Consumption of dairy products and odds of ulcerative colitis: An Iranian case-control study.

The association between dairy product consumption and the risk of ulcerative colitis (UC) is not well elucidated. This case-control study examined the association between Iranian adults' dairy consumption and UC risk. We used a valid food frequency questionnaire to analyze dietary intakes in 340 patients with pathologically confirmed cases of UC and 782 controls as part of a case-control research. Pasteurized milk, cheese, and yogurt dietary intakes were calculated along with dairy products. Other variables were acquired using questionnaires. Study participants' mean (± SD) age and body mass index were 41.5 ± 14.1 years and 27.4 ± 4.77 kg/m2, respectively. After adjusting for potential variables, individuals who consumed more total dairy products were less likely to get UC than those who consumed less (odds ratio [OR]: 0.44; 95% confidence interval (CI): 0.24, 0.79). We found a significant reverse association between milk intake (OR: 0.13; 95% CI: 0.07-0.24) and yogurt intake (OR: 0.52; 95% CI: 0.29-0.91) and UC, after controlling for potential confounders. Also, no significant association was found between cheese and UC risk (OR: 1.38; 95% CI: 0.84-2.28). Higher consumption of total dairy products may reduce UC risk. To be specific, milk and yogurt are inversely associated with this disorder. However, no link was found between cheese intake and UC. Longitudinal observational studies, especially cohorts, are needed to further assess these associations.

The association between dietary patterns and disease severity in patients with ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease involving the colon and rectum. One of the most modifiable environmental factors affecting UC severity is the patient's dietary pattern. Although the role of dietary patterns on UC aetiology has been investigated previously, its relationship with disease severity has not yet been elucidated. This study examined the association between UC patients' dietary patterns and disease severity. This cross-sectional study was conducted in 340 UC patients. Using an FFQ, food patterns were assessed. Twenty-five food categories were categorised based on the similarity of the nutrient composition of the food using the factor analysis method. A simple clinical colitis activity index was used to determine disease severity. Three dietary patterns were identified based on the factor analysis: healthy, unhealthy and Western dietary pattern. After adjusting for potential confounding factors, patients who were in the highest tertile of healthy dietary pattern compared with the lowest tertile were 92 % less likely to have severe UC (OR: 0·08; 95 % CI: 0·03, 0·22). Also, those in the highest tertile of the Western dietary pattern were 3·86 times more likely to have severe UC than those in the lowest tertile (OR: 3·86; 95 % CI: 1·86, 8·00). Even after controlling for confounding variables, unhealthy dietary pattern did not increase the risk of severe UC. Our data indicate the beneficial role of healthy dietary pattern in amelioration of disease severity in UC patients. To confirm this association, more studies are needed, especially prospective cohort studies.

Intestinal microbiota changes pre- and post-fecal microbiota transplantation for treatment of recurrent Clostridioides difficile infection among Iranian patients with concurrent inflammatory bowel disease.

Introduction: Patients with inflammatory bowel disease (IBD) are at a greater risk for the recurrence of Clostridioides difficile infection (rCDI) that is triggered by intestinal microbiota dysbiosis. Fecal microbiota transplantation (FMT) has emerged as a highly effective therapeutic option for this complication. However, little is known about the impact of FMT on intestinal microbiota alterations in rCDI patients suffering from IBD. In this study, we aimed to investigate post-FMT intestinal microbiota alterations in Iranian rCDI patients with underlying IBD. Methods: A total of 21 fecal samples were collected including 14 samples pre- and post-FMT and 7 samples from healthy donors. Microbial analysis was performed by quantitative real-time PCR (RT-qPCR) assay targeting the 16S rRNA gene. The pre-FMT profile and composition of the fecal microbiota were compared to the microbial changes of samples collected 28 days after FMT. Results and discussion: Overall, the fecal microbiota profile of recipients was more similar to donor samples after the transplantation. We observed a significant increase in the relative abundance of Bacteroidetes post-FMT, compared to the pre-FMT microbial profile. Furthermore, there were remarkable differences between the microbial profile of pre-FMT, post-FMT, and healthy donor samples by PCoA analysis based on the ordination distance. This study demonstrates FMT as a safe and effective approach to restore the indigenous composition of the intestinal microbiota in rCDI patients and ultimately results in the treatment of concurrent IBD.

Evaluating macro- and micronutrients and food groups intake with the risk of developing inflammatory bowel disease: Is there any association?

Growing clinical evidence represented that certain dietary components are involved in inflammatory bowel disease (IBD) development and progression. This research, therefore, aimed to evaluate whether there exists any relationship between nutrients and IBD. This case-control study from 2017 to 2019 was performed on 145 newly diagnosed IBD patients and 145 BMI-, sex-, and age-matched healthy controls who were recruited from a hospital clinic. A validated 168-item food frequency questionnaire was completed by each participant. Anthropometric measurements and physical activity levels were measured for all participants. Stata software was used to analyze all data. Of the 234 study individuals who participated, 112 were IBD patients and 122 were healthy people. The higher amount of seafood and cholesterol was related to an increased risk of IBD and ulcerative colitis development; however, individuals who had a higher intake of calcium were less likely to have Crohn's compared to the healthy group. There was a positive relation between honey and jam, seafood, organ meats, salt, fruits on trees, fruit juice, olives, and nuts and the probability of IBD, but there was a negative association between refined grains, potatoes, salty snacks, legumes, dairy, and cruciferous and the probability of IBD. Higher consumption of seafood and cholesterol was positively connected with a higher risk of IBD development in the current case-control study. A substantial association was seen between honey and jam, seafood, organmeats, salt, fruit on trees, fruit juice, olives, and nut consumption and IBD developement.

High Prevalence Rate of Microbial Contamination in Patient-Ready Gastrointestinal Endoscopes in Tehran, Iran: an Alarming Sign for the Occurrence of Severe Outbreaks.

An alarmingly increasing number of outbreaks caused by contaminated gastrointestinal (GI) endoscopes are being reported as a particularly concerning issue. This study is the first large-scale multicenter survey to evaluate the contamination of GI endoscopes in Tehran, Iran. This multicenter study was conducted among 15 tertiary referral and specialized gastrointestinal settings. Reprocessed GI endoscopes were sampled by the sequence of the flush-brush-flush method. Bacterial and viral contamination, as well as antimicrobial resistance, were explored by culture and molecular assays. A total of 133 reprocessed and ready-to-use GI endoscopes were investigated. In phase I and phase II, 47% and 32%, respectively, of the GI endoscopes were determined to be contaminated. GI flora was the most prevalent contaminant isolated from GI endoscopes, in which the most predominant bacteria were Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, in both phase I and II evaluations. The majority of the isolated bacteria in the current study were considered multidrug-resistant organisms (MDROs). More importantly, we recovered carbapenem-resistant nonfermentative Gram-negative bacilli (CRNFGNB), carbapenem-resistant Enterobacterales (CRE), extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales (ESBL-E), multidrug-resistant Clostridioides difficile, vancomycin-resistant Enterococcus (VRE), and drug-resistant Candida spp. Disconcertingly, our molecular assays revealed contamination of some reprocessed GI endoscopes with hepatitis B virus (HBV), hepatitis C virus (HCV), and even HIV. This multicenter study indicates a higher-than-expected contamination rate among reprocessed and ready-for-patient-use GI endoscopes, which suggests a higher-than-expected endoscopy-associated infection (EAI) risk, and potentially, morbidity and mortality rate, associated with endoscopy procedures in Tehran, Iran. IMPORTANCE In the light of severe outbreaks caused by multidrug-resistant microorganisms due to contaminated GI endoscopes, understanding to what extent GI endoscopes are inadequately reprocessed is crucial. Several studies assessed contamination of GI endoscopes with various outcomes across the world; however, the prevalence and risk factors of contaminated GI endoscopes and potential subsequent nosocomial spread are still unknown in Iran. The present study is the first large-scale multicenter survey to evaluate the microbial contamination of repossessed and ready-to-use GI endoscopes in Tehran, Iran. Our study showed a higher-than-expected contamination rate among reprocessed GI endoscopes, which suggests potential seeding of deadly but preventable outbreaks associated with endoscopy procedures in Iran. These results suggest that the current reprocessing and process control guidelines do not suffice in Iran. The current study is of particular importance and could provide insights into unrecognized and unidentified endoscopy-associated outbreaks in Iran.

High prevalence of SARS-Coronavirus-2 in patients with inflammatory bowel disease and the role of soluble angiotensin converting Enzyme2.

Context: Patients with inflammatory bowel disease (IBD) were found to have the higher intestinal expression of Angiotensin-Converting Enzyme2 (ACE2) that could consequently increase susceptibility to COVID-19 infection.Objective: This study reports the outcomes of COVID-19 infection in a large cohort of IBD patients. We compare levels of serum ACE and IFN-α between COVID19 patients with and without IBD. We performed a cross-sectional retrospective multicenter study.Methods: We enrolled patients with IBD screened for SARS-COV-2 in six medical centres in Iran from June to November 2020. The blood samples were drawn to measure COVID-19 IgM and IgG, and serum levels of sACE2, sACE1, and interferon-α, regardless of suspicious symptoms have done the molecular test.Results: A total of 534 IBD patients were included in the study. Of these, 109 (20.0%) cases had detectable IgG and IgM against SARS-CoV-2. sACE2 levels were higher in IBD patients than controls, whereas ACE1and IFN-α levels were similar among groups.

Serological response to SARS-CoV-2 is attenuated in patients with inflammatory bowel disease and can affect immunization.

In this study we indicated that impaired serological responses to SARS-CoV-2 infection among patients with IBD, could have significant implications for this group of patients and should be considered in vaccination program.

Carriage of CdtB Encoding Campylobacter spp., Salmonella enterica, and Yersinia entercolitica in Patients with Gastroenteritis and Irritable Bowel Syndrome.

INTRODUCTION: Cytolethal distending toxin (Cdt) is one of the bacterial toxins that present in a variety of gram-negative human pathogens, such as E. coli, Salmonella spp., and Campylobacter spp. CDT is composed of three subunits encoded by three adjacent genes, including cdtA, cdtB, and cdtC. cdtB has been shown to have toxic activity and cause DNA damage in host cells. Despite its presence in different bacterial species, the role of CdtB in acute and chronic infections, such as gastroenteritis and irritable bowel syndrome (IBS), is unclear. To analyze this correlation, we studied the prevalence of cdtB among different enteropathogenic bacteria in patients with gastroenteritis and IBS compared with healthy people. MATERIALS AND METHODS: In this cross-sectional descriptive study, 230 stool samples were collected from patients with gastroenteritis, IBS, and healthy people. The presence of CdtB encoding bacteria, including Escherichia coli, Campylobacter spp., Yersinia entercolitica, Providencia alkalifacience, and Salmonella enterica, was examined by polymerase chain reaction using genus-specific primers. RESULTS: Out of 230 stool samples, CdtB encoding Campylobacter spp. were found in 34.6% (52/150), 6.25% (5/80), and 4% (2/50) of the patients with gastroenteritis, IBS, and the control group, respectively. Carriage of CdtB encoding Salmonella enterica was characterized among 5.3% (8/150) of the patients with gastroenteritis and 17.5% (14/80) of the IBS patients. Although none of the patients carried CdtB encoding E. coli and Providencia spp., cdtB of Y. enterocolitica was detected in one of the patients with gastroenteritis (0.6%). Statistical analysis showed significant correlation between infection with CdtB encoding Campylobacter spp. and IBS-D subtype. No significant correlation was found between infection with CdtB encoding bacteria and other clinical and demographic data. CONCLUSION: Our results confirmed a relatively higher frequency of CdtB encoding bacteria in the intestine of patients with gastroenteritis and those with IBS compared with healthy individuals. Regarding the frequency of CdtB encoding Salmonella and Campylobacter bacteria, it was proposed that infection with these enteropathogens could be considered a risk factor for the development or progression of IBS among Iranian patients. Further studies are needed to establish this involvement.

The effect of low FODMAP diet with and without gluten on irritable bowel syndrome: A double blind, placebo controlled randomized clinical trial.

BACKGROUND & AIM: Although the effects of low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet on amelioration of irritable bowel syndrome (IBS) symptoms have been reported previously, it has not yet been elucidated whether the gluten of wheat and barley induces the symptoms or only their fructans lead to aggravation of the symptoms. The aim of this study was to assess the effect of low FODMAPs diet with vs. without gluten on clinical symptoms in IBS patients. METHODS: In this double-blind, placebo-controlled randomized trial, forty nine IBS patients were randomly assigned to placebo and/or intervention group. Patients in the intervention group received 5 gr/day of gluten powder with low FODMAP diet, while placebo group received 5 gr of rice flour as placebo, with low FODMAP diet. Quality of life (QoL) and IBS-SSS (symptom severity score) were measured before and after the intervention using a valid QoL questionnaire and a standard visual analog scale, respectively. RESULTS: Significant improvements were observed in total scores of IBS-SSS (-32% vs. - 49%), abdominal pain intensity (-45% vs. -52%), and frequency (-26 vs. -46%), abdominal distension (-29% vs. -63%), Interference with community function (-14% vs. -45%) and quality of life (+23 vs. +32%) in both gluten and placebo groups respectively (P < 0.05). Only 5 patients in the gluten-containing diet reported exacerbation of their symptoms. CONCLUSION: Exacerbation of IBS symptoms after wheat and barley consumption is due to their fructan, and not related to their gluten content in most of the patients. CLINICAL TRIAL REGISTRATION NO: IRCT20100524004010N29.

Small Intestine Perforation in a 69-Year-Old Man with COVID-19.

Coronavirus disease 2019 (COVID-19) had caused pandemia with a high rate of mortality and morbidity. Lung involvement is the main cause of mortality, but central nervous system and cardiac disease, and thromboemboli may participate in increasing mortality. A wide spectrum of organs involvement and complication has been reported as data gathering during the pandemia has progressed. We report a 69-year-old man who was admitted to Imam Khomeini hospital in Tehran and complained of severe abdominal pain and fever. He had been admitted 10 days earlier because of dyspnea and fever. At the first admission, based on the findings in the lung computed tomography (CT) and a positive nasopharyngeal polymerase chain reaction (PCR) test for COVID-19, he was treated with intravenous remdesivir for 5 days and prophylactic anti-coagulant heparin during hospital admission. Two days before the new admission, he was discharged with relative recovery. During the new admission, because of the absence of hypoxemia and leukocytosis diagnostic approach to abdominal pain was planned. In abdominal imaging, evidence of bowel perforation appeared. In laparotomy, suppurative peritonitis and proximal jejunal perforation without definite etiology were seen, and bowel resection and primary anastomosis were done. After 5 days, the patient was discharged in good condition. This case is reported to inform that bowel perforation due to ischemia or vasculitis may complicate the course of COVID-19 and, in cases of gastrointestinal symptoms, should be considered.

Malakoplakia as a Rare Cause of Diarrhea: Case Presentation and Review of Literature.

Colonic malakoplakia is a rare chronic granulomatous disease that can involve many organs such as the lung, brain, pancreas, bone, adrenal glands, and genitourinary tract. The most common site of involvement outside the genitourinary tract is the gastrointestinal tract. We report a case of colonic malakoplakia who presented with unintentional weight loss, abdominal pain, and chronic diarrhea. There was a history of lupus nephritis and Sjogren disease, receiving various immunosuppressive drugs. Physical examination other than pallor was unremarkable in this patient, but colonoscopy revealed multiple polyps in the rectum with a cobblestone appearance in the cecum. The histopathological assessment showed infiltration of numerous lymphoplasma cells and neutrophils in the lamina propria, and rare Michaelis-Gutmann bodies were seen in foamy epithelioid histiocytes. These findings are suggestive of malakoplakia. We treated the patient with tetracycline, and after 3 months of follow-up, clinical improvement was achieved.

Fecal microbiota transplantation for recurrent Clostridioides difficile infection in patients with concurrent ulcerative colitis.

Treatment of recurrent Clostridioides difficile infection (rCDI) has emerged as an important management dilemma particularly in patients with underlying inflammatory bowel disease (IBD). Fecal microbiota transplantation (FMT) has been used as a safe and highly effective treatment option for rCDI refractory to standard antibiotic therapies. The aim of this study was to report the efficacy of FMT in Iranian rCDI patients with concurrent IBD. A total of seven consecutive patients with ulcerative colitis (UC) who had experienced 3 episodes of rCDI were enrolled in this study. All patients received at least a single FMT administered during colonoscopy by direct infusion of minimally processed donor stool. Patients were followed for a minimum of 6 months for assessment of treatment efficacy and adverse events (AEs) attributable to FMT. All 7 UC patients (100%) experienced a durable clinical response to a single FMT following 2 months after the procedure. One patient received a second FMT in which a successful resolution of rCDI was ultimately achieved. No serious AEs from FMT were noted. FMT through colonoscopy was a safe, simple and effective alternative treatment approach for rCDI in patients with underlying IBD. However, its use and efficacy should be pursued in long-term prospective controlled trials.

Effects of coenzyme Q10 on health-related quality of life, clinical disease activity and blood pressure in patients with mild to moderate ulcerative colitis: a randomized clinical trial.

Background: Ulcerative colitis (UC) is specified by a chronic mucosal inflammation that has a deleterious impact on the quality of life (QoL). Coenzyme Q10 (CoQ10) appears to influence disease activity by its obvious properties. Therefore, the current research intends to assess the impacts of CoQ10 on QoL, disease activity, and blood pressure in UC patients. Methods: This clinical trial performed on men and women with UC in 2017 who were attended the gastrointestinal center of Hazrat Rasool Akram Hospital and private clinic. Eighty-eight UC patients were randomly allocated to receive either CoQ10 (200 mg/day) or placebo for 8 weeks. The anthropometric parameters, blood pressure, inflammatory bowel disease questionnaire-32 (IBDQ-32) score, and the Simple Clinical Colitis Activity Index (SCCAI) score were measured pre and post-intervention. P-value <0.05 was considered to be statistically significant. All statistical analysis was done using SPSS software version 24. Results: Eighty-six UC patients (44 males) with a mean age of 39.29 (10.19) years completed the trial. The results of between- and within-group analysis revealed that the SCCAI score (p<0.001 and p<0.001, respectively), diastolic blood pressure (p=0.025 and p=0.001, respectively), and systolic blood pressure (p=0.001 and p<0.001, respectively) decremented significantly; while, the mean IBDQ-32 (p<0.001 and p=0.001, respectively) increased substantially in the CoQ10 group; whereas there was no significant difference in anthropometric indices in both groups. Conclusion: Findings suggest that CoQ10 can be used as a potential intervention for diminishing the disease severity and blood pressure and may improve QoL and UC patients. IRCT number: IRCT20090822002365N17.

A randomized controlled trial on the coloprotective effect of coenzyme Q10 on immune-inflammatory cytokines, oxidative status, antimicrobial peptides, and microRNA-146a expression in patients with mild-to-moderate ulcerative colitis.

PURPOSE: Coenzyme Q10 (CoQ10), having potent antioxidant and anti-inflammatory pharmacological properties, has recently been shown to be a safe and promising agent in maintaining remission of ulcerative colitis (UC). This trial was, therefore, designed to determine CoQ10 efficacy on inflammation and antioxidant status, antimicrobial peptides, and microRNA-146a expression in UC patients. METHODS: In this randomized double-blind controlled trial, 88 mild-to-moderate UC patients were randomly allocated to receive CoQ10 (200 mg/day) or placebo (rice flour) for 2 months. At the baseline and at an 8-week follow-up, serum levels of Nrf2, cathelicidin LL-37, ß-defensin 2, IL-10, IL-17, NF-κB p65 activity in peripheral blood mononuclear cells (PBMCs), simple clinical colitis activity index questionnaire (SCCAIQ), and quality of life (IBDQ-32 score), as well as an expression rate of microRNA-146a were measured. RESULTS: A significant reduction was detected in the serum IL-17 level, activity of NF-κB p65 in PBMCs, and also SCCAI score in the CoQ10 group compared to the placebo group, whereas IL-10 serum concentrations and IBDQ-32 score of the CoQ10 group considerably increased versus the control group; the changes of these variables were also significantly different within and between groups at the end of the study. Furthermore, CoQ10 remarkably increased serum levels of cathelicidin LL-37. A significant change in serum cathelicidin LL-37 levels was also observed between the two groups. No statistical difference, however, was seen between the two groups in terms of the serum levels of Nrf2 and ß-defensin 2 and the relative expression of microRNA-146a. CONCLUSIONS: Our results indicate that CoQ10 supplementation, along with drug therapy, appears to be an efficient reducer of inflammation in patients with mild-to-moderate UC at a remission phase. TRIAL REGISTRATION: The research has also been registered at the Iranian Registry of Clinical Trials (IRCT): IRCT20090822002365N17.

Glutamine Supplementation Enhances the Effects of a Low FODMAP Diet in Irritable Bowel Syndrome Management.

Background and Aims: Although irritable bowel syndrome is one of the most common gastrointestinal disorders presented to gastroenterologists, therapeutic strategies are not yet well-established. Accordingly, we conducted a randomized, double-blind, placebo-controlled, clinical trial to evaluate the possible superiority of adding glutamine supplement to low fermentable oligo- di- monosaccharides and polyols (FODMAP) diet in patients with irritable bowel syndrome (IBS). Methods: Eligible adults were randomized to receive a low FODMAP diet either with glutamine (15 g/day) or a placebo for 6 weeks. The primary endpoint was a significant reduction in IBS-symptom severity score (IBS-SSS). Secondary endpoints were changes in IBS symptoms, stool frequency, consistency, and quality of life. Results: The study group enrolled 50 patients, among which 22 participants from each group completed the study protocol. The glutamine group had significant changes in total IBS-severity score, dissatisfaction of bowel habit and interference with community function (58% reduction; P < 0.001, 57% reduction; P < 0.001, 51% reduction; P = 0.043, respectively). Improvement in IBS-severity score of more than 45% was observed in 22 of 25 participants (88%) in the glutamine group, while it was only 15 of 25 participants (60%) in the control group (p = 0.015). No serious adverse events were observed. Conclusions: Our findings indicated the superiority of adding glutamine supplementation to a low FODMAP diet in amelioration of IBS symptoms while confirming the beneficial effects of a low FODMAP diet in IBS management.

Colonic Mucosal Infiltration of IgG4 Plasma Cells and Ulcerative Colitis: Determinant of Presence, Activity, Extension, and Duration of Disease.

BACKGROUND Infiltration of IgG4 positive plasma cells has been detected in the colonic mucosa of patients with ulcerative colitis (UC). The aim of the study was to investigate the association between colonic mucosal infiltration of IgG4 plasma cells and the presence, activity, extension, and duration of UC. METHODS In this case-control study (2009-2014), 102 subjects (84 with UC/18 controls) were enrolled. Clinical records and rectosigmoid biopsies of UC patients were selected, and biopsies were stained with IgG4 monoclonal antibodies. IgG4 positive plasma cells were counted by a single pathologist. RESULTS Amongst 84 patients with UC, 73.8% had UC without primary sclerosing cholangitis (PSC), and 26.2% had UC with PSC. IgG4 plasma cells were seen in 35 (41.7%) patients with UC and 0% of controls (p = 0.001). The mean amount of IgG4 containing plasma cells was significantly different between active and inactive patients with UC, although it was not significantly different between UC patients with and without PSC. The presence of IgG4 infiltration was significantly associated with the extension and duration of the disease. Furthermore, IgG4 count had a sensitivity/specificity of 78.6%/83.3% for the diagnosis of UC. CONCLUSION Our study revealed the diagnostic role of IgG4 plasma cells in the colonic mucosa of patients with UC and its association with activity, extension, and duration of disease.

Association of Dietary Fiber, Fruit, and Vegetable Consumption with Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

No previous investigation has summarized findings from prospective cohort studies on the association between dietary intake of fiber, fruit, and vegetables and risk of inflammatory bowel disease (IBD). Dietary fiber and its major sources can influence the risk of IBD by modulation of the gut microbiota. This study summarizes findings from published cohort studies on the association between dietary fiber, fruit, and vegetable consumption and risk of IBD. Relevant articles published up to January 2019 were searched via PubMed, MEDLINE, Scopus, Embase, Cochrane Library, and Google Scholar. All prospective cohort studies investigating the association between dietary fiber, fruit, and vegetable intake and risk of IBD were included. Combining 7 effect sizes from 6 studies, no significant association was found between dietary intake of fiber and risk of ulcerative colitis (UC) (RR: 1.09; 95% CI: 0.88, 1.34). However, a significant inverse association was found between dietary fiber intake and risk of Crohn disease (CD) (RR: 0.59; 95% CI: 0.46, 0.74), based on 5 studies with 6 effect sizes. Pooling information from 4 studies, we found a significant protective association between dietary intake of fruit and risk of UC (RR: 0.69; 95% CI: 0.55, 0.86) and CD (RR: 0.47; 95% CI: 0.38, 0.58). We also found a significant inverse association between vegetable consumption and risk of UC (RR: 0.56; 95% CI: 0.48, 0.66) and CD (RR: 0.52; 95% CI: 0.46, 0.59). In conclusion, dietary intake of fruit and vegetables was inversely associated with risk of IBD and its subtypes. Dietary fiber intake was also inversely associated with incidence of IBD and CD, but not with UC. Further studies are warranted to examine the association of other fiber-rich foods with IBD.

Analysis of Killer Cell Immunoglobulin-Like Receptor Genes and Their HLA Ligands in Inflammatory Bowel Diseases.

Genetic studies have illustrated that killer cell immunoglobulin-like receptor (KIR) genes could participate in various autoimmune disorders. We aimed to clarify the role of KIR genes, HLA ligands, HLA-KIR interactions, and their genotypes in inflammatory bowel disease (IBD) susceptibility. The study population was composed of 183 IBD subjects, comprising 100 ulcerative colitis (UC) patients, 83 Crohn's disease (CD) patients, and 274 healthy subjects. Polymerase chain reaction with sequence-specific primers (PCR-SSP) was used to evaluate the absence or presence of the 15 KIR genes, 5 HLA class I ligands, and 2 pseudogenes. We did not find any significant difference in allele frequency of KIRs and pseudogenes between IBD patients and healthy controls. In the case of HLA genes, there was a significant difference in HLA-B-Bw4Thr80 frequency between UC patients and healthy controls (P = 0.03, OR = 0.06, 95%CI = 0.008-0.4). Furthermore, we found a significant difference in HLA-C1Asn80 frequency between CD patients and healthy controls (P = 0.04, OR = 0.49, 95% CI = 0.3-0.8). In the full-array combination of KIR genes, there was no significant frequency difference between UC patients and healthy controls, while two KIR genotypes showed a significant susceptible association with CD. Our data do not support a strong role of NK cells in IBD susceptibility, but it does not rule out a role for KIR variability in IBD patients. However, there are some protective associations such as Bw4 alleles; these associations may be due to the interaction of the alleles to TCRs rather than KIRs.