Possible involvement of Enterococcus infection in the pathogenesis of chronic pancreatitis and cancer

The role of microbiome in pancreatic cancer

Recent studies of the human microbiome have offered new insights into how the microbiome can impact cancer development and treatment. Specifically, in pancreatic ductal adenocarcinoma (PDAC), the microbiota has been shown to modulate PDAC risk, contribute to tumorigenesis, impact the tumor microenvironment, and alter treatment response. These findings provide rationale for further investigations into leveraging the microbiome to develop new strategies to diagnose and treat PDAC patients. There is growing evidence that microbiome analyses have the potential to become easily performed, non-invasive diagnostic, prognostic, and predictive biomarkers in pancreatic cancer. More excitingly, there is now emerging interest in developing interventions based on the modulation of microbiota. Fecal microbiota transplantation, probiotics, dietary changes, and antibiotics are all potential strategies to augment the efficacy of current therapeutics and reduce toxicities. While there are still challenges to overcome, this is a rapidly growing field that holds promise for translation into clinical practice and provides a new approach to improving patient outcomes.

The Role of the Oral Microbiota in the Etiopathogenesis of Oral Squamous Cell Carcinoma

Dysbiosis in the oral environment may play a role in the etiopathogenesis of oral squamous cell carcinoma (OSCC). This review aims to summarize the current knowledge about the association of oral microbiota with OSCC and to describe possible etiopathogenetic mechanisms involved in processes of OSCC development and progression. Association studies included in this review were designed as case–control/case studies, analyzing the bacteriome, mycobiome, and virome from saliva, oral rinses, oral mucosal swabs, or oral mucosal tissue samples (deep and superficial) and comparing the results in healthy individuals to those with OSCC and/or with premalignant lesions. Changes in relative abundances of specific bacteria (e.g., Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus sp.) and fungi (especially Candida sp.) were associated with OSCC. Viruses can also play a role; while the results of studies investigating the role of human papillomavirus in OSCC development are controversial, Epstein–Barr virus was positively correlated with OSCC. The oral microbiota has been linked to tumorigenesis through a variety of mechanisms, including the stimulation of cell proliferation, tumor invasiveness, angiogenesis, inhibition of cell apoptosis, induction of chronic inflammation, or production of oncometabolites. We also advocate for the necessity of performing a complex analysis of the microbiome in further studies and of standardizing the sampling procedures by establishing guidelines to support future meta-analyses.

Pancreatic cancer: A review of epidemiology, trend, and risk factors

Despite rapid advances in modern medical technology and significant improvements in survival rates of many cancers, pancreatic cancer is still a highly lethal gastrointestinal cancer with a low 5-year survival rate and difficulty in early detection. At present, the incidence and mortality of pancreatic cancer are increasing year by year worldwide, no matter in the United States, Europe, Japan, or China. Globally, the incidence of pancreatic cancer is projected to increase to 18.6 per 100000 in 2050, with the average annual growth of 1.1%, meaning that pancreatic cancer will pose a significant public health burden. Due to the special anatomical location of the pancreas, the development of pancreatic cancer is usually diagnosed at a late stage with obvious clinical symptoms. Therefore, a comprehensive understanding of the risk factors for pancreatic cancer is of great clinical significance for effective prevention of pancreatic cancer. In this paper, the epidemiological characteristics, developmental trends, and risk factors of pancreatic cancer are reviewed and analyzed in detail.

Micro- and Mycobiota Dysbiosis in Pancreatic Ductal Adenocarcinoma Development

BACKGROUND

Dysbiosis of the intestinal flora has emerged as an oncogenic contributor in different malignancies. Recent findings suggest a crucial tumor-promoting role of micro- and mycobiome alterations also in the development of pancreatic ductal adenocarcinoma (PDAC).

METHODS

To summarize the current knowledge about this topic, a systematic literature search of articles published until October 2020 was performed in MEDLINE (PubMed).

RESULTS

An increasing number of publications describe associations between bacterial and fungal species and PDAC development. Despite the high inter-individual variability of the commensal flora, some studies identify specific microbial signatures in PDAC patients, including oral commensals like Porphyromonas gingivalis and Fusobacterium nucleatum or Gram-negative bacteria like Proteobacteria. The role of Helicobacter spp. remains unclear. Recent isolation of Malassezia globosa from PDAC tissue suggest also the mycobiota as a crucial player of tumorigenesis. Based on described molecular mechanisms and interactions between the pancreatic tissue and the immune system this review proposes a model of how the micro- and the mycobial dysbiosis could contribute to tumorigenesis in PDAC.

CONCLUSIONS

The presence of micro- and mycobial dysbiosis in pancreatic tumor tissue opens a fascinating perspective on PDAC oncogenesis. Further studies will pave the way for novel tumor markers and treatment strategies.

Branched-chain amino acids protect the liver from cirrhotic injury via suppression of activation of lipopolysaccharide-binding protein, toll-like receptor 4, and signal transducer and activator of transcription 3, as well as Enterococcus faecalis translocation

OBJECTIVES

Branched-chain amino acids (BCAAs) are used as nutritional support and for improving prognosis in liver cirrhosis. Here we investigate the molecular mechanisms of BCAA treatment and liver damage focused on pathways related to lipopolysaccharide-binding protein (LBP).

METHODS

Serum LBP levels were measured in cirrhotic patients and in cirrhotic rats treated with BCAA to examine the correlation between liver function and survival. In cirrhotic rats, liver damage, Enterococcus faecalis translocation, serum capsular polysaccharide, and intestinal tight junction levels were assessed. Damaged HepG2 cells were cultured with BCAA-supplemented, BCAA-deficient, or control amino acid medium, followed by examination of LBP expression.

RESULTS

Serum LBP levels were significantly increased in deceased patients individuals with liver cirrhosis. The survival rate in patients with lower serum LBP (<3.48 μg/mL) was significantly improved. In BCAA-treated rat liver samples, protein expression of LBP, toll-like receptor 4 (TLR4), and phosphorylated signal transduction and activator of transcription 3 (STAT3) were significantly reduced. Also in BCAA-treated rats, intestinal zonula occludens gene expression was increased, whereas hepatic translocation of E. faecalis and serum capsular polysaccharide levels were reduced. In damaged HepG2 cells, lipopolysaccharide-induced elevation of LBP expression was rapidly and strongly repressed in BCAA-enriched medium.

CONCLUSIONS

Serum LBP level is a prognostic biomarker in liver cirrhosis. BCAA treatment reduced translocation of E. faecalis through intestinal tight junction recovery and reduced LBP expression in the liver, which repressed activation of LBP, toll-like receptor 4, and signal transduction and activator of transcription 3. Our findings suggest that BCAA supplementation protects the liver from damage via multiple pathways.

Oral-Gut Microbiome Axis in Gastrointestinal Disease and Cancer

It is well-known that microbiota dysbiosis is closely associated with numerous diseases in the human body. The oral cavity and gut are the two largest microbial habitats, playing a major role in microbiome-associated diseases. Even though the oral cavity and gut are continuous regions connected through the gastrointestinal tract, the oral and gut microbiome profiles are well-segregated due to the oral-gut barrier. However, the oral microbiota can translocate to the intestinal mucosa in conditions of the oral-gut barrier dysfunction. Inversely, the gut-to-oral microbial transmission occurs as well in inter- and intrapersonal manners. Recently, it has been reported that oral and gut microbiomes interdependently regulate physiological functions and pathological processes. Oral-to-gut and gut-to-oral microbial transmissions can shape and/or reshape the microbial ecosystem in both habitats, eventually modulating pathogenesis of disease. However, the oral-gut microbial interaction in pathogenesis has been underappreciated to date. Here, we will highlight the oral-gut microbiome crosstalk and its implications in the pathogenesis of the gastrointestinal disease and cancer. Better understanding the role of the oral-gut microbiome axis in pathogenesis will be advantageous for precise diagnosis/prognosis and effective treatment.

Oral–Gut Microbiome Axis in Gastrointestinal Disease and Cancer

It is well-known that microbiota dysbiosis is closely associated with numerous diseases in the human body. The oral cavity and gut are the two largest microbial habitats, playing a major role in microbiome-associated diseases. Even though the oral cavity and gut are continuous regions connected through the gastrointestinal tract, the oral and gut microbiome profiles are well-segregated due to the oral–gut barrier. However, the oral microbiota can translocate to the intestinal mucosa in conditions of the oral–gut barrier dysfunction. Inversely, the gut-to-oral microbial transmission occurs as well in inter- and intrapersonal manners. Recently, it has been reported that oral and gut microbiomes interdependently regulate physiological functions and pathological processes. Oral-to-gut and gut-to-oral microbial transmissions can shape and/or reshape the microbial ecosystem in both habitats, eventually modulating pathogenesis of disease. However, the oral–gut microbial interaction in pathogenesis has been underappreciated to date. Here, we will highlight the oral–gut microbiome crosstalk and its implications in the pathogenesis of the gastrointestinal disease and cancer. Better understanding the role of the oral–gut microbiome axis in pathogenesis will be advantageous for precise diagnosis/prognosis and effective treatment.

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.

Research Progress of Pancreas-Related Microorganisms and Pancreatic Cancer

Pancreatic cancer is one of the most common digestive system cancers. Early diagnosis is difficult owing to the lack of specific symptoms and reliable biomarkers. The cause of pancreatic cancer remains ambiguous. Smoking, drinking, new-onset diabetes, and chronic pancreatitis have been proven to be associated with the occurrence of pancreatic cancer. In recent years, a large number of studies have clarified that a variety of microorganisms colonized in pancreatic cancer tissues are also closely related to the occurrence and development of pancreatic cancer, and the specific mechanisms include inflammatory induction, immune regulation, metabolism, and microenvironment changes caused by microorganism. The mechanism of action of the pancreatic colonized microbiome in the tumor microenvironment, as well as immunotherapy approaches require further study in order to find more evidence to explain the complex relationship between the pancreatic colonized microbiome and PDAC. Relevant studies targeting the microbiome may provide insight into the mechanisms of PDAC development and progression, improving treatment effectiveness and overall patient prognosis. In this article, we focus on the research relating to the microorganisms colonized in pancreatic cancer tissues, including viruses, bacteria, and fungi. We also highlight the microbial diversity in the occurrence, invasion, metastasis, treatment, and prognosis of pancreatic cancer in order to elucidate its significance in the early diagnosis and new therapeutic treatment of pancreatic cancer, which urgently need to be improved in clinical practice. The elimination or increase in diversity of the pancreatic microbiome is beneficial for prolonging the survival of PDAC patients, improving the response to chemotherapy drugs, and reducing tumor burden. The colonization of microorganisms in the pancreas may become a new hotspot in the diagnosis and treatment of pancreatic cancer.

Bidirectional and dynamic interaction between the microbiota and therapeutic resistance in pancreatic cancer

Pancreatic ductal adenocarcinoma is one of the most lethal malignancies and is known for its high resistance and low response to treatment. Cancer treatments can reshape the microbiota and in turn, the microbiota influences the therapeutic efficacy by regulating immune response and metabolism. This crosstalk is bidirectional, heterogeneous, and dynamic. In this review, we elaborated on the interactions between the microbiota and therapeutic resistance in pancreatic ductal adenocarcinoma. Regulating the microbiota in pancreatic tumor microenvironment may not only generate direct anti-cancer but also synergistic effects with other treatments, providing new directions in cancer therapy.

The Emerging Role of Microbiota and Microbiome in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignant tumors due to the absence of biomarkers for early-stage detection and poor response to therapy. Since mounting evidence supports the role of microbiota composition in tumorigenesis and cancer treatment, the link between microbiome and PDAC has been described. In this review, we summarize the current knowledge regarding the impact of the gut and oral microbiome on the risk of PDAC development. Microenvironment-driven therapy and immune system interactions are also discussed. More importantly, we provide an overview of the clinical trials evaluating the microbiota role in the risk, prognosis, and treatment of patients suffering from PDAC and solid tumors. According to the research findings, immune tolerance might result from the microbiota-derived remodeling of pancreatic tumor microenvironment. Thus, microbiome profiling and targeting represent the potential trend to enhance antitumor immunity and improve the efficacy of PDAC treatment.

The Role of the Microbiome in Oral Squamous Cell Carcinoma with Insight into the Microbiome-Treatment Axis

Oral squamous cell carcinoma (OSCC) is one of the leading presentations of head and neck cancer (HNC). The first part of this review will describe the highlights of the oral microbiome in health and normal development while demonstrating how both the oral and gut microbiome can map OSCC development, progression, treatment and the potential side effects associated with its management. We then scope the dynamics of the various microorganisms of the oral cavity, including bacteria, mycoplasma, fungi, archaea and viruses, and describe the characteristic roles they may play in OSCC development. We also highlight how the human immunodeficiency viruses (HIV) may impinge on the host microbiome and increase the burden of oral premalignant lesions and OSCC in patients with HIV. Finally, we summarise current insights into the microbiome–treatment axis pertaining to OSCC, and show how the microbiome is affected by radiotherapy, chemotherapy, immunotherapy and also how these therapies are affected by the state of the microbiome, potentially determining the success or failure of some of these treatments.

Gut Microbiota: Its Potential Roles in Pancreatic Cancer

Pancreatic cancer is considered a lethal disease with a low survival rate due to its late-stage diagnosis, few opportunities for resection and lack of effective therapeutic strategies. Multiple, highly complex effects of gut microbiota on pancreatic cancer have been recognized as potential strategies for targeting tumorigenesis, development and treatment in recent decades; some of the treatments include antibiotics, probiotics, and fecal microbiota transplantation. Several bacterial species are associated with carcinogenesis of the pancreas, while some bacterial metabolites contribute to tumor-associated low-grade inflammation and immune responses via several proinflammatory factors and signaling pathways. Given the limited evidence on the interplay between gut microbiota and pancreatic cancer, risk factors associated with pancreatic cancer, such as diabetes, chronic pancreatitis and obesity, should also be taken into consideration. In terms of treatment of pancreatic cancer, gut microbiota has exhibited multiple effects on both traditional chemotherapy and the recently successful immunotherapy. Therefore, in this review, we summarize the latest developments and advancements in gut microbiota in relation to pancreatic cancer to elucidate its potential value.

Microbiota-Dependent Effects of IL-22

Cytokines are important contributors to immune responses against microbial and environmental threats and are of particular importance at epithelial barriers. These interfaces are continuously exposed to external factors and thus require immune components to both protect the host from pathogen invasion and to regulate overt inflammation. Recently, substantial efforts have been devoted to understanding how cytokines act on certain cells at barrier sites, and why the dysregulation of immune responses may lead to pathogenesis. In particular, the cytokine IL-22 is involved in preserving an intact epithelium, maintaining a balanced microbiota and a functioning defense system against external threats. However, a tight regulation of IL-22 is generally needed, since uncontrolled IL-22 production can lead to the progression of autoimmunity and cancer. Our aim in this review is to summarize novel findings on IL-22 and its interactions with specific microbial stimuli, and subsequently, to understand their contributions to the function of IL-22 and the clinical outcome. We particularly focus on understanding the detrimental effects of dysregulated control of IL-22 in certain disease contexts.

The Great ESKAPE: Exploring the Crossroads of Bile and Antibiotic Resistance in Bacterial Pathogens

Throughout the course of infection, many pathogens encounter bactericidal conditions that threaten the viability of the bacteria and impede the establishment of infection. Bile is one of the most innately bactericidal compounds present in humans, functioning to reduce the bacterial burden in the gastrointestinal tract while also aiding in digestion. It is becoming increasingly apparent that pathogens successfully resist the bactericidal conditions of bile, including bacteria that do not normally cause gastrointestinal infections. This review highlights the ability of Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter (ESKAPE), and other enteric pathogens to resist bile and how these interactions can impact the sensitivity of bacteria to various antimicrobial agents. Given that pathogen exposure to bile is an essential component to gastrointestinal transit that cannot be avoided, understanding how bile resistance mechanisms align with antimicrobial resistance is vital to our ability to develop new, successful therapeutics in an age of widespread and increasing antimicrobial resistance.

Regulation and modulation of antitumor immunity in pancreatic cancer

Pancreatic ductal adenocarcinoma carries a dismal prognosis, and outcomes have improved little with modern therapeutics. Checkpoint-based immunotherapy has failed to elicit responses in the vast majority of patients with pancreatic cancer. Alongside tumor cell-intrinsic mechanisms associated with oncogenic KRAS-induced inflammation, the tolerogenic myeloid cell infiltrate has emerged as a critical impediment to adaptive antitumor immune responses. Furthermore, the discovery of an intratumoral microbiome and the elucidation of host-microbe interactions that curtail antitumor immunity also present opportunities for intervention. Here we review the mechanisms of immunotherapy resistance in pancreatic ductal adenocarcinoma and discuss strategies to directly augment T cell responses in parallel with myeloid cell- and microbiome-targeted approaches that may enable immune-mediated control of this malignancy.

Oncobiosis and Microbial Metabolite Signaling in Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma is one of the most lethal cancers in both men and women, with a median five-year survival of around 5%. Therefore, pancreatic adenocarcinoma represents an unmet medical need. Neoplastic diseases, such as pancreatic adenocarcinoma, often are associated with microbiome dysbiosis, termed oncobiosis. In pancreatic adenocarcinoma, the oral, duodenal, ductal, and fecal microbiome become dysbiotic. Furthermore, the pancreas frequently becomes colonized (by Helicobacter pylori and Malassezia, among others). The oncobiomes from long- and short-term survivors of pancreatic adenocarcinoma are different and transplantation of the microbiome from long-term survivors into animal models of pancreatic adenocarcinoma prolongs survival. The oncobiome in pancreatic adenocarcinoma modulates the inflammatory processes that drive carcinogenesis. In this review, we point out that bacterial metabolites (short chain fatty acids, secondary bile acids, polyamines, indole-derivatives, etc.) also have a role in the microbiome-driven pathogenesis of pancreatic adenocarcinoma. Finally, we show that bacterial metabolism and the bacterial metabolome is largely dysregulated in pancreatic adenocarcinoma. The pathogenic role of additional metabolites and metabolic pathways will be identified in the near future, widening the scope of this therapeutically and diagnostically exploitable pathogenic pathway in pancreatic adenocarcinoma.

Draft Genome Sequence of Enterococcus faecalis Strain OB15, a Probiotic Strain Recently Isolated from Tunisian Rigouta Cheese

Enterococcus faecalis OB15 is a probiotic strain that was isolated from rigouta, a popular traditional Tunisian fermented cheese. We report here the draft genome sequence of this strain, consisting of 2,912,159 bp, with an average G+C content of 37.49%.

Pancreatic Cancer: A Review of Risk Factors, Diagnosis, and Treatment

This review aims to summarize the latest knowledge on factors, diagnosis, and treatment of pancreatic cancer, and aims to promote further research on this under-studied malignant tumor. At present, we urgently need to identify high-risk patients with precancerous diseases through screening approaches, so that medical professionals and the general public may better understand prevention strategies or early detection measures. Pancreatic cancer is a highly invasive malignant tumor with a fatal risk, mainly seen in men and older adults (60-85 years old). Pancreatic cancer is now increasingly observed in young patients. Because the disease has no early symptoms and can quickly invade surrounding tissues and organs, it is one of the deadliest cancers. With a view to identify the important factors for the development of pancreatic cancer, previous studies have found that smoking, alcohol, and chronic pancreatitis are considered high-risk factors. Recent studies have shown that abnormal metabolism of human microorganisms, blood type, and glucose and lipid levels are also important factors in the development of pancreatic cancer. Identifying early diagnosis options is an important way to improve detection and survival rates of pancreatic cancer. None of the many tumor markers associated with pancreatic cancer are highly specific, which also indicates further research is required to improve the early detection rate. Future directions in terms of treatment evaluating the relationship between the microbiology-free system and immunotherapy will bring a major breakthrough and is expected to bring exciting clinical applications in improving the life-cycle of pancreatic cancer patients.

The Diverse Involvement of Cigarette Smoking in Pancreatic Cancer Development and Prognosis

Despite extensive research in the pathogenesis, early detection, and therapeutic approaches of pancreatic ductal adenocarcinoma (PDAC), it remains a devastating and incurable disease. As the global incidence and prevalence of PDAC continue to rise, there is a pressing need to place strong emphasis on its prevention. Although it is widely recognized that cigarette smoking, a potentially modifiable risk factor, has been linked to PDAC development, its contribution to prognosis is still uncertain. Moreover, the mechanistic pathways of PDAC progression secondary to smoking are various and lack a summative narration. Herein, we update and summarize the direct and indirect roles cigarette smoking plays on PDAC development, review literature to conclude the impact cigarette smoking has on prognosis, and postulate a comprehensive mechanism for cigarette smoking-induced PDAC.

Demystifying the manipulation of host immunity, metabolism, and extraintestinal tumors by the gut microbiome

The trillions of microorganisms in the gut microbiome have attracted much attention recently owing to their sophisticated and widespread impacts on numerous aspects of host pathophysiology. Remarkable progress in large-scale sequencing and mass spectrometry has increased our understanding of the influence of the microbiome and/or its metabolites on the onset and progression of extraintestinal cancers and the efficacy of cancer immunotherapy. Given the plasticity in microbial composition and function, microbial-based therapeutic interventions, including dietary modulation, prebiotics, and probiotics, as well as fecal microbial transplantation, potentially permit the development of novel strategies for cancer therapy to improve clinical outcomes. Herein, we summarize the latest evidence on the involvement of the gut microbiome in host immunity and metabolism, the effects of the microbiome on extraintestinal cancers and the immune response, and strategies to modulate the gut microbiome, and we discuss ongoing studies and future areas of research that deserve focused research efforts.

The Microbiota and Pancreatic Cancer

Pancreatic cancer is one of the most lethal diseases. In pancreatic cancer development and progression, genetic (gene mutations and activation of oncogenes) and environmental factors (smoking, alcohol consumption, type 2 diabetes mellitus, obesity) play an essential role. Recently, molecular studies revealed that dysbiosis of microbiota also has influence on cancer development. Research indicates that bacteria and viruses can lead to chronic inflammation, antiapoptotic changes, cell survival, and cell invasion. This review presents bacteria and viruses oncogenic for the pancreas. Possible mechanisms of carcinogenic action are also described.

The microbiota of the bilio-pancreatic system: a cohort, STROBE-compliant study

Background: The gut microbiota play an essential role in protecting the host against pathogenic microorganisms by modulating immunity and regulating metabolic processes. In response to environmental factors, microbes can hugely alter their metabolism. These factors can substantially impact the host and have potential pathologic implications.  Particularly pathogenic microorganisms colonizing pancreas and biliary tract tissues may be involved in chronic inflammation and cancer evolution. Purpose: To evaluate the effect of bile microbiota on survival in patients with pancreas and biliary tract disease (PBD). Patients and Methods: We investigated 152 Italian patients with cholelithiasis (CHL), cholangitis (CHA), cholangiocarcinoma (CCA), gallbladder carcinoma (GBC), pancreas head carcinoma (PHC), ampullary carcinoma (ACA), and chronic pancreatitis (CHP). Demographics, bile cultures, therapy, and survival rates were analyzed in cohorts (T1 death <6 months; T2 death <12 months; T3 death <18 months, T3S alive at 18 months). Results: The most common bacteria in T1 were E. coli , K. pneumoniae, and P. aeruginosa. In T2, the most common bacteria were E. coli and P. aeruginosa. In T3, there were no significant bacteria isolated, while in T3S the most common bacteria were like those found in T1. E. coli and K. pneumoniae were positive predictors of survival for PHC and ACA, respectively. E. coli , K. pneumoniae, and P. aeruginosa showed a high percentage of resistant bacteria to 3CGS, aminoglycosides class, and quinolone group especially at T1 and T2 in cancer patients. Conclusions: An unprecedented increase of E. coli in bile leads to a decrease in survival. We suggest that some strains isolated in bile samples may be considered within the group of risk factors in carcinogenesis and/or progression of hepato-biliary malignancy. A better understanding of bile microbiota in patients with PBD should lead to a multifaceted approach to rapidly detect and treat pathogens before patients enter the surgical setting in tandem with the implementation of the infection control policy.

The microbiota and microbiome in pancreatic cancer: more influential than expected

Microbiota is just beginning to be recognized as an important player in carcinogenesis and the interplay among microbes is greater than expected. Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease for which mortality closely parallels incidence. Early detection would provide the best opportunity to increase survival rates. Specific well-studied oral, gastrointestinal, and intrapancreatic microbes and some kinds of hepatotropic viruses and bactibilia may have potential etiological roles in pancreatic carcinogenesis, or modulating individual responses to oncotherapy. Concrete mechanisms mainly involve perpetuating inflammation, regulating the immune system-microbe-tumor axis, affecting metabolism, and altering the tumor microenvironment. The revolutionary technology of omics has generated insight into cancer microbiomes. A better understanding of the microbiota in PDAC might lead to the establishment of screening or early-stage diagnosis methods, implementation of cancer bacteriotherapy, adjustment of therapeutic efficacy even alleviating the adverse effects, creating new opportunities and fostering hope for desperate PDAC patients.

Probiotic Potential and Safety Evaluation of Enterococcus faecalis OB14 and OB15, Isolated From Traditional Tunisian Testouri Cheese and Rigouta, Using Physiological and Genomic Analysis

Lactic acid bacteria (LAB) strains OB14 and OB15 were isolated from traditional Tunisian fermented dairy products, Testouri cheese and Rigouta, respectively. They were identified as Enterococcus faecalis by the MALDI TOF-MS (matrix assisted laser desorption-ionization time of flight mass spectrometry) biotyper system and molecular assays (species-specific PCR). These new isolates were evaluated for probiotic properties, compared to E. faecalis Symbioflor 1 clone DSM 16431, as reference. The bacteria were found to be tolerant to the harsh conditions of the gastrointestinal tract (acidity and bile salt). They were low to moderate biofilm producers, can adhere to Caco-2/TC7 intestinal cells and strengthen the intestinal barrier through the increase of the transepithelial electrical resistance (TER). Susceptibility to ampicillin, vancomycin, gentamicin and erythromycin has been tested using the broth microdilutions method. The results demonstrated that E. faecalis OB14 and OB15 were sensitive to the clinically important ampicillin (MIC = 1 μg/mL) and vancomycin (MIC = 2 μg/mL) antibiotics. However, Whole Genome Sequencing (WGS) showed the presence of tetracycline resistance and cytolysin genes in E. faecalis OB14, and this led to high mortality of Galleria Mellonella larvae in the virulence test. Hierarchical cluster analysis by MALDI TOF-MS biotyper showed that E. faecalis OB15 was closely related to the E. faecalis Symbioflor 1 probiotic strain than to OB14, and this has been confirmed by WGS using the average nucleotide identity (ANI) and Genome-to-Genome Hybridization similarity methods. According to these results, E. faecalis OB15 seems to be reliable for future development as probiotic, in food or feed industry.