The Gut Microbiome in Pancreatic Disease

Gut Microbiota Dynamics during Chemotherapy in Epithelial Ovarian Cancer Patients Are Related to Therapeutic Outcome

Simple Summary

This pilot study on the trajectory of the gut microbiota (GM) in patients with epithelial ovarian cancer undergoing neoadjuvant and adjuvant chemotherapy highlighted peculiar dynamics associated with the therapeutic outcome. In particular, platinum-resistant patients showed a marked temporal reduction in GM diversity and increased instability with loss of health-associated taxa and increased proportions of lactate-producing microorganisms compared to those sensitive to platinum. These potential GM signatures of therapeutic failure are detectable within the first half of chemotherapy cycles, suggesting that early integrated treatments also aimed at modulating GM could influence therapeutic outcome. Further studies in larger cohorts combining multiple omics and possibly animal models are urgently needed for in-depth mechanistic understanding.

Abstract

Epithelial ovarian cancer (EOC) is one of the most lethal and silent gynecological tumors. Despite appropriate surgery and chemotherapy, relapse occurs in over half of patients with a poor prognosis. Recently, the gut microbiota (GM) was hypothesized to influence the efficacy of anticancer therapies, but no data are available in EOC. Here, by 16S rRNA gene sequencing and inferred metagenomics, we profiled the GM of EOC patients at diagnosis and reconstructed its trajectory along the course of neoadjuvant or adjuvant chemotherapy up to follow-up. Compared to healthy subjects, the GM of EOC patients appeared unbalanced and severely affected by chemotherapy. Strikingly, discriminating patterns were identified in relation to the therapeutic response. Platinum-resistant patients showed a marked temporal reduction in GM diversity and increased instability with loss of health-associated taxa and increased proportions of Coriobacteriaceae and Bifidobacterium. Notably, most of these microorganisms are lactate producers, suggesting increased lactate production as supported by inferred metagenomics. In contrast, the GM of platinum-sensitive patients appeared overall more diverse and stable and enriched in lactate utilizers from the Veillonellaceae family. In conclusion, we identified potential GM signatures of therapeutic outcome in EOC patients, which could open up new opportunities for cancer prognosis and treatment.

The Gut Microbiome in Patients With Chronic Pancreatitis Is Characterized by Significant Dysbiosis and Overgrowth by Opportunistic Pathogens

Exocrine pancreatic function is a critical host factor in determining the intestinal microbiota composition. Diseases affecting the exocrine pancreas could therefore influence the gut microbiome. We investigated the changes in gut microbiota of patients with chronic pancreatitis (CP).

Gut microbiota in pancreatic diseases: possible new therapeutic strategies

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

Anti-tumor effect of statin on pancreatic adenocarcinoma: From concept to precision medicine

A statin is a cholesterol-lowering agent, which inhibits HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase and subsequently reduces the cholesterol precursor, and was first used commercially in 1987. The concept of cholesterol restriction leading to cancer cell dysfunction was proposed in 1992. The interruption of different signaling pathways has been proved in preclinical experiments to elucidate the anti-tumor mechanism of statins in pancreatic adenocarcinoma. Observational studies have shown that the clinical use of statins is beneficial in patients with pancreatic adenocarcinoma, including a chemoprevention effect, post-surgical resection follow-up and therapeutic prognosis of advanced cancer stage. Arrest of the cancer cell cycle by the combined use of gemcitabine and statin was observed in a cell line study. The effect of microbiota on the tumor microenvironment of pancreatic adenocarcinoma is a new therapeutic approach as statins can modulate the gut microbiota. Hence, further randomized trials of statins in pancreatic adenocarcinoma treatment will be warranted with application of precision medicine from microbiota-derived, cell cycle-based and signaling pathway-targeted research.

Impact of the Gut Microbiota Balance on the Health-Disease Relationship: The Importance of Consuming Probiotics and Prebiotics

Gut microbiota is a group of microorganisms that are deposited throughout the entire gastrointestinal tract. Currently, thanks to genomic tools, studies of gut microbiota have pointed towards the understanding of the metabolism of important bacteria that are not cultivable and their relationship with human homeostasis. Alterations in the composition of gut microbiota could explain, at least in part, some epidemics, such as diabetes and obesity. Likewise, dysbiosis has been associated with gastrointestinal disorders, neurodegenerative diseases, and even cancer. That is why several studies have recently been focused on the direct relationship that these types of conditions have with the specific composition of gut microbiota, as in the case of the microbiota-intestine-brain axis. In the same way, the control of microbiota is related to the diet. Therefore, this review highlights the importance of gut microbiota, from its composition to its relationship with the human health-disease condition, as well as emphasizes the effect of probiotic and prebiotic consumption on the balance of its composition.

Assessment of small intestinal bacterial overgrowth in chronic pancreatitis patients using jejunal aspirate culture and glucose hydrogen breath test

BACKGROUND

A subset of chronic pancreatitis patients respond poorly to pancreatic enzyme replacement therapy. Small intestinal bacterial overgrowth (SIBO) is considered to be one of the major reasons for this poor response. Previous studies have reported a wide range of prevalence of SIBO in patients with chronic pancreatitis. We aimed to assess the prevalence of SIBO in chronic pancreatitis using quantitative jejunal aspirate culture and glucose hydrogen breath test (GHBT). The sensitivity and specificity of GHBT for the diagnosis of SIBO in chronic pancreatitis were also estimated.

METHODS

Newly diagnosed chronic pancreatitis patients were recruited into the study. A detailed history and relevant laboratory tests were done. All patients underwent an endoscopy and jejunal fluid aspiration for bacterial cultures and GHBT to detect SIBO. The results of GHBT were compared with jejunal fluid aspirate culture.

RESULTS

The jejunal aspirate culture was positive in 18/48 (37.5%) patients while the GHBT showed that 14/48 (29%) patients had SIBO. The sensitivity, specificity, positive and negative predictive value of GHBT in our study was 44.4, 80, 57.14 and 70.59%, respectively.

CONCLUSIONS

SIBO is not uncommon in chronic pancreatitis patients. One-third of our study population had SIBO. GHBT has low sensitivity but had high specificity in the diagnosis of SIBO in chronic pancreatitis.

High fat diet, gut microbiome and gastrointestinal cancer

Gastrointestinal cancer is currently one of the main causes of cancer death, with a large number of cases and a wide range of lesioned sites. A high fat diet, as a public health problem, has been shown to be correlated with various digestive system diseases and tumors, and can accelerate the occurrence of cancer due to inflammation and altered metabolism. The gut microbiome has been the focus of research in recent years, and associated with cell damage or tumor immune microenvironment changes via direct or extra-intestinal effects; this may facilitate the occurrence and development of gastrointestinal tumors. Based on research showing that both a high fat diet and gut microbes can promote the occurrence of gastrointestinal tumors, and that a high fat diet imbalances intestinal microbes, we propose that a high fat diet drives gastrointestinal tumors by changing the composition of intestinal microbes.

Intestinal Dysbiosis and Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a chronic fibro-inflammatory disorder of the pancreas. Recent clinicopathological analysis revealed that most cases of AIP are pancreatic manifestations of systemic IgG4-related disease (IgG4-RD), a newly established disease characterized by enhanced IgG4 antibody responses and the involvement of multiple organs. Although the immuno-pathogenesis of AIP and IgG4-RD has been poorly defined, we recently showed that activation of plasmacytoid dendritic cells (pDCs) with the ability to produce large amounts of IFN-α and IL-33 mediates chronic fibro-inflammatory responses in experimental and human AIP. Moreover, M2 macrophages producing a large amount of IL-33 play pathogenic roles in the development of human IgG4-RD. Interestingly, recent studies including ours provide evidence that compositional alterations of gut microbiota are associated with the development of human AIP and IgG4-RD. In addition, intestinal dysbiosis plays pathological roles in the development of chronic pancreatic inflammation as dysbiosis mediates the activation of pDCs producing IFN-α and IL-33, thereby causing experimental AIP. In this Mini Review, we focus on compositional alterations of gut microbiota in AIP and IgG4-RD to clarify the mechanisms by which intestinal dysbiosis contributes to the development of these disorders.

Pancreatic Cancer Meets Human Microbiota: Close Encounters of the Third Kind

Simple Summary

The microorganisms colonizing the epithelial surfaces of the human body, called microbiota, have been shown to influence the initiation, progression and response to therapy of many solid tumors, including pancreatic ductal adenocarcinoma, the most prominent form of pancreatic cancer. Here, we summarize the current knowledge about the influence of oral, gut and intratumoral microbiota on pancreatic ductal adenocarcinoma development and chemoresistance.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal types of cancer with a dismal prognosis. The five-year survival rate has not changed significantly in over 40 years. Current first-line treatments only offer a modest increase in overall survival in unselected populations, and there is an urgent need to personalize treatment in this aggressive disease and develop new therapeutic strategies. Evolving evidence suggests that the human microbiome impacts cancerogenesis and cancer resistance to therapy. The mechanism of action and interaction of microbiome and PDAC is still under investigation. Direct and indirect effects have been proposed, and the use of several microbiome signatures as predictive and prognostic biomarkers for pancreatic cancer are opening new therapeutic horizons. In this review, we provide an overview for the clinicians of studies describing the influence and associations of oral, gastrointestinal and intratumoral microbiota on PDAC development, progression and resistance to therapy and the potential use of microbiota as a diagnostic, prognostic and predictive biomarker for PDAC.

Microbiome and pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) incidence and related-deaths are increasing worldwide. PDAC is characterized by poor prognosis due to late diagnosis, high metastatic capacity and resistance to therapy. This is partially due to its specific microenvironment, where the stroma is prominent over tumor cells. Besides the oral and gut microbiota, the intratumor microbiome, i.e. the bacterial and fungal microorganisms present within the tumor, was recently introduced as a new partner of the tumor microenvironment of PDAC modulating pancreatic carcinogenesis, intratumor immune infiltrates, and response to chemotherapy. In this review, we propose an overview of current knowledge about the roles of bacteria and fungi in PDAC development and biology, and discuss potential therapeutic implications.

Nutritional management of chronic pancreatitis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Malnutrition is a frequent complication of chronic pancreatitis. Adequate nutritional support is imperative, but there is still uncertainty about the optimal nutritional treatment. This work systematically compiles evidence from randomized controlled trials investigating dietary interventions in chronic pancreatitis and, in a further step, contrasts those findings with existing dietary recommendations.

METHODS

The literature search (PubMed and Cochrane Central Register of Controlled Trials) included English and German full-text articles, which had been published in peer-reviewed journals. Two independent reviewers identified and selected studies. For meta-analysis, forest plots with 95% confidence intervals were generated using a random-effects model.

RESULTS

Eleven randomized controlled trials fulfilled all selection criteria. In these trials, the following dietary interventions were tested: antioxidant treatment (n = 6), vitamin D supplementation (n = 3), supplementation with oral nutritional supplements (n = 1), and symbiotics supplementation (n = 1). Studies were of good methodological quality (mean Jadad score of 3.6) but heterogeneous in terms of interventions and study populations. Only for vitamin D, there was convincing evidence for efficacy of supplementation. We found no effect for antioxidant treatment on pain relief (standardized mean difference = -0.12; 95% confidence interval -0.73 to 0.48) and limited generalizability for interventions with oral nutritional supplements and symbiotics.

CONCLUSIONS

Nutritional management in chronic pancreatitis remains challenging. As well-designed randomized controlled trials are scarce, in large part, recommendations can only be based on low-level evidence studies or expert opinion. For now, consumption of a balanced diet remains the cornerstone recommendation for prevention, whereas more goal-directed interventions are indicated for specific nutrient deficiencies.

Nutritional Management of Acute Pancreatitis

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

Gut microbiome as a response marker for pancreatic enzyme replacement therapy in a porcine model of exocrine pancreas insufficiency

Background

Exocrine pancreatic insufficiency (EPI) is characterized by the loss of active pancreatic enzymes and a resulting severely reduced food digestion. EPI therapy requires orally applied pancreatic enzyme replacement. The gut microbiome is a known mediator of intestinal diseases and may influence the outcome of EPI and the effects of a pancreatic enzyme replacement therapy (PERT). Here, we analyzed the effects of EPI and PERT on the gut microbiome in the model of pancreatic duct ligated minipigs.

Results

The microbial community composition in pig feces was analyzed by next generation sequencing of 16S rRNA amplicons. The data were evaluated for α- and β-diversity changes and changes at the different Operational Taxonomic Unit (OTU) levels by Shannon–Wiener and inverse Simpson index calculation as well as by Principal Coordinates Analysis based on Bray–Curtis dissimilarity. Microbial α-diversity was reduced after EPI induction and reverted to nearly healthy state after PERT. Analysis of microbial composition and β-diversity showed distinctive clusters of the three study groups and a change towards a composition comparable to healthy animals upon PERT. The relative abundance of possible pathobionts like Escherichia/Shigella, Acinetobacter or Stenotrophomonas was reduced by PERT.

Conclusion

These data demonstrate that EPI-induced dysbiosis could be reverted by PERT to a nearly healthy state. Elevated α-diversity and the reduction of bacterial overgrowth after PERT promises benefits for EPI patients. Non-invasive microbiome studies may be useful for EPI therapy monitoring and as marker for response to PERT.

Analysis of biliary MICRObiota in hepatoBILIOpancreatic diseases compared to healthy people [MICROBILIO]: Study protocol

Background

The performance of the microbiota is observed in several digestive tract diseases. Therefore, reaching the biliary microbiota may suggest ways for studies of biomarkers, diagnoses, tests and therapies in hepatobiliopancreatic diseases.

Methods

Bile samples will be collected in endoscopic retrograde cholangiopancreatography patients (case group) and living liver transplantation donors (control group). We will characterize the microbiome based on two types of sequence data: the V3/V4 regions of the 16S ribosomal RNA (rRNA) gene and total shotgun DNA. For 16S sequencing data a standard 16S processing pipeline based on the Amplicon Sequence Variant concept and the qiime2 software package will be employed; for shotgun data, for each sample we will assemble the reads and obtain and analyze metagenome-assembled genomes.

Results

The primary expected results of the study is to characterize the specific composition of the biliary microbiota in situations of disease and health. In addition, it seeks to demonstrate the existence of changes in the case of illness and also possible disease biomarkers, diagnosis, interventions and therapies in hepatobiliopancreatic diseases.

Trial registration

NCT04391426. Registered 18 May 2020, https://clinicaltrials.gov/ct2/show/NCT04391426.

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.

Gut microbiome alterations in type 1 autoimmune pancreatitis after induction of remission by prednisolone

Although increasing evidence demonstrates the association between intestinal dysbiosis and pancreatic diseases such as chronic pancreatitis and pancreatic cancer, it remains largely unknown whether intestinal dysbiosis is involved in the immunopathogenesis of autoimmune pancreatitis (AIP). Recently, we found that intestinal dysbiosis mediates experimental AIP via the activation of plasmacytoid dendritic cells (pDCs), which can produce interferon (IFN)-α and interleukin (IL)-33. However, candidate intestinal bacteria, which promote the development of AIP, have not been identified. Fecal samples were obtained from type 1 AIP patients before and after prednisolone (PSL) treatment and subjected to 16S ribosomal RNA sequencing to evaluate the composition of intestinal bacteria. Induction of remission by PSL was associated with the complete disappearance of Klebsiella species from feces in two of the three analyzed patients with type 1 AIP. To assess the pathogenicity of Klebsiella species, mild experimental AIP was induced in MRL/MpJ mice by repeated injections of 10 μg of polyinosinic-polycytidylic acid [poly(I:C)], in combination with oral administration of heat-killed Klebsiella pneumoniae. The AIP pathology score was significantly higher in MRL/MpJ mice that received both oral administration of heat-killed K. pneumoniae and intraperitoneal injections of poly(I:C) than in those administered either agent alone. Pancreatic accumulation of pDCs capable of producing large amounts of IFN-α and IL-33 was also significantly higher in mice that received both treatments. These data suggest that intestinal colonization by K. pneumoniae may play an intensifying role in the development of type 1 AIP.

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.

Sensitive mass spectrometric analysis of carbonyl metabolites in human urine and fecal samples using chemoselective modification

Metabolites with ketone or aldehyde functionalities comprise a large proportion of the human metabolome, most notably in the form of sugars. However, these reactive molecules are also generated through oxidative stress or gut microbiota metabolism and have been linked to disease development. The discovery and structural validation of this class of metabolites over the large concentration range found in human samples is crucial to identify their links to pathogenesis. Herein, we have utilized an advanced chemoselective probe methodology alongside bioinformatic analysis to identify carbonyl-metabolites in urine and fecal samples. In total, 99 metabolites were identified in urine samples and the chemical structure for 40 metabolites were unambiguously validated using a co-injection procedure. We also describe the preparation of a metabolite-conjugate library of 94 compounds utilized to efficiently validate these ketones and aldehydes. This method was used to validate 33 metabolites in a pooled fecal sample extract to demonstrate the potential for rapid and efficient metabolite detection over a wide metabolite concentration range. This analysis revealed the presence of six metabolites that have not previously been detected in either sample type. The constructed library can be utilized for straightforward, large-scale, and expeditious analysis of carbonyls in any sample type.

Acute Pancreatitis: Exploring Nutrition Implications

Diseases of the pancreas vary by type, etiology, pathophysiology, and outcomes. One of the principle therapeutic considerations in all types of pancreatic diseases is nutrition. This review will consider acute pancreatitis (AP). Choice of patient, type and composition of nutrition, and timing of initiation will be discussed as components for achieving the maximum benefits of nutrition therapy in AP. The paradigm of nutrition therapy in AP has shifted to early enteral and/or oral nutrition based on disease severity to help mitigate the underlying inflammatory cascade of events leading to AP, beginning with anatomic and functional intestinal changes. Additionally, newer research investigating the inflammatory changes that instigate, maintain, and propagate AP will be discussed in terms of the nutrition effects on systemic inflammation. Nutrition therapy can mitigate the inflammatory changes in the intestinal tract and help with intestinal motility, bacterial overgrowth and translocation. It can help maintain intestinal bacterial composition and abundance similar to predisease levels. This review will also discuss the changes in the intestinal microbiome and effects of probiotics in AP.

Pancreatic Cancer, Gut Microbiota, and Therapeutic Efficacy

Pancreatic cancer remains one of the leading causes of cancer-related death worldwide and has a poor prognosis. Current treatment relies on surgical resection and adjuvant therapies. The gut microbiota plays important roles in metabolism and immunomodulation. Accumulating evidence has implied that the gut microbiota is involved in the metabolism of chemotherapeutic drugs and the tumor microenvironment (TME), which could affect the efficacy of both conventional chemotherapy and immunotherapy for pancreatic cancer. Herein, we comprehensively reviewed the history and highlights of the interactions among pancreatic cancer, the gut microbiota and therapeutic efficacy and showed the promising future of manipulating the gut microbiota to improve clinical outcomes of pancreatic cancer.

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.

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.

Maternal exercise before and during pregnancy alleviates metabolic dysfunction associated with high-fat diet in pregnant mice, without significant changes in gut microbiota

Although maternal exercise before and during pregnancy is beneficial, the effects of exercise on microbiota changes during pregnancy are unknown. Here we tested the hypothesis that maternal exercise before and during pregnancy would positively affect glucose homeostasis, pancreatic cell function, and gut microbiota dysbiosis in high-fat diet (HFD) fed dams. Female C57BL/6 mice were fed either a HFD or a low-fat diet (LFD) for 12 weeks. The HFD mice were split into two groups for 4 weeks prior to pregnancy initiation and throughout the pregnancy: sedentary (HFD) or exercised (HFD + Ex). Food intake, body weight, body composition, and glucose and insulin tolerance were measured. At gestation day 19, blood, pancreas, gonadal visceral and subcutaneous fat, plantaris muscle, and cecum were collected for analysis. Both HFD and HFD + Ex mice had impaired glucose clearance compared to LFD mice at 15 days of gestation. No changes were found in pancreatic α- or β-cell health. HFD + Ex mice had significantly reduced visceral fat mass, serum insulin, and leptin levels and increased high-density lipoprotein levels, compared to HFD-fed mice. In contrast to our hypothesis, microbiota diversity and composition were not different among groups. The relative abundance of five bacterial phyla, such as Firmicutes, Bacteroidetes, Verrucomicrobia, Deferribacteres, and Actinobacteria, were not significantly altered with diet or exercise during pregnancy. Our findings suggest that maternal exercise prevents excess visceral fat accumulation, hyperinsulinemia, and hyperleptinemia associated with a HFD, but not through the alterations of gut microbiota composition or diversity during pregnancy.

Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary field that addresses heterogeneous effects of exogenous and endogenous factors (collectively termed 'exposures'), including microorganisms, on disease occurrence and consequences, utilising molecular pathological signatures of the disease. In parallel with the paradigm of precision medicine, findings from MPE research can provide aetiological insights into tailored strategies of disease prevention and treatment. Due to the availability of molecular pathological tests on tumours, the MPE approach has been utilised predominantly in research on cancers including breast, lung, prostate, and colorectal carcinomas. Mounting evidence indicates that the microbiome (inclusive of viruses, bacteria, fungi, and parasites) plays an important role in a variety of human diseases including neoplasms. An alteration of the microbiome may be not only a cause of neoplasia but also an informative biomarker that indicates or mediates the association of an epidemiological exposure with health conditions and outcomes. To adequately educate and train investigators in this emerging area, we herein propose the integration of microbiology into the MPE model (termed 'microbiology-MPE'), which could improve our understanding of the complex interactions of environment, tumour cells, the immune system, and microbes in the tumour microenvironment during the carcinogenic process. Using this approach, we can examine how lifestyle factors, dietary patterns, medications, environmental exposures, and germline genetics influence cancer development and progression through impacting the microbial communities in the human body. Further integration of other disciplines (e.g. pharmacology, immunology, nutrition) into microbiology-MPE would expand this developing research frontier. With the advent of high-throughput next-generation sequencing technologies, researchers now have increasing access to large-scale metagenomics as well as other omics data (e.g. genomics, epigenomics, proteomics, and metabolomics) in population-based research. The integrative field of microbiology-MPE will open new opportunities for personalised medicine and public health. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The microbiota-gut-brain axis: A promising avenue to foster healthy developmental outcomes

Fostering healthy developmental growth in the first years of life is associated with numerous favorable cognitive, social, and economic outcomes. Funding and promoting research aimed at identifying potential targets for early intervention should be a top priority for lawmakers and funders. One promising avenue of research and potential early intervention is the microbiota–gut–brain axis. In this report, we briefly examine the role of the gut microbiota in human life, focusing on links with health, cognition, and behavior. We then discuss the development of the gut microbiota and the critical early window in which colonization occurs. Then, we review current nonnutritive means of influencing the gut microbiota in early life. Finally, we discuss the implications this work has for early intervention in low‐income communities and end with recommendations regarding further research and research funding priorities.