Comparison of microbiological profile of enterotoxigenic Bacteroides fragilis (ETBF) isolates from subjects with colorectal cancer (CRC) or intestinal pre-cancerous lesions versus healthy individuals and evaluation of environmental factors involved in intestinal dysbiosis.

OBJECTIVE: The aim of this study was to analyze enterotoxigenic Bacteroides fragilis (ETBF) isolates from colorectal biopsies of subjects with a histological analysis positive for colorectal cancer (CRC), pre-cancerous lesions (pre-CRC) or with a healthy intestinal tissue and to evaluate the environmental factors that may not only concur to CRC development but may also affect gut microbiota composition. METHODS: ETBF isolates were typed using the ERIC-PCR method, while PCR assays were performed to investigate the bft alleles, the B. fragilis pathogenicity island (BFPAI) region and the cepA, cfiA and cfxA genes. Susceptibility to antibiotics was tested using the agar dilution method. Environmental factors that could play a role in promoting intestinal dysbiosis were evaluated throughout a questionnaire administered to the subjects enrolled. RESULTS: Six different ERIC-PCR types were identified. The type denominated C in this study was the most prevalent, in particular among the biopsies of subjects with pre-CRC, while an isolate belonging to a different type, denominated F, was detected in a biopsy from a subject with CRC. All the ETBF isolates from pre-CRC or CRC subjects had a B. fragilis pathogenicity island (BFPAI) region pattern I, while those from healthy individuals showed also different patterns. Furthermore, 71% of isolates from subjects with pre-CRC or CRC were resistant to two or more classes of antibiotics vs 43% of isolates from healthy individuals. The B. fragilis toxin BFT1 was the most frequently detected in this study, confirming the constant circulation of this isoform strains in Italy. Interestingly, BFT1 was found in 86% of the ETBF isolates from patients with CRC or pre-CRC, while the BFT2 was prevalent among the ETBF isolates from healthy subjects. No substantial differences based on sex, age, tobacco and alcohol consumption were observed between healthy and non-healthy individuals included in this study, while most of the subjects with CRC or pre-CRC lesions were subjected to pharmacological therapy (71%) and showed a body mass index (BMI) that falls within the overweight range (86%). CONCLUSIONS: Our data suggest that some types of ETBF seem to better adapt and colonize the human gut and that the selective pressure exerted by factors related to lifestyle, such as pharmacological therapy and weight, could facilitate their persistence in the gut and their possible involvement in CRC development.

Levothyroxine treatment and gastric juice pH in humans: the proof of concept.

PURPOSE: Despite the absorption of oral thyroxine (T4) occurs in the small bowel, several patients with gastric disorders show an increased need for T4. In vitro evidence suggested that medium pH variations interfere with T4 dissolution. This study was aimed at finding the proof of concept of a direct relationship between the minimal effective dose of T4 and the actual gastric juice pH. PATIENTS AND METHODS: Among 311 consecutively thyroxine-treated patients, 61 bearing Hashimoto's thyroiditis (52 F/9 M; median age = 51 years) who complained persistent dyspepsia and/or upper abdominal symptoms following a noninvasive workup for gastrointestinal disorders, underwent EGDS with multiple biopsies and gastric juice pH measurement. All patients accepted to take thyroxine in fasting conditions, abstaining from eating or drinking for one hour. RESULTS: Thyroxine requirement increased along with the rising gastric pH (ρ = 0.4229; p = 0.0007). A multivariate analysis revealed that gastric pH was, beside body mass index, the far more important independent variable in determining the effective dose of T4 (p = 0.001). The ROC curve revealed that the pH threshold for an increased thyroxine requirement was at 2.28, being the AUC by 78%. Subdividing patients by the histologic findings, it appeared a significant increase (p = 0.0025) along with the progressive damage of gastric mucosa. CONCLUSION: The in vivo measurement of gastric pH highlighted its key role in determining the minimal effective dose of oral T4 and may explain the interference of food, of some drugs and gut disorders on levothyroxine treatment.

Association of Polygenic Risk Score and Bacterial Toxins at Screening Colonoscopy with Colorectal Cancer Progression: A Multicenter Case-Control Study.

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and its incidence is correlated with infections, chronic inflammation, diet, and genetic factors. An emerging aspect is that microbial dysbiosis and chronic infections triggered by certain bacteria can be risk factors for tumor progression. Recent data suggest that certain bacterial toxins implicated in DNA attack or in proliferation, replication, and death can be risk factors for insurgence and progression of CRC. In this study, we recruited more than 300 biopsy specimens from people undergoing colonoscopy, and we analyzed to determine whether a correlation exists between the presence of bacterial genes coding for toxins possibly involved in CRC onset and progression and the different stages of CRC. We also analyzed to determine whether CRC-predisposing genetic factors could contribute to bacterial toxins response. Our results showed that CIF toxin is associated with polyps or adenomas, whereas pks+ seems to be a predisposing factor for CRC. Toxins from Escherichia coli as a whole have a higher incidence rate in adenocarcinoma patients compared to controls, whereas Bacteroides fragilis toxin does not seem to be associated with pre-cancerous nor with cancerous lesions. These results have been obtained irrespectively of the presence of CRC-risk loci.

Proton pump inhibitors and dysbiosis: Current knowledge and aspects to be clarified.

Proton pump inhibitors (PPIs) are common medications within the practice of gastroenterology. These drugs, which act through the irreversible inhibition of the hydrogen/potassium pump (H+/K+-ATPase pump) in the gastric parietal cells, are used in the treatment of several acid-related disorders. PPIs are generally well tolerated but, through the long-term reduction of gastric acid secretion, can increase the risk of an imbalance in gut microbiota composition (i.e., dysbiosis). The gut microbiota is a complex ecosystem in which microbes coexist and interact with the human host. Indeed, the resident gut bacteria are needed for multiple vital functions, such as nutrient and drug metabolism, the production of energy, defense against pathogens, the modulation of the immune system and support of the integrity of the gut mucosal barrier. The bacteria are collected in communities that vary in density and composition within each segment of the gastrointestinal (GI) tract. Therefore, every change in the gut ecosystem has been connected to an increased susceptibility or exacerbation of various GI disorders. The aim of this review is to summarize the recently available data on PPI-related microbiota alterations in each segment of the GI tract and to analyze the possible involvement of PPIs in the pathogenesis of several specific GI diseases.

Helicobacter pylori Infection and Gastric Dysbiosis: Can Probiotics Administration Be Useful to Treat This Condition?

Helicobacter pylori (Hp) is responsible for one of the most common infections in the world. The prevalence exceeds 50% of the population in developing countries, and approximately one-third of the adults are colonized in North Europe and North America. It is considered a major pathogenic agent of chronic gastritis, peptic ulcer, atrophic gastritis, gastric cancer, and mucosa-associated lymphoid tissue lymphoma (MALT). Hp colonization modifies the composition of gastric microbiota that could drive the development of gastric disorders. Currently, an emerging problem in Hp treatment is represented by the increasing rate of antimicrobial therapy resistance. In this context, the search for adjuvant agents can be very useful to overcome this issue and probiotics administration can represent a valid option. The aim of this review is to describe the gastric microbiota changes during Hp colonization, the mechanisms of action, and a possible role of probiotics in the treatment of this infection.

Helicobacter pylori infection: antibiotic resistance and eradication rate in patients with gastritis showing previous treatment failures.

Forty patients infected by Helicobacter pylori were studied. The treatment was based on the positivity or negativity of cultures (tailored therapy or empiric therapy). The eradication rate was 68% and 82% respectively. Genotypic susceptibility testing proved very useful in case of heteroresistance or mixed infections that represent a real problem possibly leading to a resistance underestimation. Real-time PCR detected the resistant population at a very low concentration not detectable by phenotypic tests. Bismuth quadruple therapy (PPI, bismuth, metronidazole, tetracycline, PBMT) was effective in the Hp eradication rate consistent with a high level of clarithromycin resistance.

Antibiotic susceptibility, heteroresistance, and updated treatment strategies in Helicobacter pylori infection.

In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp) eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach) is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016) are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently approved in Japan, is also considered to be a promising solution for Hp eradication, even for clarithromycin-resistant strains. Furthermore, there is growing interest in finding new therapeutic strategies, such as the development of vaccines or the use of natural resources, including probiotics, plants, or nutraceuticals.

Intestinal, Systemic, and Oral Gluten-related Alterations in Patients With Nonceliac Gluten Sensitivity.

BACKGROUND: Nonceliac gluten sensitivity (NCGS) is an emergent condition, the framework of which is yet unclear, whereas the diagnosis is suggested only by gluten-dependent symptoms after excluding wheat allergy and celiac disease (CD). Our goal was to highlight intestinal, systemic, and oral alterations to clarify the NCGS pathogenesis and identify new diagnostic tools. STUDY: A total of 60 NCGS patients, 20 untreated CD, 20 treated CD, and 20 healthy volunteers were recruited. The differential diagnosis among gluten-related disorders was performed by serological, allergy, and histologic tools. NCGS patients were also subjected to antigliadin antibody (AGA) detection and HLA typing. All participants underwent an oral mucosa patch test for gluten (GOMPT), whereas an oral provocation test (OPT) for gluten was performed in 26 NCGS patients. RESULTS: About 6/60 (10%) NCGS patients showed IgG AGA-positive results, whereas 45/60 (75%) patients carried HLA-DQ2 and/or HLA-DQ8 genes. GOMPT showed positive results in 45/60 (75%) NCGS patients, 3/20 (15%) untreated CD patients, 5/20 (25%) treated CD patients, and in no healthy volunteers. No significant difference was found between the severity of symptoms reported by NCGS patients subjected to OPT with gluten-containing croissants and those who underwent OPT with gluten-free croissants. CONCLUSIONS: GOMPT seems to be a specific tool for NCGS diagnosis, although further investigations are needed to overcome limits due to the small population studied and to contextualize GOMPT false-positive results.

Are clinical features able to predict Helicobacter pylori gastritis patterns? Evidence from tertiary centers.

Outcome of Helicobacter pylori infection is different according to gastritis extension (i.e. antrum-restricted gastritis or pangastritis). The aim of this study is to evaluate whether different gastritis patterns are associated with specific gastrointestinal symptoms or clinical signs that could be suggestive of the topography of gastritis. 236 consecutive symptomatic outpatients were recruited in two tertiary centers. They filled in a validated and self-administered Rome III modular symptomatic questionnaire, and underwent gastroscopy with histological sampling. 154 patients with Helicobacter pylori infection were included. Clinical presentation did not differ between antrum-restricted gastritis and pangastritis, gastro-esophageal reflux disease being present in 48.2 and 54.1 % of patients and dyspepsia in 51.8 and 45.9 %, respectively. However, pangastritis statistically differed from antrum-restricted gastritis in that the presence of clinical signs (p < 0.0001) was observed in 33.7 % of the patients, consisting of iron deficiency (31.6 %), iron deficiency-anemia (20.4 %) and levothyroxine malabsorption (3.1 %). Symptoms are not helpful in suggesting gastritis pattern whereas their association with signs, accurately detected, is indicative for the presence of pangastritis.

A Western single-center experience with endoscopic submucosal dissection for early gastrointestinal cancers.

Endoscopic submucosal dissection (ESD) has gained worldwide acceptance as a treatment for early gastrointestinal cancers (EGICs). However, the management of these tumors in the Western world is still mainly surgical. Our aim was to evaluate the safety and feasibility of ESD at a European center. Based on the knowledge transferred by one of the most experienced Japanese institutions, we conducted a pilot study on 25 consecutive patients with EGICs located in the esophagus (n = 3), stomach (n = 7), duodenum (n = 1), and colon (n = 14) at our tertiary center over a 2-year-period. The main outcome measurements were complete (R0) resection, as well as en-bloc resection and the management of complications. The R0 and en-bloc resection rates were 100% and 84%, respectively. There were three cases of bleeding and five cases of perforation. With a median follow up of 18 months, two recurrences were observed. We conclude that ESD for early esophageal and gastric cancers is feasible and effective, while colonic ESD requires more expertise.

Improvement in the fertility rate after placement of microsurgical shunts in men with recurrent varicocele.

OBJECTIVE: To evaluate the effectiveness of microsurgical shunts for secondary varicocele repair after ligation-like procedures, focusing on long-term functional outcomes. DESIGN: Long-term survey (mean follow-up, 8.5 years) of infertile men after secondary microsurgical reconstructive varicocelectomy. SETTING: University-based medical center. PATIENT(S): Thirty-four infertile men (group A, <30 years of age; and group B, >30 years) with recurrent palpable varicocele after varicocelectomy, according to Ivanissevich (n = 28), or after angiographic vein occlusion (n = 6). Ten patients presented bilateral recurrence. INTERVENTION(S): Microsurgical shunts between spermatic vein and inferior epigastric vein. MAIN OUTCOME MEASURE(S): Sperm count, pregnancy rate, and ultrasound evaluation of varicosity. RESULT(S): Complete disappearance of varicosity was achieved in 97.06% of patients, while in 2.94%, a consistent reduction in size was observed. In patients with severe infertility, a significant postoperative increase in seminal parameters was observed. Pregnancy rates were 43.75% in group A and 22.22% in group B. CONCLUSION(S): Microsurgical drainage in patients with recurrent varicocele after ligation-like procedures was shown to be an effective minimally invasive treatment, with immediate hemodynamic recovery of testicular venous outflow and excellent long-term results in patients with left or bilateral recurrences.

Potentially fatal bleeding in acute pancreatitis: pathophysiology, prevention, and treatment.

INTRODUCTION: Massive bleeding may complicate the course of either acute or chronic pancreatitis. Although the latter is more frequently involved when bleeding occurs in the acute form, a poorer prognosis is to be expected. Abscess, severe inflammation, regional necrosis, and pseudocysts may cause major vessel erosion, with or without pseudoaneurysm formation, whose eventual rupture may result in massive bleeding into the gastrointestinal tract, retroperitoneum, and peritoneal cavity. AIMS: To define the most important pathophysiologic mechanisms and factors that might contribute to a better understanding, better prevention, and more efficient treatment of severe hemorrhage complicating acute necrotizing pancreatitis. Awareness of high-risk conditions occurring during the natural evolution of the disease (from extensive local severe enzymatic damage to late septic sequelae), avoidance of a too early and too aggressive approach to sterile pancreatic necrosis, and providing prompt and effective treatment of local septic complications, when they occur, are crucial steps for bleeding prevention. METHODOLOGY: Forty-four cases of severe bleeding following acute pancreatitis that were reported during the last decade since 1992 (including the six cases reported here) are reviewed, analyzed, and summarized. RESULTS: The overall mortality rate was 34.1%. Splenic artery, portal vein, spleen, and unspecified peripancreatic vessels were the most commonly involved sources of bleeding, with associated mortality rates of 33.3%, 50.0%, 30%, and 28.5%, respectively. Massive hemorrhage was more frequently associated with severe necrosis, with a mortality rate of 37.9%. CONCLUSION: The increased use of diagnostic and interventional radiology, in association with prompt surgical treatment, appears to be the way to improve survival rates in cases of arterial bleeding. Venous bleeding due to lesion of major peripancreatic veins or diffuse bleeding represents a therapeutic challenge, and treatment of these conditions should be tailored to the individual case, as no general rule can be suggested. In extreme cases, open packing or salvage emergency pancreatectomy may represent the only chances for survival.