The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients

Introduction

The study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators.

Methods

Case collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate.

Results

Among the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP.

Discussion

According to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance.

Possible role of nuclear factor erythroid 2-related factor 2 in the progression of human colon precancerous lesions

BACKGROUND

Increased levels of oxidative stress/cell inflammation contribute to colorectal cancer (CRC) onset. Nuclear factor-erythroid 2-related factor 2 (Nrf2) and its controlled growth factor erv1-like (Gfer) gene regulate redox-sensitive and anti-inflammatory mechanisms, respectively, which can contribute to promoting cancer development.

AIM

We evaluated Nrf2 and Gfer RNA expression and Nrf2 protein expression in colon mucosa in order to establish their possible involvement in the early stage of CRC.

METHODS

Forty subjects were enrolled after a histological evaluation of their colon biopsies. They included 20 subjects with a sporadic colorectal adenoma (SpCA group) and 20 without precancerous lesions (controls). Biopsy samples were processed for gene expression analysis and protein expression, using Real-time PCR and immunofluorescence confocal microscopy, respectively.

RESULTS

Nrf2 and Gfer mRNA expression were significantly reduced (p=0.007 and p<0.003, respectively) in SpCA tissues compared to normal mucosa from controls. Furthermore, immunofluorescence analysis confirmed a relevant reduction of Nrf2 in SpCA tissue compared to normal tissue from controls.

CONCLUSIONS

Our data confirm the hypothesis that Nrf2 and Gfer expression may be involved in the initial hits contributing to the multistep process of colon carcinogenesis. Further larger studies are needed to confirm if Nrf2 and Gfer are potential risk/prognostic factors for cancer development.

Twelve Months with COVID-19: What Gastroenterologists Need to Know

Corona virus disease-19 (COVID-19) is the latest global pandemic. COVID-19 is mainly transmitted through respiratory droplets and, apart from respiratory symptoms, patients often present with gastrointestinal symptoms and liver involvement. Given the high percentage of COVID-19 patients that present with gastrointestinal symptoms (GIS), in this review, we report a practical up-to-date reference for the physician in their clinical practice with patients affected by chronic gastrointestinal (GI) diseases (inflammatory bowel disease, coeliac disease, chronic liver disease) at the time of COVID-19. First, we summarised data on the origin and pathogenetic mechanism of SARS-CoV-2. Then, we performed a literature search up to December 2020 examining clinical manifestations of GI involvement. Next, we illustrated and summarised the most recent guidelines on how to adhere to GI procedures (endoscopy, liver biopsy, faecal transplantation), maintaining social distance and how to deal with immunosuppressive treatment. Finally, we focussed on some special conditions such as faecal-oral transmission and gut microbiota. The rapid accumulation of information relating to this condition makes it particularly essential to revise the literature to take account of the most recent publications for medical consultation and patient care.

Long-term safety of rituximab in rheumatic patients with previously resolved hepatitis B virus infection

Conflicting results can be found in the literature on the frequency of hepatitis B virus (HBV) reactivation (HBVr) on rituximab (RTX) in rheumatic patients with previously resolved HBV (prHBV) infection. Here, we report the frequency of HBVr in a large historical cohort of caucasian rheumatic patients with prHBV receiving RTX. Registry data of rheumatic patients treated with RTX were retrospectively analysed. Demographic and clinical characteristics including evaluation of anti-HCV and HBV markers, annual HBV-DNA determination and aminotransferase levels assessed every three months, were recorded. Kaplan-Meier estimate was used to compare the risk of being still under therapy at different time points in patients with or without prHBV infection. Cox regression analysis was used to determine the association between recorded variables and treatment discontinuation. A total of 311 patients treated with RTX, 44 (14.1%) with and 267 (85.9%) without prHBV were analysed. No significant difference between the two groups regarding demographic and clinical characteristics was observed. During RTX treatment, detectable HBV-DNA and reappearance of HBsAg in patients with prHBV (seroreversion) were never observed. Kaplan-Meier functions were similar in patients with or without prHBV infection which was not associated with RTX discontinuation neither at univariate nor at multivariate analysis. These data are in favor of the concept that patients with rheumatologic diseases have a very low risk of reactivation of the HBV infection under RTX treatment. However, future prospective studies, including a larger number of patients, are still necessary to draw definitive conclusions.

Liver involvement in inflammatory bowel disease: What should the clinician know?

Inflammatory bowel disease (IBD) may show a wide range of extraintestinal manifestations. In this context, liver involvement is a focal point for both an adequate management of the disease and its prognosis, due to possible serious comorbidity. The association between IBD and primary sclerosing cholangitis is the most known example. This association is relevant because it implies an increased risk of both colorectal cancer and cholangiocarcinoma. Additionally, drugs such as thiopurines or biologic agents can cause drug-induced liver damage; therefore, this event should be considered when planning IBD treatment. Additionally, particular consideration should be given to the evidence that IBD patients may have concomitant chronic viral hepatitis, such as hepatitis B and hepatitis C. Chronic immunosuppressive regimens may cause a hepatitis flare or reactivation of a healthy carrier state, therefore careful monitoring of these patients is necessary. Finally, the spread of obesity has involved even IBD patients, thus increasing the risk of non-alcoholic fatty liver disease, which has already proven to be more common in IBD patients than in the non-IBD population. This phenomenon is considered an emerging issue, as it will become the leading cause of liver cirrhosis.

Esophageal Eosinophilia and Eosinophilic Esophagitis in Celiac Children: A Ten Year Prospective Observational Study

The association between eosinophilic esophagitis and celiac disease is still controversial and its prevalence is highly variable. We aimed to investigate the prevalence of esophageal eosinophilia and eosinophilic esophagitis in a large group of children with celiac disease, prospectively followed over 11 years.

METHODS

Prospective observational study performed between 2008 and 2019. Celiac disease diagnosis was based on ESPGHAN criteria. At least four esophageal biopsies were sampled in patients who underwent endoscopy. The presence of at least 15 eosinophils/HPF on esophageal biopsies was considered suggestive of esophageal eosinophilia; at the same time, eosinophilic esophagitis was diagnosed according to the International Consensus Diagnostic Criteria for Eosinophilic Esophagitis.

RESULTS

A total of 465 children (M 42% mean age 7.1 years (range: 1-16)) were diagnosed with celiac disease. Three hundred and seventy patients underwent endoscopy, and esophageal biopsies were available in 313. The prevalence of esophageal eosinophilia in children with celiac disease was 1.6% (95% CI: 0.54-2.9%). Only one child was diagnosed as eosinophilic esophagitis; we calculated a prevalence of 0.3% (95% CI: 0.2-0.5%). The odds ratio for an association between eosinophilic esophagitis and celiac disease was at least 6.5 times higher (95% CI: 0.89-47.7%; p = 0.06) than in the general population.

CONCLUSION

The finding of an increased number of eosinophils (>15/HPF) in celiac patients does not have a clinical implication or warrant intervention, and therefore we do not recommend routine esophageal biopsies unless clinically indicated.

Minimal portosystemic encephalopathy: A new nosological entity in patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Portosystemic shunts in Hereditary Haemorrhagic Telangiectasia (HHT) are often overlooked by conventional imaging although they could reduce hepatic clearance of gut-derived toxins.

AIMS

To evaluate, the presence of subclinical neurological alterations (SNAs), that we named "minimal portosystemic encephalopathy" (mPSE) in HHT patients without advanced liver disease (ALD).

METHODS

In this cross sectional study, consecutive HHT outpatients were firstly screened by critical flicker frequency (CFF) test (abnormal ≤39Hz), and the simplified animal naming test (S-ANT₁) (abnormal <15) was used to confirm the diagnosis of mPSE. Furthermore, we evaluated the effect of lactulose administration on mPSE. Multi-slice CT, cerebral dynamic magnetic resonance, laboratory analyses and transient elastography were also used.

RESULTS

None of the 37 enrolled patients showed portosystemic shunts at imaging techniques. However, 33 patients had normal CFF values (CFF-) and 4 displayed CFF alterations (37.0±0.7Hz, CFF+). The S-ANT₁ confirmed an impaired neurological performance (10.2±2.8) in CFF+ patients thus confirming the presence of mPSE. Noteworthy, lactulose administration determined a CFF increase (39.1±0.4Hz) and S-ANT₁ normalization in these patients. Neither mPSE- nor mPSE+ patients had ALD and showed similar demographic, clinical and laboratory parameters. Finally, no mPSE+ patient showed radiologically-detectable brain vascular malformations or other brain abnormalities at imaging.

CONCLUSIONS

HHT patients represent a human model of mPSE secondary to portosystemic shunts escaping radiological detection. mPSE evaluation should be incorporated in HHT surveillance protocols since it can affect both health-related/social aspects and pharmacokinetics of orally administered drugs with a narrow therapeutic index and high hepatic first-pass uptake.

Iodine Absorption in Celiac Children: A Longitudinal Pilot Study

Background: non-autoimmune thyroid disorder is a common finding in celiac patients, more frequent than in the general population. An impairment of iodine absorption has been hypothesized, but it has never been investigated so far. We aimed to evaluate the iodine absorption in children and adolescents with newly diagnosed celiac disease. Methods: 36 consecutive celiac patients (age 7.4 years, range 2.4-14.5 years) before starting a gluten-free diet (GFD) were enrolled. We assayed the urinary iodine concentration (UIC) in a 24-h urine sample, at baseline (T0) after 3 (T1) and 12 months (T2) of GFD. Results: UIC at T0 was 64 μg/L (IQR 45-93.25 μg/L) with an iodine deficiency rate of 77.8%. UIC was not different according to histological damage, clinical presentation (typical vs atypical); we found no correlation with the thyroid function tests and auxological parameters. UIC was not statistically different at T1 (76 μg/L) and T2 (89 μg/L) vs T0. UIC at T2 was similar between patients with positive and negative anti-transglutaminase antibodies at T2. No patients presented overt hypothyroidism during the study. Conclusions: We found that iodine absorption in celiac children is impaired compared to the general population; it increases slightly, but not significantly, during the GFD. We should regularly reinforce the need for a proper iodine intake in celiac disease patients to reduce iodine deficiency risk.

Anti-Inflammatory and Immunomodulatory Effects of Probiotics in Gut Inflammation: A Door to the Body

Hosting millions of microorganisms, the digestive tract is the primary and most important part of bacterial colonization. On one side, in cases of opportunistic invasion, the abundant bacterial population inside intestinal tissues may face potential health problems such as inflammation and infections. Therefore, the immune system has evolved to sustain the host-microbiota symbiotic relationship. On the other hand, to maintain host immune homeostasis, the intestinal microflora often exerts an immunoregulatory function that cannot be ignored. A field of great interest is the association of either microbiota or probiotics with the immune system concerning clinical uses. This microbial community regulates some of the host's metabolic and physiological functions and drives early-life immune system maturation, contributing to their homeostasis throughout life. Changes in gut microbiota can occur through modification in function, composition (dysbiosis), or microbiota-host interplays. Studies on animals and humans show that probiotics can have a pivotal effect on the modulation of immune and inflammatory mechanisms; however, the precise mechanisms have not yet been well defined. Diet, age, BMI (body mass index), medications, and stress may confound the benefits of probiotic intake. In addition to host gut functions (permeability and physiology), all these agents have profound implications for the gut microbiome composition. The use of probiotics could improve the gut microbial population, increase mucus-secretion, and prevent the destruction of tight junction proteins by decreasing the number of lipopolysaccharides (LPSs). When LPS binds endothelial cells to toll-like receptors (TLR 2, 4), dendritic cells and macrophage cells are activated, and inflammatory markers are increased. Furthermore, a decrease in gut dysbiosis and intestinal leakage after probiotic therapy may minimize the development of inflammatory biomarkers and blunt unnecessary activation of the immune system. In turn, probiotics improve the differentiation of T-cells against Th2 and development of Th2 cytokines such as IL-4 and IL-10. The present narrative review explores the interactions between gut microflora/probiotics and the immune system starting from the general perspective of a biological plausibility to get to the in vitro and in vivo demonstrations of a probiotic-based approach up to the possible uses for novel therapeutic strategies.

Prevalence and associated factors of obesity in inflammatory bowel disease: A case-control study

BACKGROUND

In recent years, an increasing prevalence of obesity in inflammatory bowel disease (IBD) has been observed. Obesity, moreover, has been directly correlated with a more severe clinical course and loss of response to treatment.

AIM

To assess the prevalence and associated factors of obesity in IBD.

METHODS

We collected data about IBD disease pattern and activity, drugs and laboratory investigations in our center. Anthropometric measures were retrieved and obesity defined as a body mass index (BMI) > 30. Then, we compared characteristics of obese vs non obese patients, and Chi-squared test and Student’s t test were used for discrete and continuous variables, respectively, at univariate analysis. For multivariate analysis, we used binomial logistic regression and estimated odd ratios (OR) and 95% confidence intervals (CI) to ascertain factors associated with obesity.

RESULTS

We enrolled 807 patients with IBD, either ulcerative colitis (UC) or Crohn’s disease (CD). Four hundred seventy-four patients were male (58.7%); the average age was 46.2 ± 13.2 years; 438 (54.2%) patients had CD and 369 (45.8%) UC. We enrolled 378 controls, who were comparable to IBD group for age, sex, BMI, obesity, diabetes and abdominal circumference, while more smokers and more subjects with hypertension were observed among controls. The prevalence of obesity was 6.9% in IBD and 7.9% in controls (not statistically different; P = 0.38). In the comparison of obese IBD patients and obese controls, we did not find any difference regarding diabetes and hypertension prevalence, nor in sex or smoking habits. Obese IBD patients were younger than obese controls (51.2  ± 14.9 years vs 60.7 ± 12.1 years, P = 0.03). At univariate analysis, obese IBD were older than normal weight ones (51.2 ± 14.9 vs 44.5 ± 15.8, P = 0.002). IBD onset age was earlier in obese population (44.8 ± 13.6 vs 35.6 ± 15.6, P = 0.004). We did not detect any difference in disease extension. Obese subjects had consumed more frequently long course of systemic steroids (66.6% vs 12.5%, P = 0.02) as well as antibiotics such as metronidazole or ciprofloxacin (71.4% vs 54.7%, P = 0.05). No difference about other drugs (biologics, mesalazine or thiopurines) was observed. Disease activity was similar between obese and non obese subjects both for UC and CD. Obese IBD patients suffered more frequently from arterial hypertension, type 2 diabetes, non-alcoholic fatty liver disease. Regarding laboratory investigations, obese IBD patients had higher levels of triglyceridemia, fasting blood glucose, gamma-glutamyl-transpeptidase. On multivariate analysis, however, the only factor that appeared to be independently linked to obesity in IBD was the high abdominal circumference (OR = 16.3, 95%CI: 1.03-250, P = 0.04).

CONCLUSION

Obese IBD patients seem to have features similar to general obese population, and there is no disease-specific factor (disease activity, extension or therapy) that may foster obesity in IBD.

Trends of Liver Stiffness in Inflammatory Bowel Disease with Chronic Hepatitis C

Concomitant inflammatory bowel disease (IBD) and hepatitis C virus (HCV) infection is a relevant comorbidity since IBD itself exposes to a high risk of liver damage. We aimed to evaluate liver stiffness (LS) in IBD-HCV after antiviral treatment. We enrolled IBD patients with HCV. All patients at baseline underwent LS measurement by elastography. Patients who were eligible for antiviral therapy received direct antiviral agents (DAAs) and sustained viral response was evaluated at the 12th week. A control group was selected within IBD patients without HCV. One year later, all IBD-HCV patients and controls repeated LS measurement. Twenty-four IBD-HCV patients and 24 IBD controls entered the study. Only twelve out of 24 received DAAs and all achieved sustained viral response (SVR). All IBD subjects were in remission at enrollment and maintained remission for one year. After one year, IBD patients who eradicated HCV passed from a liver stiffness of 8.5 ± 6.2 kPa to 7.1 ± 3.9, p = 0.13. IBD patients who did not eradicate HCV worsened liver stiffness: from 7.6 ± 4.4 to 8.6 ± 4.6, p = 0.01. In the IBD control group, stiffness decreased from 7.8 ± 4.4 to 6.0 ± 3.1, p < 0.001. In conclusion, HCV eradication is able to stop the evolution of liver fibrosis in IBD, while failure to treat may lead to its progression. A stable IBD remission may improve LS even in non-infected subjects.

Chronic Viral Hepatitis in a Cohort of Inflammatory Bowel Disease Patients from Southern Italy: A Case-Control Study

We performed an epidemiologic study to assess the prevalence of chronic viral hepatitis in inflammatory bowel disease (IBD) and to detect their possible relationships. Methods: It was a single centre cohort cross-sectional study, during October 2016 and October 2017. Consecutive IBD adult patients and a control group of non-IBD subjects were recruited. All patients underwent laboratory investigations to detect chronic hepatitis B (HBV) and C (HCV) infection. Parameters of liver function, elastography and IBD features were collected. Univariate analysis was performed by Student's t or chi-square test. Multivariate analysis was performed by binomial logistic regression and odds ratios (ORs) were calculated. We enrolled 807 IBD patients and 189 controls. Thirty-five (4.3%) had chronic viral hepatitis: 28 HCV (3.4%, versus 5.3% in controls, p = 0.24) and 7 HBV (0.9% versus 0.5% in controls, p = 0.64). More men were observed in the IBD-hepatitis group (71.2% versus 58.2%, p < 0.001). Patients with IBD and chronic viral hepatitis had a higher mean age and showed a higher frequency of diabetes, hypertension and wider waist circumference. They suffered more frequently from ulcerative colitis. Liver stiffness was greater in subjects with IBD and chronic viral hepatitis (7.0 ± 4.4 versus 5.0 ± 1.2 KPa; p < 0.001). At multivariate analysis, only old age directly correlated with viral hepatitis risk (OR = 1.05, 95%CI 1.02-1.08, p < 0.001). In conclusion, the prevalence of HBV/HCV in IBD is low in our region. Age may be the only independent factor of viral hepatitis-IBD association. Finally, this study firstly measured liver stiffness in a large scale, showing higher values in subjects with both diseases.

Undefined/non-malignant hepatic nodules are associated with early occurrence of HCC in DAA-treated patients with HCV-related cirrhosis

BACKGROUND & AIM

An unexpected early increase in incidence, recurrence and clinical aggressiveness of hepatocellular carcinoma (HCC) has been reported (and refuted) in patients with HCV-related cirrhosis following direct-acting antiviral (DAA) treatment. To address this controversy, we performed a prospective multicenter study on consecutively enrolled cirrhotic patients, with or without a history of HCC, undergoing DAA therapy.

PATIENTS AND METHODS

A total of 1,161 HCC-free cirrhotics (group 1) and 124 cirrhotics who had received a curative treatment for an HCC (group 2) were enrolled. Clinical features, including presence of undefined/non-malignant liver nodules (UNMNs), were analyzed with respect to HCC incidence and recurrence.

RESULTS

During a median study time of 17 months in group 1 and 16 months in group 2, de novo HCC developed in 48 patients (yearly incidence 3.1/100 patient-years, 75% BCLC 0-A) and recurred in 40 (mean yearly incidence 29.9/100 patient-years, 83% BCLC 0-A). A peak of HCC instant incidence was observed at 4.2 months in group 1 patients with UNMNs, and at 7.7 months in group 2. By multivariable Cox regression models, UNMNs (hazard ratio [HR] 3.11; 95% CI 1.47-6.57: p = 0.003), ascites detected any time before enrolment (HR 3.04; 95% CI 1.23-7.51; p = 0.02), and alpha-fetoprotein log-value (HR 1.90; 95% CI 1.05-3.44; p = 0.03) were the variables independently associated with the incidence of de novo HCC, while history of alcohol abuse (HR 2.10; 95% CI 1.08-4.09; p = 0.03) and history of recurrence of HCC (HR 2.87; 95% CI 1.35-6.09; p = 0.006) were associated with HCC recurrence.

CONCLUSION

An early high incidence of both de novo HCC, in patients with UNMNs, and recurrent HCC was observed in DAA-treated patients; this was not accompanied by increased tumor aggressiveness.

LAY SUMMARY

This prospective study focuses on the risk of developing de novo or recurrent hepatocellular carcinoma (HCC) after direct-acting antiviral (DAA) treatment in patients with hepatitis C-related cirrhosis. We found that DAA treatment was associated with an early high HCC incidence in patients with undefined or non-malignant nodules, as well as in those with a history of complete response to HCC treatment. Whether this is related to the presence of clinically undetectable nests of cancer cells or to precancerous lesions that may progress to overt HCC upon DAA treatment remains unanswered. No evidence of increased clinical aggressiveness was reported in de novo or recurrent HCC.

The perplexity of targeting genetic alterations in hepatocellular carcinoma

Genetic heterogeneity is a well-recognized feature of hepatocellular carcinoma (HCC). The coexistence of multiple genetic alterations in the same HCC nodule contributes to explain why gene-targeted therapy has largely failed. Targeting of early genetic alterations could theoretically be a more effective therapeutic strategy preventing HCC. However, the failure of most targeted therapies has raised much perplexity regarding the role of genetic alterations in driving cancer as the main paradigm. Here, we discuss the methodological and conceptual limitations of targeting genetic alterations and their products that may explain the limited success of the novel mechanism-based drugs in the treatment of HCC. In light of these limitations and despite the era of the so-called "precision medicine," prevention and early diagnosis of conditions predisposing to HCC remain the gold standard approach to prevent the development of this type of cancer. Finally, a paradigm shift to a more systemic approach to cancer is required to find optimal therapeutic solutions to treat this disease.

The Role of Circulating Adiponectin and SNP276G>T at ADIPOQ Gene in BRCA-mutant Women

BACKGROUND

Environmental factors may influence the lifetime risk of cancer (penetrance) in women with a BRCA mutation.

MATERIALS AND METHODS

In 89 BRCA-mutant women, affected or unaffected by breast/ovarian cancer, we explored serum levels of adipokines and their relation with the polymorphism SNP276G>T as modulators of BRCA penetrance.

RESULTS

Affected women had significantly lower adiponectin than healthy women. Affected women with rs1501299 TT had significantly lower adiponectin and higher leptin than GT and GG genotypes. GT genotype was significantly associated with the disease status [odds ratio (OR)=3.24, 95% confidence interval (95% CI)=1.03-10.17]. Women in the lower tertile of serum adiponectin had a RR of BRCA-associated cancer of 2.80, 95% CI=1.1-7.1 (p for trend=0.03) compared with women in the higher tertile.

CONCLUSION

In the SNP rs1501299 the T allele was significantly associated with lower serum levels of adiponectin in affected women, suggesting that the T allele might be related to cancer.

Advances in understanding the potential therapeutic applications of gut microbiota and probiotic mediated therapies in celiac disease

INTRODUCTION

Celiac Disease (CD) is an autoimmune enteropathy caused by exposure to gluten in genetically predisposed people. While gluten is the main driving force in CD, evidence has shown that microbiota might be involved in the pathogenesis, development, and clinical presentation of CD. Microbiota manipulation may modify its functional capacity and may be crucial for setting-up potential preventive or therapeutic application. Moreover, probiotics are an excellent source of endopeptidases for digesting gluten.

AREAS COVERED

In this narrative review we illustrate all the recent scientific discoveries in this field including CD pathogenetic mechanism where gut microbiota might be involved and possible use of probiotics in CD prevention and treatment.

EXPERT OPINION

In the future, probiotics could be used as an add-on medication for strengthening/facilitating the gluten-free diet (GFD) and improving symptoms; the prospect of using it for therapeutic purposes is to be sought in a more distant future.

Silymarin, boswellic acid and curcumin enriched dietetic formulation reduces the growth of inherited intestinal polyps in an animal model

BACKGROUND

Some substances of plant origin have been reported to exert an effect in reducing intestinal neoplasm development, especially in animal models. Adenomatous polyposis coli multiple intestinal neoplasia - Apc^Min/+ is the most studied murine model of genetic intestinal carcinogenesis.

AIM

To assess whether an enriched nutritional formulation (silymarin, boswellic acid and curcumin) with proven “in vitro” and “in vivo” anti-carcinogenetic properties may prevent inherited intestinal cancer in animal model.

METHODS

Forty adenomatous polyposis coli multiple intestinal neoplasia - Apc^Min/+ mice were used for the study of cancer prevention. They were divided into two groups: 20 assumed standard and 20 enriched diet. At the 110^th d animals were sacrificed. In each group, four subgroups received intraperitoneal bromodeoxyuridine injection at different times (24, 48, 72 and 96 h before the sacrifice) in order to assess epithelial turnover. Moreover, we evaluated the following parameters: Intestinal polypoid lesion number and size on autoptic tissue, dysplasia and neoplasia areas by histological examination of the whole small intestine, inflammation by histology and cytokine mRNA expression by real-time polymerase chain reaction, bromodeoxyuridine and TUNEL immuno-fluorescence for epithelial turnover and apoptosis, respectively. Additionally, we performed western blotting analysis for the expression of estrogen alpha and beta receptors, cyclin D1 and cleaved caspase 3 in normal and polypoid tissues.

RESULTS

Compared to standard, enriched diet reduced the total number (203 vs 416) and the mean ± SD/animal (12.6 ± 5.0 vs 26.0 ± 8.8; P < 0.001) of polypoid lesions. In enriched diet group a reduction in polyp size was observed (P < 0.001). Histological inflammation and pro-inflammatory cytokine expression were similar in both groups. Areas of low-grade dysplasia (P < 0.001) and intestinal carcinoma (IC; P < 0.001) were significantly decreased in enriched diet group. IC was observed in 100% in standard and 85% in enriched formulation assuming animals. Enriched diet showed a faster epithelial migration and an increased apoptosis in normal mucosa and low-grade dysplasia areas (P < 0.001). At western blotting, estrogen receptor beta protein was well expressed in normal mucosa of enriched and standard groups, with a more marked trend associated to the first one. Estrogen receptor alpha was similarly expressed in normal and polypoid mucosa of standard and enriched diet group. Cleaved caspase 3 showed in normal mucosa a stronger signal in enriched than in standard diet. Cyclin D1 was more expressed in standard than enriched diet group of both normal and polypoid tissue.

CONCLUSION

Our results are suggestive of a chemo-preventive synergic effect of the components (silymarin, boswellic acid and curcumin) of an enriched formulation in inherited IC. This effect may be mediated by the reduction of epithelial proliferation, the increase of apoptosis and the acceleration of villous cell renewal due to dietary formulation intake.

Soy Metabolism by Gut Microbiota from Patients with Precancerous Intestinal Lesions

BACKGROUND

Colorectal cancer (CRC) requires the presence of a variety of factors predisposing a tumorigenic milieu. Excluding familial clustering and hereditary CRC syndromes, the development of sporadic CRC from precancerous lesions is influenced by tissue inflammation, modulation of intestinal immunity, hormones, dietary habits and gut microbiota composition. As concerning the last two aspects, the intestinal presence of equol, the most biologically active metabolite of the soy isoflavone daidzein and the presence of a genetic determinant of gut microbiota able to metabolize daidzein, seem to lower the CRC risk. It has been hypothesized that the anaerobic microorganisms of the Bacteroides genus play a role in equol production.

AIM

To evaluate the presence of (i) anaerobic gut microbiota and (ii) the urinary levels of soy isoflavones (daidzein, genistein and equol) in patients with and without precancerous lesions, challenged with a daidzein-rich soy extract.

METHODS

Consecutive subjects undergoing colonoscopy participated to the study. Feces were collected from all patients one week before colonoscopy for gut microbiota studies. After the endoscopy examination and the histological evaluation, 40 subjects, 20 with sporadic colorectal adenomas (SCA/P group) and 20 without proliferative lesions (control group) were enrolled for the study. Urine levels of soy isoflavones daidzein, genistein and their metabolite equol, were determined by high performance liquid chromatographic (HPLC) analysis and gut microbiota analysis was performed by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) procedure.

RESULTS

Seventeen different bacterial species were identified in the fecal samples of the forty subjects participating to the study. Ten bacterial species resulted anaerobic Gram-negative bacteria, all belonging to the Bacteroides genus. A significant difference of bacteria species was evidenced in the fecal samples of the two groups of subjects. Particularly important was the evidence of Parabacteroides distasonis, Clostridium clostridioforme and Pediococcus pentasaceus only in control fecal samples, such as the presence of Bacteroides fragilis and Prevotella melaningenica only in SCA/P fecal samples. Concerning the soy isoflavones levels, no statistically significant differences were revealed in the genistein and daidzein urinary levels between the two groups of subjects. On the contrary, urinary equol levels were undetectable in ten SCA/P subjects and in two controls; moreover, when present, the levels of urinary equol were significantly lower in SCA/P subjects compared to controls (0.24 ± 0.27 mg/24 hrs vs. 21.25 ± 4.3 mg/24 hrs, respectively, p = 1.12 × 10^-6).

CONCLUSIONS

Our results suggest that the presence of anaerobic Bacteroides in the colon, and the production of equol from soy, could determine a milieu able to contrast the development of colonic mucosa proliferative lesions.

Evaluation of Non-Celiac Gluten Sensitivity in Patients with Previous Diagnosis of Irritable Bowel Syndrome: A Randomized Double-Blind Placebo-Controlled Crossover Trial

Background. To date, there is no reliable marker for the diagnosis of non-celiac gluten sensitivity (NCGS), which benefits from a gluten-free diet (GFD). This condition is characterized by functional gastrointestinal symptoms similar to those occurring in the course of irritable bowel syndrome (IBS). However, IBS has a higher prevalence, and often benefits from the administration of a low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet. The overlap of symptoms between these two pathologies has led to an overestimation of self-made diagnosis NCGS. Aims. To better identify NCGS in subjects with a previous diagnosis of IBS. Methods. All subjects received a low FODMAP diet that was also gluten-free (low FODMAP-GFD), and those presenting an improvement of symptoms were exposed to gluten or placebo (double-blind challenge with wash-out and crossover). The response to dietary treatments was evaluated by visual analogue scale (VAS). Results. Of 30 patients (23 women, seven men, aged 42.2 ± 12.5 years, body mass index (BMI ) 24.7 ± 4.1 kg/m²), 26 benefited from the administration of low FODMAP-GFD and were exposed to the gluten/placebo challenge. After the challenge, using an increase of visual analogue scale VAS (Δ-VAS) ≥30%, 46.1% of the patients were NCGS+. However, this percentage became only 19.2% using a different method (mean ∆-VAS score plus two standard deviations). Conclusions. FODMAP intolerance could hide the response to a challenge test with gluten for the identification of NCGS in IBS patients. A low FODMAP-GFD followed by gluten/placebo challenge is able to identify patients with NCGS better. ClinicalTrials.gov registration number NCT04017585.

Nonsense variant of ATP8B1 gene in heterozygosis and benign recurrent intrahepatic cholestasis: A case report and review of literature

BACKGROUND

Benign recurrent intrahepatic cholestasis is a genetic disorder with recurrent cholestatic jaundice due to ATP8B1 and ABCB11 gene mutations encoding for hepato-canalicular transporters. Herein, we firstly provide the evidence that a nonsense variant of ATP8B1 gene (c.1558A>T) in heterozygous form is involved in BRIC pathogenesis.

CASE SUMMARY

A 29-year-old male showed severe jaundice and laboratory tests consistent with intrahepatic cholestasis despite normal gamma-glutamyltranspeptidase. Acute and chronic liver diseases with viral, metabolic and autoimmune etiology were excluded. Normal intra/extra-hepatic bile ducts were demonstrated by magnetic resonance. Liver biopsy showed: Cholestasis in the centrilobular and intermediate zones with bile plugs and intra-hepatocyte pigment, Kupffer’s cell activation/hyperplasia and preserved biliary ducts. Being satisfied benign recurrent intrahepatic cholestasis diagnostic criteria, ATP8B1 and ABCB11 gene analysis was performed. Surprisingly, we found a novel nonsense variant of ATP8B1 gene (c.1558A>T) in heterozygosis. The variant was confirmed by Sanger sequencing following a standard protocol and tested for familial segregation, showing a maternal inheritance. Immunohistochemistry confirmed a significant reduction of mutated gene related protein (familial intrahepatic cholestasis 1). The patient was treated with ursodeoxycholic acid 15 mg/kg per day and colestyramine 8 g daily with total bilirubin decrease and normalization at the 6^th and 12^th mo.

CONCLUSION

A genetic abnormality, different from those already known, could be involved in familial intrahepatic cholestatic disorders and/or pro-cholestatic genetic predisposition, thus encouraging further mutation detection in this field.

Breath Tests for the Non-invasive Diagnosis of Small Intestinal Bacterial Overgrowth: A Systematic Review With Meta-analysis

BACKGROUND/AIMS

Small intestinal bacterial overgrowth (SIBO) diagnosis is usually based on non-invasive breath tests (BTs), namely lactulose BT (LBT) and glucose BT (GBT). However, divergent opinions and problems of parameter standardization are still controversial aspects. We aim to perform a meta-analysis to analyze diagnostic performance of LBT/GBT for SIBO diagnosis.

METHODS

We searched in main literature databases articles in which SIBO diagnosis was achieved by LBT/GBT in comparison to jejunal aspirate culture (reference gold standard). We calculated pooled sensitivity, specificity, positive, and negative likelihood ratios and diagnostic odd ratios. Summary receiver operating characteristic curves were drawn and pooled areas under the curve were calculated.

RESULTS

We selected 14 studies. Pooled sensitivity of LBT and GBT was 42.0% and 54.5%, respectively. Pooled specificity of LBT and GBT was 70.6% and 83.2%, respectively. When delta over baseline cut-off > 20 H₂ parts per million (ppm) was used, GBT sensitivity and specificity were 47.3% and 80.9%; when the cutoff was other than and lower than > 20 ppm, sensitivity and specificity were 61.7% and 86.0%. In patients with abdominal surgery history, pooled GBT sensitivity and specificity gave the impression of having a better performance (81.7% and 78.8%) compared to subjects without any SIBO predisposing condition (sensitivity = 40.6% and specificity = 84.0%).

CONCLUSIONS

GBT seems to work better than LBT. A cut-off of delta H2 expired other than and lower than > 20 ppm shows a slightly better result than > 20 ppm. BTs demonstrate the best effectiveness in patients with surgical reconstructions of gastrointestinal tract.

Randomised trial of chronic supplementation with a nutraceutical mixture in subjects with non-alcoholic fatty liver disease

A mixture of natural ingredients, namely, DHA, phosphatidylcholine, silymarin, choline, curcumin and d-α-tocopherol, was studied in subjects with non-alcoholic fatty liver disease (NAFLD). Primary endpoints were serum levels of hepatic enzymes, and other parameters of liver function, the metabolic syndrome and inflammation were the secondary endpoints. The coagulation-fibrinolysis balance was also thoroughly investigated, as NAFLD is associated with haemostatic alterations, which might contribute to increased cardiovascular risk of this condition. The present study involved a double-blind, randomised, multicentre controlled trial of two parallel groups. Subjects with NAFLD (18-80 years, either sex) received the active or control treatment for 3 months. All assays were performed on a total of 113 subjects before and at the end of supplementation. The hepatic enzymes aspartate aminotransferase (AST), alanine aminotransferase and γ-glutamyl transpeptidase decreased from 23·2 to 3·7 % after treatment, only the AST levels reaching statistical significance. However, no differences were found between control and active groups. Metabolic and inflammatory variables were unchanged, except for a slight (less than 10 %) increase in cholesterol and glucose levels after the active treatment. Coagulation-fibrinolytic parameters were unaffected by either treatment. In conclusion, chronic supplementation with the mixture of dietary compounds was well tolerated and apparently safe in NAFLD subjects. The trial failed to demonstrate any efficacy on relevant physiopathological markers, but its protocol and results may be useful to design future studies with natural compounds.

Gut Microbiota Imbalance is Related to Sporadic Colorectal Neoplasms. A Pilot Study

(1) Background: Colorectal cancer (CRC) development is sustained by multiple factors including the gut microbiota, as suggested by a growing body of evidence. Most CRCs have a sporadic (non-hereditary) onset and develop from sporadic colorectal adenomas/polyp (SCA/P). In the present study, we investigated the characteristic of anaerobic microorganisms in stool samples obtained from 20 patients with SCA/P and 20 subjects without evidence of proliferative lesions at colonoscopy (Controls). (2) Material and Methods: We designed this clinical trial using adaptive randomization by minimization. Selective culture media and Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) mass spectrometry techniques were used to identify the components of microbiota. The data obtained revealed a different variability of gut microbiota in stool samples of controls and SCA/P subjects. (3) Results: The most interesting difference was observed for Bacteroides species, which represent the 50% of all bacterial species identified in the stool samples: two species, Bacteroides stercoris and Parabacteroides distasonis, were found only in the feces from control group, whereas Bacteroides fragilis and Prevotella melaningenica species were presents only in SCA/P patients. Among Gram+ bacteria also, specific species were found in the two groups of feces: Clostridium clostridioforme, Propionibacterium avidum and Pediococcus pentasaceus were identified only in controls, while Eubacterium limosum, Clostridium innocuum and Corybebacterium xerosus were identified in SCA/P stool samples only. (4) Conclusions: Our findings suggest that, compared to control stool samples, a different intestinal microbiota is present in SCA/P stool samples, that may create a micro-environment predisposing for the development of proliferative phenomena. As a consequence, gut microbiota manipulation could be a future target for personalized treatments.

Nutritional prognostic factors for survival in amyotrophic lateral sclerosis patients undergone percutaneous endoscopic gastrostomy placement

Objective: There are conflicting data on nutritional factors influencing survival in amyotrophic lateral sclerosis (ALS) patients after percutaneous endoscopic gastrostomy (PEG) placement. We performed an observational cross-sectional study evaluating body mass index (BMI) categories and cholesterol levels as prognostic factors for survival after PEG. Moreover, we assessed body composition in a subgroup of patients to better explain the influence of BMI on survival. Methods: Neurological and nutritional parameters were evaluated at the time of PEG implantation in 47 consecutive patients. Moreover, body composition was evaluated in a subgroup of 22 patients by bioelectrical impedance analysis. Survival was calculated as the time from the PEG placement to death. Results: Underweight patients had a significantly increased risk of death as compared to normal-weight patients using Cox regression analysis [HR = 3.37 (1.29-8.81); p = 0.04]. Similarly, older age at the onset of symptoms significantly increased the risk of death [HR = 1.07 (1.02-1.12); p = 0.001]. Neither overweight/obesity nor hypercholesterolemia affected survival. All ALS patients showed an altered body composition compared to the general population. In addition, a BMI <18.5 kg/m² identified patients with a significant reduction of body cell mass (BCM) and phase angle (PhA) compared to patients with normal BMI taken as the reference value. Conclusions: In the later stages of the disease, only a BMI < 18.5 kg/m² and older age at symptom onset had a prognostic value on survival. Dyslipidemia did not affect survival. The low BCM and PhA characterizing underweight patients support the role of BMI as a predictor of survival.