Exposure sources, amounts and time course of gluten ingestion and excretion in patients with coeliac disease on a gluten-free diet.

BACKGROUND: A major deficit in understanding and improving treatment in coeliac disease (CD) is the lack of empiric data on real world gluten exposure. AIMS: To estimate gluten exposure on a gluten-free diet (GFD) using immunoassays for gluten immunogenic peptides (GIP) and to examine relationships among GIP detection, symptoms and suspected gluten exposures METHODS: Adults with biopsy-confirmed CD on a GFD for 24 months were recruited from a population-based inception cohort. Participants kept a diary and collected urine samples for 10 days and stools on days 4-10. 'Doggie bags' containing » portions of foods consumed were saved during the first 7 days. Gluten in food, stool and urine was quantified using A1/G12 ELISA. RESULTS: Eighteen participants with CD (12 female; age 21-70 years) and three participants on a gluten-containing diet enrolled and completed the study. Twelve out of 18 CD participants had a median 2.1 mg gluten per exposure (range 0.2 to >80 mg). Most exposures were asymptomatic and unsuspected. There was high intra-individual variability in the interval between gluten ingestion and excretion. Participants were generally unable to identify the food. CONCLUSIONS: Gluten exposure on a GFD is common, intermittent, and usually silent. Excretion kinetics are highly variable among individuals. The amount of gluten varied widely, but was typically in the milligram range, which was 10-100 times less than consumed by those on an unrestricted diet. These findings suggest that a strict GFD is difficult to attain, and specific exposures are difficult to detect due to variable time course of excretion.

Can individuals with celiac disease identify gluten-free foods correctly?

BACKGROUND & AIMS: Patients with celiac disease (CD) often report inadvertent gluten exposures and challenges reading labels. The most common cause of non-responsive CD is gluten exposure. We aimed to assess whether recently diagnosed CD patients can determine whether a food is gluten-free based on labeling, and to assess skills over time. A secondary aim was to identify factors associated with label reading proficiency. METHODS: Inception cohort with follow-up at 6, 12, and 24 months after diagnosis. Participants were asked to determine whether 25 food items were gluten-free based on labeling information. Diet adherence was assessed using the Celiac Diet Assessment Tool (CDAT) and the Gluten-Free Eating Assessment Tool (GF-EAT). 144 adults with newly diagnosed celiac disease were enrolled. The initial quiz at 6 months was completed by 83%. Quizzes were completed by 72% at 12 months and 70% at 24 months. RESULTS: Median overall accuracy scores were: 23/25, 24/25 and 21/25 at 6, 12 and 24 months respectively. Gluten-free products with explicit "gluten-free" claims had the fewest errors. Quiz scores were not correlated with tTG IgA levels, or CDAT or GF-EAT scores. Diet adherence was generally good (>85% with CDAT <13 suggesting adequate GFD adherence); however, at 24 months, only 11% reported no gluten exposure. CONCLUSIONS: CD patients may be unable to consistently choose gluten-free foods based on product labeling. Explicit identification of gluten-free products may be helpful. Label reading ability appears stable over time. Further studies are needed to evaluate whether erroneous label reading or misleading labels are associated with persistent villous atrophy.

The effect of dietary n-3 long-chain polyunsaturated fatty acids on femur mineral density and biomarkers of bone metabolism in healthy, diabetic and dietary-restricted growing rats.

INTRODUCTION: Dietary fish oil promotes bone formation in healthy states, but its effect during insulin deficiency or nutrient restriction is unclear. METHODS: Eighty weanling male rats were randomized to receive an injection of streptozotocin to induce insulin deficiency (diabetes) or saline (control) and a diet containing soy oil or corn + fish oil for 35 days. Half of the saline-injected rats were randomized to 20% dietary restriction. Measurements were growth, biomarkers of bone metabolism and femur bone mass. RESULTS: Density of femur was elevated in the corn + fish group and reduced in the diabetes group. Plasma osteocalcin and bone prostaglandin E2 (PGE2) were reduced by the corn + fish diet. N-telopeptide, IGF-1, bone PGE2 and urinary Ca were highest and calcitriol lowest in the diabetes group. CONCLUSIONS: These data suggest that the benefit of a diet high in n-3 long-chain polyunsaturated fatty acid is most advantageous to long bone density in healthy states.