Dysbiosis of Intestinal Microbiota Associated With Inflammation Involved in the Progression of Acute Pancreatitis

Potential Application of Lonicera japonica Extracts in Animal Production: From the Perspective of Intestinal Health

Lonicera japonica (L. japonica) extract is rich in active substances, such as phenolic acids, essential oils, flavones, saponins, and iridoids, which have a broad spectrum of antioxidant, anti-inflammatory, and anti-microbial effect. Previous studies have demonstrated that L. japonica has a good regulatory effect on animal intestinal health, which can be used as a potential antibiotic substitute product. However, previous studies about intestinal health regulation mainly focus on experimental animals or cells, like mice, rats, HMC-1 Cells, and RAW 264.7 cells. In this review, the intestinal health benefits including antioxidant, anti-inflammatory, and antimicrobial activity, and its potential application in animal production were summarized. Through this review, we can see that the effects and mechanism of L. japonica extract on intestinal health regulation of farm and aquatic animals are still rare and unclear. Further studies could focus on the regulatory mechanism of L. japonica extract on intestinal health especially the protective effects of L. japonica extract on oxidative injury, inflammation, and regulation of intestinal flora in farm animals and aquatic animals, thereby providing references for the rational utilization and application of L. japonica and its extracts in animal production.

Hepatocellular Carcinoma Immunotherapy and the Potential Influence of Gut Microbiome

Disruptions in the human gut microbiome have been associated with a cycle of hepatocyte injury and regeneration characteristic of chronic liver disease. Evidence suggests that the gut microbiota can promote the development of hepatocellular carcinoma through the persistence of this inflammation by inducing genetic and epigenetic changes leading to cancer. As the gut microbiome is known for its effect on host metabolism and immune response, it comes as no surprise that the gut microbiome may have a role in the response to therapeutic strategies such as immunotherapy and chemotherapy for liver cancer. Gut microbiota may influence the efficacy of immunotherapy by regulating the responses to immune checkpoint inhibitors in patients with hepatocellular carcinoma. Here, we review the mechanisms by which gut microbiota influences hepatic carcinogenesis, the immune checkpoint inhibitors currently being used to treat hepatocellular carcinoma, as well as summarize the current findings to support the potential critical role of gut microbiome in hepatocellular carcinoma (HCC) immunotherapy.

Comprehensive Mechanism, Novel Markers and Multidisciplinary Treatment of Severe Acute Pancreatitis-Associated Cardiac Injury - A Narrative Review

Acute pancreatitis (AP) is one of the common acute abdominal inflammatory diseases in clinic with acute onset and rapid progress. About 20% of the patients will eventually develop into severe acute pancreatitis (SAP) characterized by a large number of inflammatory cells infiltration, gland flocculus flaky necrosis and hemorrhage, finally inducing systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Pancreatic enzyme activation, intestinal endotoxemia (IETM), cytokine activation, microcirculation disturbance, autonomic nerve dysfunction and autophagy dysregulation all play an essential role in the occurrence and progression of SAP. Organ dysfunction is the main cause of early death in SAP. Acute kidney injury (AKI) and acute lung injury (ALI) are common, while cardiac injury (CI) is not, but the case fatality risk is high. Many basic studies have observed obvious ultrastructure change of heart in SAP, including myocardial edema, cardiac hypertrophy, myocardial interstitial collagen deposition. Moreover, in clinical practice, patients with SAP often presented various abnormal electrocardiogram (ECG) and cardiac function. Cases complicated with acute myocardial infarction and pericardial tamponade have also been reported and even result in stress cardiomyopathy. Due to the molecular mechanisms underlying SAP-associated cardiac injury (SACI) remain poorly understood, and there is no complete, unified treatment and sovereign remedy at present, this article reviews reports referring to the pathogenesis, potential markers and treatment methods of SACI in recent years, in order to improve the understanding of cardiac injury in severe pancreatitis.

Gut microbiota in pancreatic diseases: possible new therapeutic strategies

Pancreatic diseases such as pancreatitis, type 1 diabetes and pancreatic cancer impose substantial health-care costs and contribute to marked morbidity and mortality. Recent studies have suggested a link between gut microbiota dysbiosis and pancreatic diseases; however, the potential roles and mechanisms of action of gut microbiota in pancreatic diseases remain to be fully elucidated. In this review, we summarize the evidence that supports relationship between alterations of gut microbiota and development of pancreatic diseases, and discuss the potential molecular mechanisms of gut microbiota dysbiosis in the pathogenesis of pancreatic diseases. We also propose current strategies toward gut microbiota to advance a developing research field that has clinical potential to reduce the cost of pancreatic diseases.

Alteration of gut microbiota in acute pancreatitis and associated therapeutic strategies

Gut microbiome is considered as a crucial regulator of human health. Alteration of gut microbiome has been reported in acute pancreatitis (AP) and probably contributes to the severity of disease. Explore the precise role of gut microbiome in the pathogenesis of AP could offer new strategies to improve the clinical outcomes of AP. This review summarizes the role of gut microbiome in AP, lists possible mechanisms associated with it and offers an overview of current treatments based on gut microbiome.

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.

Variations in Gut Microbiome are Associated with Prognosis of Hypertriglyceridemia-Associated Acute Pancreatitis

Hypertriglyceridemia-associated acute pancreatitis (HTGAP) is linked with increased severity and morbidity. Intestinal flora plays an important role in the progression of acute pancreatitis (AP). However, pathogenetic association between gut microbiota and HTGAP remains unknown. In this study, we enrolled 30 HTGAP patients and 30 patients with AP that is evoked by other causes. The V3–V4 regions of 16S rRNA sequences of the gut microbiota were analyzed. Clinical characteristics, microbial diversity, taxonomic profile, microbiome composition, microbiological phenotype, and functional pathways were compared between the two groups. Our results showed that the HTGAP group had a higher proportion of severe AP (46.7% vs. 20.0%), organ failure (56.7% vs. 30.0%), and a longer hospital stay (18.0 days vs. 6.5 days). HTGAP group also had poorer microbial diversity, higher abundances of Escherichia/Shigella and Enterococcus, but lower abundances of Dorea longicatena, Blautia wexlerae, and Bacteroides ovatus as compared with non-HTGAP group. Correlation analysis revealed that gut bacterial taxonomic and functional changes were linked with local and systemic complications, ICU admission, and mortality. This study revealed that alterations of gut microbiota were associated with disease severity and poor prognosis in HTGAP patients, indicating a potential pathophysiological link between gut microbiota and hypertriglyceridemia related acute pancreatitis.

Western-type diet influences mortality from necrotising pancreatitis and demonstrates a central role for butyrate

OBJECTIVE

The gut microbiota are the main source of infections in necrotising pancreatitis. We investigated the effect of disruption of the intestinal microbiota by a Western-type diet on mortality and bacterial dissemination in necrotising pancreatitis and its reversal by butyrate supplementation.

DESIGN

C57BL/6 mice were fed either standard chow or a Western-type diet for 4 weeks and were then subjected to taurocholate-induced necrotising pancreatitis. Blood and pancreas were collected for bacteriology and immune analysis. The cecum microbiota composition of mice was analysed using 16S rRNA gene amplicon sequencing and cecal content metabolites were analysed by targeted (ie, butyrate) and untargeted metabolomics. Prevention of necrotising pancreatitis in this model was compared between faecal microbiota transplantation (FMT) from healthy mice, antibiotic decontamination against Gram-negative bacteria and oral or systemic butyrate administration. Additionally, the faecal microbiota of patients with pancreatitis and healthy subjects were analysed.

RESULTS

Mortality, systemic inflammation and bacterial dissemination were increased in mice fed Western diet and their gut microbiota were characterised by a loss of diversity, a bloom of Escherichia coli and an altered metabolic profile with butyrate depletion. While antibiotic decontamination decreased mortality, Gram-positive dissemination was increased. Both oral and systemic butyrate supplementation decreased mortality, bacterial dissemination, and reversed the microbiota alterations. Paradoxically, mortality and bacterial dissemination were increased with FMT administration. Finally, patients with acute pancreatitis demonstrated an increase in Proteobacteria and a decrease of butyrate producers compared with healthy subjects.

CONCLUSION

Butyrate depletion and its repletion appear to play a central role in disease progression towards necrotising pancreatitis.

Shotgun metagenomics reveals significant gut microbiome features in different grades of acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) has a broad spectrum of severity and is associated with considerable morbidity and mortality. Dysbiosis of gut microbiota may be associated with AP severity.

AIMS

We aimed to evaluate the composition and functional effects of gut microbiota in different grades of AP severity.

METHODS

We carried out shotgun metagenomic sequencing on rectal swab samples from three patients with mild acute pancreatitis (MAP), three with moderately severe acute pancreatitis (MSAP), three with severe acute pancreatitis (SAP) and three normal control persons (NOR). Differences analysis in gut microbiota composition and functional enrichment was performed.

RESULTS

Gut microbiota in AP patients was characterized by decreased species richness. The most representative gut microbiota in mild acute pancreatitis (MAP), moderately severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP) was Streptococcus, Escherichia-coli, and Enterococcus, respectively. Each of the three AP-associated genera could differentiate AP from healthy control population. Representative pathways associated with the glutathione metabolism, lipopolysaccharide biosynthesis, and amino acid metabolism (valine, leucine and isoleucine degradation) were enriched in MAP, MSAP, and SAP, respectively.

CONCLUSIONS

The study shows a potential association of gut microbiome composition and function to the progression of AP severity.

Nutritional Management of Acute Pancreatitis

Acute pancreatitis (AP) remains among the most common gastrointestinal disorders leading to hospital admission. Optimizing nutritional support and maintaining gut function is instrumental in recovery of patients with AP. Enteral nutrition remains one of the only interventions with demonstrated mortality benefit in AP largely through preservation of gut function, serving to preserve the gut barrier as means to mitigate immune dysregulation and systemic inflammation inherent to AP. Practice variation remains in timing, route, and composition of nutritional support. This review highlights contemporary evidence regarding optimal nutritional support in AP and provides recommendations for management in line with current consensus opinions.

An Updated Systematic Review With Meta-analysis: Efficacy of Prebiotic, Probiotic, and Synbiotic Treatment of Patients With Severe Acute Pancreatitis

OBJECTIVES

The aim of this study was to systematically review the clinical outcomes of all randomized controlled trials of patients with severe acute pancreatitis (SAP) and treated with pre/pro/synbiotics.

METHODS

A systematic literature search of the MEDLINE, Embase, clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials was conducted. Eligible studies were randomized controlled trials that evaluated the clinical outcomes of patients with SAP treated with pre/pro/synbiotics.

RESULTS

Eleven trials comprising 930 patients were included. Patients treated with pre/pro/synbiotics had a significantly shorter hospital stay [weighted mean difference, -4.33 days; 95% confidence interval (CI), -7.71 to -0.95; P = 0.010; I2 = 66.9%] compared with control. In a subgroup analysis where only patients classified as SAP were included, those treated with pre/pro/synbiotics had lower risk of single- or multiple-organ failure (relative risk, 0.62; 95% CI, 0.44-0.88; P = 0.995; I2 = 0.0%) and decreased hospital stay (weighted mean difference, -0.65 days; 95% CI, -0.90 to -0.41; P = 0.121; I2 = 45.3%) compared with control.

CONCLUSIONS

Patients with SAP treated with pre/pro/synbiotics did not have a worse clinical outcome and had lower risk of organ failure and duration of hospital stay. Further studies should examine the optimal timing, type, and dosages of these promising treatments.

Altered intestinal microflora and barrier injury in severe acute pancreatitis can be changed by zinc

To investigate the effect of zinc (Zn) supplementation on intestinal microflora changes and bacterial translocation in rats with severe acute pancreatitis (SAP), the rats were divided into the sham surgery (SS), SAP, SS + Zn, and SAP + Zn groups. Saline (0.1 mL/100g) and 5% sodium taurocholate were injected into the pancreaticobiliary duct of the rats in the SS and SAP + Zn groups, respectively. Intraperitoneal injection of 5 mg/kg Zn was performed immediately after injecting saline or 5% sodium taurocholate into the rats in both groups. Serum amylase and Zn levels, plasma endogenous endotoxin, intestinal permeability, and the positive rate of intestinal bacterial translocation were detected, haematoxylin and eosin (H&E) staining was performed, and the pancreatic tissue scores were calculated for each group. In addition, immunohistochemical (IHC) staining was performed to evaluate the expression of IL-1β and TNF-α. Real-time fluorescence quantitative PCR was used to quantify the gene copy numbers of Escherichia, Bifidobacterium, and Lactobacillus in the cecum. The levels of amylase and plasma endotoxin in the SAP group were significantly higher than those in the SS and SS + Zn groups. Intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were increased in the SAP group. However, the levels of amylase and plasma endotoxin were decreased as a result of zinc supplementation in the SAP group. The expression of IL-1β and TNF-α was also reduced to a greater degree in the SAP + Zn group than in the SAP group. Moreover, alleviated intestinal mucosal permeability and intestinal bacterial translocation in the liver, pancreas, and mesenteric lymph nodes were found in the SAP + Zn group. The results of real-time quantitative PCR showed that the gene copy number of Escherichia increased with time, and the gene copy numbers of Lactobacillus and Bifidobacterium decreased over time. Zn supplementation prevented the release of TNF-α and IL-1β, alleviated intestinal permeability and endotoxemia, reduced bacterial translocation, and inhibited changes in pathogenic intestinal flora in rats with SAP.

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.

Compositional and drug-resistance profiling of pathogens in patients with severe acute pancreatitis: a retrospective study

Background

Infection is one of the important causes of death in patients with severe acute pancreatitis (SAP), but the bacterial spectrum and antibiotic resistance are constantly changing. Making good use of antibiotics and controlling multi-drug-resistant (MDR) bacterial infections are of vital importance in improving the cure rate of SAP. We conducted a retrospective study in the hope of providing references for antibiotic selection and control of drug-resistant bacteria.

Methods

Retrospective analysis was performed on the data of patients hospitalized in our hospital due to acute pancreatitis (AP) in the past 5 years. General data were classified and statistically analyzed. Subsequently, the bacterial spectrum characteristics and the data related to drug-resistant bacterial infection of 569 AP patients were analyzed. Finally, unconditional logistic regression analysis was conducted to analyze the risk factors of MDR infection.

Results

A total of 398 patients were enrolled in this study and the hospitalization data and associated results were analyzed. A total of 461 strains of pathogenic bacteria were detected, including 223 (48.4%) gram-negative bacterial strains, 190 (41.2%) gram-positive bacterial strains and 48 (10.4%) fungal strains. The detection rates of resistance in gram-negative and gram-positive bacterial strains were 48.0% (107/223) and 25.3% (48/190), respectively. There were significant differences between the MDR group and the non-MDR group for the factors of precautionary antibiotic use, kinds of antibiotics used, receipt of carbapenem, tracheal intubation, hemofiltration and number of hospitalization days in the intensive care unit. Unconditional logistic regression revealed 2 risk factors for MDR bacterial infection.

Conclusions

Our results illustrate that gram-negative bacteria were the most common pathogens in SAP infection, and the proportion of gram-positive bacteria increased notably. The rate of antibiotic resistance was higher than previously reported. Unconditional logistic regression analysis showed that using more types of antibiotics and the number of hospitalization days in the ICU were the risk factors associated with MDR bacterial infection.

The interplay between the gut microbiota and NLRP3 activation affects the severity of acute pancreatitis in mice

Early dysbiosis of the gut microbiota is associated with the severity of acute pancreatitis (AP), although the underlying mechanism is unclear. Here, we investigated the role of crosstalk between NLRP3 and the gut microbiota in the development of AP utilizing gut microbiota deficient mice, as well as NLRP3 knockout (KO) mouse models. Pancreatic damage and systemic inflammation were improved in antibiotic-treated (Abx) and germ-free (GF) mice, accompanied by weakened activity of the intestinal NLRP3 inflammasome. Interestingly, fecal microbiota transplantation (FMT) reactivated the intestinal NLRP3 inflammasome and exacerbated the disease in Abx and GF mice. Although the gut barrier in GF and Abx mice was disrupted, gut microbiota deficiency ameliorated the severity of AP, probably due to the reduction in bacterial translocation from the gut to the pancreas. The composition of the gut microbiota was significantly different between NLRP3 KO mice and wild-type (WT) mice at baseline, and there were alterations in response to the induction of AP. While a dramatic shift in the gut microbiota with overgrowth of Escherichia-Shigella was observed in WT mice suffering from AP, there was no significant change in NLRP3 KO mice with or without AP, suggesting that NLRP3 deficiency counteracts AP-induced microbial disturbance. With a strengthened gut barrier and decreased systemic inflammation, NLRP3 KO mice showed less severe AP, as revealed by reduced pancreatic neutrophilic infiltration and necrosis. Taken together, these results identified the bidirectional modulation between the gut microbiota and NLRP3 in the progression of AP, which suggests the interplay of the host and microbiome during AP.

Pancreatic Diseases and Microbiota: A Literature Review and Future Perspectives

Gut microbiota represent an interesting worldwide research area. Several studies confirm that microbiota has a key role in human diseases, both intestinal (such as inflammatory bowel disease, celiac disease, intestinal infectious diseases, irritable bowel syndrome) and extra intestinal disorders (such as autism, multiple sclerosis, rheumatologic diseases). Nowadays, it is possible to manipulate microbiota by administering prebiotics, probiotics or synbiotics, through fecal microbiota transplantation in selected cases. In this scenario, pancreatic disorders might be influenced by gut microbiota and this relationship could be an innovative and inspiring field of research. However, data are still scarce and controversial. Microbiota manipulation could represent an important therapeutic strategy in the pancreatic diseases, in addition to standard therapies. In this review, we analyze current knowledge about correlation between gut microbiota and pancreatic diseases, by discussing on the one hand existing data and on the other hand future possible perspectives.

Identification of Dysfunctional Gut Microbiota Through Rectal Swab in Patients with Different Severity of Acute Pancreatitis

BACKGROUND

Acute pancreatitis (AP) has a wide spectrum of severity and can be associated with considerable morbidity and mortality. Whether gut microbiota dysbiosis is associated with AP severity remains obscure.

AIMS

We aim to investigate the differences in the alterations of gut microbiota in different grades of AP severity.

METHODS

We collected clinical information and rectal swab samples from 80 individuals. The gut microbiota was tested by 16S rRNA gene sequencing, gut microbiota species composition analysis, difference analysis, random forest model prediction analysis, and gut microbiota species correlation network analysis.

RESULTS

There was a different microbiota profile in different severity grades. Bacteroides, Escherichis-Shigella, and Enterococcus were dominant species in mild, moderately severe, and severe AP, respectively. Finegoldia was the most significantly increased and Blautia the most decreased species in mild AP. Anaerococcus was the most significantly increased and Eubacterium hallii the most decreased species in moderately severe AP. Enterococcus was the most significantly increased and Eubacterium hallii the most decreased species in severe AP. Finegoldia, Eubacterium_hallii, and Lachnospiraceae were potential diagnostic biomarkers for mild AP and Eubacterium_hallii and Anaerococcus for moderately severe AP. There was a positive interaction between Firmicutes and Bacteroidetes in mild AP.

CONCLUSIONS

The disturbed gut microbiota is different among grades of AP, suggesting their potential role in the progression of disease severity. There was a different microbiota profile in different severity grades. Bacteroides, Escherichis-Shigella, and Enterococcus were dominant gut microbiota species in MAP, MSAP, and SAP, respectively. Finegoldia was the most significantly increased and Blautia the most decreased gut microbiota species in MAP. Anaerococcus was the most significantly increased and Eubacterium hallii the most decreased species in MSAP. Enterococcus was the most significantly increased and Eubacterium hallii the most decreased species in SAP. Finegoldia, Eubacterium_hallii, and Lachnospiraceae were potential diagnostic biomarkers for MAP and Eubacterium_hallii and Anaerococcus for MSAP. There was a positive interaction between Firmicutes and Bacteroidetes in MAP.

Intestinal barrier damage, systemic inflammatory response syndrome, and acute lung injury: A troublesome trio for acute pancreatitis

Severe acute pancreatitis (SAP), a serious inflammatory disease of the pancreas, can easily lead to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndromes (MODS). Acute lung injury (ALI) is one of the most serious complications of SAP. However, the specific pathogenesis of SAP-associated ALI is not fully understood. Crosstalk and multi-mechanisms involving pancreatic necrosis, bacteremia, intestinal barrier failure, activation of inflammatory cascades and diffuse alveolar damage is the main reason for the unclear pathological mechanism of SAP-associated ALI. According to previous research on SAP-associated ALI in our laboratory and theories put forward by other scholars, we propose that the complex pattern of SAP-associated ALI is based on the "pancreas-intestine-inflammation/endotoxin-lung (P-I-I/E-L) pathway". In this review, we mainly concentrated on the specific details of the "P-I-I/E-L pathway" and the potential treatments or preventive measures for SAP-associated ALI.

Zinc: Roles in pancreatic physiology and disease

Zinc is an essential trace element. Deficiencies are frequently seen with gastrointestinal diseases, including chronic pancreatitis, nutritional deficiency, and reduced intestinal absorption. Additionally, reduced zinc levels have been linked to cellular changes associated with acute pancreatitis such as enhanced inflammation with increased macrophage activation and production of inflammatory cytokines such as IL-1β, impaired autophagy, and modulation of calcium homeostasis. Preliminary data suggest that zinc deficiency may lead to pancreatic injury in animal models. The purpose of this review is to explore the biologic effects of zinc deficiency that could impact pancreatic disease. MESH KEYWORDS: Malnutrition, inflammation, trace element.

Gut Barrier Dysfunction Induced by Aggressive Fluid Resuscitation in Severe Acute Pancreatitis is Alleviated by Necroptosis Inhibition in Rats

Fluid resuscitation is the first-line antishock treatment in severe acute pancreatitis (SAP). Currently, although mentions of complications related to aggressive fluid resuscitation are very frequent, a lack of proper handling of complications remains. One of the most important complications is intestinal barrier injury, including intestinal ischemia-reperfusion injury following aggressive fluid resuscitation. Once injured, the intestinal barrier may serve as the source of additional diseases, including systemic inflammatory response syndrome and multiple organ dysfunction syndrome, which aggravate SAP. This study focused on the underlying mechanisms of gut barrier dysfunction in rats induced by aggressive fluid resuscitation in SAP. This study further indicated the important role of necroptosis in intestinal barrier injury which could be relieved by using necroptosis-specific inhibitor Nec-1 before aggressive fluid resuscitation, thus reducing intestinal barrier damage. We also found pancreas damage after intestinal ischemia/reperfusion challenge and indicated the effects of high mobility group protein B1 in the vicious cycle between SAP and intestinal barrier damage.

Bile Acid Supplementation Improves Murine Pancreatitis in Association With the Gut Microbiota

Disorders of bile acids (BAs) are closely related to the development of liver and intestinal diseases, including acute pancreatitis (AP). However, the mechanism underlying the involvement of BAs in AP development remains unclear. We used intraperitoneal injection of cerulein to construct AP mouse models. These mice had significantly reduced tauroursodeoxycholic acid (TUDCA) and an imbalance of intestinal microbiota, based on 16S rDNA gene sequencing. To explore the role of AP-induced intestinal microbiota changes in the development of AP, we transplanted the stool obtained from AP mice to antibiotic-treated, microbiota-depleted healthy mice. Microbiota-depleted mice presented injury to the intestinal barrier function and pancreas. Additionally, microbiota depletion reduced AP-associated pancreatic injury. This indicated that the gut microbiota may worsen AP. As TUDCA was deficient in AP mice, we gavaged AP mice with it, and evaluated subsequent expression changes in the bile acid signaling receptors farnesoid-x-receptor (FXR) and its target gene fibroblast growth factor (FGF) 15. These were downregulated, and pancreatic and intestinal barrier function injury were mitigated. The gut microbiota is known to regulate bile acid production and signaling, and our analysis of changes to the gut microbiota in AP indicated that Lactobacilli may be the key contributors of TUDCA. Taken together, our study shows that supplementation with BAs could reduce pancreatic and intestinal injury, and that this effect may be associated with the gut microbiota.

Connecting the Dots Between Inflammatory Bowel Disease and Metabolic Syndrome: A Focus on Gut-Derived Metabolites

The role of the microbiome in health and disease has gained considerable attention and shed light on the etiology of complex diseases like inflammatory bowel disease (IBD) and metabolic syndrome (MetS). Since the microorganisms inhabiting the gut can confer either protective or harmful signals, understanding the functional network between the gut microbes and the host provides a comprehensive picture of health and disease status. In IBD, disruption of the gut barrier enhances microbe infiltration into the submucosae, which enhances the probability that gut-derived metabolites are translocated from the gut to the liver and pancreas. Considering inflammation and the gut microbiome can trigger intestinal barrier dysfunction, risk factors of metabolic diseases such as insulin resistance may have common roots with IBD. In this review, we focus on the overlap between IBD and MetS, and we explore the role of common metabolites in each disease in an attempt to connect a common origin, the gut microbiome and derived metabolites that affect the gut, liver and pancreas.

Role of gut microbiota on intestinal barrier function in acute pancreatitis

Acute pancreatitis (AP) is a common gastrointestinal disorder. Approximately 15%-20% of patients develop severe AP. Systemic inflammatory response syndrome and multiple organ dysfunction syndrome may be caused by the massive release of inflammatory cytokines in the early stage of severe AP, followed by intestinal dysfunction and pancreatic necrosis in the later stage. A study showed that 59% of AP patients had associated intestinal barrier injury, with increased intestinal mucosal permeability, leading to intestinal bacterial translocation, pancreatic tissue necrosis and infection, and the occurrence of multiple organ dysfunction syndrome. However, the real effect of the gut microbiota and its metabolites on intestinal barrier function in AP remains unclear. This review summarizes the alterations in the intestinal flora and its metabolites during AP development and progression to unveil the mechanism of gut failure in AP.

Intestinal dysbiosis mediates experimental autoimmune pancreatitis via activation of plasmacytoid dendritic cells

Autoimmune pancreatitis (AIP) is a pancreatic manifestation of a newly proposed disease entity, IgG4-related disease (IgG4-RD), characterized by enhanced IgG4 antibody responses and involvement of multiple organs. We have previously reported that innate immune activation contributes to the development of AIP and IgG4-RD, as these diseases are characterized by the production of IFN-α and IL-33 by plasmacytoid dendritic cells (pDCs) that mediate chronic fibroinflammatory responses. In this study, we investigated the roles played by innate immunity against intestinal microflora in experimental AIP induced in MRL/MpJ mice by repeated administrations of 100 µg of polyinosinic-polycytidylic acid [poly (I:C)]. Bowel sterilization with a broad spectrum of antibiotics inhibited pancreatic accumulation of pDCs producing IFN-α and IL-33, and thereby suppressed the development of AIP. Mice treated with 10 µg of poly (I:C) developed severe AIP equivalent to that induced by 100 µg of poly (I:C) upon co-housing with mice treated with 100 µg of poly (I:C). Fecal microbiota transplantation (FMT) from donor mice treated with 100 µg of poly (I:C) led to the development of severe AIP in the recipient mice upon injection with 10 µg of poly (I:C). Induction of severe AIP in mice with 10 µg of poly (I:C) was associated with pancreatic accumulation of pDCs producing IFN-α and IL-33 in the co-housing and FMT experiments. These data collectively suggest that innate immune responses against intestinal microflora are involved in the development of experimental AIP, and that intestinal dysbiosis increases sensitivity to experimental AIP via activation of pDCs.

Alterations of the Predominant Fecal Microbiota and Disruption of the Gut Mucosal Barrier in Patients with Early-Stage Colorectal Cancer

Growing evidence indicated that the gut microbiota was the intrinsic and essential component of the cancer microenvironment, which played vital roles in the development and progression of colorectal cancer (CRC). In our present study, we investigated the alterations of fecal abundant microbiota with real-time quantitative PCR and the changes of indicators of gut mucosal barrier from 53 early-stage CRC patients and 45 matched healthy controls. We found that the traditional beneficial bacteria such as Lactobacillus and Bifidobacterium decreased significantly and the carcinogenic bacteria such as Enterobacteriaceae and Fusobacterium nucleatum were significantly increased in CRC patients. We also found gut mucosal barrier dysfunction in CRC patients with increased levels of endotoxin (LPS), D-lactate, and diamine oxidase (DAO). With Pearson's correlation analysis, D-lactate, LPS, and DAO were correlated negatively with Lactobacillus and Bifidobacterium and positively with Enterobacteriaceae and F. nucleatum. Our present study found dysbiosis of the fecal microbiota and dysfunction of the gut mucosal barrier in patients with early-stage CRC, which implicated that fecal abundant bacteria and gut mucosal barrier indicators could be used as targets to monitor the development and progression of CRC in a noninvasive and dynamic manner.

Early Systemic Inflammatory Response Syndrome Duration Predicts Infected Pancreatic Necrosis

BACKGROUND AND PURPOSE

Systemic inflammatory response syndrome (SIRS) was considered to play an important role in the progress of acute pancreatitis, but its specific relation with infected pancreatic necrosis remains largely unclear. We aimed to investigate the correlation between SIRS duration and infected pancreatic necrosis, and its application in prediction of infected pancreatic necrosis.

METHODS

A prospective observational cohort study of 2130 patients with acute pancreatitis from 2012 to 2017. The SIRS duration at the first week was registered daily, and demographic, radiology, and all clinical laboratory data were prospectively collected and retrospectively reviewed.

RESULTS

A significant upward tendency of infected pancreatic necrosis incidence was observed with increased SIRS duration. In multivariate logistic regression, SIRS duration (odds ratio, 1.305; 95% CI, 1.161-1.468) was independently associated with infected pancreatic necrosis. ROC analysis demonstrated that the areas under curves of SIRS duration for predicting persistent multi-organ failure, pancreatic infection, and mortality were 0.97 (95% CI, 0.96-0.98), 0.92 (95% CI, 0.91-0.94), and 0.86 (95% CI, 0.83-0.90), respectively, which were comparable to, or even greater than, the area under curves of APACHE II and CT severity index scores.

CONCLUSIONS

Early SIRS duration was strongly associated with infected pancreatic necrosis and could serve as an easy bedside indicator to predict pancreatic infection.

Association between increased breath hydrogen methane concentration and prevalence of glucose intolerance in acute pancreatitis

Pancreatic damage, in the form of pancreatitis, intestinal bacteria and glucose imbalance could be interrelated. The aim of this study was to investigate the breath hydrogen (H₂) and methane (CH₄), which can indicate small intestinal bacterial overgrowth (SIBO) status, and assess the link between SIBO and glucose tolerance in patients with acute pancreatitis (AP). This prospective study enrolled 75 patients who were admitted for AP. A glucose breath test (GBT) which detects breath hydrogen H₂ and CH₄ for SIBO with an oral glucose tolerance test (OGTT) for 120 min was simultaneously performed to determine SIBO and glucose tolerance. Patient demographic data, laboratory test data, and computed tomography severity index (CTSI) were also evaluated. The levels of total breath H₂ and CH₄ in patients with AP were significantly higher than those in controls, respectively (p < 0.01). There were no significant differences in the incidence of SIBO between patients with AP and controls. The OGTT indicated that blood glucose levels at 30, 60, 90, and 120 min were higher in SIBO-positive patients than in SIBO-negative patients. No significant differences in CTSI, patient demographic data or laboratory test data were observed between the two groups. Breath H₂ and CH₄ concentrations are relatively higher in patients with AP, indicating a correlation between high levels of intestinal bacteria and AP. Furthermore, higher breath H₂ and CH₄ concentrations appear to be associated with oral glucose intolerance, with hyperglycemia occurring in patients with AP.

Gut microbiota dysbiosis in patients with hepatitis B virus-induced chronic liver disease covering chronic hepatitis, liver cirrhosis and hepatocellular carcinoma

The information regarding the effect of hepatitis B virus (HBV) infection on gut microbiota and the relationship between gut microbiota dysbiosis and hepatitis B virus-induced chronic liver disease (HBVCLD) is limited. In this study, we aimed at characterizing the gut microbiota composition in the three different stages of hepatitis B virus-induced chronic liver disease patients and healthy individuals. Faecal samples and clinical data were collected from HBVCLD patients and healthy individuals. The 16S rDNA gene amplification products were sequenced. Bioinformatic analysis including alpha diversity and PICRUSt was performed. A total of 19 phyla, 43 classes, 72 orders, 126 families and 225 genera were detected. The beta-diversity showed a separate clustering of healthy controls and HBVCLD patients covering chronic hepatitis (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC); and gut microbiota of healthy controls was more consistent, whereas those of CHB, LC and HCC varied substantially. The abundance of Firmicutes was lower, and Bacteroidetes was higher in patients with CHB, LC and HCC than in healthy controls. Predicted metagenomics of microbial communities showed an increase in glycan biosynthesis and metabolism-related genes and lipid metabolism-related genes in HBVCLD than in healthy individuals. Our study suggested that HBVCLD is associated with gut dysbiosis, with characteristics including, a gain in potential bacteria and a loss in potential beneficial bacteria or genes. Further study of CHB, LC and HCC based on microbiota may provide a novel insight into the pathogenesis of HBVCLD as well as a novel treatment strategy.

Altered diversity and composition of gut microbiota in Chinese patients with chronic pancreatitis

BACKGROUND/OBJECTIVES

Gut microbiota alterations in chronic pancreatitis (CP) are seldomly described systematically. It is unknown whether pancreatic exocrine insufficiency (PEI) and different etiologies in patients with CP are associated with gut microbiota dysbiosis.

METHODS

The fecal microbiota of 69 healthy controls (HCs) and 71 patients with CP were compared to investigate gut microbiome alterations in CP and the relationship among gut microbiome dysbiosis, PEI and different etiologies. Fecal microbiomes were analyzed through 16S ribosomal RNA gene profiling, based on next-generation sequencing. Pancreatic exocrine function was evaluated by determining fecal elastase 1 activity.

RESULTS

Patients with CP showed gut microbiota dysbiosis with decreased diversity and richness, and taxa-composition changes. On the phylum level, the gut microbiome of the CP group showed lower Firmicutes and Actinobacteria abundances than the HC group and higher Proteobacteria abundances. The abundances of Escherichia-Shigella and other genera were high in gut microbiomes in the CP group, whereas that of Faecalibacterium was low. Kyoto Encyclopedia of Genes and Genomes pathways (lipopolysaccharide biosynthesis and bacterial invasion of epithelial cells) were predicted to be enriched in the CP group. Among the top 5 phyla and 8 genera (in terms of abundance), only Fusobacteria and Eubacterium rectale group showed significant differences between CP patients, with or without PEI. Correlation analysis showed that Bifidobacterium and Lachnoclostridium correlated positively with fecal elastase 1 (r = 0.2616 and 0.2486, respectively, P < 0.05).

CONCLUSIONS

The current findings indicate that patients with CP have gut microbiota dysbiosis that is partly affected by pancreatic exocrine function.

Antibacterial and Antifungal Therapy for Patients with Acute Pancreatitis at High Risk of Pancreatogenic Sepsis (Review)

Controlling infection is crucial in treating patients with acute pancreatitis (AP). The infectious process in AP often predisposes to subsequent sepsis by damaging not only the pancreas, but retroperitoneal tissues as well. Among other AP-associated factors, are the rapidly developing immune imbalance, the poor penetration of antimicrobial agents into necrotic tissue, and the impossibility of a single surgical debridement. Antibacterial and antifungal therapy for patients with infected necrosis and AP-associated extra-pancreatic infections remains a complex and largely unresolved problem, partially due to the high occurrence of multiresistant pathogens. The preventive use of antimicrobial agents has been discussed in the literature; however, the lack of consistent results makes it difficult to develop a unified strategy and clinical guidelines on this specific issue. Recent meta-analyses provide no conclusive evidence that antibacterial prophylaxis reduces the infection rate, mortality, or the need for surgical treatment in patients with necrotizing pancreatitis. We found only two studies indicating the benefits of using carbapenems for prophylactic purposes and one meta-analysis indicating a reduction in mortality under antibiotic treatment started no later than 72 h after the onset of the attack. Selective bowel decontamination is considered as one of the preventive anti-infection measures, although the available data may not be fully reliable. The main indications for antibacterial therapy in patients with AP are confirmed infected necrosis or extra-pancreatic infection, as well as clinical symptoms of suspected infection. Intra-arterial administration or local treatment with antibiotics can increase the efficacy of antibacterial therapy. No randomized studies on antifungal prophylaxis in AP are available; some reports though recommend using such therapy among patients at high risk of invasive candidiasis.

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.

Paneth Cell Ablation Aggravates Pancreatic and Intestinal Injuries in a Rat Model of Acute Necrotizing Pancreatitis after Normal and High-Fat Diet

We previously reported that acute necrotizing pancreatitis (ANP) after normal or high-fat diet is associated with a decreased number of Paneth cells in ileal crypts. Here, we ablated Paneth cells in a rat model of ANP after normal and high-fat diet to investigate the effects on disease symptoms. Adult male Sprague-Dawley rats received standard rat chow or a high-fat diet for 2 weeks, after which they were treated with dithizone to deplete Paneth cells. Six hours later, ANP was established by retrograde injection of sodium taurocholate into the biliopancreatic duct. Rats were sacrificed at 6, 12, and 24 h for assessment. We found dithizone aggravated ANP-associated pathological injuries to the pancreas and ileum in rats on high-fat or standard diets. Lysozyme expression in ileal crypts was decreased, while serum inflammatory cytokines (TNFα, IL-1β, and IL-17A) and intestinal permeability (serum DAO activity and D-lactate) were increased. Expression of tight junction proteins (claudin-1, zo-1, and occludin) was decreased. Using high-throughput 16S rRNA sequencing, we found dithizone reduced microbiota diversity and altered microbiota composition in rats on high-fat or standard diets. Dithizone decreased fecal short-chain fatty acids (SCFAs) in rats on high-fat or standard diets. Changes in intestinal microbiota correlated significantly with SCFAs, lysozyme, DAO activity, D-lactate, inflammatory cytokines, and pathological injury to the pancreas and ileum in rats on high-fat or standard diets. In conclusion, ablation of Paneth cells exacerbates pancreatic and intestinal injuries in ANP after normal and high-fat diet. These symptoms may be related to changes in the intestinal microbiota.

Gastrointestinal microecology: a crucial and potential target in acute pancreatitis

In the early stage of acute pancreatitis (AP), abundant cytokines induced by local pancreatic inflammation enter the bloodstream, further cause systemic inflammatory response syndrome (SIRS) by "trigger effect", which eventually leads to multiple organ dysfunction syndrome (MODS). During SIRS and MODS, the intestinal barrier function was seriously damaged accompanied by the occurrence of gut-derived infection which forms a "second hit summit" by inflammatory overabundance. Gastrointestinal microecology, namely the biologic barrier, could be transformed into a pathogenic state, which is called microflora dysbiosis when interfered by the inflammatory stress during AP. More and more evidences indicate that gastrointestinal microflora dysbiosis plays a key role in "the second hit" induced by AP gut-derived infection. Therefore, the maintenance of gastrointestinal microecology balance is likely to provide an effective method in modulating systemic infection of AP. This article reviewed the progress of gastrointestinal microecology in AP to provide a reference for deeply understanding the pathogenic mechanisms of AP and identifying new therapeutic targets.

Risk and Outcomes of Clostridium difficile Infection With Chronic Pancreatitis

OBJECTIVES

Chronic pancreatitis (CP) is associated with high rates of recurrent hospitalizations, which predisposes to Clostridium difficile infection (CDI). We investigate the burden of CDI in CP.

METHODS

We identified records of patients with CP from the Nationwide Inpatient Sample (NIS) 2012-2014 and estimated the impact of CDI on their outcomes. We calculated the adjusted odds ratio (AOR) of CP on having CDI (NIS 2014). From NIS 2007-2014, we plotted the trends of CDI and its interaction with CP.

RESULTS

From 2012 to 2014, 886 (2.72%) of the 32,614 CP patients had concomitant CDI, which was associated with poorer outcomes: acute kidney injury (AOR, 2.57 [95% confidence interval {CI}, 2.11-3.13]), length of stay (13.3 vs 7.4 days), and charges (US $127,496 vs US $72,767), but not mortality (AOR, 0.93 [95% CI, 0.28-3.05]). In 2014, CP was associated with an increased risk of CDI (crude odds ratio, 2.10 [95% CI, 1.95-2.26]), which persisted after multivariate adjustment (AOR, 2.03 [95% CI, 1.87-2.19]). From 2007 to 2014, the annual prevalence of CDI was 106.4 cases per 10,000 hospitalizations, increasing from 2007 (95.5/10,000) to 2014 (118.4/10,000), with a 3.7 times higher annual rate of increase among CP versus no-CP patients (13.4/10,000 vs 3.7/10,000 population/year).

CONCLUSIONS

Chronic pancreatitis patients have high burden of CDI and may benefit from CDI prophylaxis.

Pancreas–Microbiota Cross Talk in Health and Disease

The pancreas controls metabolism through endocrine and exocrine functions. Pancreatic diseases comprise a spectrum of mild to life-threatening conditions, including acute and chronic pancreatitis, diabetes, and pancreatic cancer, which affect endocrine and exocrine pancreatic function and impose a substantial disease burden on individuals. Increasing experimental evidence demonstrates that the intestinal microbiota has an important impact on pancreatic function and diseases. This influence may be conferred by bacterial metabolites, such as short-chain fatty acids, or the modulation of immune responses. In turn, pancreatic factors, such as the excretion of antimicrobials, might have a substantial impact on the composition and functional properties of the gut microbiota. Here, we summarize experimental and clinical approaches used to untie the intricate pancreas–microbiota cross talk. Future advances will allow clinicians to manipulate the intestinal microbiota and guide patient management in pancreatic diseases.

Microbiota-Immune Interaction in the Pathogenesis of Gut-Derived Infection

Gut-derived infection is among the most common complications in patients who underwent severe trauma, serious burn, major surgery, hemorrhagic shock or severe acute pancreatitis (SAP). It could cause sepsis and multiple organ dysfunction syndrome (MODS), which are regarded as a leading cause of mortality in these cases. Gut-derived infection is commonly caused by pathological translocation of intestinal bacteria or endotoxins, resulting from the dysfunction of the gut barrier. In the last decades, the studies regarding to the pathogenesis of gut-derived infection mainly focused on the breakdown of intestinal epithelial tight junction and increased permeability. Limited information is available on the roles of intestinal microbial barrier in the development of gut-derived infection. Recently, advances of next-generation DNA sequencing techniques and its utilization has revolutionized the gut microecology, leading to novel views into the composition of the intestinal microbiota and its connections with multiple diseases. Here, we reviewed the recent progress in the research field of intestinal barrier disruption and gut-derived infection, mainly through the perspectives of the dysbiosis of intestinal microbiota and its interaction with intestinal mucosal immune cells. This review presents novel insights into how the gut microbiota collaborates with mucosal immune cells to involve the development of pathological bacterial translocation. The data might have important implication to better understand the mechanism underlying pathological bacterial translocation, contributing us to develop new strategies for prevention and treatment of gut-derived sepsis.

Clostridium butyricum Strains Suppress Experimental Acute Pancreatitis by Maintaining Intestinal Homeostasis

SCOPE

Acute pancreatitis (AP) is a common abdominal inflammatory disease. Disturbed gut homeostasis secondary to pancreatic inflammation aggravates the condition retroactively. The current study investigates potential beneficial effects of Clostridium butyricum (C. butyricum) strains on AP and underlying mechanisms.

METHODS AND RESULTS

C. butyricum strains MIYAIRI 588 (CBM588) and CGMCC0313.1 (CB0313.1) were supplemented to mice for three weeks before experimental AP or SAP induction. Both CBM588 and CB0313.1 protected against AP, as evidenced by reduced serum amylase and lipase levels, pancreatic edema, and myeloperoxidase activity. Amelioration of both experimental AP and SAP by CB0313.1 indicated a non-model-specific effect. Moreover, C. butyricum inhibited pancreatic neutrophil and dendritic cell infiltration, nucleotide-binding domain leucine-rich repeat-containing family, pyrin domain-containing 3 inflammasome activation, and pro-inflammatory pathways. Additionally in the gut, C. butyricum strains attenuated AP-associated intestinal inflammation and barrier dysfunction, accompanied with reduced pathogenic bacteria Escherichia coli and Enterococcus penetration into pancreas. Gut microbiome analyses further revealed that beneficial effects of C. butyricum on pancreatic-gut homeostasis were correlated with improved dysbiosis. In particular, relative abundance of Desulfovibrionaceae decreased, and Verrucomicrobiaceae Clostridiaceae and Lactobacillaceae increased.

CONCLUSIONS

For the first time, a protective effect of C. butyricum in AP by modulating intestinal homeostasis is demonstrated.

Improvement of Gut Microbiota by Inhibition of P38 Mitogen-Activated Protein Kinase (MAPK) Signaling Pathway in Rats with Severe Acute Pancreatitis

Background

Gut microbiota dysbiosis plays a key role in pathogenesis of severe acute pancreatitis (SAP). In this study, we explored the protective effects of the p38 MAPK inhibitor, SB203580, against gut inflammation and microbiota dysbiosis induced by pancreatic duct injection with 3.5% sodium taurocholate in an SAP rat model.

Material/Methods

Ninety male Sprague-Dawley rats were randomly assigned to sham-operated, SAP model, and SAP plus SB203580 groups (n=30/group). Histological examination was conducted to assess gut and pancreatitis injury. The levels of amylase, D-lactate, diamine oxidase, tumor necrosis factor α, IL-6, IL-1β, and phospho-p38MAPK in the plasma and intestine were evaluated at 3, 6, or 12 h after SAP induction. The gut microbiome was investigated based on16S rDNA gene sequencing at 12 h after SAP induction.

Results

Histological examination revealed edema and inflammatory infiltrations in the pancreas and distal ileum. The expression of tumor necrosis factor α, IL-1β, and IL-6 in plasma and distal ileum was increased in the SAP group, which were restored after treatment with SB203580. Significantly lower bacterial diversity and richness was found in the SAP group. In the SAP group, the abundance of Bacteroidetes and Firmicutes was decreased, and there was a higher proportion of Proteobacteria at the phylum level. The SAP plus SB203580 group exhibited significantly less damage to the gut microbiota, with higher bacterial diversity and a more normal proportion of intestinal microbiota.

Conclusions

SB203580 mediated suppression of the p38 MAPK signaling pathway via reduced gut inflammatory response and microbiota dysbiosis.

Commensal Escherichia coli Aggravates Acute Necrotizing Pancreatitis through Targeting of Intestinal Epithelial Cells

An increase of Escherichia-Shigella was previously reported in acute necrotizing pancreatitis (ANP). We investigated whether Escherichia coli MG1655, an Escherichia commensal organism, increased intestinal injury and aggravated ANP in rats. ANP was induced by retrograde injection of 3.5% sodium taurocholate into the biliopancreatic duct. Using gut microbiota-depleted rats, we demonstrated that gut microbiota was involved in the pancreatic injury and intestinal barrier dysfunction in ANP. Using 16S rRNA gene sequencing and quantitative PCR, we found intestinal dysbiosis and a significant increase of E. coli MG1655 in ANP. Afterward, administration of E. coli MG1655 by gavage to gut microbiota-depleted rats with ANP was performed. We observed that after ANP induction, E. coli MG1655-monocolonized rats presented more severe injury in the pancreas and intestinal barrier function than gut microbiota-depleted rats. Furthermore, Toll-like receptor 4 (TLR4)/MyD88/p38 mitogen-activated protein (MAPK) and endoplasmic reticulum stress (ERS) activation in intestinal epithelial cells were also increased more significantly in the MG1655-monocolonized ANP rats. In vitro, the rat ileal epithelial cell line IEC-18 displayed aggravated tumor necrosis factor alpha-induced inflammation and loss of tight-junction proteins in coculture with E. coli MG1655, as well as TLR4, MyD88, and Bip upregulation. In conclusion, our study shows that commensal E. coli MG1655 increases TLR4/MyD88/p38 MAPK and ERS signaling-induced intestinal epithelial injury and aggravates ANP in rats. Our study also describes the harmful potential of commensal E. coli in ANP.IMPORTANCE This study describes the harmful potential of commensal E. coli in ANP, which has not been demonstrated in previous studies. Our work provides new insights into gut bacterium-ANP cross talk, suggesting that nonpathogenic commensals could also exhibit adverse effects in the context of diseases.

Serum D-dimer levels at admission for prediction of outcomes in acute pancreatitis

BACKGROUND

Systemic alterations in coagulation are associated with complications of acute pancreatitis (AP). D-dimer, a fibrin degradation product, was recently described as a marker of pancreatitis outcome. Early prediction is essential for reducing mortality in AP. The present study aims to assess the relationship between elevated serum D-dimer levels and the severity of AP.

METHODS

We performed an observational retrospective study with data from 3451 enrolled patients with AP. Serum D-dimer levels were measured upon admission, after 24 h and during the week after admission by immunoturbidimetry. Univariate and multivariate analyses were used to determine whether elevated D-dimer levels were independently associated with the severity of AP.

RESULTS

Of the 3451 AP patients, 2478 (71.8%) had serum D-dimer levels measured within 24 h of hospital admission; 1273 of these patients had D-dimer levels ≤2.5 mg/L, and 1205 had D-dimer levels > 2.5 mg/L (934 patients had mild AP (MAP); 1086, moderately severe AP (MSAP); and 458, severe AP (SAP)). Patients with D-dimer levels > 2.5 mg/L (n = 1205) had higher incidences of SAP (75.5% vs. 24.5%), acute peripancreatic fluid collection (APFC) (53.3% vs. 46.7%), acute necrotic collection (ANC) (72.4% vs. 27.6%), pancreatic necrosis (PN) (65.2% vs. 34.8%), infected pancreatic necrosis (IPN) (77.7% vs. 22.8%), organ failure (OF) (68.5% vs. 31.5%), persistent organ failure (POF) (75.5% vs. 24.5%), ICU requirement (70.2% vs. 29.8%), and mortality (79.2% vs. 20.8%) than did patients with D-dimer levels ≤2.5 mg/L (n = 1273). The multivariate analysis showed that patients with higher serum D-dimer levels had poorer prognoses that worsened over time.

CONCLUSION

The measurement of D-dimer levels at admission may be useful for risk stratification of AP.

The Role of the Microbiome in Immunologic Development and its Implication For Pancreatic Cancer Immunotherapy

Our understanding of the microbiome and its role in immunity, cancer initiation, and cancer progression has evolved significantly over the past century. The "germ theory of cancer" was first proposed in the early 20^th century, and shortly thereafter the bacterium Helicobacter pylori, and later Fusobacterium nucleatum, were implicated in the development of gastric and colorectal cancers, respectively. However, with the development of reliable mouse models and affordable sequencing technologies, the most fascinating aspect of the microbiome-cancer relationship, where microbes undermine cancer immune surveillance and indirectly promote oncogenesis, has only recently been described. In this review, we highlight the essential role of the microbiome in immune system development and maturation. We review how microbe-induced immune activation promotes oncogenesis, focusing particularly on pancreatic carcinogenesis, and show that modulation of the microbiome augments the anti-cancer immune response and enables successful immunotherapy against pancreatic cancer.

Gut microbiota dysbiosis worsens the severity of acute pancreatitis in patients and mice

BACKGROUND

The gut is implicated in the pathogenesis of acute pancreatitis (AP) and the infectious complications of AP are commonly associated with enteric bacteria, yet whether gut microbiota dysbiosis participants in AP severity remains largely unknown.

METHODS

We collected clinical information and fecal samples from 165 adult participants, including 41 with mild AP (MAP), 59 with moderately severe AP (MSAP), 30 with severe AP (SAP) and 35 healthy controls (HC). The serum inflammatory cytokines and gut barrier indexes were detected. Male C57BL/6 mice with AP were established and injuries of pancreas were evaluated in antibiotic-treated mice, germ-free mice as well as those transplanted with fecal microbiota. The gut microbiota was analyzed by 16S rRNA gene sequencing.

RESULTS

The structure of gut microbiota was significantly different between AP and HC, and the disturbed microbiota was closely correlated with systematic inflammation and gut barrier dysfunction. Notably, the microbial composition changed further with the worsening of AP and the abundance of beneficial bacteria such as Blautia was decreased in SAP compared with MAP and MSAP. The increased capacity for the inferred pathway, bacterial invasion of epithelial cells in AP, highly correlated with the abundance of Escherichia-Shigella. Furthermore, the antibiotic-treated mice and germ-free mice exhibited alleviated pancreatic injury after AP induction and subsequent fecal microbiota transplantation in turn exacerbated the disease.

CONCLUSIONS

This study identifies the gut microbiota as an important mediator during AP and its dysbiosis is associated with AP severity, which suggests its role as potential therapeutic target.

Diabetic cats have decreased gut microbial diversity and a lack of butyrate producing bacteria

Obesity and inactivity are major risk factors of feline diabetes mellitus (FDM) and human type II diabetes mellitus (T2DM). In recent years, changes in the gut microbiota have been suggested as a contributing factor to T2DM. Whether the gut microbiota (GM) composition plays a role in FDM remains unknown. The aim of the current study was firstly a cross-sectional comparison of the GM of diabetic cats, to that of lean, and of obese/overweight non-diabetic cats of a similar age. Specifically, fecal samples from 82 privately-owned cats from Denmark and Switzerland were sequenced using 16S rRNA gene amplicon metabarcoding. Secondly dietary intervention data was generated, by obtaining additional samples from a subset of cats after placing them on a high-protein diet for four weeks. The GM diversity of diabetic cats was lower than that of lean cats in the cross-sectional study, and lower compared to lean and to overweight/obese cats after diet intervention. Diabetic cats also exhibited fewer Anaerotruncus, Dialister, and unknown Ruminococcaceae than lean cats. Serum fructosamine levels correlated negatively with Prevotellaceae abundance and positively with Enterobacteriaceae abundance. In summary the intestinal microbiota of diabetic cats was characterized by decreased GM diversity and loss of butyrate producing bacterial genera.

The Gut Microbiome in Pancreatic Disease

The gut microbiome increasingly is recognized for its role in human health and disease. Initial evidence has indicated that gut microbial dysbiosis is associated with several pancreatic diseases. Although it is not known if these associations are causative, gut dysbiosis is hypothesized to mediate chronic proinflammatory changes in the pancreas. Further mechanistic and epidemiologic studies of the microbiome are needed. Ultimately, targeted modulation of the microbiota could have therapeutic value.

Gut Microbiota in Alcoholic Hepatitis is Disparate from Those in Acute Alcoholic Pancreatitis and Biliary Disease

BACKGROUND

Alcoholic hepatitis (AH) is associated with gut dysbiosis. Comparative gut microbial profiles of acute alcoholic pancreatitis (AAP) and acute biliary disease (ABD) are not demonstrated. We aimed to compare gut microbiota of AH, AAP, and ABD patients with each other and with their respective healthy controls (HCs).

METHODS

From December 2016 to September 2017, consecutive patients with AH, AAP, and ABD (acute cholecystitis, acute biliary pancreatitis, and choledocholithiasis with cholangitis) were included in the study. Qualitative and functional stool microbiota comparative analysis was performed between groups, with AH as the reference comparator.

RESULTS

Of 3564, 882, and 224 patients with liver disease, pancreatic disease, and biliary disease, respectively, after exclusion, 29 patients with AH and 7 patients each with AAP and ABD and their corresponding HCs were included in the study analysis. The alpha diversity between patients with AH and AAP was found to be significantly different. Significant relative abundance (RA) of Acinetobacter and Moraxella was noted among patients with AAP. Enterobacter, Atopobium, Synergistia, and Devosia were significantly higher in patients with ABD compared to patients with AH, in whom Faecalibacterium and Megamonas were higher. Functional pathways associated with carbohydrate metabolism, phenylpropanoid biosynthesis, and ethylbenzene degradation were significantly higher in AAP when compared to AH. Fatty acid and inositol phosphate metabolism and dioxin degradation were significantly upregulated in patients with ABD while lipid and fatty acid biosynthetic pathways and pathways associated with immune processes were upregulated in patients with AH.

CONCLUSIONS

Differential gut dysbiosis is evident in both patients with AH, AAP, and ABD and also in comparison to HCs. The differential microbiota among patients with AH and AAP maybe important in promotion and progression of liver or pancreatic disease among alcohol users and may be a potential therapeutic target, which needs to be confirmed in larger multicenter studies.

Association of Dietary Habits with Severity of Acute Pancreatitis

BACKGROUND

The effect of diet on risk of acute pancreatitis (AP) has been suggested by prior studies, but the association of dietary habits with severity of AP has not been previously evaluated.

OBJECTIVE

The objective of the study was to assess differences in reported dietary habits in patients with severe AP compared with those with mild or moderate AP.

METHODS

A prospectively maintained cohort of patients with AP was utilized. A brief questionnaire on dietary habits was implemented. Dietary habits were categorized based on the overall type of diet, fruit/vegetable servings, fat content, dairy consumption, dessert/sweets consumption, and fluid intake. Patients were grouped into mild/moderate and severe AP. Multivariate analysis was used to determine whether dietary habits have an independent association with AP severity.

RESULTS

407 patients with AP were studied. Mean patient age was 51 y, and 202 (50%) were men. 29% of patients were smokers and 46% actively consumed alcohol. 225 patients had mild AP, 103 moderate AP, and 79 developed severe AP. The 3 groups were comparable in race, body mass index, etiology of AP, and comorbidities. Dietary factors were overall comparable between the groups except for diet type: subjects with severe AP had a higher percentage of consuming a meat-rich diet (84%) than patients with mild AP (72%) and moderate AP (67%) (P = 0.04). Based on multivariable logistic regression, the OR of developing severe AP was 2.5 (95% CI: 1.24-5.32, P = 0.01) between patients who eat a meat-rich diet and those who consume a vegetable-based diet.

CONCLUSIONS

A meat-rich diet is independently associated with the development of persistent organ failure (severe disease) in patients with AP. These findings require further evaluation and could be useful for patient counseling, risk stratification, and disease prevention. This study is registered at clinicaltrials.gov as NCT03075605.

Lower respiratory tract microbial composition was diversified in Pseudomonas aeruginosa ventilator-associated pneumonia patients

Background

Probiotics could prevent Pseudomonas aeruginosa colonization in lower respiratory tract (LRT) and reduced P. aeruginosa ventilator-associated pneumonia (VAP) rate. Recent studies also suggested that probiotics could improve lung inflammation in mice infected with P. aeruginosa. It seems that microbiota regulation may be a potential therapy for P. aeruginosa VAP patients. However, we know less about the LRT microbial composition and its correlation with prognosis in P. aeruginosa VAP patients. This study aimed to characterize LRT microbiota in P. aeruginosa VAP patients and explore the relationship between microbiota and patient prognosis.

Methods

Deep endotracheal secretions were sampled from subjects via intubation. Communities were identified by 16S ribosomal RNA gene sequencing. The relationship between microbiota and the prognosis of P. aeruginosa VAP patients were evaluated. Clinical pulmonary infection score and the survival of intensive care unit were both the indicators of patient prognosis.

Results

In this study, the LRT microbial composition of P. aeruginosa VAP patients was significantly different from non-infected intubation patients, and showed significant individual differences, forming two clusters. According to the predominant phylum of each cluster, these two clusters were named Pro cluster and Fir-Bac cluster respectively. Patients from Pro cluster were dominated by Proteobacteria (adj.P < 0.001), while those from Fir-Bac cluster were dominated by Firmicutes, and Bacteroidetes (both adj.P < 0.001). These two varied clusters (Pro and Fir-Bac cluster) were associated with the patients’ primary disease (χ²-test, P < 0.0001). The primary disease of the Pro cluster mainly included gastrointestinal disease (63%), and the Fir-Bac cluster was predominantly respiratory disease (89%). During the two-week dynamic observation period, despite the use of antibiotics, the dominant genera and Shannon diversity of the LRT microbiota did not change significantly in patients with P. aeruginosa VAP. In prognostic analysis, we found a significant negative correlation between Lactobacillus and clinical pulmonary infection score on the day of diagnosis (P = 0.014); but we found no significant difference of microbial composition between survivors and non-survivors.

Conclusions

LRT microbial composition was diversified among P. aeruginosa VAP patients, forming two clusters which were associated with the primary diseases of the patients.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0847-3) contains supplementary material, which is available to authorized users.

The role of extra-pancreatic infections in the prediction of severity and local complications in acute pancreatitis

BACKGROUND

The aim of our study was to determine the risk factors for extrapancreatic infection (EPI) occurrence and its predictive power for assessing severity and local complications in acute pancreatitis including infected pancreatic necrosis (IPN).

METHODS

Clinical data of 176 AP patients prospectively enrolled were analysed. EPI analysed were bacteraemia, lung infection, urinary tract infection and catheter line infection. Risk factors analysed were: Leukocyte count, C-reactive protein, liver function test, serum calcium, serum glucose, Blood urea nitrogen, mean arterial pressure at admission, total parenteral nutrition (TPN), enteral nutrition, hypotension, respiratory, cardiovascular and renal failure at admission, persistent systemic inflammatory response (SIRS) and intrapancreatic necrosis. Severity outcomes assessed were defined according to the Atlanta Criteria definition for acute pancreatitis. The predictive accuracy of EPI for morbidity and mortality was measured using area-under-the-curve (AUC) receiver-operating characteristics.

RESULTS

Forty-four cases of EPI were found (25%). TPN (OR:9.2 CI95%: 3.3-25.7), APACHE-II>8 (OR:6.2 CI95%:2.48-15.54) and persistent SIRS (OR:2.9 CI95%: 1.1-7.8), were risk factors related with EPI. Bacteraemia, when compared with others EPI, showed the best accuracy in predicting significantly persistent organ failure (AUC:0.76, IC95%:0.64-0.88), ICU admission (AUC:0.80 IC95%:0.65-0.94), and death (AUC:0.73 CI95%:0.54-0.91); and for local complications including IPN (AUC:0.72 CI95%:0.53-0.92) as well. Besides, it was also needed for an interventional procedure against necrosis (AUC:0.74 IC95%: 0.57-0.91). When bacteraemia and IPN occurs, bacteraemia preceded infected necrosis in all cases. On multivariate analysis, risk factor for IPN were lung infection (OR:6.25 CI95%1.1-35.7 p = 0.039) and TPN (OR:22.0CI95%:2.4-205.8, p = 0.007), and for mortality were persistent SIRS at first week (OR: 22.9 CI95%: 2.6-203.7, p = 0.005) and Lung infection (OR: 9.7 CI95%: 1.7-53.8).

CONCLUSION

In our study, EPI, played a role in predicting the severity and local complications in acute pancreatitis.

Brain Natriuretic Peptide-Regulated Expression of Inflammatory Cytokines in Lipopolysaccharide (LPS)-Activated Macrophages via NF-κB and Mitogen Activated Protein Kinase (MAPK) Pathways

Background

This study aimed to investigate the effects of recombinant human brain natriuretic peptide (rhBNP) on IL-6, TNF-α, and IL-10 secretion in LPS-activated RAW 264.7 cells and human peripheral blood mononuclear cells (PBMCs) in vitro and to explore the related signaling pathways of the regulation mechanisms of BNP in systemic inflammatory response syndrome (SIRS).

Material/Methods

MTT assay was used to evaluate the effects of rhBNP on cell viabilities. Lipopolysaccharide (LPS) was used to induce inflammation response. The whole study was divided into 8 groups: Control, low, middle, and high concentrations of rhBNP, LPS, LPS with low, middle, and high concentrations of rhBNP. Levels of IL-6, TNF-α, and IL-10 were evaluated using the Cytometric Bead Array Kit and RT-PCR assay. Western blotting was used to test the effects of rhBNP on inflammation-related NF-κB and MAPK pathways.

Results

Except for the concentrations ≥1.6 ng/mL, all concentrations of rhBNP showed little effect on cell viabilities of RAW264.7 cells and PBMCs after 24 h and 48 h, suggesting a weak cytotoxicity to cells. Expression of IL-6 and TNF-α significantly increased and expression of IL-10 significantly decreased at protein and mRNA levels after LPS treatment, and these effects were strongly inhibited in a dose-dependent manner by pretreatment of rhBNP. Similarly, the LPS-induced increase of NF-κB and MAPK pathway phosphorylation levels were also significantly inhibited by rhBNP.

Conclusions

rhBNP can regulate expression of IL-6, TNF-α, and IL-10 in LPS-activated RAW 264.7 cells and PBMCs through inhibiting NF-κB and MAPK pathways. These results may reveal potential causes of the increase of BNP in SIRS and may provide an experimental basis for treatment of SIRS.

Characterization of intestinal microbiota in alcoholic patients with and without alcoholic hepatitis or chronic alcoholic pancreatitis

Excessive alcohol consumption leads to severe alcoholic hepatitis (sAH) or chronic alcoholic pancreatitis (CAP) only in a subset of patients. We aimed to characterize the intestinal microbiota profiles of alcoholic patients according to the presence and nature of the complications observed: sAH or CAP. Eighty two alcoholic patients were included according to their complications: CAP (N = 24), sAH (N = 13) or no complications (alcoholic controls, AC, N = 45). We analyzed the intestinal microbiota by high-throughput sequencing. Bacterial diversity was lower in patients with CAP, who had a global intestinal microbiota composition different from that of AC. The intestinal microbiota composition of these two groups differed for 17 genera, eight of which were more frequent in patients with CAP (e.g. Klebsiella, Enterococcus and Sphingomonas). There was no significant difference in bacterial diversity between the sAH and CAP groups. However, 16 taxa were more frequent in sAH patients, and 10 were more frequent in CAP patients. After adjustment for confounding factors sAH patients were found to have higher levels of Haemophilus. For alcoholic patients, specific intestinal microbiota signatures are associated with different complications. Patients with CAP and sAH also display specific dysbiosis relative to AC.