The potential role of gut microbiota in pancreatic disease: A systematic review

Ampullary tumors exhibit increased Fusobacterium in both the tumor surface and surrounding duodenal mucosa during carcinoma progression

Understanding the complex interplay between intestinal microbiomes and ampullary tumors is crucial for distinguishing between adenomas and carcinomas, especially when considering the role of Fusobacterium. We characterized the microbiome associated with ampullary tumors using samples collected from the tumor surface (tumor samples, TSs) and surrounding normal duodenal mucosa (normal samples, NSs) via brush rubbing. In total, samples from 17 patients, divided into an adenoma group (n = 11) and a carcinoma group (n = 6), were analyzed. The Shannon α-diversity index was significantly higher in the carcinoma group compared with the adenoma group, indicating a more diverse bacterial community in the carcinoma environment. The TSs of the carcinoma group exhibited enrichment of Fusobacterium, Leptotrichia, Methylorubrum, and Micrococcus. The relative abundance of Fusobacterium increased as the tumor progressed. The NSs of the carcinoma group showed a higher presence of Fusobacterium, Porphyromonas, Granulicatella, Rikenellaceae RC9 gut group, and Solobacterium, whereas Bergeyella was more prevalent in the adenoma group. These results suggest that ampullary carcinomas exhibit a characteristic microbiome compared to adenomas. Fusobacterium is enriched in the tumor and surrounding normal duodenal mucosa, increases in abundance as the tumor progresses, and may be associated with ampullary tumors.

Comprehensive insights into pancreatic cancer treatment approaches and cutting-edge nanocarrier solutions: from pathology to nanomedicine

Pancreatic cancer is one of the most lethal malignancies worldwide. It is characterized by poor prognosis, high mortality, and recurrence rates. Various modifiable and non-modifiable risk factors are associated with pancreatic cancer incidence. Available treatments for pancreatic cancer include surgery, chemotherapy, radiotherapy, photodynamic therapy, supportive care, targeted therapy, and immunotherapy. However, the survival rates for PC are very low. Regrettably, despite efforts to enhance prognosis, the survival rate of pancreatic cancer remains relatively low. Therefore, it is essential to investigate new approaches to improve pancreatic cancer treatment. By synthesizing current knowledge and identifying existing gaps, this article provides a comprehensive overview of risk factors, pathology, conventional treatments, targeted therapies, and recent advancements in nanocarriers for its treatment, along with various clinical trials and patents that justify the safety and efficacy of innovative carriers for drug delivery systems. Ultimately, this review underscores the potential of these innovative formulations to improve outcomes and contribute significantly to the advancement of Pancreatic Cancer treatment. Together, these insights highlight nano-formulations as a promising frontier for effectively treating Pancreatic Cancer.

Exploring the Role of Gut Microbiota and Probiotics in Acute Pancreatitis: A Comprehensive Review

Acute pancreatitis (AP) is a common and potentially severe gastrointestinal condition characterized by acute inflammation of the pancreas. The pathophysiology of AP is multifactorial and intricate, involving a cascade of events that lead to pancreatic injury and systemic inflammation. The progression of AP is influenced by many factors, including genetic predispositions, environmental triggers, and immune dysregulation. Recent studies showed a critical involvement of the gut microbiota in shaping the immune response and modulating inflammatory processes during AP. This review aims to provide a comprehensive overview of the emerging role of gut microbiota and probiotics in AP. We analyzed the implication of gut microbiota in pathogenesis of AP and the modification during an acute attack. The primary goals of microbiome-based therapies, which include probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and enteral nutrition, are to alter the composition of the gut microbial community and the amount of metabolites derived from the microbiota. By resetting the entire flora or supplementing it with certain beneficial organisms and their byproducts, these therapeutic approaches aim to eradicate harmful microorganisms, reducing inflammation and avoiding bacterial translocation and the potential microbiota-based therapeutic target for AP from nutrition to pre- and probiotic supplementation to fecal transplantation.

Potential causal association between gut microbiota, inflammatory cytokines, and acute pancreatitis: A Mendelian randomization study

Background

Acute pancreatitis (AP) ranks among the most frequently encountered gastrointestinal diseases in the emergency department. Recent studies have increasingly emphasized the substantial connection among gut microbiota, inflammatory cytokines, and AP.

Methods

A two-sample Mendelian randomization (MR) study was conducted using summary statistics of gut microbiota (GM) from the largest available meta-analysis of genome-wide association studies conducted by the MiBioGen consortium (n=18,340). For cytokines, the data were obtained from a study that investigated genome variant associations with 41 inflammatory cytokines and growth factors (n=8293). The summary statistics of AP were obtained from the FinnGen consortium version R5 data (3022 cases and 195,144 controls). The inverse variance weighted (IVW) method was used as the main analysis, with MR-Egger and weighted median as complementary analytical methods. Sensitivity analyses were performed using Cochran's Q-test, MR-Egger intercept test, leave-one-out analyses, and MR-PRESSO. In addition, we employed the reverse MR analysis and MR Steiger method to estimate the orientations of exposure and outcome.

Result

Among the 211 examined GM taxa, the IVW method revealed that Bacteroidales (odds ratio [OR]=1.412, 95% confidence interval [CI]:1.057 to 1.885, P=0.019), Eubacterium fissicatena group (OR=1.240, 95% CI:1.045 to 1.470, P=0.014), and Coprococcus3 (OR=1.481, 95 % CI:1.049 to 2.090, P=0.026) exhibited a positive association with AP. Conversely, Prevotella9 (OR=0.821, 95% CI:0.680 to 0.990, P=0.038), RuminococcaceaeUCG004 (OR=0.757, 95% CI:0.577 to 0.994, P=0.045), and Ruminiclostridium6 (OR=0.696, 95% CI:0.548 to 0.884, P=0.003) displayed a negative correlation with AP. Among the 41 inflammatory cytokines, only macrophage colony-stimulating factor (M_CSF, OR=0.894, 95% CI:0.847 to 0.943, P=0.037) exhibited a negative association with AP. Sensitivity analyses revealed no evidence of pleiotropy or heterogeneity. Nevertheless, the mediation analysis showed that M_CSF did not act as a mediating factor.

Conclusion

This two-sample MR study revealed causal associations between specific GM and inflammatory cytokines with AP, respectively. However, inflammatory cytokines did not appear to act as mediating factors in the pathway from GM to AP.

Research status of risk factors and prevention of pancreatic cancer: A bibliometric and visual analysis

One of the biggest public health issues facing the globe today is pancreatic cancer (PC). To serve as a guide for clinically identifying existing research hotspots and conducting related studies in the future, bibliometric and visualization analyses of the literature on risk factors and PC prevention were carried out in this work. Results of published research from 2004 to 2024 were retrieved using the Web of Science database as a search platform. CiteSpace and VOSviewer were used for bibliometric and visual analysis. Based on the exclusion criteria, 868 articles in all were screened. Between 2004 and 2024, the quantity of articles published varied. Between 2017 and 2023, there was a consistent upward trend in the quantity of published literature. Cancer epidemiology biomarkers and prevention, cancers, and the Asian Pacific Journal of Cancer Prevention were the 3 journals with the most publications. The 2 nations with the most publications are China and the United States. The 2 nations with the most publications are China and the United States. The top 3 most published universities are Harvard University, the National Institutes of Health (NIH), and the National Cancer Institute (NCI). Buzzwords include body mass index, obesity, diabetes, smoking, and exercise.

Trend and forecast analysis of the changing disease burden of pancreatic cancer attributable to high fasting glucose in China, 1990-2021

Background

Pancreatic cancer (PC) is a malignant tumour with poor prognosis and high mortality, and high fasting plasma glucose (HFPG) is considered to be one of its important risk factors.

Methods

PC disease burden data were obtained from the Global Burden of Disease Study 2021 (GBD 2021) database. Annual percent change (APC), average APC (AAPC), and 95% confidence interval (95% CI) were analysed using joinpoint linkpoint regression models to assess the trend of PC burden of disease between 1990 and 2021. An age-period-cohort model was used to estimate the independent effects of age, period, and cohort on PC burden, and data on PC mortality attributable to HFPG in China from 2022 to 2032 were analysed on the basis of a Bayesian age-period-cohort model projection.

Results

The number of Pc deaths due to HFPG continue to rise in China from 1990 to 2021, with age-standardised mortality (ASMR) and age-standardised disability-adjusted life-year rates with increasing AAPC values of 1.12% (95% CI, 0.73-1.52) and 1.00% (95% CI, 0.63-1.37), respectively. Throughout the study, we found that the overall level of PC disease burden was significantly higher in men than that in women. In age-period-cohort analyses, the age effect of PC showed an increasing and then decreasing trend, the period effect showed an overall increasing trend during the study period, and the cohort effect showed an overall slow decreasing trend. In addition, the BAPC model predicted that ASMR is expected to decline significantly in both men and women from 2022 to 2032.

Conclusions

It was found that PC attributable to HFPG was generally on the rise in China from 1990 to 2021 and has been on the decline in recent years, and projections suggest that the country's future PC disease burden will continue to show a downward trend. Age and period of birth are the main factors affecting the disease burden, especially in men and older age groups. Early prevention, regular screening, and research into the pathogenesis of PC have, therefore, become particularly important.

Gut microbiome changes associated with chronic pancreatitis and pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

The study of changes in the microbiome in chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) holds significant potential for developing noninvasive diagnostic tools as well as innovative interventions to alter the progression of diseases. This systematic review and meta-analysis aimed to analyze in detail the taxonomic and functional characteristics of the gut microbiome in patients with CP and PDAC.

METHODS

Two researchers conducted a systematic search across public databases to gather all published research up to June 2023. Diversity and gut microbiota composition are the main outcomes the authors focus on.

RESULTS

This meta-analysis included 14 studies, involving a total of 1511 individuals in the PDAC ( n =285), CP ( n =342), and control ( n =649) groups. Our results show a significant difference in the composition of gut microbiota between PDAC/CP patients compared to healthy controls (HC), as evidenced by a slight decrease in α-diversity, including Shannon (SMD=-0.33; P =0.002 and SMD=-0.59; P <0.001, respectively) and a statistically significant β-diversity ( P <0.05). The pooled results showed that at the phylum level, the proportion of Firmicutes was lower in PDAC and CP patients than in HC patients. At the genus level, more than two studies demonstrated that four genera were significantly increased in PDAC patients compared to HC (e.g. Escherichia-Shigella and Veillonella ). CP patients had an increase in four genera (e.g. Escherichia-Shigella and Klebsiella ) and a decrease in eight genera (e.g. Coprococcus and Bifidobacterium ) compared to HC. Functional/metabolomics results from various studies also showed differences between PDAC/CP patients and HC. In addition, this study found no significant differences in gut microbiota between PDAC and CP patients.

CONCLUSIONS

Current evidence suggests changes in gut microbiota is associated with PDAC/CP, commonly reflected by a reduction in beneficial species and an increase in the pathogenic species. Further studies are needed to confirm these findings and explore therapeutic possibilities.

Chronic pancreatitis-associated metabolic bone diseases: epidemiology, mechanisms, and clinical advances

Chronic pancreatitis (CP) is a progressive inflammatory disease with an increasing global prevalence. In recent years, a strong association between CP and metabolic bone diseases (MBDs), especially osteoporosis, has been identified, attracting significant attention in the research field. Epidemiological data suggest a rising trend in the incidence of MBDs among CP patients. Notably, recent studies have highlighted a profound interplay between CP and altered nutritional and immune profiles, offering insights into its linkage with MBDs. At the molecular level, CP introduces a series of biochemical disturbances that compromise bone homeostasis. One critical observation is the disrupted metabolism of vitamin D and vitamin K, both essential micronutrients for maintaining bone integrity, in CP patients. In this review, we provide physio-pathological perspectives on the development and mechanisms of CP-related MBDs. We also outline some of the latest therapeutic strategies for treating patients with CP-associated MBDs, including stem cell transplantation, monoclonal antibodies, and probiotic therapy. In summary, CP-associated MBDs represent a rising medical challenge, involving multiple tissues and organs, complex disease mechanisms, and diverse treatment approaches. More in-depth studies are required to understand the complex interplay between CP and MBDs to facilitate the development of more specific and effective therapeutic approaches.

Quantitative evaluation of gut microbiota composition in pancreatic cancer: A pooled study

BACKGROUND

Prior research has demonstrated a positive association between the composition of gut microbiota and the incidence of pancreatic cancer. Nevertheless, a thorough quantitative and systematic evaluation of the distinct properties of gut microbiota in individuals diagnosed with pancreatic cancer has yet to be conducted. The objective of this study is to examine alterations in the diversity of intestinal microbiota in individuals diagnosed with pancreatic cancer.

METHODS

Search for relevant literature published before July 2023 in 4 databases: PubMed, Embase, Web of Science, and Cochrane Library, without any language restrictions.

RESULTS

A total of 12 studies were included, including 535 patients with pancreatic cancer and 677 healthy controls. Analysis was conducted on 6 phyla, 16 genera, and 6 species. The study found significant and distinctive changes in the α-diversity of gut microbiota, as well as in the relative abundance of multiple gut bacterial groups at the phylum, genus, and species levels in pancreatic cancer patients.

CONCLUSION

Overall, there are certain characteristic changes in the gut microbiota of pancreatic cancer patients. However, further research is warranted to elucidate the specific mechanism of action and the potential for treatment.

Pancreatic Ductal Adenocarcinoma and Nutrition: Exploring the Role of Diet and Gut Health

The incidence of pancreatic cancer is increasing worldwide. The most common form is represented by pancreatic ductal adenocarcinoma (PDAC) which has been shown to be linked to chronic inflammation. Notably, the gut microbiota has emerged as a critical player in regulating immune responses and inflammation. Indeed, intestinal dysbiosis, characterized by an imbalance in the gut microbiota composition, can contribute to the initiation of chronic inflammation. Sterile chronic inflammation can occur, probably activated by the translocation of bacterial components, such as lipopolysaccharide (LPS), the major component of Gram-negative microbiota, with the consequent induction of innate mucosal immunity, through the activation of Toll-like receptors (TLRs). Furthermore, the interaction between LPS and TLRs could enhance cancer progression. Recent research has shed light on the pivotal role of nutrition, as a modifiable risk factor, in PDAC immunological processes, particularly focusing on the immuno-modulatory effects of the gut microbiota. Different dietary regimens, fiber intake, immunonutrients, and antioxidants have the potential to either exacerbate or mitigate chronic inflammation, thereby influencing the pathogenesis and natural history of PDAC. These dietary components may affect the gut microbiota composition and, consequently, the level of inflammation, either promoting or protecting against PDAC. In this review of reviews, we discuss the modulatory role of nutrition and the gut microbiota in PDAC's immunological processes to explore a translational therapeutic approach that could improve the survival and quality of life of these patients.

Gut microbiota controls the development of chronic pancreatitis: A critical role of short-chain fatty acids-producing Gram-positive bacteria

Chronic pancreatitis (CP) is a progressive and irreversible fibroinflammatory disorder, accompanied by pancreatic exocrine insufficiency and dysregulated gut microbiota. Recently, accumulating evidence has supported a correlation between gut dysbiosis and CP development. However, whether gut microbiota dysbiosis contributes to CP pathogenesis remains unclear. Herein, an experimental CP was induced by repeated high-dose caerulein injections. The broad-spectrum antibiotics (ABX) and ABX targeting Gram-positive (G+) or Gram-negative bacteria (G-) were applied to explore the specific roles of these bacteria. Gut dysbiosis was observed in both mice and in CP patients, which was accompanied by a sharply reduced abundance for short-chain fatty acids (SCFAs)-producers, especially G+ bacteria. Broad-spectrum ABX exacerbated the severity of CP, as evidenced by aggravated pancreatic fibrosis and gut dysbiosis, especially the depletion of SCFAs-producing G+ bacteria. Additionally, depletion of SCFAs-producing G+ bacteria rather than G- bacteria intensified CP progression independent of TLR4, which was attenuated by supplementation with exogenous SCFAs. Finally, SCFAs modulated pancreatic fibrosis through inhibition of macrophage infiltration and M2 phenotype switching. The study supports a critical role for SCFAs-producing G+ bacteria in CP. Therefore, modulation of dietary-derived SCFAs or G+ SCFAs-producing bacteria may be considered a novel interventive approach for the management of CP.

How A Patient with Resectable or Borderline Resectable Pancreatic Cancer should Be Treated-A Comprehensive Review

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with high morbidity and mortality in which long-term survival rates remain disastrous. Surgical resection is the only potentially curable treatment for early pancreatic cancer; however, the right patient qualification is crucial for optimizing treatment outcomes. With the rapid development of radiographic and surgical techniques, resectability decisions are made by a multidisciplinary team. Upfront surgery (Up-S) can improve the survival of patients with potentially resectable disease with the support of adjuvant therapy (AT). However, early recurrences are quite common due to the often-undetectable micrometastases occurring before surgery. Adopted by international consensus in 2017, the standardization of the definitions of resectable PDAC (R-PDAC) and borderline resectable PDAC (BR-PDAC) disease was necessary to enable accurate interpretation of study results and define which patients could benefit from neoadjuvant therapy (NAT). NAT is expected to improve the resection rate with a negative margin to provide significant local control and eliminate micrometastases to prolong survival. Providing information about optimal sequential multimodal NAT seems to be key for future studies. This article presents a multidisciplinary concept for the therapeutic management of patients with R-PDAC and BR-PDAC based on current knowledge and our own experience.

The Impact of the COVID-19 Pandemic on Outcomes in Acute Pancreatitis: A Propensity Score Matched Study Comparing before and during the Pandemic

We aimed to evaluate the outcomes and survival of patients with acute pancreatitis who shared the same clinical form, age, and sex before the pandemic, during the pandemic, and among those with confirmed COVID-19 infection upon hospital admission. This consideration used the sparse data in the existing literature on the influence of the pandemic and COVID-19 infection on patients with acute pancreatitis. To accomplish this, we conducted a multicentric, retrospective case-control study using propensity score matching with a 2:1 match of 28 patients with SARS-CoV-2 infection and acute pancreatitis, with 56 patients with acute pancreatitis pre-pandemic, and 56 patients with acute pancreatitis during the pandemic. The study outcome demonstrated a six-fold relative risk of death in patients with acute pancreatitis and SARS-CoV-2 infection compared to those with acute pancreatitis before the pandemic. Furthermore, restrictive measures implemented during the pandemic period led to a partial delay in the care of patients with acute pancreatitis, which likely resulted in an impairment of their immune state. This, in certain circumstances, resulted in a restriction of surgical treatment indications, leading to a three-fold relative risk of death in patients with acute pancreatitis during the pandemic compared to those with acute pancreatitis before the pandemic.

Diet, Gut Microbiome, and Their End Metabolites Associate With Acute Pancreatitis Risk

INTRODUCTION

Diet and decreased gut microbiome diversity has been associated with acute pancreatitis (AP) risk. However, differences in dietary intake, gut microbiome, and their impact on microbial end metabolites have not been studied in AP. We aimed to determine differences in (i) dietary intake (ii) gut microbiome diversity and sulfidogenic bacterial abundance, and (iii) serum short-chain fatty acid (SCFA) and hydrogen sulfide (H 2 S) concentrations in AP and control subjects.

METHODS

This case-control study recruited 54 AP and 46 control subjects during hospitalization. Clinical and diet data and stool and blood samples were collected. 16S rDNA sequencing was used to determine gut microbiome alpha diversity and composition. Serum SCFA and H 2 S levels were measured. Machine learning (ML) model was used to identify microbial targets associated with AP.

RESULTS

AP patients had a decreased intake of vitamin D 3 , whole grains, fish, and beneficial eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids. AP patients also had lower gut microbiome diversity ( P = 0.021) and a higher abundance of sulfidogenic bacteria including Veillonella sp. and Haemophilus sp., which were associated with AP risk. Serum acetate and H 2 S concentrations were significantly higher in the AP group ( P < 0.001 and P = 0.043, respectively). ML model had 96% predictive ability to distinguish AP patients from controls.

DISCUSSION

AP patients have decreased beneficial nutrient intake and gut microbiome diversity. An increased abundance of H 2 S-producing genera in the AP and SCFA-producing genera in the control group and predictive ability of ML model to distinguish AP patients indicates that diet, gut microbiota, and their end metabolites play a key role in AP.

Therapeutic Approaches in Pancreatic Cancer: Recent Updates

Cancer is a significant challenge for effective treatment due to its complex mechanism, different progressing stages, and lack of adequate procedures for screening and identification. Pancreatic cancer is typically identified in its advanced progression phase with a low survival of ~5 years. Among cancers, pancreatic cancer is also considered a high mortality-causing casualty over other accidental or disease-based mortality, and it is ranked seventh among all mortality-associated cancers globally. Henceforth, developing diagnostic procedures for its early detection, understanding pancreatic cancer-linked mechanisms, and various therapeutic strategies are crucial. This review describes the recent development in pancreatic cancer progression, mechanisms, and therapeutic approaches, including molecular techniques and biomedicines for effectively treating cancer.

Acute idiopathic pancreatitis is associated with more aggressive disease course in Crohn's disease but not in ulcerative colitis

PURPOSE

Patients with inflammatory bowel disease (IBD), whether Crohn's disease (CD) or ulcerative colitis (UC), have an increased risk of acute pancreatitis. The prognostic value of diagnosing acute idiopathic pancreatitis in patients with IBD is not well understood.

METHODS

A retrospective review of 56 patients with IBD and acute pancreatitis was conducted in a tertiary center from 2011 to 2020. Aggressive disease course was defined as (i)biologic change, (ii)biologic dose escalation, or (iii)IBD-related surgeries occurring within 1 year of acute pancreatitis diagnosis. Logistic regression modelling identified associations between covariates and an aggressive disease course.

RESULTS

Baseline characteristics between idiopathic pancreatitis and other causes of acute pancreatitis, in both CD and UC cohorts, were similar. Idiopathic pancreatitis was significantly associated with an aggressive disease course in CD (P = 0.04). No confounding factors were associated with an aggressive disease course in CD. Idiopathic pancreatitis, however, was not associated with an aggressive disease course in UC (P = 0.35).

CONCLUSION

The diagnosis of acute idiopathic pancreatitis may provide a prognostic indicator of a more severe disease course in CD. No such association appears to exist with UC. To the best of our knowledge, this is the first study that identifies an association and possible prognostic value between idiopathic pancreatitis and a more severe disease course in CD. More studies with a larger sample size are needed to validate these findings, further define idiopathic pancreatitis as an extraintestinal manifestation of IBD and elucidate a clinical strategy to optimize care in patients with aggressive CD and idiopathic pancreatitis.

Role of microbiota and microbiota-derived short-chain fatty acids in PDAC

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive lethal diseases among other cancer types. Gut microbiome and its metabolic regulation play a crucial role in PDAC. Metabolic regulation in the gut is a complex process that involves microbiome and microbiome-derived short-chain fatty acids (SCFAs). SCFAs regulate inflammation, as well as lipid and glucose metabolism, through different pathways. This review aims to summarize recent developments in PDAC in the context of gut and oral microbiota and their associations with short-chain fatty acid (SCFA). In addition to this, we discuss possible therapeutic applications using microbiota in PDAC.

Cross-sectional evaluation of gut microbial-host cometabolites in patients with chronic pancreatitis

OBJECTIVES

Gut bacteria facilitate nutrient metabolism and generate small molecules that form part of the broader "metabolome". It is unclear whether these metabolites are disturbed in chronic pancreatitis (CP). This study aimed to evaluate the gut microbial-host cometabolites and their relationship in patients with CP.

METHODS

Fecal samples were collected from 40 patients with CP and 38 healthy family members. Each sample was examined with 16S rRNA gene profiling and gas chromatography time-of-flight mass spectrometry to estimate the relative abundances of specific bacterial taxa between the two groups and to profile any changes in the metabolome, respectively. Correlation analysis was used to evaluate the differences in metabolites and gut microbiota between the two groups.

RESULTS

The abundance of Actinobacteria was lower at the phylum level, and that of Bifidobacterium was lower at the genus level in the CP group. Eighteen metabolites had significantly different abundances and the concentrations of 13 metabolites were significantly different between the two groups. Oxoadipic acid and citric acid levels were positively correlated with Bifidobacterium abundance (r = 0.306 and 0.330, respectively, both P < 0.05), while the 3-methylindole concentration was negatively correlated with Bifidobacterium abundance (r = -0.252, P = 0.026) in CP.

CONCLUSIONS

Gut microbiome and host microbiome metabolic products might be altered in patients with CP. Evaluating gastrointestinal metabolite levels may further enhance our understanding of the pathogenesis and/or progression of CP.

Activated regulatory T-cells promote duodenal bacterial translocation into necrotic areas in severe acute pancreatitis

OBJECTIVE

In acute pancreatitis (AP), bacterial translocation and subsequent infection of pancreatic necrosis are the main risk factors for severe disease and late death. Understanding how immunological host defence mechanisms fail to protect the intestinal barrier is of great importance in reducing the mortality risk of the disease. Here, we studied the role of the T_reg/Th17 balance for maintaining the intestinal barrier function in a mouse model of severe AP.

DESIGN

AP was induced by partial duct ligation in C57Bl/6 or DEREG mice, in which regulatory T-cells (T_reg) were depleted by intraperitoneal injection of diphtheria toxin. By flow cytometry, functional suppression assays and transcriptional profiling we analysed T_reg activation and characterised T-cells of the lamina propria as well as intraepithelial lymphocytes (IELs) regarding their activation and differentiation. Microbiota composition was examined in intestinal samples as well as in murine and human pancreatic necrosis by 16S rRNA gene sequencing.

RESULTS

The prophylactic T_reg-depletion enhanced the proinflammatory response in an experimental mouse model of AP but stabilised the intestinal immunological barrier function of Th17 cells and CD8⁺/γδTCR⁺ IELs. T_reg depleted animals developed less bacterial translocation to the pancreas. Duodenal overgrowth of the facultative pathogenic taxa Escherichia/Shigella which associates with severe disease and infected necrosis was diminished in T_reg depleted animals.

CONCLUSION

T_regs play a crucial role in the counterbalance against systemic inflammatory response syndrome. In AP, T_reg-activation disturbs the duodenal barrier function and permits translocation of commensal bacteria into pancreatic necrosis. Targeting T_regs in AP may help to ameliorate the disease course.

Association between type 2 diabetes and 5-year overall survival in early-stage pancreatic cancer: a retrospective cohort study

Background

This study examined the association between type 2 diabetes mellitus (T2DM) and 5-year overall survival (OS) in patients with pancreatic cancer (PC).

Methods

This retrospective cohort study included patients diagnosed with stage I/II PC at Shengjing Hospital of China Medical University from January 2012 to December 2017. All patients had pancreatic ductal adenocarcinoma or its subtypes. The outcome was the 5-year OS rate based on data from the patient charts. Data analysis was performed using SPSS 22.0.

Results

A total of 238 patients were included: 72 with T2DM and 166 without T2DM. There were significant differences in blood glucose levels and OS between the two groups (all P < 0.05). The median OS was 11.4 (95% confidence interval CI [8.49-14.31]) months in the T2DM group and 16.3 (95% CI [12.44-20.16], P = 0.023) months in the non-T2DM group. After adjustment for confounders, T2DM was an independent factor affecting 5-year OS (P = 0.010). Compared with non-T2DM patients, T2DM patients had a higher risk of death (HR = 1.475, 95% CI [1.096-1.985]).

Conclusions

T2DM is associated with 5-year OS in patients with PC.

Gut bacterial profiles in Parkinson's disease: A systematic review

INTRODUCTION

Recent advances have highlighted the relationships between gut dysbiosis and Parkinson's disease (PD). Microbiota transplantation from PD patients to mice can induce increased alpha-synuclein-mediated motor deficits. Human studies have identified differences in the gut microbiota of PD patients compared to healthy controls. We undertook a systematic review to evaluate the available evidence for the involvement of gut bacteria in the etiology of PD.

METHODS

The PubMed databank, the China National Knowledge Infrastructure databank, and Wanfang Data were searched from inception until June 2021 to identify human case-control studies that investigated relationships between PD and microbiota quantified from feces. We evaluated the resulting studies focusing on bacterial taxa that were different between PD patients and healthy controls.

RESULTS

Twenty-six studies were found in which 53 microbial families and 98 genera exhibited differences between patients with PD and healthy controls. The genera identified by more than two studies as increased in PD were Bifidobacterium, Alistipes, Christensenella, Enterococcus, Oscillospira, Bilophila, Desulfovibrio, Escherichia/Shigella, and Akkermansia, while Prevotella, Blautia, Faecalibacterium, Fusicatenibacter, and Haemophilus had three or more reports of being lower in PD patients. More than one report demonstrated that Bacteroides, Odoribacter, Parabacteroides, Butyricicoccus, Butyrivibrio, Clostridium, Coprococcus, Lachnospira, Lactobacillus, Megasphaera, Phascolarctobacterium, Roseburia, Ruminococcus, Streptococcus, and Klebsiella were altered in both directions.

CONCLUSION

Our review shows that the involvement of the gut microbiome in the etiology of PD may involve alterations of short-chain fatty acids (SCFAs)-producing bacteria and an increase in putative gut pathobionts. SCFAs-producing bacteria may vary above or below an "optimal range," causing imbalances. Considering that Bifidobacterium, Lactobacillus, and Akkermansia are beneficial for human health, increased Bifidobacterium and Lactobacillus in the PD gut microbiome may be associated with PD medications, especially COMT inhibitors, while a high level of Akkermansia may be associated with aging.

Decreased Intestinal Microbiota Diversity Is Associated With Increased Gastrointestinal Symptoms in Patients With Chronic Pancreatitis

OBJECTIVES

Chronic pancreatitis (CP) is characterized by abdominal pain, recurrent hospitalizations, frequent exposure to antibiotics, nutritional deficiencies, and chronic opioid use. Data describing the gut microbial community structure of patients with CP is limited. We aimed to compare gut microbiota of a group of patients with severe CP being considered for total pancreatectomy with islet autotransplantation (TPIAT) with those of healthy controls and to associate these differences with severity of clinical symptoms.

METHODS

We collected stool from healthy donors (n = 14) and patients with CP (n = 20) undergoing workup for TPIAT, in addition to clinical metadata and a validated abdominal symptoms severity survey.

RESULTS

Patients with CP had significantly lower alpha diversity than healthy controls ( P < 0.001). There was a significantly increased mean relative abundance of Faecalibacterium in healthy controls compared with patients with CP ( P = 0.02). Among participants with CP, those with lower alpha diversity reported worse functional abdominal symptoms ( P = 0.006).

CONCLUSIONS

These findings indicate that changes in gut microbial community structure may contribute to gastrointestinal symptoms and provide basis for future studies on whether enrichment of healthy commensal bacteria such as Faecalibacterium could provide clinically meaningful improvements in outcomes for CP patients undergoing TPIAT.

Isolation of pancreatic microbiota from cystic precursors of pancreatic cancer with intracellular growth and DNA damaging properties

Emerging research suggests gut microbiome may play a role in pancreatic cancer initiation and progression, but cultivation of the cancer microbiome remains challenging. This pilot study aims to investigate the possibility to cultivate pancreatic microbiome from pancreatic cystic lesions associated with invasive cancer. Intra-operatively acquired pancreatic cyst fluid samples showed culture-positivity mainly in the intraductal papillary mucinous neoplasm (IPMN) group of lesions. MALDI-TOF MS profiling analysis shows Gammaproteobacteria and Bacilli dominate among individual bacteria isolates. Among cultivated bacteria, Gammaproteobacteria, particularly Klebsiella pneumoniae, but also Granulicatella adiacens and Enterococcus faecalis, demonstrate consistent pathogenic properties in pancreatic cell lines tested in ex vivo co-culture models. Pathogenic properties include intracellular survival capability, cell death induction, or causing DNA double-strand breaks in the surviving cells resembling genotoxic effects. This study provides new insights into the role of the pancreatic microbiota in the intriguing link between pancreatic cystic lesions and cancer.

Gut Microbiome and the Role of Metabolites in the Study of Graves’ Disease

Graves’ disease (GD) is an autoimmune thyroid disease (AITD), which is one of the most common organ-specific autoimmune disorders with an increasing prevalence worldwide. But the etiology of GD is still unclear. A growing number of studies show correlations between gut microbiota and GD. The dysbiosis of gut microbiota may be the reason for the development of GD by modulating the immune system. Metabolites act as mediators or modulators between gut microbiota and thyroid. The purpose of this review is to summarize the correlations between gut microbiota, microbial metabolites and GD. Challenges in the future study are also discussed. The combination of microbiome and metabolome may provide new insight for the study and put forward the diagnosis, treatment, prevention of GD in the future.

[Etiology and pathogenesis of infected pancreatic necrosis]

Modern literature data confirm the central role of intestinal barrier complex not only as a target in acute necrotizing pancreatitis, but also as a trigger for septic complications. Intra-abdominal hypertension, endothelial dysfunction and gut microbiome changes following necrotizing pancreatitis might have an independent impact on acute intestinal distress syndrome and bacterial translocation. Monitoring of these conditions and early target therapy can improve the outcomes in patients with severe acute pancreatitis. Adverse outcomes of infected pancreatic necrosis including high mortality and morbidity are largely due to the prevalence of multidrug-resistant bacterial pathogens.

Microbiota in Pancreatic Diseases: A Review of the Literature

The gut microbiota is a critical element in the balance between human health and disease. Its impairment, defined as dysbiosis, is associated with gastroenterological and systemic diseases. Pancreatic secretions are involved in the composition and changes of the gut microbiota, and the gut microbiota may colonize the pancreatic parenchyma and be associated with the occurrence of diseases. The gut microbiota and the pancreas influence each other, resulting in a "gut microbiota-pancreas axis". Moreover, the gut microbiota may be involved in pancreatic diseases, both through direct bacterial colonization and an indirect effect of small molecules and toxins derived from dysbiosis. Pancreatic diseases such as acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, and pancreatic cancer are common gastroenterological diseases associated with high morbidity and mortality. The involvement of the microbiota in pancreatic diseases is increasingly recognized. Therefore, modifying the intestinal bacterial flora could have important therapeutic implications on these pathologies. The aim of this study is to review the literature to evaluate the alterations of the gut microbiota in pancreatic diseases, and the role of the microbiota in the treatment of these diseases.

The Role of Gut Microbiota and Genetic Susceptibility in the Pathogenesis of Pancreatitis

Pancreatitis is one of the most common inflammatory diseases of the pancreas caused by autodigestion induced by excessive premature protease activation. However, recognition of novel pathophysiological mechanisms remains a still challenge. Both genetic and environmental factors contribute to the pathogenesis of pancreatitis, and the gut microbiota is a potential source of an environmental effect. In recent years, several new frontiers in gut microbiota and genetic risk assessment research have emerged and improved the understanding of the disease. These investigations showed that the disease progression of pancreatitis could be regulated by the gut microbiome, either through a translocation influence or in a host immune response manner. Meanwhile, the onset of the disease is also associated with the heritage of a pathogenic mutation, and the disease progression could be modified by genetic risk factors. In this review, we focused on the recent advances in the role of gut microbiota in the pathogenesis of pancreatitis, and the genetic susceptibility in pancreatitis.

Disentangling the Progression of Non-alcoholic Fatty Liver Disease in the Human Gut Microbiota

Gut microbiome dysbiosis has been known to be associated with all stages of non-alcoholic fatty liver disease (NAFLD), but questions remain about microbial profiles in progression and homogeneity across NAFLD stages. We performed a meta-analysis of three publicly shotgun datasets and built predictive models to determine diagnostic capacity. Here, we found consistently microbiome shifts across NAFLD stages, of which co-occurrence patterns and core sets of new biomarkers significantly correlated with NAFLD progression were identified. Machine learning models that are able to distinguish patients with any NAFLD stage from healthy controls remained predictive when applied to patients with other NAFLD stages, suggesting the homogeneity across stages once again. Focusing on species and metabolic pathways specifically associated with progressive stages, we found that increased toxic metabolites and decreased protection of butyrate and choline contributed to advanced NAFLD. We further built models discriminating one stage from the others with an average of 0.86 of area under the curve. In conclusion, this meta-analysis firmly establishes generalizable microbiome dysbiosis and predictive taxonomic and functional signatures as a basis for future diagnostics across NAFLD stages.

Clinical Implications of Malnutrition in the Management of Patients with Pancreatic Cancer: Introducing the Concept of the Nutritional Oncology Board

Pancreatic cancer represents a very challenging disease, with an increasing incidence and an extremely poor prognosis. Peculiar features of this tumor entity are represented by pancreatic exocrine insufficiency and an early and intense nutritional imbalance, leading to the highly prevalent and multifactorial syndrome known as cancer cachexia. Recently, also the concept of sarcopenic obesity has emerged, making the concept of pancreatic cancer malnutrition even more multifaceted and complex. Overall, these nutritional derangements play a pivotal role in contributing to the dismal course of this malignancy. However, their relevance is often underrated and their assessment is rarely applied in clinical daily practice with relevant negative impact for patients' outcome in neoadjuvant, surgical, and metastatic settings. The proper detection and management of pancreatic cancer-related malnutrition syndromes are of primary importance and deserve a specific and multidisciplinary (clinical nutrition, oncology, etc.) approach to improve survival, but also the quality of life. In this context, the introduction of a "Nutritional Oncology Board" in routine daily practice, aimed at assessing an early systematic screening of patients and at implementing nutritional support from the time of disease diagnosis onward seems to be the right path to take.

Microbiome Metabolites and Thyroid Dysfunction

Thyroid diseases are common conditions that have a negative impact on the health of all populations. The literature sheds light on the differences in the composition of the intestinal microbiota in patients suffering from thyroid diseases compared to healthy individuals. The microbiome affects the proper functioning of the thyroid gland, and the existence of the gut–thyroid axis is discussed in the context of both thyroid diseases and intestinal dysbiosis. The purpose of this review is to describe associations between the microbiome and its metabolites and thyroid dysfunction. We try to explain the role of the microbiome in the metabolism of thyroid hormones and the impact of thyroid autoimmune diseases. In addition, we raise issues related to the influence of bacterial metabolites, such as short-chain fatty acids or secondary bile acids, in the functioning of the thyroid gland. Last but not least, we explored the interactions between the gut microbiota and therapeutics and supplements typically administered to patients with thyroid diseases.

Gut microbiome in acute pancreatitis: A review based on current literature

The gut microbiome is a complex microbial community, recognized for its potential role in physiology, health, and disease. The available evidence supports the role of gut dysbiosis in pancreatic disorders, including acute pancreatitis (AP). In AP, the presence of gut barrier damage resulting in increased mucosal permeability may lead to translocation of intestinal bacteria, necrosis of pancreatic and peripancreatic tissue, and infection, often accompanied by multiple organ dysfunction syndrome. Preserving gut microbial homeostasis may reduce the systemic effects of AP. A growing body of evidence suggests the possible involvement of the gut microbiome in various pancreatic diseases, including AP. This review discusses the possible role of the gut microbiome in AP. It highlights AP treatment and supplementation with prebiotics, synbiotics, and probiotics to maintain gastrointestinal microbial balance and effectively reduce hospitalization, morbidity and mortality in an early phase. It also addresses novel therapeutic areas in the gut microbiome, personalized treatment, and provides a roadmap of human microbial contributions to AP that have potential clinical benefit.

Role of microbiota-derived short-chain fatty acids in cancer development and prevention

Following cancer, cells in a particular tissue can no longer respond to the factors involved in controlling cell survival, differentiation, proliferation, and death. In recent years, it has been indicated that alterations in the gut microbiota components, intestinal epithelium, and host immune system are associated with cancer incidence. Also, it has been demonstrated that the short-chain fatty acids (SCFAs) generated by gut microbiota are vitally crucial in cell homeostasis as they contribute to the modulation of histone deacetylases (HDACs), resulting effected cell attachment, immune cell immigration, cytokine production, chemotaxis, and the programmed cell death. Therefore, the manipulation of SCFA levels in the intestinal tract by alterations in the microbiota structure can be potentially taken into consideration for cancer treatment/prevention. In the current study, we will explain the most recent findings on the detrimental or protective roles of SFCA (particularly butyrate, propionate, and acetate) in several cancers, including bladder, colon, breast, stomach, liver, lung, pancreas, and prostate cancers.

Global research trends in the microbiome related to irritable bowel syndrome: A bibliometric and visualized study

BACKGROUND

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Dysregulation of the gut-brain axis plays a central role in the pathophysiology of IBS. It is increasingly clear that the microbiome plays a key role in the development and normal functioning of the gut-brain axis.

AIM

To facilitate the identification of specific areas of focus that may be of relevance to future research. This study represents a bibliometric analysis of the literature pertaining to the microbiome in IBS to understand the development of this field.

METHODS

The data used in our bibliometric analysis were retrieved from the Scopus database. The terms related to IBS and microbiome were searched in titles or abstracts within the period of 2000-2019. VOSviewer software was used for data visualization.

RESULTS

A total of 13055 documents related to IBS were retrieved at the global level. There were 1872 scientific publications focused on the microbiome in IBS. There was a strong positive correlation between publication productivity related to IBS in all fields and productivity related to the microbiome in IBS (r = 0.951, P < 0.001). The United States was the most prolific country with 449 (24%) publications, followed by the United Kingdom (n = 176, 9.4%), China (n = 154, 8.2%), and Italy (n = 151, 8.1%). The h-index for all retrieved publications related to the microbiome in IBS was 138. The hot topics were stratified into four clusters: (1) The gut-brain axis related to IBS; (2) Clinical trials related to IBS and the microbiome; (3) Drug-mediated manipulation of the gut microbiome; and (4) The role of the altered composition of intestinal microbiota in IBS prevention.

CONCLUSION

This is the first study to evaluate and quantify global research productivity pertaining to the microbiome in IBS. The number of publications regarding the gut microbiota in IBS has continuously grown since 2013. This finding suggests that the future outlook for interventions targeting the gut microbiota in IBS remains promising.

The Unique Microbiome and Immunity in Pancreatic Cancer

ABSTRACT

Microorganisms can help maintain homeostasis in humans by providing nutrition, maintaining hormone balance, and regulating inflammatory responses. In the case of imbalances, these microbes can cause various diseases, even malignancy. Pancreatic cancer (PC) is characterized by high tumor invasiveness, distant metastasis, and insensitivity to traditional chemotherapeutic drugs, and it is confirmed that PC is closely related to microorganisms. Recently, most studies based on clinical samples or case reports discussed the positive or negative relationships between microorganisms and PC. However, the specific mechanisms are blurry, especially the involved immunological pathways, and the roles of beneficial flora have usually been ignored. We reviewed studies published through September 2020 as identified using PubMed, MEDLINE, and Web of Science. We mainly introduced the traits of oral, gastrointestinal, and intratumoral microbes in PC and summarized the roles of these microbes in tumorigenesis and tumoral development through immunological pathways, in addition to illustrating the relationships between metabolic diseases with PC by microorganism. In addition, we identified microorganisms as biomarkers for early diagnosis and immunotherapy. This review will be significant for greater understanding the effect of microorganisms in PC and provide more meaningful guidance for future clinical applications.

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.

Characteristics of Gut Microbiota in Cerulein-Induced Chronic Pancreatitis

BACKGROUND

Although clinical trials and animal models have evaluated the alterations of the microbiome in chronic pancreatitis (CP), the gut microbiota composition and diversity in cerulein-induced CP is unknown. This study aimed to evaluate the changes of gut microbiota in a CP mice model, and to determine whether these gut microbiota changes were consistent with those in patients with CP.

METHODS

A total of ten male C57BL/6j mice were randomly divided into two groups. The experimental group were injected intraperitoneally with cerulein, while the normal control group received comparable injections of saline, the entire molding process lasted 6 weeks. Histology analysis was used to assess pancreatic morphological changes and fibrosis, meanwhile the gut microbiota composition and diversity were analyzed by high throughput sequencing. Spearman correlation analysis was used to determine whether body weight and weight changes were associated with changes in gut microbial abundance.

RESULTS

The bacterial richness and diversity of CP mice decreased, and the gut microbiota changed, including lower levels of Firmicutes, decreased Firmicutes/Bacteroidetes ratio and increased abundance of Bacteroidetes, Actinobacteria and Verrucomicrobia. We found statistically significant differences in body weight and weight changes between the two groups. However, there was no significant correlation between alterations of gut microbiota and in body weight and weight changes.

CONCLUSION

Our results showed that the gut microbiota in cerulein-induced CP was changed.

Fecal microbiota transplantation for COVID-19; a potential emerging treatment strategy

At the end of 2019, an emerging outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first reported from Wuhan, China. The first manifestations of patients infected with SARS-CoV-2 was flu-like symptoms, while other type of manifestations, especially gastrointestinal manifestations were discovered recently. As of June 2020, there is no specific drug or treatment strategy for COVID-19, a disease caused by SARS-CoV-2, so different combination of antiviral drugs is currently being used. Gut microbiota mostly consists of four phyla, including Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. The interaction between gut microbiota and immune system through releasing some cytokines such as IL-1β, IL-2, IL-10, TNF-α, and IFN-γ that play roles in the severity of COVID-19. In this article, a new potential treatment for COVID-19 by fecal microbiota transplantation (FMT) is described. FMT revealed promising results in different diseases, especially recurrent clostridium difficile infection, and it might reduce length of hospital admission and severity of the disease by modification of gut microbiota composition.

Pathological Mechanisms in Diabetes of the Exocrine Pancreas: What's Known and What's to Know

The clinical significance of diabetes arising in the setting of pancreatic disease (also known as diabetes of the exocrine pancreas, DEP) has drawn more attention in recent years. However, significant improvements still need to be made in the recognition, diagnosis and treatment of the disorder, and in the knowledge of the pathological mechanisms. The clinical course of DEP is different from type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). DEP develops in patients with previous existing exocrine pancreatic disorders which damage both exocrine and endocrine parts of pancreas, and lead to pancreas exocrine insufficiency (PEI) and malnutrition. Therefore, damage in various exocrine and endocrine cell types participating in glucose metabolism regulation likely contribute to the development of DEP. Due to the limited amount of clinical and experimental studies, the pathological mechanism of DEP is poorly defined. In fact, it still not entirely clear whether DEP represents a distinct pathologic entity or is a form of T2DM arising when β cell failure is accelerated by pancreatic disease. In this review, we include findings from related studies in T1DM and T2DM to highlight potential pathological mechanisms involved in initiation and progression of DEP, and to provide directions for future research studies.

Lactobacillus Attenuate the Progression of Pancreatic Cancer Promoted by Porphyromonas Gingivalis in K-rasG12D Transgenic Mice

Simple Summary

Pancreatic cancer is aggressive and lethal with a five year survival rate of only 5–9%. While the exact pathogenesis of pancreatic cancer is not fully understood, oral pathogens associated with periodontitis, such as Porphyromonas gingivalis (P. gingivalis), are linked to the disease. The aim of our study was to investigate the causal association between exposure to P. gingivalis and subsequent carcinogenesis, and the potential modulatory effects of probiotics. We demonstrated that oral exposure to P. gingivalis can accelerate the development of pancreatic ductal adenocarcinoma in mouse models. In addition, the transforming growth factor-β (TGF-β) signaling pathway may be involved in the cancer-promoting effect of P. gingivalis and the suppressive effects of probiotics. Further understanding of the mechanisms of tumor-promoting or tumor-suppressing effects of TGF-β signaling may have potential as a treatment for pancreatic cancer.

Abstract

Accumulating evidence suggests that there is a link between the host microbiome and pancreatic carcinogenesis, and that Porphyromonas gingivalis (P. gingivalis) increases the risk of developing pancreatic cancer. The aim of the current study was to clarify the role of P. gingivalis in the pathogenesis of pancreatic cancer and the potential immune modulatory effects of probiotics. The six-week-old LSL-K-rasG12D; Pdx-1-cre (KC) mice smeared P. gingivalis on the gums, causing pancreatic intraepithelial neoplasia (PanIN) after four weeks to be similar to the extent of lesions in untreated KC mice at 24 weeks. The oral inoculation of P. gingivalis of six-week-old LSL-K-ras^G12D; Pdx-1-cre (KC) mice caused significantly pancreatic intraepithelial neoplasia (PanIN) after treatment four weeks is similar to the extent of lesions in untreated KC mice at 24 weeks. The pancreas weights of P. gingivalis plus probiotic-treated mice were significantly lower than the mice treated with P. gingivalis alone (P = 0.0028). The histological expressions of Snail-1, ZEB-1, collagen fibers, Galectin-3, and PD-L1 staining in the pancreas were also notably lower. In addition, probiotic administration reduced the histological expression of Smad3 and phosphorylated Smad3 in P. gingivalis treated KC mice. We demonstrated that oral exposure to P. gingivalis can accelerate the development of PanIN lesions. Probiotics are likely to have a beneficial effect by reducing cancer cell proliferation and viability, inhibiting PanIN progression, and cancer cell metastasis (Epithelial–mesenchymal transition, EMT). The transforming growth factor-β signaling pathway may be involved in the tumor suppressive effects of probiotics.

Broadly protective semi-synthetic glycoconjugate vaccine against pathogens capable of producing poly-β-(1→6)-N-acetyl-d-glucosamine exopolysaccharide

Poly-β-(1→6)-N-acetylglucosamine (PNAG) was first discovered as a major component of biofilms formed by Staphylococcus aureus and some other staphylococci but later this exopolysaccharide was also found to be produced by pathogens of various nature. This common antigen is considered as a promising target for construction of a broadly protective vaccine. Extensive studies of PNAG, its de-N-acetylated derivative (dPNAG, containing around 15% of residual N-acetates) and their conjugates with Tetanus Toxoid (TT) revealed the crucial role of de-N-acetylated glucosamine units for the induction of protective immunity. Conjugates of synthetic penta- (5GlcNH₂) and nona-β-(1→6)-d-glucosamines (9GlcNH₂) were tested in vitro and in different animal models and proved to be effective in passive and active protection against different microbial pathogens. Presently conjugate 5GlcNH₂-TT is being produced under GMP conditions and undergoes safety and effectiveness evaluation in humans and economically important animals. Current review summarizes all stages of this long-termed study.

State of the Art in Exocrine Pancreatic Insufficiency

Exocrine pancreatic insufficiency (EPI) is defined as the maldigestion of foods due to inadequate pancreatic secretion, which can be caused by alterations in its stimulation, production, transport, or interaction with nutrients at duodenal level. The most frequent causes are chronic pancreatitis in adults and cystic fibrosis in children. The prevalence of EPI is high, varying according to its etiology, but it is considered to be underdiagnosed and undertreated. Its importance lies in the quality of life impairment that results from the malabsorption and malnutrition and in the increased morbidity and mortality, being associated with osteoporosis and cardiovascular events. The diagnosis is based on a set of symptoms, indicators of malnutrition, and an indirect non-invasive test in at-risk patients. The treatment of choice combines non-restrictive dietary measures with pancreatic enzyme replacement therapy to correct the associated symptoms and improve the nutritional status of patients. Non-responders require the adjustment of pancreatic enzyme therapy, the association of proton pump inhibitors, and/or the evaluation of alternative diagnoses such as bacterial overgrowth. This review offers an in-depth overview of EPI in order to support the proper management of this entity based on updated and integrated knowledge of its etiopathogenesis, prevalence, diagnosis, and treatment.

Gut microbiota patterns associated with somatostatin in patients undergoing pancreaticoduodenectomy: a prospective study

Postoperative pancreatic fistula (POPF) is a common and dreaded complication after pancreaticoduodenectomy (PD). The gut microbiota has been considered as an crucial mediator of postoperative complications, however, the precise roles of gut microbiota in POPF are unclear. A prospective study was developed to explore the effects of somatostatin on gut microbiota and we aim to identify the microbial alterations in the process of POPF. A total of 45 patients were randomly divided into PD group or additional somatostatin therapy group. The fecal sample of each patient was collected preoperatively and postoperatively and the gut microbiota was analyzed by 16S rRNA sequencing. Our study found that somatostatin therapy was independent risk factor for the occurrence of POPF, and it reduced the microbial diversity and richness in patients. At genus level, somatostatin therapy led to a decreased abundance in Bifidobacterium, Subdoligranulum and Dubosiella, whereas the abundance of Akkermansia, Enterococcus and Enterobacter were increased. The abundance levels of certain bacteria in the gut microbiota have significantly shifted in patients with POPF. The LEfSe analysis revealed that Ruminococcaceae could be used as microbial markers for distinguishing patients with high risk of POPF. Furthermore, Verrucomicrobia and Akkermansia could be used as preoperative biomarkers for identifying patients without POPF. Our prospective study highlights the specific communities related with somatostatin therapy and discovers POPF-associated microbial marker, which suggests that gut microbiota may become a diagnostic biomarker and potential therapeutic target for POPF.

Association between Inflammatory Bowel Disease and Pancreatitis: A PRISMA-Compliant Systematic Review

METHODS

MEDLINE, Embase, and CENTRAL were systematically searched for correlative studies till 2 November 2019. RevMan5.3 was used to estimate relevance.

RESULTS

Three studies with 166008 participants were included. The risk of pancreatitis significantly increased in the patients with CD (OR, 3.40; 95% CI, 2.70-4.28; P < 0.00001) and UC (OR, 2.49; 95% CI, 1.91-3.26; P < 0.00001). Increased risks of CD (OR, 12.90; 95% CI, 5.15-32.50; P < 0.00001) and UC (OR, 2.80; 95% CI, 1.00-7.86; P = 0.05) were found in patients with chronic pancreatitis. As for patients with acute pancreatitis, there were significant association of CD (OR, 3.70; 95% CI, 1.90-7.60; P = 0.0002), but were not UC.

CONCLUSIONS

The evidence confirmed an association between pancreatitis and IBD. When pancreatitis patients have chronic diarrhea and mucus blood stool or IBD patients have repeated abdominal pain and weight loss, they should consult pancreatic and gastrointestinal specialists.

Thyroid-Gut-Axis: How Does the Microbiota Influence Thyroid Function?

A healthy gut microbiota not only has beneficial effects on the activity of the immune system, but also on thyroid function. Thyroid and intestinal diseases prevalently coexist-Hashimoto's thyroiditis (HT) and Graves' disease (GD) are the most common autoimmune thyroid diseases (AITD) and often co-occur with Celiac Disease (CD) and Non-celiac wheat sensitivity (NCWS). This can be explained by the damaged intestinal barrier and the following increase of intestinal permeability, allowing antigens to pass more easily and activate the immune system or cross-react with extraintestinal tissues, respectively. Dysbiosis has not only been found in AITDs, but has also been reported in thyroid carcinoma, in which an increased number of carcinogenic and inflammatory bacterial strains were observed. Additionally, the composition of the gut microbiota has an influence on the availability of essential micronutrients for the thyroid gland. Iodine, iron, and copper are crucial for thyroid hormone synthesis, selenium and zinc are needed for converting T4 to T3, and vitamin D assists in regulating the immune response. Those micronutrients are often found to be deficient in AITDs, resulting in malfunctioning of the thyroid. Bariatric surgery can lead to an inadequate absorption of these nutrients and further implicates changes in thyroid stimulating hormone (TSH) and T3 levels. Supplementation of probiotics showed beneficial effects on thyroid hormones and thyroid function in general. A literature research was performed to examine the interplay between gut microbiota and thyroid disorders that should be considered when treating patients suffering from thyroid diseases. Multifactorial therapeutic and preventive management strategies could be established and more specifically adjusted to patients, depending on their gut bacteria composition. Future well-powered human studies are warranted to evaluate the impact of alterations in gut microbiota on thyroid function and diseases.

Microbes and Cancer: Friends or Faux?

Cancer is one of the most aggressive and deadly diseases in the world, representing the second leading cause of death. It is a multifactorial disease, in which genetic alterations play a key role, but several environmental factors also contribute to its development and progression. Infections induced by certain viruses, bacteria, fungi and parasites constitute risk factors for cancer, being chronic infection associated to the development of certain types of cancer. On the other hand, susceptibility to infectious diseases is higher in cancer patients. The state of the host immune system plays a crucial role in the susceptibility to both infection and cancer. Importantly, immunosuppressive cancer treatments increase the risk of infection, by decreasing the host defenses. Furthermore, alterations in the host microbiota is also a key factor in the susceptibility to develop cancer. More recently, the identification of a tumor microbiota, in which bacteria establish a symbiotic relationship with cancer cells, opened a new area of research. There is evidence demonstrating that the interaction between bacteria and cancer cells can modulate the anticancer drug response and toxicity. The present review focuses on the interaction between microbes and cancer, specifically aiming to: (1) review the main infectious agents associated with development of cancer and the role of microbiota in cancer susceptibility; (2) highlight the higher vulnerability of cancer patients to acquire infectious diseases; (3) document the relationship between cancer cells and tissue microbiota; (4) describe the role of intratumoral bacteria in the response and toxicity to cancer therapy.

The effect of periodontal bacteria infection on incidence and prognosis of cancer: A systematic review and meta-analysis

BACKGROUND

Periodontal bacteria is the major pathogens in the oral cavity and the main cause of adult chronic periodontitis, but their association with incidence and prognosis in cancer is controversial. The aim of this study was to evaluate the effect of periodontal bacteria infection on incidence and prognosis of cancer.

METHODS

A systematic literature search of PubMed, Embase, Web of Science, and Cochrane Library databases was performed to obtain 39 studies comprising 7184 participants. The incidence of cancer was evaluated as odd ratios (OR) with a 95% confidence interval (95% CI) using Review Manager 5.2 software. Overall survival, cancer-specific survival and disease-free survival, which were measured as hazard ratios (HR) with a 95% CI using Review Manager 5.2 software.

RESULTS

Our results indicated that periodontal bacteria infection increased the incidence of cancer (OR = 1.25; 95%CI: 1.03-1.52) and was associated with poor overall survival (HR = 1.75; 95% CI: 1.40-2.20), disease-free survival (HR = 2.18; 95%CI: 1.24-3.84) and cancer-specific survival (HR = 1.85, 95%CI: 1.44-2.39). Subgroup analysis indicted that the risk of cancer was associated with Porphyromonas gingivalis (Pg) infection (OR = 2.16; 95%CI: 1.34-3.47) and Prevotella intermedia (Pi) infection (OR = 1.28; 95%CI: 1.01-1.63) but not Tannerella forsythia (Tf) (OR = 1.06; 95%CI: 0.8-1.41), Treponema denticola (Td) (OR = 1.30; 95%CI: 0.99-1.72), Aggregatibacter actinomycetemcomitans (Aa) (OR = 1.00; 95%CI: 0.48-2.08) and Fusobacterium nucleatum (Fn) (OR = 0.61; 95%CI: 0.32-1.16).

CONCLUSION

This meta-analysis revealed periodontal bacteria infection increased the incidence of cancer and predicted poor prognosis of cancer.

Disordered Gut Microbiota in Children Who Have Chronic Pancreatitis and Different Functional Gene Mutations

OBJECTIVES

Chronic pancreatitis (CP) is a serious condition whose pathogenic mechanism is unclear. Interactions of host genetic factors with gut microbiota have a role, but little is known, especially in children with CP (CCP), in which the external factors are less important. Our objective was to identify the main gut microbiota genera in CCP and to characterize the functional mutations of these patients.

METHODS

We used 16S rRNA sequencing to compare the gut microbiota of healthy controls with patients who had CCP and different functional gene mutations.

RESULTS

CCP is characterized by gut microbiota with remarkably reduced alpha diversity. Receiver operating characteristic curve analyses indicated that the abundances of 6 genera-Faecalibacterium, Subdoligranulum, Phascolarctobacterium, Bifidobacterium, Eubacerium, and Collinsella-were significantly decreased in CCP, with an area under curve (AUC) of 0.92 when considering all 6 genera together. Functional analysis of gut microbiota in CCP indicated reduced ribosomal activity, porphyrin and chlorophyll metabolism, starch and sucrose metabolism, and aminoacyl-tRNA biosynthesis, but an enrichment of phosphotransferase system pathways. The abundance of Butyricicoccus was significantly decreased in CCP in the presence of CFTR mutations when combined with mutations in CASR, CTSB, SPINK1, and/or PRSS1. The abundance of Ruminococcaceae was significantly increased in CCP when there were mutations in CASR, CTSB, SPINK1, and/or PRSS1. Patients with CCP but no gene mutations had greater abundances of Veillonella and reduced abundances of Phascolarctobacterium.

DISCUSSION

CCP is associated with a depletion of probiotic gut microbiota, and CCP patients with different functional gene mutations have different gut microbiota.

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.

Role of the microbiome in occurrence, development and treatment of pancreatic cancer

Pancreatic cancer is one of the most lethal malignancies. Recent studies indicated that development of pancreatic cancer may be intimately connected with the microbiome. In this review, we discuss the mechanisms through which microbiomes affect the development of pancreatic cancer, including inflammation and immunomodulation. Potential therapeutic and diagnostic applications of microbiomes are also discussed. For example, microbiomes may serve as diagnostic markers for pancreatic cancer, and may also play an important role in determining the efficacies of treatments such as chemo- and immunotherapies. Future studies will provide additional insights into the various roles of microbiomes in pancreatic cancer.

The potential role of P.gingivalis in gastrointestinal cancer: a mini review

Bacterial infection may be involved in the entire process of tissue carcinogenesis by directly or indirectly affecting the occurrence and development of tumors. Porphyromonas gingivalis (P.gingivalis) is an important pathogen causing periodontitis. Periodontitis may promote the occurrence of various tumors. Gastrointestinal tumors are common malignant tumors with high morbidity, high mortality, and low early diagnosis rate. With the rapid development of molecularbiotechnology, the role of P.gingivalis in digestive tract tumors has been increasingly explored. This article reviews the correlation between P.gingivalis and gastrointestinal cancer and the pathogenesis of the latter. The relationship among P.gingivalis, periodontal disease, and digestive tract tumors must be clarifiedthrough a multi-center, prospective, large-scale study.