Individual variability in patterns and dynamics of fecal gluten immunogenic peptides excretion after low gluten intake

Novel probiotic preparation with in vivo gluten-degrading activity and potential modulatory effects on the gut microbiota

Gluten possesses unique properties that render it only partially digestible. Consequently, it exerts detrimental effects on a part of the worldwide population who are afflicted with celiac disease (1%) or related disorders (5%), particularly due to the potential for cross-contamination even when adhering to a gluten-free diet (GFD). Finding solutions to break down gluten during digestion has a high nutritional and social impact. Here, a randomized double-blind placebo-controlled in vivo challenge investigated the gluten-degrading activity of a novel probiotic preparation comprising lactobacilli and their cytoplasmic extracts, Bacillus sp., and bacterial protease. In our clinical trial, we collected feces from 70 healthy volunteers at specific time intervals. Probiotic/placebo administration lasted 32 days, followed by 10 days of wash-out. After preliminary GFD to eliminate residual gluten from feces, increasing amounts of gluten (50 mg-10 g) were administered, each one for 4 consecutive days. Compared to placebo, the feces of volunteers fed with probiotics showed much lower amounts of residual gluten, mainly with increased intakes. Probiotics also regulate the intestinal microbial communities, improving the abundance of genera pivotal to maintaining homeostasis. Quantitative PCR confirmed that all probiotics persisted during the intervention, some also during wash-out. Probiotics promoted a fecal metabolome with potential immunomodulating activity, mainly related to derivatives of branched-chain amino acids and short-chain fatty acids.

IMPORTANCE

The untapped potential of gluten-degrading bacteria and their application in addressing the recognized limitations of gluten-related disorder management and the ongoing risk of cross-contamination even when people follow a gluten-free diet (GFD) emphasizes the significance of the work. Because gluten, a common protein found in many cereals, must be strictly avoided to stop autoimmune reactions and related health problems, celiac disease and gluten sensitivity present difficult hurdles. However, because of the hidden presence of gluten in many food products and the constant danger of cross-contamination during food preparation and processing, total avoidance is frequently challenging. Our study presents a novel probiotic preparation suitable for people suffering from gluten-related disorders during GFD and for healthy individuals because it enhances gluten digestion and promotes gut microbiota functionality.

Stool Gluten Peptide Detection Is Superior to Urinary Analysis, Coeliac Serology, Dietary Adherence Scores and Symptoms in the Detection of Intermittent Gluten Exposure in Coeliac Disease: A Randomised, Placebo-Controlled, Low-Dose Gluten Challenge Study

Monitoring adherence to a gluten-free diet is an important goal of coeliac disease management. Urine and stool gluten immunogenic peptide (GIP) assays provide an objective readout of gluten ingestion, with the former favoured due to its convenience and acceptability. This study assessed stool GIP excretion after low-dose gluten challenge designed to mimic accidental gluten exposure. A total of 52 coeliac participants undertook a randomised, double-blind gluten (50-1000 mg) or placebo challenge. Stool and urinary GIP, serology, dietary adherence and symptoms were assessed. Stool GIP was 100% sensitive for gluten intake ≥250 mg and 71% for 50 mg. Peak GIP detection was 12-36 h after gluten exposure. The mean stool GIP after 1000 mg gluten ingestion remained above the limit of quantification for 5 days. Urine GIP assessment had poor sensitivity for GIP excretion compared to stool. Serology, dietary adherence score and symptoms did not correlate with gluten excretion during lead-in. We conclude that stool GIP detection is highly sensitive, with levels related to gluten dose and time from ingestion. Weekly or bi-weekly testing will detect low-level exposure more effectively than urine GIP assessments or traditional methods. In this seronegative, apparently well-treated cohort, a high frequency of baseline-positive GIP suggests ongoing gluten exposure, but the assessment of patient behaviour and assay specificity is needed.

A gluten degrading probiotic Bacillus subtilis LZU-GM relieve adverse effect of gluten additive food and balances gut microbiota in mice

Gluten accumulation damages the proximal small intestine and causes celiac disease (CeD) which has not been effectively treated except by using a gluten-free diet. In this study, strain Bacillus subtilis LZU-GM was isolated from Pakistani traditional fermented sourdough and could degrade 73.7% of gluten in 24 h in vitro. Strain LZU-GM was employed for practical application to investigate gluten degradation in mice models. The results showed that strain LZU-GM was colonized in mice and the survival rate was around 0.95 % (P < 0.0001). The gluten degradation was 3-fold higher in the small intestine of the strain LZU-GM treated mice group remaining 1511.96 ng/mL of gluten peptides than the untreated mice group (6500.38 ng/mL). Immunochemical analysis showed that gluten-treated mice established positive antigliadin antibodies (AGA) in serum (IgA, IgG, and anti-TG2 antibodies) as compared to the strain LZU-GM treatment group. Furthermore, the number of IFN-γ, TNF-α, IL-10, and COX-2 cells decrease in the lamina propria of the strain LZU-GM treatment group (P < 0.0001). Microbial community bar plot analysis showed that Lactobacillus, Dubosiella, and Enterococcus genera were restored and stabilized in the LZU-GM treatment group while Blautia and Ruminococcus were found lower. The oral gavage of probiotic strain LZU-GM might be useful for gluten metabolism in the intestine during digestion and would be a long-term dietary treatment for CeD management.

Gluten Immunogenic Peptides Are Not Correlated With Reported Adherence to Gluten-Free Diet in Children With Celiac Disease

OBJECTIVE

There is no gold standard to assess adherence to gluten-free diet (GFD) among patients with celiac disease (CeD). Gluten immunogenic peptides (GIPs) in urine and stool were suggested as novel markers for evaluating adherence to GFD. Our aim was to assess the presence of GIP in pediatric patients with CeD, and to compare the results with alternative methods for evaluating GFD adherence.

METHODS

Pediatric patients diagnosed with CeD, who were on GFD for at least 1 year, were enrolled and followed prospectively between November 2018 and January 2021. Study visits included clinical assessment, a dietitian interview, Biagi score, food questionnaires, anthropometric and laboratory measurements, and urine and stool samples obtained for laboratory GIP analysis.

RESULTS

The study included 74 patients (63.5% females), with median (interquartile range, IQR) age of 9.9 (7.8-11.7) years, and median (IQR) duration on GFD of 2.5 (2-5.5) years. Good GFD adherence, assessed by Biagi score, was reported in 93.1% of cases. GIP was evaluated during 134 visits, with GIP detected in 27 of 134 (20.1%) of the visits (16.3% of stool samples and 5.3% of urine samples). Positive GIP results were significantly more common in males compared to females (30.6% vs 14.1%, respectively, P < 0.05). Detection of positive GIP was not associated with dietary assessment of GFD adherence, celiac serology results, or reported symptoms.

CONCLUSIONS

Stool and urine GIP can be detected in children with CeD, even when dietary assessment indicate good adherence to GFD. The role of GIP testing in clinical practice should be further explored.

The use of urine peptidomics to define dietary gluten peptides from patients with celiac disease and the clinical relevance

INTRODUCTION

Determination of urinary gluten immunogenic peptides (GIP) has emerged as one of the most attractive test to monitor the adherence to the gluten-free diet (GFD) of patients with celiac disease (CD), being a simple, noninvasive and direct method to detect gluten contamination of the GFD.

AREAS COVERED

We conducted a scoping review in Medline (PubMed) of articles published up to April 2023 that analyzed any aspect of the clinical relevance of the use of urinary GIP measurement in patients with CD. A total of 17 articles reporting the clinical use of urinary peptidomics for the follow-up of CD patients were finally included.

EXPERT OPINION

Available data suggest that a negative urinary GIP result is a reliable noninvasive predictor of intestinal mucosa healing in CD patients treated with the GFD, especially if testing three urine samples on different days including the weekend. Due to conflicting results about the sensitivity and the specificity of the urinary GIP determination, additional in-depth information is needed, particularly related to (1) the relationship between the amount of ingested gluten and the quantity of urinary GIP excreted in treated CD patients, (2) the GIP kinetics and best timing for sample collection.

The Importance of an Early Evaluation after Establishing a Gluten-Free Diet in Children with Celiac Disease

A gluten-free diet (GFD) is the only treatment available for celiac disease (CD); hence, it is important to ensure correct adherence to the diet and adequate monitoring of the diet. The present study aims to assess the importance of an early follow-up of celiac patients after diagnosis of the disease, identify the role of stool gluten immunogenic peptides (GIPs) in the assessment of GFD adherence, and analyze possible nutritional imbalances or deficiencies in the GFD. This is a cross-sectional study carried out in pediatric patients with newly diagnosed CD in a tertiary hospital in Spain. Of the 61 patients included, 14% had positive stool GIPS at 4 months after CD diagnosis, Among them, 88% had negative stool GIPS at 9 months after diagnosis, following dietary advice. We found nutritional deficiencies in the GFD, such as vitamin D (with only 27% of patients with adequate intakes), folate, calcium, magnesium, and fiber. Similarly, we found imbalances: excess protein and fat intakes and a high percentage of total daily energy intake came from ultra-processed foods (UPF). These findings emphasize the importance of early follow-up of children after diagnosis of CD. It is also crucial to identify patients with poor GFD compliance based on stool GIPS and analyze GFD nutritional imbalances and deficits. Our findings may contribute to the development of specific strategies for the early follow-up of patients with CD, including appropriate nutritional counselling.

Biomarkers to Monitor Adherence to Gluten-Free Diet by Celiac Disease Patients: Gluten Immunogenic Peptides and Urinary miRNAs

Celiac disease (CD) is a multifactorial autoimmune enteropathy with a prevalence greater than 1% in the pediatric population. The only therapy for CD patients is a strict gluten-free diet (GFD). Gluten-free food contamination by other cereals during packaging and cooking or accidental ingestion of gluten may cause several intestinal and extraintestinal symptoms in CD patients. Therefore, the monitoring of gluten contamination in food and assessing the level of ingested gluten by analytical biomarkers has been of great interest in recent years. To this aim, small gluten immunogenic peptides (GIPs) obtained by the hydrolysis of gluten and present in urine and feces have been studied as biomarkers of gluten intake and to monitor adherence to GFD by CD patients. More recently, the use of circulating, fecal and urinary miRNAs has emerged as a novel diagnostic tool that can be potentially applied to assess adherence to GFD. Moreover, the presence of GIPs and miRNAs in both feces and urine suggests a similar excretion modality and the possibility of using urinary miRNAs, similarly to GIPs, as potential biomarkers of GFD in CD patients.

Dose-Escalating (50–500 mg) Gluten Administration Leads to Detectable Gluten-Immunogenic-Peptides in Urine of Patients with Coeliac Disease Which Is Unrelated to Symptoms, a Placebo Controlled Trial

Background: To determine the applicability and sensitivity of a urine self-test to detect gluten-immunogenic-peptides (GIP) in daily-life for patients with coeliac disease and correlate the test results with reported symptoms. Methods: We performed a prospective double-blinded placebo-controlled study, including adults with coeliac disease adhering to a strictly gluten-free diet. Patients were administered gluten in test-cycles of ascending doses of 50, 100, 200, and 500 mg alternated with placebo. Urine portions from 2, 5–17 h after the ingestion were collected and analyzed for GIP using the iVYCHECK-GIP-Urine rapid lateral flow test. Patients completed a diary mapping symptoms (nausea, bloating, diarrhea, abdominal pain, and lower level of energy). Results: We enrolled 15 patients and 7 received all 4 cycles with increasing gluten dosing. GIP was detected from urine in 47% of the patients receiving 50 mg gluten and in 86% with 500 mg gluten. We detected GIP in 20–50% of urine samples after placebo. There was no correlation between symptoms, gluten administration and/or GIP in urine. Conclusions: Gluten intake, even with a dose as low as 50 mg, leads to detectable urinary GIP concentrations. There is no correlation of coeliac disease ascribed symptoms with detection of urinary GIP.