low BBW ratio, and high titer of antibody against IBDV each correlated with the rate of total condemnations (P = 0.0188, P = 0.0001, and P = 0.0073, respectively). Nucleotide sequencing of IBDV isolated from the BF identified the variant strains Delaware-E and 586. Condemnation because of hepatic lesions was correlated with titer of antibody against IBDV and BBW (P = 0.016 and P = 0.027). The results of this study demonstrate that hepatic lesions in Saskatchewan chickens are not currently caused by a primary bacterial pathogen but are associated with indicators of immunosuppression that is likely due to variant IBDV.

Hepatic abscesses after adhesiolysis

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Prolonged ileus can cause bacterial translocation.

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Development of hepatic abscesses after ileus is possible.

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Prophylactic antibiotics should always be considered.

Introduction

Hematogenous spread of bacteria from the bowel due to bacterial translocation has been postulated in animal and trauma studies. This case presents a patient with possible hematogenous bacterial spreading after acute laparotomy.

Case presentation

A 57-year old woman was admitted with abdominal pain. A computed tomography showed mechanical small bowel obstruction. A laparotomy was performed showing no contamination, and no bowel resection was performed. The patient was not given any antibiotics during this time. The patient was re-admitted 24 h after discharge with fever, elevated white count and abdominal pain. A computed tomography showed newly developed intrahepatic abscesses. These were treated with antibiotics, and the patient was discharged with follow-up ultrasound showing diminished abscesses.

Discussion

This case discusses the possible pathophysiology behind the development of intrahepatic abscesses after small bowel obstruction.

Conclusion

Febrilia and pain in upper right quadrant of the abdomen days after a simple operation for bowel obstruction could be caused by translocation of intestinal bacteria and subsequent formation of hepatic abscesses.

Periarrest intestinal bacterial translocation and resuscitation outcome

During the periarrest period, intestinal ischemia may result in barrier dysfunction and bacterial translocation, which has clear mechanistic links to inflammation and cascade stimulation, especially in patients who are treated with therapeutic hypothermia. Despite optimal management, periarrest bacterial translocation may worsen the outcome of cardiac arrest victims.

Rhein inhibits lipopolysaccharide-induced intestinal injury during sepsis by blocking the toll-like receptor 4 nuclear factor-κB pathway

Sepsis is one of the leading causes of mortality in severe systemic inflammatory syndrome. The endotoxin-induced inflammatory response has been linked to the development of sepsis. Rhein is a lipophilic anthraquinone isolated from Rheum rhabarbarum (rhubarb), which has a protective effect on intestinal damage in vivo. However, the underlying mechanism responsible for the protective effects of rhein remains to be elucidated. In the present study, mice were exposed to 20 mg/kg lipopolysaccharide (LPS), prior to being treated with either 100 mg/kg rhein or 0.3 mg/kg toll‑like receptor 4 (TLR4) signaling inhibitor TAK‑242. In the rhein‑treated mice, the colon length (cm) was extended and colon injury was attenuated. In addition, treatment with rhein significantly decreased the expression levels of the LPS‑induced inflammatory cytokines interleukin (IL)‑1β, IL‑6, IL‑8, and tumor necrosis factor‑α, in both the plasma and colon tissue. However, mice treated with TAK‑242 exhibited increased expression levels of IL‑10, as determined by ELISA and western blot analysis. In addition, immunohistochemistry and western blot analyses demonstrated that treatment with rhein was able to reduce TLR4 expression and inhibit nuclear factor‑κB (NF‑κB) phosphorylation in colon tissue. Furthermore, LPS induction was blocked by TAK‑242. These results demonstrate that the observed rhein‑attenuated inflammatory response during sepsis may be achieved via the TLR4 NF‑κB signaling pathway. In conclusion, the results of the present study provide a novel insight into the protective effects of rhein on LPS‑induced intestinal inflammation, and demonstrate that rhein may act as a beneficial therapeutic agent in the treatment of sepsis-induced intestinal damage.

Fecal ESBL Escherichia coli carriage as a risk factor for bacteremia in patients with hematological malignancies

PURPOSE

The purpose of this study is to evaluate the impact of fecal extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) colonization for bloodstream infection (BSI), clinical outcome, and costs in patients with hematologic malignancies (HM) and severe neutropenia.

METHODS

This is a cohort study, carried out at a cancer-referral hospital. The study population comprises patients with HM, hospitalized prior to administration of the first chemotherapy cycle. A stool culture was taken during the first 48 h; they were grouped as colonized by ESBL-EC or non-ESBL-EC. Patients were followed upon completion of chemotherapy or death. The sum of the days of antibiotics and the length of stay of all hospitalizations in the different cycles of chemotherapy were recorded.

RESULTS

We included 126 patients with a recent diagnosis of HM, grouped as 63 patients colonized by ESBL-EC and 63 colonized by non-ESBL-EC, aged 42 ± 16 years old, 78 males (62%). BSI by ESBL-EC developed in 14 patients (22.2%) colonized by the same strain and in 5 (7.9%) in the group colonized with non-ESBL-EC. BSI by non-ESBL-EC was observed in 3 patients (4.7%) colonized by ESBL-EC and in 17 (26.9%) patients colonized by non-ESBL-EC. Colonization with ESBL-EC increased the risk of BSI by the same strain (relative risk (RR) = 3.4, 95% confidence interval (95% CI) 1.5-7.8, p = 0.001), shorter time to death (74 ± 62 vs. 95 ± 83 days, p < 0.001), longer hospital stay (64 ± 39 vs. 48 ± 32 days, p = 0.01), and higher infection-related costs ($6528 ± $4348 vs. $4722 ± $3173, p = 0.01). There was no difference in overall mortality between both groups.

CONCLUSIONS

Fecal colonization by ESBL-EC is associated with increased risk of BSI by this strain, longer hospital stay, and higher related costs.

Gut Microbiota and Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common complication of liver diseases such as those related to viral hepatitis and liver cirrhosis. The gut-liver axis is gaining increasing attention as a key pathophysiological mechanism responsible for the progression of HCC. Here, we will review the data from the published literature to address the association between HCC and gut microbiota.

SUMMARY

The presence of high levels of endotoxemia in the blood results in portal hypertension and ensuing hepatocyte damage, thus leading to the development of HCC. Probiotics can be used to treat or prevent the progression of HCC, because they may decrease the counts of gut microbiota and thus improve the endotoxemia.

KEY MESSAGE

Increased bacterial translocation can result in endotoxemia, which may play a critical role in the progression of HCC. Modulation of the gut microbiota by probiotics may represent a new avenue for therapeutic intervention in HCC.

PRACTICAL IMPLICATIONS

Breakdown in intestinal barrier function and bacterial overgrowth are main events in the development of HCC. When the intestinal barrier function is disrupted, large amounts of bacterial products can enter the liver and induce inflammation through their receptors, leading to liver diseases. Altering the gut microflora has been proposed as an adjunctive therapy to reduce bacterial translocation and prevent progression of HCC. The purpose of this review is to discuss the relationship between gut microbiota and HCC in both pathogenesis and treatment by probiotics.

New aspects on the metabolic role of intestinal microbiota in the development of atherosclerosis

Gut microbiota remains a very interesting, yet largely unexplored ecosystem inside the human organism. The importance of this ecosystem for the physiology and the pathophysiology of the organism is being slowly unraveled. Recent studies reveal a connection between intestinal microbiota and atherosclerosis development. It seems that alterations in the function and composition of this bacterial population lead through complex mechanisms to a high risk for atherosclerosis. Although these mechanisms remain largely unknown, published studies show that microbiota can lead to atherosclerosis either by augmenting known risk factors or via other, more "direct" mechanisms. This review article summarizes the available literature regarding this matter.

Clinical impact of prophylactic antibiotic treatment for self-expandable metallic stent insertion in patients with malignant colorectal obstruction

Purpose. The aim of this study was to determine the efficacy of prophylactic antibiotics (PA) for reducing the infectious complications and the potential risk factors responsible for the infectious complications after stent insertion for malignant colorectal obstruction. Methods. We performed a retrospective review of 224 patients who underwent self-expandable metallic stent (SEMS) insertion for malignant colorectal obstruction from May 2004 to December 2012. Results. There were 145 patients in the PA group and 79 in non-PA group. The CRP level in PA group was significantly higher than that in non-PA. Abdominal tenderness and mechanical ileus were significantly more frequent in PA group than those in non-PA. The frequency of post-SEMS insertion fever, systemic inflammatory response syndrome (SIRS), and bacteremia was not significantly different between PA and non-PA groups. In multivariate analysis, the CRP level was risk factor related to post-SEMS insertion SIRS. However, in propensity score matching analysis, there was no independent risk factor related to post-SEMS insertion fever, SIRS, and bacteremia. Conclusion. The use of PA in patients with malignant colorectal obstruction may be not effective to prevent the development of infectious complications after SEMS insertion.

The presence and management of contaminants in non-certified, agriculturally sourced food items used as enrichment for laboratory animals

One enrichment strategy for laboratory animals is the provision of food variety and foraging opportunities. Fresh agricultural items, including produce or packaged human food items, provide variation in palatability, texture and complexity and can therefore be used as enrichment for lab animals. But concerns are often raised that these food items might sometimes carry contaminants that could affect research subjects and confound experimental results. The author discusses the potential for agriculturally sourced foods used as enrichment for lab animals to be contaminated with mycotoxins, microorganisms and pesticide residues and the effects these contaminants might have on lab animals. He also suggests strategies for reducing the risk of contamination.

Successful Treatment of Septic Shock due to Spontaneous Esophageal Perforation 96 Hours after Onset by Drainage and Enteral Nutrition

Spontaneous esophageal perforation is relatively uncommon, but carries a high mortality rate if diagnosis or treatment is delayed. We report the case of a 68-year-old man with spontaneous esophageal perforation who was successfully treated over 96 h after onset by thoracic drainage and jejunostomy for enteral nutrition. He vomited after drinking alcohol, soon followed by epigastralgia. Heart failure was suspected on admission to another hospital. Spontaneous esophageal perforation was diagnosed 48 h after admission. Chest tube drainage was performed, but his general condition deteriorated and he was transferred to our hospital. Emergent surgery was performed and esophageal perforation combined with pyothorax and mediastinitis was identified on the left side of the lower esophagus. The left thoracic cavity was rinsed and thoracic drainage was performed. Feeding jejunostomy was performed for postoperative enteral nutrition. Effective drainage and sufficient nutrition management appear extremely valuable in treating spontaneous esophageal perforation.

Impact of global Fxr deficiency on experimental acute pancreatitis and genetic variation in the FXR locus in human acute pancreatitis

Background

Infectious complications often occur in acute pancreatitis, related to impaired intestinal barrier function, with prolonged disease course and even mortality as a result. The bile salt nuclear receptor farnesoid X receptor (FXR), which is expressed in the ileum, liver and other organs including the pancreas, exhibits anti-inflammatory effects by inhibiting NF-κB activation and is implicated in maintaining intestinal barrier integrity and preventing bacterial overgrowth and translocation. Here we explore, with the aid of complementary animal and human experiments, the potential role of FXR in acute pancreatitis.

Methods

Experimental acute pancreatitis was induced using the CCK-analogue cerulein in wild-type and Fxr^-/- mice. Severity of acute pancreatitis was assessed using histology and a semi-quantitative scoring system. Ileal permeability was analyzed in vitro by Ussing chambers and an in vivo permeability assay. Gene expression of Fxr and Fxr target genes was studied by quantitative RT-PCR. Serum FGF19 levels were determined by ELISA in acute pancreatitis patients and healthy volunteers. A genetic association study in 387 acute pancreatitis patients and 853 controls was performed using 9 tagging single nucleotide polymorphisms (SNPs) covering the complete FXR gene and two additional functional SNPs.

Results

In wild-type mice with acute pancreatitis, ileal transepithelial resistance was reduced and ileal mRNA expression of Fxr target genes Fgf15, SHP, and IBABP was decreased. Nevertheless, Fxr^-/- mice did not exhibit a more severe acute pancreatitis than wild-type mice. In patients with acute pancreatitis, FGF19 levels were lower than in controls. However, there were no associations of FXR SNPs or haplotypes with susceptibility to acute pancreatitis, or its course, outcome or etiology.

Conclusion

We found no evidence for a major role of FXR in acute human or murine pancreatitis. The observed altered Fxr activity during the course of disease may be a secondary phenomenon.

Association between probiotics and enteral nutrition in an experimental acute pancreatitis model in rats

BACKGROUND/OBJECTIVES

Recently, a randomized controlled trial showed that probiotic prophylaxis was associated with an increased mortality in enterally fed patients with predicted severe pancreatitis. In a rat model for acute pancreatitis, we investigated whether an association between probiotic prophylaxis and enteral nutrition contributed to the higher mortality rate.

METHODS

Male Sprague-Dawley rats were allocated to four groups: 1) acute pancreatitis (n = 9), 2) acute pancreatitis and probiotic prophylaxis (n = 10), 3) acute pancreatitis and enteral nutrition (n = 10), and 4) acute pancreatitis, probiotic prophylaxis and enteral nutrition (n = 11). Acute pancreatitis was induced by intraductal glycodeoxycholate and intravenous cerulein infusion. Enteral nutrition, saline, probiotics and placebo were administered through a permanent jejunal feeding. Probiotics or placebo were administered starting 4 days before induction of pancreatitis and enteral nutrition 1 day before start until the end of the experiment, 6 days after induction of pancreatitis. Tissue samples and body fluids were collected for microbiological and histological examination.

RESULTS

In all animals, serum amylase was increased six hours after induction of pancreatitis. After fulfilling the experiment, no differences between groups were found in histological severity of pancreatitis, degree of discomfort, weight loss, histological examination of small bowel and bacterial translocation (all p > 0.05). Overall mortality was 10% without differences between groups (p = 0.54).

CONCLUSION

No negative association was found between prophylactic probiotics and enteral nutrition in acute pancreatitis. No new clues for a potential mechanism responsible for the higher mortality and bowel ischaemia in the PROPATRIA study were found.

Elevated levels of circulating DNA in cardiovascular disease patients: metagenomic profiling of microbiome in the circulation

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. An expanding body of evidence supports the role of human microbiome in the establishment of CVDs and, this has gained much attention recently. This work was aimed to study the circulating human microbiome in CVD patients and healthy subjects. The levels of circulating cell free DNA (circDNA) was higher in CVD patients (n = 80) than in healthy controls (n = 40). More specifically, the relative levels of circulating bacterial DNA and the ratio of 16S rRNA/β-globin gene copy numbers were higher in the circulation of CVD patients than healthy individuals. In addition, we found a higher circulating microbial diversity in CVD patients (n = 3) in comparison to healthy individuals (n = 3) by deep shotgun sequencing. At the phylum level, we observed a dominance of Actinobacteria in CVD patients, followed by Proteobacteria, in contrast to that in healthy controls, where Proteobacteria was predominantly enriched, followed by Actinobacteria. The circulating virome in CVD patients was enriched with bacteriophages with a preponderance of Propionibacterium phages, followed by Pseudomonas phages and Rhizobium phages in contrast to that in healthy individuals, where a relatively greater abundance of eukaryotic viruses dominated by Lymphocystis virus (LCV) and Torque Teno viruses (TTV) was observed. Thus, the release of bacterial and viral DNA elements in the circulation could play a major role leading to elevated circDNA levels in CVD patients. The increased circDNA levels could be either the cause or consequence of CVD incidence, which needs to be explored further.

[Bacterial translocation: gap in the shield]

The gastrointestinal tract is not only regarded as a system where nutrient absorption takes place, but also as a vital barrier against intraluminal pathogens entering the circulation and the maintenance of immune homeostasis. Bacterial translocation is defined as the penetration of viable bacteria or bacterial compounds from the gastrointestinal tract to extraintestinal sites. This disorder has been described in several clinical conditions. The main promoting factors for bacterial translocation have been proposed to be changes in the intestinal microflora, mucosal barrier failure and defects in host immunity. The presence of bacterial translocation has been associated with higher complications and mortality rates; therefore it should be taken into account in the therapeutic strategies of patients with predisposing factors.

Effect of deoxynivalenol and other Type B trichothecenes on the intestine: a review

The natural food contaminants, mycotoxins, are regarded as an important risk factor for human and animal health, as up to 25% of the world's crop production may be contaminated. The Fusarium genus produces large quantities of fusariotoxins, among which the trichothecenes are considered as a ubiquitous problem worldwide. The gastrointestinal tract is the first physiological barrier against food contaminants, as well as the first target for these toxicants. An increasing number of studies suggest that intestinal epithelial cells are targets for deoxynivalenol (DON) and other Type B trichothecenes (TCTB). In humans, various adverse digestive symptoms are observed on acute exposure, and in animals, these toxins induce pathological lesions, including necrosis of the intestinal epithelium. They affect the integrity of the intestinal epithelium through alterations in cell morphology and differentiation and in the barrier function. Moreover, DON and TCTB modulate the activity of intestinal epithelium in its role in immune responsiveness. TCTB affect cytokine production by intestinal or immune cells and are supposed to interfere with the cross-talk between epithelial cells and other intestinal immune cells. This review summarizes our current knowledge of the effects of DON and other TCTB on the intestine.

Association analysis of genetic variants in the myosin IXB gene in acute pancreatitis

INTRODUCTION

Impairment of the mucosal barrier plays an important role in the pathophysiology of acute pancreatitis. The myosin IXB (MYO9B) gene and the two tight-junction adaptor genes, PARD3 and MAGI2, have been linked to gastrointestinal permeability. Common variants of these genes are associated with celiac disease and inflammatory bowel disease, two other conditions in which intestinal permeability plays a role. We investigated genetic variation in MYO9B, PARD3 and MAGI2 for association with acute pancreatitis.

METHODS

Five single nucleotide polymorphisms (SNPs) in MYO9B, two SNPs in PARD3, and three SNPs in MAGI2 were studied in a Dutch cohort of 387 patients with acute pancreatitis and over 800 controls, and in a German cohort of 235 patients and 250 controls.

RESULTS

Association to MYO9B and PARD3 was observed in the Dutch cohort, but only one SNP in MYO9B and one in MAGI2 showed association in the German cohort (p < 0.05). Joint analysis of the combined cohorts showed that, after correcting for multiple testing, only two SNPs in MYO9B remained associated (rs7259292, p = 0.0031, odds ratio (OR) 1.94, 95% confidence interval (95% CI) 1.35-2.78; rs1545620, p = 0.0006, OR 1.33, 95% CI 1.16-1.53). SNP rs1545620 is a non-synonymous SNP previously suspected to impact on ulcerative colitis. None of the SNPs showed association to disease severity or etiology.

CONCLUSION

Variants in MYO9B may be involved in acute pancreatitis, but we found no evidence for involvement of PARD3 or MAGI2.

Survival, distribution, and translocation of Enterococcus faecalis and implications for pregnant mice

Pregnant mothers are susceptible to bacterial infections, which may compromise the health of mothers and offspring. Enterococcus faecalis is a ubiquitous species found in food, restaurants, and hospitals where pregnant woman frequently become exposed to this bacterium. However, the survival, distribution, translocation, and corresponding influence of E. faecalis have not been investigated during the pregnancy period, when the mother and fetus are susceptible to bacterial infection. In this study, a fluorescing E. faecalis strain was used to track the fate of the bacterium in pregnant mice. Orally administered E. faecalis were found to survive and disseminate to all regions of the intestinal tract. It also altered the bacterial community structure by significantly decreasing the diversity of Lactobacillus species, impairing the normal structure and function of the intestinal barrier, which may contribute to the bacterial translocation into the blood, spleen, placenta, and fetus. This may affect fetal and placental growth and development.

Heat shock protein 90β inhibits apoptosis of intestinal epithelial cells induced by hypoxia through stabilizing phosphorylated Akt

Intestinal epithelial cell (IEC) apoptosis induced by hypoxia compromise intestinal epithelium barrier function. Both Akt and Hsp90 have cytoprotective function. However, the specific role of Akt and Hsp90β in IEC apoptosis induced by hypoxia has not been explored. We confirmed that hypoxia-induced apoptosis was reduced by Hsp90β overexpression but enhanced by decreasing Hsp90β expression. Hsp90β overexpression enhanced BAD phosphorylation and thus reduced mitochondrial release of cytochrome C. Reducing Hsp90β expression had opposite effects. The protective effect of Hsp90β against apoptosis was negated by LY294002, an Akt inhibitor. Further study showed that Akt phosphorylation was enhanced by Hsp90β, which was not due to the activation of upstream PI3K and PDK1 but because of stabilization of pAkt via direct interaction between Hsp90β and pAkt. These results demonstrate that Hsp90β may play a significant role in protecting IECs from hypoxia-induced apoptosis via stabilizing pAkt to phosphorylate BAD and reduce cytochrome C release. [BMB Reports 2013;46(1): 47-52]

Transient lipopolysaccharide-induced resistance to aerosolized Bacillus anthracis in New Zealand white rabbits

Previous studies have demonstrated that prior infection by various bacterial pathogens induces nonspecific resistance to subsequent infection by other gram-negative and gram-positive bacterial pathogens. In the present study, we evaluated whether underlying inflammation enhanced host resistance to inhalational Bacillus anthracis infection in New Zealand White rabbits (SPF; Bordetella- and Pasteurella-free). Accordingly, rabbits were pretreated with either the inflammagen bacterial LPS (60,000 EU/kg), a component of the outer membrane of gram-negative bacteria, or saline (vehicle). Administration of LPS resulted in brief pyrexia and a significant increase in the proinflammatory cytokine TNFα, thus confirming LPS-induced inflammation. At 24 h after LPS treatment, rabbits were exposed to aerosolized B. anthracis spores (Ames strain; approximately 300 LD50). Blood samples collected at various times after challenge were cultured. Compared with their saline-pretreated counterparts, LPS-pretreated, B. anthracis challenged rabbits exhibited delays in 2 biomarkers of B. anthracis infection-anthrax-induced pyrexia (25 h versus 66 h after challenge, respectively) and bacteremia (26 h versus 63 h, respectively)-and survived longer (41 h versus 90 h, respectively). Similar to control animals, all LPS-pretreated, B. anthracis-challenged rabbits exhibited pathology consistent with inhalational anthrax. Taken together, these results suggest that prior or underlying stimulation of the innate immune system induces transient host resistance to subsequent B. anthracis infection in SPF New Zealand white rabbits. In particular, our results emphasize the importance of using animals that are free of underlying infections to prevent confounding data in studies for inhalational anthrax characterization and medical countermeasure evaluation.

The molecular pathogenesis of cholestasis in sepsis

Sepsis-induced cholestasis is a complication of infection. Infections cause systemic and intrahepatic increase in proinflammatory cytokines which result in impaired bile flow ie. cholestasis. Several other mediators of impairment in bile flow have been identified under conditions of sepsis such as increased nitric oxide production and decreased aquaporin channels. The development of cholestasis may also further worsen inflammation. The molecular basis of normal bile flow and mechanisms of impairment in sepsis are discussed.