Nutrition Assessment and Management in Celiac Disease

Celiac disease (CeD) is the most common immune condition affecting the gastrointestinal tract; it is triggered by gluten and the only available treatment is a strict gluten-free diet (GFD). Therefore, for patients with CeD, adopting a GFD is not a lifestyle choice. The major problem is that a GFD is restrictive and, like all restrictive diets, it has the potential for adverse nutritional outcomes, especially if adopted for a long term. It is well known that GFD can be nutritionally inadequate and is frequently associated with vitamin and mineral deficiencies; it is also associated with excessive sugar and fat intake, particularly when gluten-free substitutes are consumed. Consequently, people with CeD are affected by higher rates of overweight and obesity and metabolic complications, such as fatty liver and cardiovascular disease. Therefore, assessment of nutritional status and diet quality at diagnosis and while on a long-term GFD is key in the management of CeD. This narrative review addresses nutritional considerations in CeD and management of common challenges associated with a GFD.

A19 INVESTIGATING MECHANISMS THAT DRIVE SYMPTOMS IN IRRITABLE BOWEL SYNDROME PATIENTS WITH PERCEIVED GLUTEN SENSITIVITY

Background

Patients with irritable bowel syndrome (IBS) often report gastrointestinal symptoms after consuming wheat and gluten-containing foods. It is, however, unclear whether gluten is the main driver of symptoms, as other immunogenic peptides, such as amylase trypsin inhibitors (ATI), poorly digestible fiber (inulin, part of FODMAP) or even the nocebo effect may contribute to symptom generation.

Purpose

To evaluate whether whole wheat containing ATIs and/or purified gluten trigger gastrointestinal symptoms compared to nocebo in patients with IBS adopting a gluten-free diet (GFD).

Method

We conducted a double-blind, randomized, nocebo-controlled crossover study in adult IBS patients (Rome IV criteria) who previously perceived improvement of symptoms while on a GFD. The study was approved by the Hamilton Research Ethics Board (HiREB #4367). Participants were challenged for 7 days with whole wheat, purified gluten, and nocebo (gluten-free flour) added to low FODMAP cereal bars. Each challenge was followed by a 2-week washout. Patients remained on a GFD throughout the study, diet adherence was assessed by a dietitian and stool gluten immunogenic peptides (GIP; Biomedal). Gastrointestinal symptoms were assessed by IBS Symptom Severity Score (IBS-SSS); increases >50 points were considered a significant worsening. Blood samples were collected to assess immune markers and celiac (HLA DQ2, DQ8 and DQ7) genotype. Statistical comparisons used Friedman rank sum tests and paired Wilcoxon signed rank tests.

Result(s)

Twenty-nine IBS patients (27 female, mean age=42, SD=14.4 years) were enrolled in the study; 1 dropped. Similar proportions of patients reacted symptomatically to wheat (11/28, 39.3%), gluten (10/28, 35.7%) and nocebo (8/28, 28.6%). However, there was an overall significant increase in IBS symptoms after wheat (+39.5 on IBS-SSS; p=0.030) but not after gluten (+27.5; p=0.051) or nocebo (+5.5; p=0.236) challenges (Figure 1). Ten participants experienced IBS-SSS symptoms >175 during baseline and did not worsen further during the challenges. TNF-α trended from 1.35 pg/mL after nocebo, 1.47 pg/mL after gluten, to 1.57 pg/mL after wheat; however, this was not significant. Baseline adherence to a GFD was rated excellent in 19 (68%), good in 6 (21%), and fair in 3 (11%) participants. Median GIP levels were 0.584 µg/g after wheat, 0.432 µg/g after gluten, and 0.095 µg/g after nocebo; p<0.0001. Celiac predisposition genes were present in 19/24 participants (10/24 had DQ2, 2/24 had DQ8, and 9/24 had DQ7).

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Conclusion(s)

IBS patients self-reporting wheat or gluten sensitivity had worse symptoms after whole wheat, but not purified gluten or nocebo challenge. However, similar proportions of IBS patients reacted to each intervention, suggesting that central mechanisms play an important role in symptom genesis. Furthermore, one third of patients had high symptoms during a GFD and did not react to wheat or gluten challenges, suggesting that other mechanisms are driving their IBS symptoms.

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CIHR, Other

Please indicate your source of funding;

Society for the Study of Celiac Disease (Nestle); Canadian Digestive Health Foundation

Disclosure of Interest

None Declared

A13 THE RATE OF ADVERSE EVENTS AFTER COVID-19 VACCINATION IS SIMILAR IN PATIENTS WITH CELIAC DISEASE AND NON-CELIAC POPULATION: RESULTS OF A LARGE INTERNATIONAL CROSS-SECTIONAL STUDY

Background

Patients with celiac disease (CeD) reported increased COVID-19 vaccine hesitancy due to a fear of adverse events (AEs). However, the risk of AEs post-COVID-19 vaccination in patients with CeD is unknown.

Purpose

To assess whether the rate of common side effects (SEs) and AEs due to COVID vaccines are higher in patients with CeD compared to a non-CeD population.

Method

We conducted a collaborative international cross-sectional study in 16 countries between April 2022 and July 2022. An online survey was distributed to patients with CeD through patients’ local societies, and to non-CeD from the general population in each country through social media posts, word-of-mouth, and through academic institutions. We collected data on participant demographics, medical conditions, CeD diagnosis, GFD adherence, history of COVID-19 vaccinations (type and doses) and self-reported SEs and AEs post-COVID-19 vaccine. SEs included pain/swelling at the site, fatigue, fever, chills, nausea and/or headaches. AEs included thrombosis, myocarditis, anaphylactic reaction, and hospitalization related to the vaccine. Logistic regression models were used to assess predictors such as CeD diagnosis, age, gender, vaccine type and comorbidities on the likelihood of reporting SEs and AEs post-vaccine.

Result(s)

: A total of 17,795 participants completed the survey, 13,638 with CeD (median age of 45[27]) and 4,157 non-CeD controls (median age of 43[20]). There were no significant differences in sex between CeD and controls. Overall, CeD patients had similar odds of SEs compared with non-CeD individuals (aOR=1.02;95% CI=0.92-1.14). SEs were slightly increased only in the second dose of the vaccine in the CeD population compared to non-CeD individuals (aOR= 1.35; 95% CI=1.19-1.53). The most common reported SEs in CeD and controls were pain/swelling at the injection site (29% vs 23 %, p< 0.0001) and fatigue (29% vs 24%, p<0.0001). The odds of SEs were higher with Moderna Spikevax, AstraZeneca/Oxford and Johnson and Johnson vaccines than after the Pfizer vaccine (p< 0.0001). The overall rate of AEs post-vaccine was similar between patients with CeD and non-CeD individuals (aOR= 1.29; 95% CI= 0.89-1.87). Overall, female gender, older age, GFD adherence, respiratory conditions, obesity and receiving immunosuppressive medications increased the odds of SEs, while only age and a history of allergies increased the odds of AEs.

Conclusion(s)

In this large international study, patients with CeD reported similar rates of SEs and AEs post-COVID vaccine compared to non-CeD individuals. This information is highly relevant as it addresses the main concern leading to COVID-19 vaccine hesitancy in CeD patients.

Disclosure of Interest

None Declared

A248 THE ROLE OF DIETARY TRYPTOPHAN IN INDOLE AND KYNURENINE PRODUCTION AND IMMUNE MODULATION IN HEALTHY INDIVIDUALS

Background

Natural supplements are widely consumed by the general public, with little evidence of mechanistic support. Tryptophan has gained central attention, being transformed by host and gut microbial enzymes into multiple bioactive metabolites that regulate immunity and mood. Indoles are activators of the aryl hydrocarbon receptor (AhR), crucial for the maintenance of intestinal homeostasis. Tryptophan has been advocated to prevent chronic inflammatory conditions, however the clinical data to support this are missing.

Aims

To investigate clinical, immune, and metabolic parameters in response to tryptophan supplementation, in healthy subjects on a low tryptophan diet.

Methods

We performed a randomized, double blind, placebo-controlled crossover study in 20 healthy volunteers (18 - 75 years old). Subjects were instructed to start a low tryptophan diet and then randomly assigned to a 3-week tryptophan supplementation (3g/day) or placebo, in enteric coated capsules. After a 2-week washout period, subjects crossed over to the opposite intervention arm. Questionnaires were used to assess bowel symptoms, anxiety, depression and stress levels (GSRS, HADS and DASS21, respectively). Stool, urine, blood and duodenal aspirates were collected to measure tryptophan metabolites and cytokines.

Results

Tryptophan supplementation had no changes in gastrointestinal symptoms or behavioral parameters. Compared with placebo, tryptophan increased urinary and plasma levels of indoleamine 2,3-dioxygenase/kynurenine (p= 0.002 and p= 0.02, respectively) and indoles (p= 0.001 and p= 0.01, respectively), suggestive of activation of host and microbial metabolic pathways. Urinary and plasma metabolites were higher than in feces (p=<0.05), suggesting their active absorption in the small intestine. There were no differences in AhR activity in duodenal aspirates or in stool. Although no changes in the cytokine production were detected, serum kynurenine pathway metabolites negatively correlated with IL-8 levels (R=-0.72; p=0.001). Fecal tryptophan metabolites levels positively correlated with anxiety and depression scores, suggesting that the microbial metabolism of dietary tryptophan in the colon impacts host behavior.

Conclusions

Tryptophan supplementation in healthy individuals was safe and had a measurable influence on microbial and host metabolism, mainly kynurenine and indole pathways, with known immunomodulatory properties. Tryptophan was metabolized and absorbed in the small intestine, reflected by the high metabolite levels in plasma and urine. Fecal metabolites correlating with clinical parameters reflect subjects’ long-term diet. Further studies are warranted to study tryptophan supplementation in disorders with altered AhR pathways.

Funding Agencies

CIHR

A255 INCREASED ENERGY EXPENDITURE AND REDUCED EXERCISE CAPACITY IN CELIAC DISEASE PATIENTS ON A GLUTEN-FREE DIET

Background

Celiac disease (CeD) patients often exhibit impaired nutritional status due to nutrient malabsorption and altered metabolism. Accurate clinical assessment of malnutrition, muscle function and energy requirements are thus essential to prevent and treat malnutrition. Indirect calorimetry (IC) is the most accurate method to measure energy needs, but it is underutilized in outpatient settings.

Aims

To assess the use of IC testing in estimating the resting energy expenditure and exercise-related energy utilization in treated CeD patients compared to patients with other gastrointestinal (GI) conditions.

Methods

Adult patients attending the Celiac and Nutrition Clinic at McMaster University that underwent rest and exercise testing as a part of their nutritional assessment were enrolled. CeD diagnosis was based on positive CeD serology and confirmed by biopsy, and all of them were on a GFD for at least 6 months. Patients with inflammatory bowel disease (IBD), functional gastrointestinal disorders (FGID) and undernutrition due to other causes (UN) were included as controls. Resting energy expenditure was assessed using 3

methods

1) predictive formula (25kcal/kg), 2) Harris Benedict and 3) estimation of VO2 by IC. Exercise capacity and energy expenditure (EE) during exercise was estimated at baseline, moderate and maximum exercise. Statistical analysis was performed using SPSS. ANOVA with Bonferroni corrections and Chi2 test were used to assess differences between continuous and categorical variables, respectively.

Results

A total of 66 patients (CeD n=24; IBD n=15; FGID n=17; UN n=10) were included in the analysis. The REE of GI patients measured using the HB equation and the predictive formula were significantly underestimated compared to IC [Mean Difference (MD)=229 kcal/day p=0.03 and MD=365 kcal/day p&lt;0.001, respectively]. The EE during exercise increased with intensity of exercise. CeD patients had the highest EE during moderate and strenuous exercise (Mean EE = 286 kcal/h and 494 kcal/h respectively) compared to patients with other GI conditions (Moderate and Strenuous for IBD= 218kcal/h and 373kcal/h; for FGIDs 296kcal/hand 467kcal/h, for UN, Mean EE = 181kcal/h and 294kcal/h). Exercise capacity was reduced in CeD compared to predicted exercise capacity (Mean = 86% predicted work capacity, range 72.5–107%), but was significantly higher than IBD (86% vs 73%; p=0.65) and UN patients (86% vs 46%; p=0.004).

Conclusions

Increased energy consumption and reduced exercise capacity is suggestive of chronic impaired nutritional status in treated CeD patients. Future studies with larger sample sizes are needed to understand whether incorporating accurate estimations of energy expenditure in nutritional practices can improve CeD outcomes.

Funding Agencies

CAG

A46 BIOGEOGRAPHIC VARIATION AND FUNCTIONAL PATHWAYS OF THE GUT MICROBIOTA IN CELIAC DISEASE

Background

Genes and gluten are necessary, but insufficient to cause celiac disease (CeD), as risk alleles (DQ2 or DQ8) are prevalent in ~30–40% of the healthy population consuming gluten. Gut microbiota shifts and infections have been proposed as risk modulators. Biogeographic characterization of the microbiota in CeD patients and its functional significance are limited, particularly at the duodenum, the main site of inflammation.

Aims

We studied microbiota composition and predicted function along the gastrointestinal tract and investigated the impact of host genetics and CeD activity.

Methods

We used 16S rRNA gene sequencing (Illumina) and predicted gene function analysis (PICRUSt2), to study the microbiota in duodenal biopsies (D1, D2 and D3), duodenal aspirates, and fecal samples from patients with active CeD (n= 24) (biopsy and serology confirmed) and controls (non-celiac, n= 41). CeD alleles were determined in consented participants using DQ-CD typing. Small intestinal samples from controls (DQ2^-/- = 14; DQ2^+/- = 7) and CeD (DQ2^+/- = 12) were used for further analysis and to colonize C57BL/6 germ-free mice for gluten metabolism studies.

Results

Microbiota community composition and predicted function was mainly determined by intestinal location (P= 0.001). Within the duodenum, but not in stool, CeD patients had increased abundance of opportunistic pathogens. Escherichia coli was increased in D1, Streptococcus pneumoniae in D2, and Neisseria in D3 versus controls. Predicted bacterial protease and peptidase genes were altered in CeD DQ2^+/- patients versus DQ2^-/- controls. In DQ2^+/- controls, fewer predicted bacterial genes were altered compared to CeD DQ2^+/- patients. Impaired capacity to metabolize gluten was confirmed in germ-free mice colonized with microbiota from CeD (DQ2^+/-), but not DQ2^+/- or DQ2^-/- controls.

Conclusions

In the duodenum, CeD is associated with increased opportunistic pathogens and altered bacterial proteolytic profile. These are not determined by genetic predisposition, as CeD and controls with similar genetic background differed in its predicted bacterial proteolytic function, which was confirmed in mice colonized with duodenal microbiota using these cohorts. Our study highlights the need for defining sampling location in studies investigating the role of microbiota in CeD.

Funding Agencies

CAG, CCC, CIHR

A251 USE OF INDIRECT CALORIMETRY TESTING TO DIRECT NUTRITION SUPPORT IN CRITICALLY ILL PATIENTS WITH GASTROINTESTINAL CONDITIONS

Background

Indirect calorimetry (IC), which measures oxygen uptake and carbon dioxide output, determines energy expenditure (EE) more precisely than predictive equations in critically ill patients. It is unknown whether the use of IC affects energy provision in critically ill patients with gastrointestinal (GI) conditions that affect absorption and digestion

Aims

To (1) compare IC and predictive equations for determining energy needs and (2) evaluate whether IC results affect changes in nutrition support in critically ill patients with GI conditions.

Methods

In a prospective, observational study, IC was performed for 25 to 55 mins in critically ill patients admitted to intensive care or clinical wards at 2 tertiary-care hospitals in Hamilton, Ontario between Feb 2018 to Sept 2021. EE measured by IC was compared to EE determined by a predictive equation (25 kcal/kg) or the Harris-Benedict (HB) formula. A change in energy provision was defined as a change of >10% directed by IC. Continuous data are expressed as means and standard deviation (SD), and categorical data as a proportion of patients. The Mann Whitney U Test (SPSSv26) was used to compare GI and non-GI populations.

Results

Of 296 IC tests in 229 patients, 39 of them were in 30 GI patients (11 female; mean age 62 yrs; SD 19). Admission GI diagnoses were pancreatitis (33%), liver disease (20%), Crohn’s disease/ autoimmune enteropathy (20%), post-bowel resection (10%), chronic abdominal pain (10%), and cholangitis (7%). The predictive formula underestimated EE in 67% of GI patients (mean deficit 503 kcal/day) compared to IC, corresponding to a mean deficit of 25% of patients’ energy needs. The HB formula underestimated EE in 73% of patients (mean deficit 652 kcal/day), a mean deficit of 28% of patients’ energy needs compared to IC. Pancreatitis was the majority diagnosis (75% of the predictive equation; 50% HB) among patients with the highest deficit (>30%) in energy needs when compared to IC. There were no significant differences in the rates of underestimation of energy needs based on predictive and HB formulas between the GI and non-GI patients or between luminal GI and non-luminal GI conditions. After IC, 63% of tests led to changes in energy provisions in GI patients; most requiring an increase in energy provisions (53%).

Conclusions

The use of IC to accurately measure EE led to changes in energy provisions in critically ill GI patients. Preventing over- and underfeeding with the implementation of IC to guide nutrition has the potential to improve outcomes in critically ill patients with gastrointestinal conditions.

Funding Agencies

None

A194 THE ADDITION OF DEAMIDATED GLIADIN PEPTIDE TO TISSUE TRANSGLUTAMINASE ANTIBODIES DOES NOT INCREASE THE ODDS OF CELIAC DISEASE DIAGNOSIS IN AN IGA SUFFICIENT POPULATION

Background

Previous studies proposed that the combination of IgA anti-tissue transglutaminase 2 IgA (TTG) and IgG deamidated gliadin peptide IgG (DGP) antibodies increases celiac disease (CeD) detection rates. However, this remains controversial.

Aims

To evaluate the performance of adding DGP to TTG antibodies, for the diagnosis of celiac disease (CeD) in the immunoglobulin A (IgA)-sufficient population.

Methods

We included consecutive patients with suspected CeD who had both TTG and DGP serology performed simultaneously from 2017–2020 in Hamilton, Canada. Chart review was performed by 3 reviewers to extract data on biopsies, diagnosis of CeD and genetic HLA-DQ2/DQ8. CeD was defined as positive serology (either TTG and/or DGP) and villous atrophy in duodenal biopsies (≥Marsh-3a). A case was defined as an instance of TTG and DGP performed at a single timepoint. A single patient could have represented multiple cases if TTG and DGP were measured at multiple time points. Sensitivity, specificity, negative and positive predictive values were calculated, and ROC curves were generated. Diagnostic odds ratios (DOR) assessed the performance of each serological strategy compared to duodenal biopsies.

Results

There were 580 patients constituting 823 cases that met inclusion criteria, of whom 441 had CeD. IgA-deficient patients (n=100) were excluded. Of the 723 cases remaining, 337 (214 adult;123 pediatric) had serology performed at the time of CeD diagnosis. TTG increased the odds of CeD diagnosis compared with DGP, Diagnostic Odds Ratio (DOR)=53.22 (95% CI 22.63–119.80) vs DOR=21.28 (95% CI 10.67–42.46). The addition of DGP to TTG did not increase the odds of CeD diagnosis [DGP+TTG DOR=51.39 (95% CI 19.36–135.61) vs TTG alone DOR=53.22 (95% CI 22.63–119.80)]. There were 37 discordant cases where only one of either TTG or DGP was positive. HLA-DQ2/DQ8 were absent in 2/9 cases with isolated increased DGP. Among the discordant cases, TTG outperformed DGP (DOR TTG= 4.29; 95% CI 1.09–16.83 vs DOR DGP=0.23; 95% CI 0.06–0.92).

Conclusions

In the IgA-sufficient population, the addition of DGP to TTG testing does not increase the diagnostic accuracy of CeD serologic screening. This has implications in health-care costs as false positive results prompt further investigations. Given these findings, larger prospective studies should be completed prior to adding DGP antibodies to routine TTG serology.

Funding Agencies

None

A34 GLUTEN-FREE DIET IMPROVES DYSPEPTIC SYMPTOMS IN PATIENTS WITH TYPE 1 DIABETES IN WHOM CELIAC DISEASE WAS EXCLUDED

Background

Patients with type 1 Diabetes Mellitus (T1DM) often suffer from dyspeptic symptoms, such as abdominal pain, bloating, early satiety, nausea and vomiting. T1DM shares genetic risk factors (HLA-DQ2 and DQ8) with celiac disease, an autoimmune disorder caused by an immune reaction to gluten. Patients with concomitant T1DM and celiac disease benefit from a gluten-free diet (GFD), as it improves their symptoms, gastric emptying and small intestinal inflammation. However, it is unknown whether GFD has any benefit in patients with T1DM without celiac disease, who present with symptoms of dyspepsia or gastroparesis.

Aims

To investigate the role of a GFD in the management of moderate to severe dyspeptic symptoms in non-celiac patients with T1DM.

Methods

We enrolled 13 adult T1DM patients, in whom celiac disease was ruled out, suffering from two or more upper GI symptoms. The patients were instructed to adhere to a strict GFD for a period of 1 month, under the supervision of a dietitian. Glycemic levels were monitored by a continuous glucose monitoring device (CGM) for 2 weeks before, and at the end of the GFD period. Standardized questionnaires were used to assess upper GI symptoms (Gastroparesis Cardinal Symptoms Index, Short Form Leeds Dyspepsia questionnaire), general quality of life (Patient Assessment of Upper GI Disorders Quality of Life), and anxiety and depression (Hospital Anxiety Depression scale). Blood samples were collected to assess glycaemia (Hb1Ac) and immune markers. Scintigraphy and videofluoroscopy were used to assess gastric emptying.

Results

After one month on a GFD, T1DM patients reported a significant improvement in nausea (p<0.05), sensation of fullness (p<0.001) and bloating (p<0.0001). Overall dyspepsia symptoms also improved (p<0.01), with 92% of patients reporting decreased dyspepsia scores. Moreover, there was an improvement in the quality of life (p<0.01), and decreased scores of anxiety and depression (p<0.01 and p<0.05, respectively). There were no changes in gastric emptying or glycemic management metrics, such as mean glucose level, time in target, glucose variance or HbA1c levels. Interestingly, one year after the end of the study, 63.6% of participants continued to follow a GFD. The most common reason to remain on a GFD reported by these patients was “because it improved GI symptoms”. Questionnaire data collected at the follow-up demonstrated that the improvement of dyspeptic symptoms persisted after 1 year on GFD (p<0.001).

Conclusions

GFD improves dyspeptic symptoms in T1D patients without concomitant celiac disease, without affecting their glycemic levels or gastric emptying. Although these results need to be validated in a larger study, our data suggest that GFD could be used as a therapeutical tool for T1DM patients grappling with burdensome upper GI symptoms.

Gluten-Free diet improves dyspepsia symptoms in Type 1 Diabetes patients, after 1 month and 1 year

Funding Agencies

CIHR

A192 CONSUMPTION OF FOOD LOWER IN TRYPTOPHAN IS ASSOCIATED WITH SIGNIFICANT ANXIETY IN PATIENTS WITH CELIAC DISEASE

Background

Tryptophan, an essential amino acid found in many protein-based foods, has been involved in the pathogenesis of mood disorders and celiac disease (CeD). However, dietary tryptophan consumption has not been investigated in CeD.

Aims

To estimate 1) differences in tryptophan content in food consumed in CeD patients compared to matched healthy controls (HC), and 2) whether consumption of tryptophan is associated with the presence of anxiety and depression in patients with CeD.

Methods

This prospective observational study examined adult patients with a diagnosis of CeD, based on positive specific serology and confirmed by duodenal biopsies, enrolled in the Celiac Registry at McMaster University. A group of sex matched HC were recruited from within the community. Participants completed several questionnaires to evaluate, gastrointestinal symptoms (GSRS), Anxiety and Depression (HADS), and dietary intake of tryptophan (Modified Food Frequency Questionnaire). In addition, CeD patients were assessed for celiac disease activity (CSI), gluten-free diet (GFD) adherence (CDAT) and nutritional status. HADs >11 denoted significant anxiety or depression. Cut-off for low vs high amount of tryptophan content in food was established based on the median tryptophan food content in the HC population.

Results

A total of 443 participants were enrolled in the study; 222 with CeD and 221 controls. The majority of participants were female (74.3%) and the adherence to the GFD was very good (Median CDAT=13; IQR 11–15). The CeD patients were older than HC (Median age, yrs. CD= 40 vs HC= 35; p<0.01). Patients with CeD consumed higher amount of tryptophan compared with HC (Median tryptophan g/day CeD=4.41 vs HC=3.31; p<0.01). There were 157 active CeD patients (CSI ≧ 30). There was no difference in tryptophan consumption between patients with and without active CeD (OR=1.021; 95%CI 0.86–1.21; p=0.88). There was no association between tryptophan consumption and gastrointestinal symptoms or depression scores. Fifteen % of the overall population and 18% of the CeD population had anxiety. There was an increased risk of anxiety in the overall population that consumed low amount of tryptophan (OR=1.87; 95%CI 1.01–3.11; p=0.04), and the risk was greater in the CeD population (OR=4.57; 95%CI 1.26–16.41; p<0.01).

Conclusions

Consumption of food with lower amounts of tryptophan in patients with CeD is associated with significant anxiety, which may influence disease management. Future studies should evaluate whether increasing tryptophan in the diet compared to supplements improves outcomes in CeD population, especially in those with anxiety.

Funding Agencies

None

A51 ROLE OF GUT MICROBIOTA IN THE EPISODIC NATURE OF SYMPTOMS IN IRRITABLE BOWEL SYNDROME

Background

Irritable bowel syndrome (IBS) is a complex functional gastrointestinal disorder with likely heterogenous pathophysiology, multiple symptoms, and comorbidities. Growing evidence shows that the gut microbiota composition and function are altered in IBS patients. However, identifying the critical drivers of clinical expression remains challenging due to the episodic occurrence of IBS symptoms, the inherent variability in composition of gut microbiota across individuals, and high sensitivity of gut microbiota to dietary and environmental cues.

Aims

To identify whether changes in gut microbiota composition accompany or, predict the occurrence of symptoms.

Methods

28 IBS patients (IBS-D n=20, IBS-C n=8) and 10 healthy controls (HC) were followed longitudinally for 25 weeks, collecting stool samples, and recording their symptoms weekly. Stool microbiota profiles were assessed by 16S rRNA gene sequencing using Illumina platform. The sequences were preprocessed, filtered, and annotated using DADA2 and phyloseq pipelines; statistical analyses were performed using FactomineR and microbiomeanalyst packages in R. Statistical significance was set at p<0.05.

Results

Multifactorial analysis of clinical data classified 950 samples in 6 clusters. Distribution of samples among the clusters was based on Bristol stool scale defining symptomatic periods (scores <3 and >4 indicating abnormal stool) and asymptomatic periods (scores 3 or 4), with several gut and mood symptoms varying significantly between the two categories. IBS-D patients, but not IBS-C patients presented with changes in symptoms severity, such as pain, diarrhea, constipation, and anxiety during the symptomatic periods. Depression scores were, however, higher in IBS-C compared to IBS-D patients. In contrast, immune makers such as fecal b-defensin-2 and calprotectin were higher during asymptomatic periods in IBS-D, but not in IBS-C patients. Bacterial diversity profiles differed among IBS patients (IBS-D and IBS-C) and HC, namely Shannon index and Bray-Curtis distance, but they did not change significantly between the symptomatic and asymptomatic periods within each subtype. Despite this, several bacterial taxa unique to each cluster were identified using linear mixed models.

Conclusions

Our results demonstrate the need to study patterns of co-occurrence of IBS symptoms and their severity during symptomatic and asymptomatic periods to better understand the role of identified bacterial taxa in the symptom generation. Identifying their temporal changes and cross-feeding patterns in individual patients will shed light on the underlying mechanistic role of gut microbiota in IBS, which might be otherwise obscured by group generalizations.

Funding Agencies

CIHR

A193 PERCEIVED BARRIERS TO GLUTEN-FREE FOOD ACCESS ON-CAMPUS EXPERIENCED BY STUDENTS FROM DIFFERENT CANADIAN UNIVERSITIES AND COLLEGES

Background

Students with gluten-related disorders (GRD), a spectrum of conditions including celiac disease (CeD) and non-celiac wheat sensitivity (NCWS), often experience challenges when accessing gluten-free (GF) foods.

Aims

To identify barriers perceived by students with GRD to access GF products on-campus of universities and colleges across Canada.

Methods

We conducted a cross sectional survey using the RedCap platform and distributed it to the Canadian Celiac Association community. We included students who reported adopting a GFD for various reasons including CeD and other GRD. We collected data on adherence to the GFD using a validated questionnaire (CDAT), presence of perceived barriers to follow a GFD while dining on campus, persistent symptoms, and altered quality of life. Continuous data are expressed as median (IQR), and categorical data as proportions of patients. Mann-Whitney U and Chi2 with Fisher correction were used to assess differences between groups.

Results

Seventy nine students responded to the survey (5% male and median age = 25 yrs) and 78 had complete data for analysis. Of the 78 students, 52 (66.6%) reported a diagnosis of CeD, while 26 were adopting a GFD for other reasons (non-CeD). The majority were enrolled in university programs (72/78) and 18% were living on-campus. Almost 90% reported difficulties maintaining a GFD while dining on-campus. Similar proportion of CeD and non-CeD reported eating gluten accidentally (75% vs 80%), while 15% reported eating gluten intentionally on-campus at least a few times per week. This was observed more frequently in non-CeD compared with students with CeD (61% vs 17%; p=0.04). Barriers identified in CeD versus non-CeD groups were related to a reduced GF-food variety (48% vs 69%), lack of availability of GF food (21% vs 46%) and increased cost (46% vs 81%) compared with gluten-containing counterparts. The majority of participants were concerned whether the food available on-campus was truly GF (80% vs 54%) as they reported foods not properly labelled. The majority of participants considered their overall health (79%) and quality of life (65%) was fair to terrible while dining on campus. During the pandemic, 76% of them perceived that it was easier to stick to a GF diet.

Conclusions

Students from various universities and colleges across Canada experience barriers to access GF food on-campus. This has a significant impact on their overall health and quality of life. Proper food labeling, GF certification and improving the variety of GF food on-campus are options for improvement.

Funding Agencies

None

Declining Use of Corticosteroids for Crohn's Disease Has Implications for Study Recruitment: Results of a Pilot Randomized Controlled Trial

Background

Corticosteroids (CS) have been used extensively to induce remission in Crohn’s disease (CD); however, they are associated with severe side effects. We hypothesized that the administration of an exclusive enteral nutrition (EEN) formula to CS would lead to increased CD remission rates and to decreased CS-related adverse events. We proposed to undertake a pilot study comparing EEN and CS therapy to CS alone to assess decrease symptoms and inflammatory markers over 6 weeks.

Aim

The overall aim was to assess study feasibility based on recruitment rates and acceptability of treatment in arms involving EEN

Methods

The pilot study intended to recruit 100 adult patients with active CD who had been prescribed CS to induce remission as part of their care. The patients were randomized to one of three arms: (i) standard-dose CS; (ii) standard-dose CS plus EEN (Modulen 1.5 kcal); or (iii) short-course CS plus EEN.

Results

A total of 2009 CD patients attending gastroenterology clinics were screened from October 2018 to November 2019. Prednisone was prescribed to only 6.8% (27/399) of patients with active CD attending outpatient clinics. Of the remaining 372 patients with active CD, 34.8% (139/399) started or escalated immunosuppressant or biologics, 49.6% (198/399) underwent further investigation and 8.8% (35/399) were offered an alternative treatment (e.g., antibiotics, surgery or investigational agents in clinical trials). Only three patients were enrolled in the study (recruitment rate 11%; 3/27), and the study was terminated for poor recruitment.

Conclusion

The apparent decline in use of CS for treatment of CD has implications for CS use as an entry criterion for clinical trials.

Risk perception and knowledge of COVID-19 in patients with celiac disease

BACKGROUND

We recently demonstrated that the odds of contracting coronavirus disease 2019 (COVID-19) in patients with celiac disease (CeD) is similar to that of the general population. However, how patients with CeD perceive their COVID-19 risk may differ from their actual risk.

AIM

To investigate risk perceptions of contracting COVID-19 in patients with CeD and determine the factors that may influence their perception.

METHODS

We distributed a survey throughout 10 countries between March and June 2020 and collected data on demographics, diet, COVID-19 testing, and risk perceptions of COVID-19 in patients with CeD. Participants were recruited through various celiac associations, clinic visits, and social media. Risk perception was assessed by asking individuals whether they believe patients with CeD are at an increased risk of contracting COVID-19 when compared to the general population. Logistic regression was used to determine the influencing factors associated with COVID-19 risk perception, such as age, sex, adherence to a gluten-free diet (GFD), and comorbidities such as cardiac conditions, respiratory conditions, and diabetes. Data was presented as adjusted odds ratios (aORs)

RESULTS

A total of 10737 participants with CeD completed the survey. From them, 6019 (56.1%) patients with CeD perceived they were at a higher risk or were unsure if they were at a higher risk of contracting COVID-19 compared to the non-CeD population. A greater proportion of patients with CeD perceived an increased risk of contracting COVID-19 when compared to infections in general due to their CeD (56.1% vs 26.7%, P < 0.0001). Consequently, 34.8% reported taking extra COVID-19 precautions as a result of their CeD. Members of celiac associations were less likely to perceive an increased risk of COVID-19 when compared to non-members (49.5% vs 57.4%, P < 0.0001). Older age (aOR: 0.99; 95%CI: 0.99 to 0.99, P < 0.001), male sex (aOR: 0.84; 95%CI: 0.76 to 0.93, P = 0.001), and strict adherence to a GFD (aOR: 0.89; 95%CI: 0.82 to 0.96, P = 0.007) were associated with a lower perception of COVID-19 risk and the presence of comorbidities was associated with a higher perception of COVID-19 risk (aOR: 1.38; 95%CI: 1.22 to 1.54, P < 0.001).

CONCLUSION

Overall, high levels of risk perceptions, such as those found in patients with CeD, may increase an individual’s pandemic-related stress and contribute to negative mental health consequences. Therefore, it is encouraged that public health officials maintain consistent communication with the public and healthcare providers with the celiac community. Future studies specifically evaluating mental health in CeD could help determine the consequences of increased risk perceptions in this population.

A22 PREVALENCE OF IRON DEFICIENCY AND SUPPLEMENTATION PRACTICES FOR PATIENTS ON HOME PARENTERAL NUTRITION

Background

Iron deficiency (ID) is common in patients receiving parenteral nutrition (PN), likely due to a lack of iron in the PN formula. There is no clear consensus on how often serum iron should be tested or iron supplementation should be given, at which dose or route, in patients on long-term PN. Within the Hamilton Health Sciences (HHS) home PN (HPN) program, the prevalence of ID or iron deficiency anemia (IDA) is unknown. This knowledge will contribute to better iron prescribing practices with ultimate benefit on patient’s health.

Aims

To assess the prevalence of ID and IDA in patients enrolled in the HHS HPN Program. The secondary aim was to assess supplementation practices for patients enrolled in the HPN program according to gastrointestinal(GI) diagnosis and duration on PN.

Methods

We conducted a retrospective study including consecutive adult patients enrolled in the HHS-HPN program from January 2015 to November 2020. We collected data on demographics (age, sex, and GI diagnosis), iron supplementation (dose, duration, and route), and information related to iron-deficiency (hemoglobin, serum iron, ferritin, TIBC, and folate) at pre-set intervals (enrollment, 3, 6, 12, 18, 24, 30, 36, 48, 60 months) and last measured. ID was defined as ferritin ≤45μg/L or serum iron ≤9μmol/L. IDA was defined as hemoglobin &lt;130g/L in men or &lt;120g/L in women in the context of ID. Data were expressed as median (IQR) for continuous variables and n/N(%) for categorical variables. Chi2 was performed to assess differences between groups and logistic regression to assess predictors of ID and IDA. The analysis was conducted using SPSS software(v26).

Results

The analysis included 125 HPN patients (50 males, median age of 55 (40–65) years). Patients received PN for a median of 195 (83–521) days. The most common diagnoses were malignancy (36.8%) and inflammatory bowel disease (23.2%); the most common indications for HPN was short bowel (29.6%) and bowel obstruction (27.2%). Iron profiles were measured in 77% of patients. At enrollment, 42.2% of patients had ID and 38.9% had IDA. Only 13% of patients with ID and 22.8% with IDA had iron supplementation (Figure 1). A total of 38 patients received iron either oral or IV (oral=44.7% vs IV=55.3%; p=0.66). There was no correlation between low levels of serum iron or ferritin with iron supplementation (p=0.23, 0.45 respectively). Age, sex, diagnosis, or reason for PN did not correlate with ID or IDA at any time point.

Conclusions

Iron-deficiency and IDA are common in patients enrolled in the HHS HPN program independently of age, sex, diagnosis and reason for PN. Prospective studies are needed to implement the most effective way to ensure proper monitoring and treatment of iron deficiency in this population.

Funding Agencies

None

A11 RISK PERCEPTION AND KNOWLEDGE OF COVID-19 IN PATIENTS WITH CELIAC DISEASE

Background

Celiac disease (CeD) has been associated with an increased risk of respiratory infections, however, we recently demonstrated that the odds of contracting COVID-19 in patients with CeD is similar to that of the general population. Due to this discrepancy, how patients with CeD perceive their risk may differ from their actual risk.

Aims

The aim of this study was to investigate the risk perceptions for contracting COVID-19 in patients with CeD and to determine the factors that may influence their perceptions.

Methods

We distributed a survey throughout 10 countries between March and June 2020 and collected data on demographics, diet, COVID-19 testing, and risk perceptions of COVID-19 in patients with CeD. Participants were recruited through various celiac associations, clinic visits, and social media. Risk perception was assessed by asking individuals whether they believe patients with CeD are at an increased risk of contracting COVID-19 compared to the general population. Logistic regression was used to determine the influencing factors associated with COVID-19 risk perception, such as age, sex, adherence to a gluten-free diet (GFD), and comorbidities such as cardiac/respiratory conditions and diabetes. Data was presented as adjusted odds ratios (aORs).

Results

A total of 10,737 participants with CeD completed the survey. From them, 6,019 (56.1%) patients with CeD perceived they were at a higher risk or were unsure if they were at a higher risk of contracting COVID-19 compared to the non-CeD population. A greater proportion of patients with CeD had high levels of COVID-19 risk perceptions when compared to infections in general (56.1% vs 26.7%; p<0.0001). Consequently, 28.8% reported taking extra COVID-19 precautions as a result of their CeD. Members of celiac associations had lower rates of perceiving an increased risk of COVID-19 when compared to non-members (49.5% vs 57.4%, p<0.0001). Older age (aOR: 0.9; 95% CI: 0.9 to 1, p<0.001), male sex (aOR: 0.85; 95% CI: 0.76 to 0.94, p=0.001), and strict adherence to a GFD (aOR: 0.89; 95% CI 0.82 to 0.97, p=0.007) were associated with a lower perception of COVID-19 risk. Meanwhile, the presence of comorbidities was associated with a higher perception of COVID-19 risk (aOR: 1.34; 95% CI: 1.20 to 1.51, p<0.001).

Conclusions

Overall, a large proportion of patients with CeD, particularly females, those with comorbidities, or those not adhering to a strict GFD, believed they were or were unsure if they were at a higher risk of contracting COVID-19 due to their condition. As high levels of risk perception may increase an individual’s pandemic-related stress and contribute to negative mental health consequences, healthcare providers should maintain consistent communication with the celiac community and provide them with evidence-based recommendations.

Funding Agencies

None

Effect of Bifidobacterium infantis NLS super strain in symptomatic coeliac disease patients on long-term gluten-free diet - an exploratory study

Bifidobacterium infantis NLS super strain (B. infantis NLS-SS) was previously shown to alleviate gastrointestinal symptoms in newly diagnosed coeliac disease (CD) patients consuming gluten. A high proportion of patients following a gluten-free diet experiences symptoms despite dietary compliance. The role of B. infantis in persistently symptomatic CD patients has not been explored. The aim of the study was to evaluate the effect of B. infantis NLS-SS on persistent gastrointestinal symptoms in patients with CD following a long-term GFD. We conducted a randomised, cross-over, double-blind, placebo-controlled trial in symptomatic adult CD patients on a GFD for at least two years. After one-week run-in, patients were randomised to B. infantis NLS-SS or placebo for 3 weeks with cross-over after a 2-week wash-out period. We estimated changes (Δ) in celiac symptom index (CSI) before and after treatment. Stool samples were collected for faecal microbiota analysis (16S rRNA sequencing). Gluten immunogenic peptide (GIP) excretion in stool and urine samples was measured at each study period. Eighteen patients were enrolled; six patients were excluded due violations in protocol. For patients with the highest clinical burden, CD symptoms were lower in probiotic than in placebo treatment (P=0.046). B. infantis and placebo treated groups had different microbiota profiles as assessed by beta diversity clustering. In probiotic treated groups, we observed an increase in abundance of B. infantis. Treatment with B. infantis was associated with decreased abundance of Ruminococcus sp. and Bifidobacterium adolescentis. GIP excretion in stools and urine was similar at each treatment period. There were no differences in adverse effects between the two groups. B. infantis NLS-SS improves specific CD symptoms in a subset of highly symptomatic treated patients (GFD). This is associated with a shift in stool microbiota profile. Larger studies are needed to confirm these findings. ClinicalTrials.gov: NCT03271138.

A108 PROBIOTICS FOR CELIAC DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

Background

Celiac disease is a chronic autoimmune disorder triggered by dietary gluten. The only available treatment for celiac disease is strict compliance to the gluten-free diet. Despite adherence to a gluten-free diet, many celiac patients still experience symptoms which may be mediated by the gut microbiota. Different studies have assessed the use of probiotics as an adjuvant treatment for celiac disease.

Aims

We performed a systematic review and meta-analysis to evaluate the efficacy of probiotics in improving gastrointestinal symptoms and quality of life in patients with celiac disease.

Methods

We searched MEDLINE (1966 to February 2019), EMBASE (1974 to February 2019), CINAHL, Web of Science, CENTRAL, DARE, and Sigle up to February 2019 for randomized controlled trials (RCTs) assessing the effects of probiotics on celiac disease. We collected data on gastrointestinal symptoms, quality of life, adverse events, serum tumor necrosis factor α (TNF-α), intestinal permeability, and microbiota composition.

Results

Out of 2831 records screened, 7 articles from 6 RCTs with a total of 279 participants were eligible for quantitative analysis. Probiotic supplementation for a minimum of 2 weeks improved gastrointestinal symptoms when assessed by the Gastrointestinal Symptoms Rating Scale (GSRS) (2 studies; 131 participants; mean difference (MD) symptom reduction: -28.7%; 95% CI -43.96 to -13.52; P=0.0002). No differences in gastrointestinal symptoms after probiotics were observed when pooling data from the GSRS, Celiac Symptoms Index (CSI), and the Celiac Disease Questionnaire (CDQ) (4 studies; 197 participants; standardized mean difference (SMD) symptom reduction: -0.48; 95% CI -1.21 to +0.25; P=0.20). TNF-α levels did not change after probiotics (SMD: -0.52; 95% CI -1.08 to +0.04; P=0.07). Levels of Bifidobacteria species increased (MD: increase by 0.85 log CFU/g; 95% CI +0.38 to +1.32 log CFU/g; P=0.0003) but there was no difference in Lactobacilli species (MD: change of 1.13 log CFU/g; 95% CI -0.67 to +2.93 log CFU/g; P=0.22) after probiotic supplementation. No difference in quality of life or adverse events was observed after probiotics. There was insufficient evidence to assess the effects of probiotics on intestinal permeability. The overall quality of the evidence ranged from very low to low.

Conclusions

Probiotics may improve gastrointestinal symptoms in patients with celiac disease; however, our confidence in these results is limited by the low quality of the evidence. Further large clinical trials with a more rigorous design are needed to improve the quality of the evidence.

Funding Agencies

None

A22 ADVERSE EARLY LIFE EVENTS ARE COMMON IN PATIENTS WITH FUNCTIONAL AND ORGANIC GASTROINTESTINAL DISORDERS

Background

Stressful events in childhood have been associated with the development of functional gastrointestinal (GI) disorders in adulthood, especially irritable bowel syndrome. The influence of early life adverse events in patients with common organic disorders, such as celiac disease and inflammatory bowel disease (IBD), has been poorly investigated.

Aims

To evaluate the frequency of early life adverse events in patients with organic and functional gastrointestinal disorders compared to healthy controls.

Methods

Adult patients with an established diagnosis of IBS (Rome IV criteria), celiac disease and inflammatory bowel disease (IBD) attending a tertiary medical center, as well as healthy volunteers were interviewed by a psychologist. Early life adverse events were assessed during the semi-structured interview using a modified version of the Adverse Childhood Experience (ACE) questionnaire. Number of early life events and the presence of GI and extraintestinal symptoms based on a 10-point Likert scale were quantified. Data are presented as Median (IQR) and n (%). Statistical analysis was performed using Mann-Whitney and Fisher’s exact tests as appropriate.

Results

Sixty-eight patients (18 IBS, 28 celiac, 22 IBD) and 23 healthy controls were enrolled in the study. Patients with IBS, celiac disease and IBD had increased number of early life events compared with healthy controls (6.5 (4.8–8.3), 5.0 (3.0–9.0), 6.0 (4–8.3) vs 2.0 (1.0–4.0) respectively, p&lt;0.0001). Patients reported a higher number of mental disorders in their mothers (IBS p=0.01; celiac disease p=0.01; IBD p=0.001) and increased number of close family member abusing alcohol or drugs during their childhood (IBS p=0.01; celiac p=0.02; IBD p=0.02) compared to healthy controls. History of sexual abuse was higher in patients with IBS (p=0.01), while history of verbal abuse was higher in patients celiac disease and IBD (p=0.003 and p=0.001, respectively) compared to healthy controls. The number of early life adverse events was strongly correlated with number of GI (r= 0.91; p=0.01) and extra-intestinal (r=0.87; p=0.02) symptoms, but not with symptoms severity. Most patients with IBS (83.3%), celiac disease (89.3%) and IBD (85.7%) reported stressful events before the onset of their disease.

Conclusions

Adverse events in childhood are frequent in patients with chronic GI disorders, both of functional and organic origin. Furthermore, stressful events often precede their diagnosis. These data strongly suggest that better psychosocial assessment in patients with chronic GI disorders is needed to improve their overall management.

Funding Agencies

None

A193 GLUTEN-FREE DIET IMPROVES DYSPEPSIA-LIKE SYMPTOMS IN A PILOT STUDY OF PATIENTS WITH TYPE 1 DIABETES MELLITUS

Background

Patients with type 1 Diabetes Mellitus (T1DM) often suffer with gastrointestinal (GI) symptoms, such as abdominal pain, bloating, early satiety, nausea and vomiting. T1DM patients are at a higher risk to develop celiac disease, and those patient with both disorders benefit from a gluten-free diet (GFD). However, it is unknown whether GFD has any benefit in patients with T1DM without celiac disease who present with upper GI symptoms.

Aims

To investigate the role of GFD in the management of moderate to severe dyspeptic symptoms in non-celiac patients with T1DM.

Methods

We enrolled adult T1DM patients, in whom celiac disease was ruled out by serology and/or endoscopy, suffering with two or more of upper GI symptoms. The patients were instructed to undergo a strict GFD for a period of 1 month, under supervision of a dietitian. Glycemic levels were monitored by a continuous glucose monitoring device (CGM) for 2 weeks before, and for 2 weeks at the end of the GFD period. Upper GI symptoms, general quality of life, anxiety and depression were assessed using standardized questionnaires. Blood samples were collected to assess glycaemia (Hb1Ac) and lipid profiles. Scintigraphy and videofluoroscopy were used to assess gastric emptying.

Results

Seven patients finished the study so far. They reported a significant improvement in nausea (p&lt;0.05), sensation of fullness (p&lt;0.01), bloating (p&lt;0.01), feeling of excessive fullness after meals (p&lt;0.01) and having stomach visibly larger after meals (p&lt;0.01). 5 out of the 7 patients reported an improvement in general quality of life, based on PAGI-QOL (Patient Assessment of Upper Gastrointestinal Disorders – Quality of Life), and decreased anxiety levels (HADS, Hospital Anxiety and Depression Score). There was no significant change in mean glucose level, time in target, glucose variance and HbA1c levels after GFD. However, there was a trend for less time spent in hypoglycemia, namely in those patients who experienced frequent hypoglycemia prior to GFD. Overall, there was no change in serum lipid profile or gastric emptying.

Conclusions

One month of GFD improved dyspepsia-like symptoms, general quality of life and anxiety levels in T1D patients without concomitant celiac disease. GFD also improved the blood glucose management of patients with frequent hypoglycemia. Thus, this dietary intervention appears to improve upper GI symptoms in T1D patients but the results need to be replicated in a larger patient cohort.

Funding Agencies

CIHR

A23 NUTRITIONAL DEFICIENCIES ARE FREQUENT IN CELIAC PATIENTS ON A GLUTEN-FREE DIET, REGARDLESS OF THE DURATION AND COMPLIANCE OF THE DIET

Background

The only available treatment for celiac disease (CD) is adherence to a strict gluten-free diet (GFD). CD is associated with several nutritional deficiencies, which could be explained by malabsorption when the disease is active. However, the magnitude of nutritional deficiencies in treated CD and how this is influenced by the duration and compliance of GFD is less clear.

Aims

We aim to evaluate the presence of nutritional deficiencies in celiac patients on short term (≤2yrs) vs long-term (&gt;2yrs) GFD, and in those with persistent symptoms or asymptomatic in the follow up.

Methods

We included consecutive biopsy-proven CD patients attending the McMaster Adult Celiac Clinic. GFD adherence was assessed by validated Celiac Dietary Adherence Test (CDAT) and by anti-tissue transglutaminase antibody IgA(tTG IgA) levels. Serology, vitamins and minerals were measured in blood samples collected at enrolment. Continuous data was expressed as Median (IQR) and categorical data as proportion%. Mann-U-Whitney and Chi2 were used to compare difference between groups.

Results

We enrolled 171 CD patients (80% female; Median age 43 years). 76/171 (44%) of CD patients were following a GFD for over 2 years. Eighty-two percent of the patients (141/171) had persistent symptoms in the follow up and 80.7% had normal tTG IgA levels. The most common nutritional abnormalities were deficiencies in zinc (56%), iron (23%), copper (20%). Chromium was increased in 74% of patients. There were no differences in nutritional deficiencies between group of patients with short and long-term duration of GFD, nor between those strictly compliant with GFD compared to those fairly compliant (p&gt;0.05).

Conclusions

Nutritional deficiencies are frequent in celiac patients on a GFD regardless of the presence of symptoms, dietary compliance or duration. The previous suggest that nutrients deficiencies may be more related to GFD nutritional inadequacy rather than malabsorption.

Funding Agencies

None

A194 PRESENCE OF CELIAC DISEASE IN PATIENTS WITH BARRETT’S ESOPHAGUS IS ASSOCIATED WITH FASTER DEVELOPMENT OF DYSPLASIA AND HIGHER RATES OF ESOPHAGEAL ADENOCARCINOMA

Background

Celiac disease (CD) has an estimated prevalence of 1% worldwide, including North America. Barrett’s esophagus (BE) is a complication of chronic gastroesophageal reflux disease (GERD), which predisposes to development of dysplasia, which can transition to esophageal adenocarcinoma (EAC). GERD is commonly found in patients with CD and there is evidence that reflux symptoms improve after starting the gluten-free diet. However, the prevalence of CD in patients with BE, and its impact on progression to EAC have not been studied.

Aims

To assess the prevalence of CD in patients with BE and its impact on development of dysplasia and EAC.

Methods

We performed a retrospective review of medical records of patients attending the Digestive Diseases Clinic and the specialized Barrett’s Clinic at McMaster University Medical Centre. We collected information related to demographics, esophageal and duodenal biopsies, as well as CD serological markers. CD diagnosis was based on the presence of Marsh III lesions in duodenal biopsies and/or positive tissue transglutaminase IgA antibodies (TTG). Categorical data was presented as n/N and %, continuous data as mean ±SD. Logistic regression was performed to estimate the association between BE and CD. For dysplasia development, Kaplan Meyer Breslow survival curve was used.

Results

CD was found in 1.8% of patients attending the Digestive Diseases Clinic (n=4800). Two hundred and sixteen patients with BE from the Digestive Diseases Clinic and the Barret’s Clinic (age 63 ±11.2, 70.3% males; follow-up period 7.0 ±5.5 years) were included in the analysis. Patients with or without CD were similar in demographic factors, concomitant diseases or previous surgeries, use of PPI, presence of symptoms and duration of treatment. The prevalence of CD was increased 5-fold in patients with BE (OR=6.0; 95% CI 2.1–17.4; p=0.006). BE patients with CD developed dysplasia earlier than those without CD (Long Rank 0.004; mean 6.0; 95% CI 3.0–4.97[PB1]). The risk of EAC was higher in BE patients with CD compared to those without CD (2/11 vs 2/205; OR=22.5; 95% CI 2.8–178.8; p= 0.003). The mean time for development of EAC from the time of BE diagnosis [PB2] was 1.5 years in patients with CD and 6.5 years in patients without CD.

Conclusions

The prevalence of CD is higher in patients with BE compared with the population attending a tertiary gastroenterology clinic, and with the general population. Patients with BE and concomitant CD are at increased risk of accelerated development of dysplasia and EAC, suggesting that both conditions may have a synergic detrimental effect.

Funding Agencies

CIHR

Derivation and validation of a diagnostic test for irritable bowel syndrome using latent class analysis

BACKGROUND

The accuracy of symptom-based diagnostic criteria for irritable bowel syndrome (IBS) is modest.

AIMS

To derive and validate a new test that utilises latent class analysis.

METHODS

Symptom, colonoscopy, and histology data were collected from 1981 patients and 360 patients in two cohorts referred to secondary care for investigation of their gastrointestinal symptoms in Canada and the UK, respectively. Latent class analysis was used to identify naturally occurring clusters in patient-reported symptoms in the Canadian dataset, and the latent class model derived from this was then applied to the UK dataset in order to validate it. Sensitivity, specificity, and positive and negative likelihood ratios (LRs) were calculated for the latent class models.

RESULTS

In the Canadian cohort, the model had a sensitivity of 44.7% (95% CI 40.0-50.0) and a specificity of 85.3% (95% CI 83.4-87.0). Positive and negative LRs were 3.03 (95% CI 2.57-3.56) and 0.65 (95% CI 0.59-0.71) respectively. A maximum positive LR of 3.93 was achieved following construction of a receiver operating characteristic curve. The performance in the UK cohort was similar, with a sensitivity and specificity of 52.5% (95% CI 42.2-62.7) and 84.3% (95% CI 79.3-88.6), respectively. Positive and negative LRs were 3.35 (95% CI 2.38-4.70) and 0.56 (95% CI 0.45-0.68), respectively, with a maximum positive LR of 4.15.

CONCLUSIONS

A diagnostic test for IBS, utilising patient-reported symptoms incorporated into a latent class model, performs as accurately as symptom-based criteria. It has potential for improvement via addition of clinical markers, such as coeliac serology and faecal calprotectin.

Poor predictive value of lower gastrointestinal alarm features in the diagnosis of colorectal cancer in 1981 patients in secondary care

BACKGROUND

Clinicians are advised to refer patients with lower gastrointestinal (GI) alarm features for urgent colonoscopy to exclude colorectal cancer (CRC). However, the utility of alarm features is debated.

AIM

To assess whether performance of alarm features is improved by using a symptom frequency threshold to trigger referral, or by combining them into composite variables, including minimum age thresholds, as recommended by the National Institute for Health and Care Excellence (NICE).

METHODS

We collected data prospectively from 1981 consecutive adults with lower GI symptoms. Assessors were blinded to symptom status. The reference standard to define CRC was histopathological confirmation of adenocarcinoma in biopsy specimens from a malignant-looking colorectal lesion. Controls were patients without CRC. Sensitivity, specificity, positive predictive values (PPVs) and negative predictive values were calculated for individual alarm features, as well as combinations of these.

RESULTS

In identifying 47 (2.4%) patients with CRC, individual alarm features had sensitivities ranging from 11.1% (family history of CRC) to 66.0% (loose stools), and specificities from 30.5% (loose stools) to 75.6% (family history of CRC). Using higher symptom frequency thresholds improved specificity, but to the detriment of sensitivity. NICE referral criteria also had higher specificities and lower sensitivity, with PPVs above 4.8%. More than 80% of those with CRC met at least one of the NICE referral criteria.

CONCLUSIONS

Using higher symptom frequency thresholds for alarm features improved specificity, but sensitivity was low. NICE referral criteria had PPVs above 4.8%, but sensitivities ranged from 2.2% to 32.6%, meaning many cancers would be missed.