Salmonella enterica serovar Typhimurium adhesion and cytotoxicity during epithelial cell stress is reduced by Lactobacillus rhamnosus GG

Background

Physiological stressors may alter susceptibility of the host intestinal epithelium to infection by enteric pathogens. In the current study, cytotoxic effect, adhesion and invasion of Salmonella enterica serovar Typhimurium (S. Typhimurium) to Caco-2 cells exposed to thermal stress (41°C, 1 h) was investigated. Probiotic bacteria have been shown to reduce interaction of pathogens with the epithelium under non-stress conditions and may have a significant effect on epithelial viability during infection; however, probiotic effect on pathogen interaction with epithelial cells under physiological stress is not known. Therefore, we investigated the influence of Lactobacillus rhamnosus GG and Lactobacillus gasseri on Salmonella adhesion and Salmonella-induced cytotoxicity of Caco-2 cells subjected to thermal stress.

Results

Thermal stress increased the cytotoxic effect of both S. Typhimurium (P = 0.0001) and nonpathogenic E. coli K12 (P = 0.004) to Caco-2 cells, and resulted in greater susceptibility of cell monolayers to S. Typhimurium adhesion (P = 0.001). Thermal stress had no significant impact on inflammatory cytokines released by Caco-2 cells, although exposure to S. Typhimurium resulted in greater than 80% increase in production of IL-6 and IL-8. Blocking S. Typhimurium with anti-ShdA antibody prior to exposure of Salmonella decreased adhesion (P = 0.01) to non-stressed and thermal-stressed Caco-2 cells. Pre-exposure of Caco-2 cells to L. rhamnosus GG significantly reduced Salmonella-induced cytotoxicity (P = 0.001) and Salmonella adhesion (P = 0.001) to Caco-2 cells during thermal stress, while L. gasseri had no effect.

Conclusion

Results suggest that thermal stress increases susceptibility of intestinal epithelial Caco-2 cells to Salmonella adhesion, and increases the cytotoxic effect of Salmonella during infection. Use of L. rhamnosus GG as a probiotic may reduce the severity of infection during epithelial cell stress. Mechanisms by which thermal stress increases susceptibility to S. Typhimurium colonization and by which L. rhamnosus GG limits the severity of infection remain to be elucidated.     

Casein hydrolysate diet controls intestinal T cell activation, free radical production and microbial colonisation in NOD mice

Aims/hypothesis

Dietary and microbial factors and the gut immune system are important in autoimmune diabetes. We evaluated inflammatory activity in the whole gut in prediabetic NOD mice using ex vivo imaging of reactive oxygen and nitrogen species (RONS), and correlated this with the above-mentioned factors.

Methods

NOD mice were fed a normal diet or an anti-diabetogenic casein hydrolysate (CH) diet. RONS activity was detected by chemiluminescence imaging of the whole gut. Proinflammatory and T cell cytokines were studied in the gut and islets, and dietary effects on gut microbiota and short-chain fatty acids were determined.

Results

Prediabetic NOD mice displayed high RONS activity in the epithelial cells of the distal small intestine, in conjunction with a proinflammatory cytokine profile. RONS production was effectively reduced by the CH diet, which also controlled (1) the expression of proinflammatory cytokines and colonisation-dependent RegIIIγ (also known as Reg3g) in ileum; (2) intestinal T cell activation; and (3) islet cytokines. The CH diet diminished microbial colonisation, increased the Bacteroidetes:Firmicutes ratio, and reduced lactic acid and butyric acid production in the gut.

Conclusions/interpretation

Epithelial RONS production and proinflammatory T cell activation appears in the ileum of NOD mice after weaning to normal laboratory chow, but not after weaning to an anti-diabetogenic CH diet. Our data suggest a link between dietary factors, microbial colonisation and mucosal immune activation in NOD mice.     

Epigenome targeting by probiotic metabolites

Background

The intestinal microbiota plays an important role in immune development and homeostasis. A disturbed microbiota during early infancy is associated with an increased risk of developing inflammatory and allergic diseases later in life. The mechanisms underlying these effects are poorly understood but are likely to involve alterations in microbial production of fermentation-derived metabolites, which have potent immune modulating properties and are required for maintenance of healthy mucosal immune responses. Probiotics are beneficial bacteria that have the capacity to alter the composition of bacterial species in the intestine that can in turn influence the production of fermentation-derived metabolites. Principal among these metabolites are the short-chain fatty acids butyrate and acetate that have potent anti-inflammatory activities important in regulating immune function at the intestinal mucosal surface. Therefore strategies aimed at restoring the microbiota profile may be effective in the prevention or treatment of allergic and inflammatory diseases.

Presentation of the hypothesis

Probiotic bacteria have diverse effects including altering microbiota composition, regulating epithelial cell barrier function and modulating of immune responses. The precise molecular mechanisms mediating these probiotic effects are not well understood. Short-chain fatty acids such as butyrate are a class of histone deacetylase inhibitors important in the epigenetic control of host cell responses. It is hypothesized that the biological function of probiotics may be a result of epigenetic modifications that may explain the wide range of effects observed. Studies delineating the effects of probiotics on short-chain fatty acid production and the epigenetic actions of short-chain fatty acids will assist in understanding the association between microbiota and allergic or autoimmune disorders.

Testing the hypothesis

We propose that treatment with specific probiotic bacteria under in vivo conditions would offer the ideal conditions to examine the microbiological, immunological and epigenetic mechanisms of action. Advances in epigenetic technology now allow investigators to better understand the complex biological properties of probiotics and their metabolites.

Implications of the hypothesis

Determining the precise mechanisms of probiotic action will lead to more specific and efficacious therapeutic strategies in the prevention or treatment of chronic inflammatory conditions.     

Restoration of impaired intestinal barrier function by the hydrolysed casein diet contributes to the prevention of type 1 diabetes in the diabetes-prone BioBreeding rat

Aims/hypothesis

Impaired intestinal barrier function is observed in type 1 diabetes patients and animal models of the disease. Exposure to diabetogenic antigens from the intestinal milieu due to a compromised intestinal barrier is considered essential for induction of the autoimmune process leading to type 1 diabetes. Since a hydrolysed casein (HC) diet prevents autoimmune diabetes onset in diabetes-prone (DP)-BioBreeding (BB) rats, we studied the role of the HC diet on intestinal barrier function and, therefore, prevention of autoimmune diabetes onset in this animal model.

Methods

DP-BB rats were fed the HC diet from weaning onwards and monitored for autoimmune diabetes development. Intestinal permeability was assessed in vivo by lactulose–mannitol test and ex vivo by measuring transepithelial electrical resistance (TEER). Levels of serum zonulin, a physiological tight junction modulator, were measured by ELISA. Ileal mRNA expression of Myo9b, Cldn1, Cldn2 and Ocln (which encode the tight junction-related proteins myosin IXb, claudin-1, claudin-2 and occludin) and Il-10, Tgf-ß (also known as Il10 and Tgfb, respectively, which encode regulatory cytokines) was analysed by quantitative PCR.

Results

The HC diet reduced autoimmune diabetes by 50% in DP-BB rats. In DP-BB rats, prediabetic gut permeability negatively correlated with the moment of autoimmune diabetes onset. The improved intestinal barrier function that was induced by HC diet in DP-BB rats was visualised by decreasing lactulose:mannitol ratio, decreasing serum zonulin levels and increasing ileal TEER. The HC diet modified ileal mRNA expression of Myo9b, and Cldn1 and Cldn2, but left Ocln expression unaltered.

Conclusions/interpretation

Improved intestinal barrier function might be an important intermediate in the prevention of autoimmune diabetes by the HC diet in DP-BB rats. Effects on tight junctions, ileal cytokines and zonulin production might be important mechanisms for this effect.     

Probiotic Lactobacillus rhamnosus GG Modulates the Mucosal Immune Response in Giardia intestinalis-Infected BALB/c Mice

Background

Gut homeostasis can be altered by the oral administration of health-promoting microorganisms, namely probiotics that are known to reinforce the host immune response.

Aim

The aim of this study was to elucidate the immunomodulatory effect of orally administered probiotic Lactobacillus rhamnosus GG (LGG) in Giardia-infected mice.

Methods

BALB/c mice were fed orally with probiotic LGG either 7 days prior to or simultaneously with the challenge dose of Giardia trophozoites. The administration of the probiotic was continued for 25 days, and immunomodulatory potentials in terms of secretory immunoglobulin A (IgA) levels, CD8+ and CD4+ T lymphocytes, and expression of pro-inflammatory [tumor necrosis factor-alpha, interferon-gamma (INF-γ)] and anti-inflammatory cytokines [interleukin (IL)-4, IL-6, IL-10] were studied.

Results

Oral feeding of LGG prior to or simultaneously with the test dose of Giardia seems to have modulated both arms (humoral and cellular) of the mucosal immune system since a significant increase in the levels of specific secretory IgA antibody, IgA+ cells, and CD4+ T lymphocytes were observed in contrast with the decreased percentage of cytotoxic CD8+ T lymphocytes. The stimulated mucosal immune response in probiotic fed Giardia-infected mice was further correlated with the enhanced levels of anti-inflammatory cytokines IL-6 and IL-10 and reduced levels of pro-inflammatory cytokine INF-γ.

Conclusions

This is the first study to show that oral administration of the effective probiotic LGG to Giardia infected mice could be used as a bacterio-therapy that restores the normal gut microflora and modulates the mucosal immune response.     

Impaired dendritic cell functions disrupt antigen-specific adaptive immune responses in mice with nonalcoholic fatty liver disease

Background/aims

The magnitude of antigen-specific immunity was assessed in a murine model of nonalcoholic fatty liver diseases (NAFLD). Because antigen-specific immunity was diminished in NAFLD mice, the underlying mechanisms were evaluated through analysis of the functions of antigen-presenting dendritic cells (DC) and other immunocytes.

Methods

For 12 weeks, NAFLD mice received a high-fat (60%) and high-calorie (520 kcal/100 g) diet. C57BL/6 mice (controls) received a standard diet. NAFLD mice and control mice were immunized with hepatitis B vaccine containing hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). Antibody to HBsAg (anti-HBs), HBsAg and HBcAg-specific cellular immune response and functions of whole spleen cells, T lymphocytes, B lymphocytes and spleen DCs of NAFLD and control mice were assessed in vitro.

Results

Levels of anti-HBs and the magnitude of proliferation of HBsAg and HBcAg-specific lymphocytes were significantly lower in NAFLD mice than control mice (P < 0.05). The spleen cells of NAFLD mice produced significantly higher levels of inflammatory cytokines (P < 0.05) and exhibited significantly increased T cell proliferation compared with control mice (P < 0.05). However, the antigen processing and presenting capacities of spleen DCs were significantly decreased in NAFLD mice compared with control mice (P < 0.05). Palmitic acid, a saturated fatty acid, caused diminished antigen processing and presenting capacity of both murine and human DCs.

Conclusions

Nonalcoholic fatty liver disease mice exhibit decreased magnitudes of antigen-specific humoral and cellular immune responses. This effect is mainly, if not solely, due to impaired antigen processing and presentation capacities of DC.     

Palmitoylethanolamide Regulates Development of Intestinal Radiation Injury in a Mast Cell-Dependent Manner

Background

Mast cells and neuroimmune interactions regulate the severity of intestinal radiation mucositis, a dose-limiting toxicity during radiation therapy of abdominal malignancies.

Aim

Because endocannabinoids (eCB) regulate intestinal inflammation, we investigated the effect of the cannabimimetic, palmitoylethanolamide (PEA), in a mast competent (+/+) and mast cell-deficient (Ws/Ws) rat model.

Methods

Rats underwent localized, fractionated intestinal irradiation, and received daily injections with vehicle or PEA from 1 day before until 2 weeks after radiation. Intestinal injury was assessed noninvasively by luminol bioluminescence, and, at 2 weeks, by histology, morphometry, and immunohistochemical analysis, gene expression analysis, and pathway analysis.

Results

Compared with +/+ rats, Ws/Ws rats sustained more intestinal structural injury (p = 0.01), mucosal damage (p = 0.02), neutrophil infiltration (p = 0.0003), and collagen deposition (p = 0.004). PEA reduced structural radiation injury (p = 0.02), intestinal wall thickness (p = 0.03), collagen deposition (p = 0.03), and intestinal inflammation (p = 0.02) in Ws/Ws rats, but not in +/+ rats. PEA inhibited mast cell-derived cellular immune response and anti-inflammatory IL-6 and IL-10 signaling and activated the prothrombin pathway in +/+ rats. In contrast, while PEA suppressed nonmast cell-derived immune responses, it increased anti-inflammatory IL-10 and IL-6 signaling and decreased activation of the prothrombin pathway in Ws/Ws rats.

Conclusions

These data demonstrate that the absence of mast cells exacerbate radiation enteropathy by mechanisms that likely involve the coagulation system, anti-inflammatory cytokine signaling, and the innate immune system; and that these mechanisms are regulated by PEA in a mast cell-dependent manner. The eCB system should be explored as target for mitigating intestinal radiation injury.     

Reduced Diversity and Imbalance of Fecal Microbiota in Patients with Ulcerative Colitis

Background

Clinical observations and experimental colitis models have indicated the importance of intestinal bacteria in the etiology of ulcerative colitis (UC), but a causative bacterial agent has not been identified.

Aim

To determine how intestinal bacteria are associated with UC, fecal microbiota and other components were compared for UC patients and healthy adults.

Methods

Fresh feces were collected from 48 UC patients. Fecal microbiota were analyzed by use of terminal-restriction fragment length polymorphism (T-RFLP), real-time PCR, and culture. The concentrations of organic acids, indole, and ammonia, and pH and moisture, which are indicators of the intestinal environment, were measured and compared with healthy control data.

Results

T-RFLP data divided the UC patients into four clusters; one cluster was obtained for healthy subjects. The diversity of fecal microbiota was significantly lower in UC patients. There were significantly fewer Bacteroides and Clostridium subcluster XIVab, and the amount of Enterococcus was higher in UC patients than in healthy subjects. The fecal concentration of organic acids was significantly lower in UC patients who were in remission.

Conclusion

UC patients have imbalances in the intestinal environment—less diversity of fecal microbiota, lower levels of major anaerobic bacteria (Bacteroides and Clostridium subcluster XIVab), and a lower concentration of organic acids.     

Myroides pelagicus from the Gut of Drosophila melanogaster Attenuates Inflammation on Dextran Sodium Sulfate-Induced Colitis

Background and Aim

Probiotics are live microorganisms that confer a health benefit on the host when administered in adequate amounts. In the present study, the putative probiotic strain was identified from the gut of Drosophila melanogaster and assessed for its protective effect in inflammatory bowel disease.

Methods

Active probiotics were screened from the Drosophila melanogaster gut by the selection criteria of gastric juice tolerance, hydrophobic property, antimicrobial potential, adhesion, and invasion properties. The active probiotics were identified by 16s rDNA sequencing and the effect of these active probiotics was evaluated in a Dextran sulphate sodium (DSS)-induced mice model by estimating inflammatory markers and histopathological changes.

Results

Nine Gram-positive and bile salt tolerant bacterial isolates were obtained from the gut samples. The isolates PTH 2, PTH 4, and PTH 7 clearly showed significant activity in antimicrobial potential, hydrophobic (>74 %) property, and intestinal juice tolerance. Among these, PTH 7 was selected for further studies due to its significant low-invasion ability and it proved capable of reducing the secretion of proinflammatory cytokines. The 16s rDNA studies revealed that PTH 7 was Myroides pelagicus. Administration of M. pelagicus to the DSS-induced colitic animals significantly suppressed myeloperoxidase, ALP, and malondialdehyde levels, and also lowered levels of proinflammatory cytokine expression. Further, the recovery from the disease by the probiotic treatment was supported by histopathological and macroscopic observation. The treated animals did not show any adverse signs in their physiology or behavior.

Conclusion

Myroides pelagicus successfully prohibited inflammatory markers and acted as a potent probiotic. Future studies with this stain might prove its efficacy as a drug for the management of colitis.     

Nutrition, Intestinal Permeability, and Blood Ethanol Levels Are Altered in Patients with Nonalcoholic Fatty Liver Disease (NAFLD)

Background

A role of an altered dietary pattern (e.g., a diet rich in sugar) but also alterations at the level of the intestinal barrier have repeatedly been discussed to be involved in the development and progression of nonalcoholic fatty liver disease (NAFLD).

Aims

To determine if the nutritional intake, intestinal flora, and permeability and the development of NAFLD are related in humans.

Methods

Ten controls and 20 patients with NAFLD ranging from simple steatosis to steatohepatitis were included in the study. Bacterial overgrowth, orocecal transit time, and intestinal permeability were assessed. Alcohol, endotoxin, and plasminogen activator inhibitor (PAI-) 1 concentration were determined in plasma. Nutritional intake was assessed using a dietary history.

Results

Despite no differences in the prevalence of bacterial overgrowth and in the orocecal transit time, intestinal permeability, alcohol, and endotoxin levels in plasma were significantly higher in patients with NAFLD than in controls. Similar results were also found for PAI-1 plasma concentrations. Patients with NAFLD had a significantly higher intake of protein, total carbohydrates, and mono- as well as disaccharides than controls. PAI-1, endotoxin, and ALT plasma levels were positively related to total protein and carbohydrate intake.

Conclusions

Taken together, our results indicate that intestinal permeability, endogenous alcohol synthesis, and nutritional intake are markedly altered in patients with NAFLD.     

Vegetarianism as a Protective Factor for Colorectal Adenoma and Advanced Adenoma in Asians

Background

Although epidemiologic and animal studies suggest a vegetarian diet protects against the development of colorectal cancer, the relationship between vegetarian diet and incidence of colorectal adenoma is not yet conclusive, especially for Asians.

Aim

The purpose of this study was to examine the protective effect of a vegetarian diet against colorectal adenoma and advanced adenoma.

Methods

This cross-sectional study compared the prevalence of colorectal adenoma among Buddhist priests, who are obligatory vegetarians, with that among age and sex-matched controls. All the subjects underwent health checkups in a health-promotion center in Korea.

Result

Colorectal adenoma and advanced adenoma were both more prevalent in the general population group than in the Buddhist priest group (25.2 vs. 17.9 %, 6.7 vs. 2.0 %). However, the prevalence of metabolic syndrome, high body mass index, and waist circumference were higher in the Buddhist priest group. According to univariate analysis, non-vegetarian diet (general population) significantly increased the prevalence of colorectal adenoma and advanced adenoma compared with a vegetarian diet (Buddhist priests) (OR 1.54, 95 % CI 1.08–2.21, P = 0.018; OR 3.60, 95 % CI 1.53–8.48, P = 0.003). In a conditional regression analysis model, non-vegetarian diet was also a significant risk factor for colorectal adenoma and advanced adenoma (OR 1.52, 95 % CI 0.75–2.07, P = 0.043; OR 2.94, CI 0.97–7.18, P = 0.036).

Conclusions

Vegetarianism may be effective in preventing both colorectal adenoma and advanced adenoma in Asians.     

Spleen and gastrosplenic ligament preserving distal pancreatectomy under a minimum incision approach assisted by laparoscopy

Background

As a modification of hand-assisted laparoscopic pancreatectomy, we devised a method of spleen and gastrosplenic ligament preserving distal pancreatectomy, in which pancreatic resection is performed under direct vision extracorporeally.

Methods

The distal pancreas and spleen are pulled out of the peritoneal cavity through the minilaparotomy at the epigastrium following hand-assisted laparoscopic dissection of the distal pancreas. Spleen-preserving pancreatectomy is performed safely under direct vision. The gastrosplenic ligament is also preserved to prevent splenic volvulus after the operation. The transected main pancreatic duct is doubly ligated, and the transected pancreatic stump is sewn manually. The preserved spleen and splenic vessels are placed back in the peritoneal cavity after resection.

Results

In the current study (n = 3), overall morbidity rate, including splenic volvulus and pancreatic fistula, was 0%.

Conclusion

Preservation of the gastrosplenic ligament and extracorporeal preparation of the transected pancreatic stump under direct vision are useful measures in spleen-preserving distal pancreatectomy under a minimum incision approach assisted by laparoscopy.     

Probiotics Can Alleviate Cardiopulmonary Bypass-Induced Intestinal Mucosa Damage in Rats

Background

Cardiopulmonary bypass (CPB) is commonly applied to support circulation during heart surgery but frequently causes adverse effects.

Aims

The purpose of this study was to examine the potential of probiotics to improve small intestinal mucosa barrier function after CPB.

Methods

Twenty-four adult male SD rats were randomly divided into sham-operated (S), CPB-operated (CPB), and probiotic-fed (Y) groups. Diamine oxidase (DAO) activity and concentrations of D-lactic acid, endotoxin, TNFα, and IL-6 were measured in portal vein blood. IgA concentrations were determined in plasma and the small intestine. Vena cava blood and tissue samples were used to monitor bacterial growth. Intestinal epithelial ultrastructure was analyzed by transmission electron microscopy (TEM). Occludin and ZO-1 expression levels in the intestinal epithelium were detected by western blotting and immunohistochemistry, respectively.

Results

D-lactic acid, endotoxin, TNFα and IL-6 levels, DAO activity, and bacterial translocation rate were increased (P < 0.05) in CPB and Y compared to the S group. The above indices were relatively lower (P < 0.05) in Y than in CPB. Plasma and small intestinal IgA levels were significantly lower (P < 0.05) in CPB, while in Y they were significantly increased (P < 0.05) but lower than in S (P < 0.05). These results were confirmed by TEM. Consistently, occludin and ZO-1 expression levels were significantly higher in Y than in CPB (P < 0.05) but still lower compared to S (P < 0.05).

Conclusion

Pre-administration of probiotics can improve, to some extent, intestinal barrier function after CPB in rats, and this effect is likely related to inhibition of the CPB-induced inflammatory response, improvement in local intestinal immune function, and increased expression of intestinal epithelial tight junction proteins.     

Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary

Aim/hypothesis

The aim of this study was to investigate the association between total and types of dairy product intake and risk of developing incident type 2 diabetes, using a food diary.

Methods

A nested case-cohort within the EPIC-Norfolk Study was examined, including a random subcohort (n?=?4,000) and cases of incident diabetes (n?=?892, including 143 cases in the subcohort) followed-up for 11 years. Diet was assessed using a prospective 7-day food diary. Total dairy intake (g/day) was estimated and categorised into high-fat (≥3.9%) and low-fat (<3.9% fat) dairy, and by subtype into yoghurt, cheese and milk. Combined fermented dairy product intake (yoghurt, cheese, sour cream) was estimated and categorised into high- and low-fat. Prentice-weighted Cox regression HRs were calculated.

Results

Total dairy, high-fat dairy, milk, cheese and high-fat fermented dairy product intakes were not associated with the development of incident diabetes. Low-fat dairy intake was inversely associated with diabetes in age- and sex-adjusted analyses (tertile [T] 3 vs T1, HR 0.81 [95% CI 0.66, 0.98]), but further adjustment for anthropometric, dietary and diabetes risk factors attenuated this association. In addition, an inverse association was found between diabetes and low-fat fermented dairy product intake (T3 vs T1, HR 0.76 [95% CI 0.60, 0.99]; p _trend?=?0.049) and specifically with yoghurt intake (HR 0.72 [95% CI 0.55, 0.95]; p _trend?=?0.017) in multivariable adjusted analyses.

Conclusions/interpretation

Greater low-fat fermented dairy product intake, largely driven by yoghurt intake, was associated with a decreased risk of type 2 diabetes development in prospective analyses. These findings suggest that the consumption of specific dairy types may be beneficial for the prevention of diabetes, highlighting the importance of food group subtypes for public health messages.     

Purified Micronized Flavonoid Fraction Ameliorates the Injury of Spleen and Ileum Secondary to Hepatic Ischemia–Reperfusion in Rats

Background

Flavonoids have been subjected to considerable investigations due to their antioxidant and anti-inflammatory properties. Yet the effects of flavonoids on the ileum and spleen against hepatic ischemia–reperfusion injury have so far not been addressed.

Aims

We aimed to investigate whether micronized purified flavonoid fraction (MPFF) protects the ileum and spleen against hepatic ischemia–reperfusion injury.

Methods

Rats were subjected to hepatic ischemia by clamping the hilar area of the rats for 60 min, followed by 60 min of reperfusion. Rats in the treatment group were treated with MPFF (80 mg/kg/day) by gavage for 3 days before surgery, 30 min prior to ischemia and just before the reperfusion. After the reperfusion period, all rats were sacrificed. Ileal and splenic tissues were taken for histological evaluation and determination of the total antioxidant capacity (TAC), catalase, total oxidant status (TOS), oxidative stress index (OSI) and myeloperoxidase (MPO) levels.

Results

TAC levels in the splenic tissue and intestinal tissue were significantly higher in the treatment group than in the control group (P < 0.01 for both). TOS, OSI, and MPO in splenic tissue (P < 0.01, P < 0.05, and P < 0.05, respectively) and intestinal tissue (P < 0.01, P < 0.01, and P < 0.001, respectively) were significantly lower in the treatment group than in the control group. Histological tissue damage of intestinal tissue was milder in the treatment group than in the control group.

Conclusion

The results of this study indicated that MPFF pretreatment significantly limited the injury to the small intestine and spleen induced by hepatic ischemia–reperfusion in rats.     

Campylobacter jejuni isolates in Finnish patients differ according to the origin of infection

Background

Recent epidemiological analyses have implicated acute Campylobacter enteritis as a factor that may incite or exacerbate inflammatory bowel disease (IBD) in susceptible individuals. We have demonstrated previously that C. jejuni disrupts the intestinal barrier function by rapidly inducing epithelial translocation of non-invasive commensal bacteria via a transcellular lipid raft-mediated mechanism ('transcytosis'). To further characterize this mechanism, the aim of this current study was to elucidate whether C. jejuni utilizes M cells to facilitate transcytosis of commensal intestinal bacteria.

Results

C. jejuni induced translocation of non-invasive E. coli across confluent Caco-2 epithelial monolayers in the absence of disrupted transepithelial electrical resistance or increased permeability to a 3 kDa dextran probe. C. jejuni -infected monolayers displayed increased numbers of cells expressing the M cell-specific marker, galectin-9, reduced numbers of enterocytes that stained with the absorptive enterocyte marker, Ulex europaeus agglutinin-1, and reduced activities of enzymes typically associated with absorptive enterocytes (namely alkaline phosphatase, lactase, and sucrase). Furthermore, in Campylobacter -infected monolayers, E. coli were observed to be internalized specifically within epithelial cells displaying M-like cell characteristics.

Conclusion

These data indicate that C. jejuni may utilize M cells to promote transcytosis of non-invasive bacteria across the intact intestinal epithelial barrier. This mechanism may contribute to the inflammatory immune responses against commensal intestinal bacteria commonly observed in IBD patients.     

Effect of Mediterranean diet on lipid peroxidation marker TBARS in obese patients with OSAHS under CPAP treatment: a randomised trial

Purpose

The aim of our study was to examine the possible effect of the Mediterranean diet on thiobarbituric acid reacting substances (TBARS) in obese patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS) who are under continuous positive airway pressure treatment.

Methods

Nine hundred patients were evaluated during a 1-year period (November 2008?COctober 2009), and 21 obese patients who met the inclusion criteria, with moderate to severe OSAHS based on overnight attended polysomnography, were included in the study. After randomisation, 11 followed the Mediterranean diet and 10 a prudent diet for a 6-month period. TBARS were measured in serum.

Results

TBARS levels decreased notably in both groups (p?p?>?0.05). There were significant differences in other characteristics. The Mediterranean diet group showed a greater reduction in weight (?10.8?±?3.8), body mass index (?3.9?±?1.6), waist circumference (?9.9?±?3.0) and percentage of body fat (?4.7?±?2.3) compared with the other group (?6.9?±?3.1, ?2.5?±?1.0, ?5.3?±?2.6 and ?2.2?±?1.5, respectively; p?Conclusions Our results showed that the Mediterranean diet did not reduce the TBARS more than the prudent diet.     

Protection from non-alcoholic steatohepatitis and liver tumourigenesis in high fat-fed insulin receptor substrate-1-knockout mice despite insulin resistance

Aims/hypothesis

Epidemiological studies have revealed that obesity and diabetes mellitus are independent risk factors for the development of non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma. However, the debate continues on whether insulin resistance as such is directly associated with NASH and liver tumourigenesis. Here, we investigated the incidence of NASH and liver tumourigenesis in Irs1 ^?/? mice subjected to a long-term high-fat (HF) diet. Our hypothesis was that hepatic steatosis, rather than insulin resistance may be related to the pathophysiology of these conditions.

Methods

Mice (8 weeks old, C57Bl/6J) were given free access to standard chow (SC) or an HF diet. The development of NASH and liver tumourigenesis was evaluated after mice had been on the above-mentioned diets for 60 weeks. Similarly, Irs1 ^?/? mice were also subjected to an HF diet for 60 weeks.

Results

Long-term HF diet loading, which causes obesity and insulin resistance, was sufficient to induce NASH and liver tumourigenesis in the C57Bl/6J mice. Obesity and insulin resistance were reduced by switching mice from the HF diet to SC, which also protected these mice against the development of NASH and liver tumourigenesis. However, compared with wild-type mice fed the HF diet, Irs1 ^?/? mice fed the HF diet were dramatically protected against NASH and liver tumourigenesis despite the presence of severe insulin resistance and marked postprandial hyperglycaemia.

Conclusions/interpretation

IRS-1 inhibition might protect against HF diet-induced NASH and liver tumourigenesis, despite the presence of insulin resistance.     

Immunogenicity of antigens from the TbD1 region present in M. africanum and missing from "modern" M. tuberculosis : a cross- sectional study

Background

Currently available tools cannot be used to distinguish between sub-species of the M. tuberculosis complex causing latent tuberculosis (TB) infection. M. africanum causes up to half of TB in West- Africa and its relatively lower progression to disease suggests the presence of a large reservoir of latent infection relative to M. tuberculosis.

Methods

We assessed the immunogenicity of the TbD1 region, present in M. africanum and absent from "modern" M. tuberculosis, in an ELISPOT assay using cells from confirmed M. africanum or M. tuberculosis infected TB patients without HIV infection in the Gambia.

Results

Antigens from the TbD1 region induced IFNγ responses in only 35% patients and did not discriminate between patients infected with M. africanum vs. M. tuberculosis, while PPD induced universally high responses.

Conclusions

Further studies will need to assess other antigens unique to M. africanum that may induce discriminatory immune responses.     

Nickel Free-Diet Enhances the Helicobacter pylori Eradication Rate: A Pilot Study

Background

The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach.

Aim

To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen.

Methods

Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet.

Results

All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups.

Conclusions

The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.