Faecal calprotectin: factors affecting levels and its potential role as a surrogate marker for risk of development of Crohn's Disease

Elevated fecal calprotectin is associated with gut microbial dysbiosis, altered serum markers and clinical outcomes in older individuals

Fecal calprotectin is an established marker of gut inflammation in inflammatory bowel disease (IBD). Elevated levels of fecal calprotectin as well as gut microbial dysbiosis have also been observed in other clinical conditions. However, systemic and multi-omics alterations linked to elevated fecal calprotectin in older individuals remain unclear. This study comprehensively investigated the relationship between fecal calprotectin levels, gut microbiome composition, serum inflammation and targeted metabolomics markers, and relevant lifestyle and medical data in a large sample of older individuals (n = 735; mean age ± SD: 68.7 ± 6.3) from the TREND cohort study. Low (0-50 μg/g; n = 602), moderate (> 50-100 μg/g; n = 64) and high (> 100 μg/g; n = 62) fecal calprotectin groups were stratified. Several pro-inflammatory gut microbial genera were significantly increased and short-chain fatty acid producing genera were decreased in high vs. low calprotectin groups. In serum, IL-17C, CCL19 and the toxic metabolite indoxyl sulfate were increased in high vs. low fecal calprotectin groups. These changes were partially mediated by the gut microbiota. Moreover, the high fecal calprotectin group showed increased BMI and a higher disease prevalence of heart attack and obesity. Our findings contribute to the understanding of fecal calprotectin as a marker of gut dysbiosis and its broader systemic and clinical implications in older individuals.

Fecal calprotectin in pediatric gastrointestinal diseases: Pros and cons

BACKGROUND

Fecal calprotectin is a valuable biomarker for assessing intestinal inflammation in pediatric gastrointestinal diseases. However, its role, pros, and cons in various conditions must be comprehensively elucidated.

AIM

To explore the role of fecal calprotectin in pediatric gastrointestinal diseases, including its advantages and limitations.

METHODS

A comprehensive search was conducted on PubMed, PubMed Central, Google Scholar, and other scientific research engines until February 24, 2024. The review included 88 research articles, 56 review articles, six meta-analyses, two systematic reviews, two consensus papers, and two letters to the editors.

RESULTS

Fecal calprotectin is a non-invasive marker for detecting intestinal inflammation and monitoring disease activity in pediatric conditions such as functional gastrointestinal disorders, inflammatory bowel disease, coeliac disease, coronavirus disease 2019-induced gastrointestinal disorders, gastroenteritis, and cystic fibrosis-associated intestinal pathology. However, its lack of specificity and susceptibility to various confounding factors pose challenges in interpretation. Despite these limitations, fecal calprotectin offers significant advantages in diagnosing, monitoring, and managing pediatric gastrointestinal diseases.

CONCLUSION

Fecal calprotectin holds promise as a valuable tool in pediatric gastroenterology, offering insights into disease activity, treatment response, and prognosis. Standardized protocols and guidelines are needed to optimize its clinical utility and mitigate interpretation challenges. Further research is warranted to address the identified limitations and enhance our understanding of fecal calprotectin in pediatric gastrointestinal diseases.

Exploring the Diagnostic Spectrum of Children with Raised Faecal Calprotectin Levels

Faecal calprotectin (FC) is a marker of gut inflammation. The cause and relevance of raised FC in children outside the context of established inflammatory bowel disease (IBD) have had minimal attention. This study aimed to address this by carrying out a retrospective study on children with abnormal FC tests aged 4-17 years without established IBD in the South Island, New Zealand. Abnormal FC results were stratified: 51-249 μg/g, 250-499 μg/g, and 500+ μg/g, and participants were categorised into diagnostic groups. Data were collected on symptoms and diagnostic tests. Three-hundred and ten children had abnormal index FC results, with a mean age of 12.9 years, and a 55% proportion of females. The median FC was 125 μg/g; 71% had levels 51-249 μg/g and 21% had levels 500+ μg/g. Of those with FC 500+ μg/g, 89% either had infectious diarrhoea or were diagnosed with IBD at the time of, or subsequent to, the index FC. Alarm symptoms did not delineate between groups with FC 500+ μg/g. Abnormalities in platelet levels, abdominal ultrasound, and colonoscopy were more frequent for children diagnosed with IBD. Repeat FC test levels were significantly reduced except for those subsequently diagnosed with IBD. Abnormal FC levels for the majority were below the level indicative of mucosal inflammation. Repeat FC testing could play an important role in distinguishing between diagnoses.

The effects of torula yeast as a protein source on apparent total tract digestibility, inflammatory markers, and fecal microbiota dysbiosis index in Labrador Retrievers with chronically poor stool quality

This study examined the effects of varying protein sources on apparent total tract digestibility, inflammatory markers, and fecal microbiota in Labrador Retrievers with historically poor stool quality. Thirty dogs (15 male, 15 female; aged 0.93 to 11.7 yr) with stool quality scores ≤2.5 on a 5-point scale (1 representing liquid stool and 5 representing firm stool) were randomly assigned to 1 of 3 nutritionally complete diets with differing protein sources and similar macronutrient profiles: 1) chicken meal (n = 10); 2) 10% brewer's yeast (n = 10); or 3) 10% torula yeast (n = 10). Another 10 dogs (five male, five female) with normal stool quality (scores ranging from 3 to 4) received diet 1 and served as negative control (NC). All dogs were fed diet 1 for 7 days, then provided their assigned treatment diets from days 7 to 37. Daily stool scores and weekly body weights were recorded. On days 7, 21, and 36, blood serum was analyzed for c-reactive protein (CRP), and feces for calgranulin C (S100A12), α1-proteinase inhibitor (α1-PI), calprotectin, and microbiota dysbiosis index. Apparent total tract digestibility was assessed using the indicator method with 2 g titanium dioxide administered via oral capsules. Stool scores were greater in NC (P < 0.01) as designed but not affected by treatment × time interaction (P = 0.64). Body weight was greater (P = 0.01) and CRP lower (P < 0.01) in NC dogs. Dry matter and nitrogen-free extract digestibility did not differ among groups (P ≥ 0.14). Negative controls had greater fat digestibility compared to BY (94.64 ± 1.33% vs. 91.65 ± 1.25%; P = 0.02). The overall effect of treatment was significant for protein digestibility (P = 0.03), but there were no differences in individual post hoc comparisons (P ≥ 0.07). Treatment did not affect S100A12 or α1-PI (P ≥ 0.44). Calprotectin decreased at a greater rate over time in TY (P < 0.01). The dysbiosis index score for BY and TY fluctuated less over time (P = 0.01). Blautia (P = 0.03) and Clostridium hiranonis (P = 0.05) abundances were reduced in BY and TY. Dogs with chronically poor stool quality experienced reduced body weights and increased serum CRP, but TY numerically increased protein digestibility, altered the microbiome, and reduced fecal calprotectin. Torula yeast is a suitable alternative protein source in extruded canine diets, but further research is needed to understand the long-term potential for improving the plane of nutrition and modulating gut health.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

Impact of Biometric Patient Data, Probiotic Supplementation, and Selected Gut Microorganisms on Calprotectin, Zonulin, and sIgA Concentrations in the Stool of Adults Aged 18-74 Years

Alterations to the intestinal barrier may be involved in the pathogenesis of various chronic diseases. The diagnosis of mucosal barrier disruption has become a new therapeutic target for disease prevention. The aim of this study was to determine whether various patient demographic and biometric data, often not included in diagnostic analyses, may affect calprotectin, zonulin, and sIgA biomarker values. Stool markers' levels in 160 samples were measured colorimetrically. The analysis of twenty key bacteria (15 genera and 5 species) was carried out on the basis of diagnostic tests, including cultures and molecular tests. The concentrations of selected markers were within reference ranges for most patients. The sIgA level was significantly lower in participants declaring probiotics supplementation (p = 0.0464). We did not observe differences in gastrointestinal discomfort in participants. We found significant differences in the sIgA level between the 29-55 years and >55 years age-related intervals groups (p = 0.0191), together with a significant decreasing trend (p = 0.0337) in age-dependent sIgA concentration. We observed complex interdependencies and relationships between their microbiota and the analyzed biomarkers. For correct clinical application, standardized values of calprotectin and sIgA should be determined, especially in elderly patients. We observed a correlation between the composition of the gut community and biomarker levels, although it requires further in-depth analysis.

Association of fecal calprotectin level with eosinophilic gastrointestinal disease in Iranian pediatrics

Introduction

Fecal calprotectin (FC) is a noninvasive biomarker for assessing the inflammatory status of the gastrointestinal tract. The aim of this study was to determine the association between FC levels and Eosinophilic colitis (EC) before and after treatment in pediatrics.

Method

In this cross-sectional study, 330 patients with rectorrhagia and FC levels > 200 μg/g were included in the study. Patients were then subjected to colonoscopy, and if 30 or more eosinophils were observed in the pathology of at least two parts of the colon, EC was diagnosed. Of the 330 patients included in the study, 14 patients were diagnosed as EC. Treatment included seven food elimination diet (food allergens) for 3 months. After 3 months, FC levels were repeated and colonoscopy was performed.

Results

The mean age of the children was 5.9 years. After the elimination diet, the number of eosinophils in all segments of colon significantly decreased (P < 0.001) and according to the pathology report, the number of eosinophils improved in 42.9% of patients. Also, the mean number of segments involved in the colon of patients was significantly decreased (P < 0.001). Mean FC levels were significantly decreased after 3 months (P < 0.001). The cut-off point of 114 μg/g of FC had sensitivity (75%), specificity (67%), positive predictive value (75%), negative predictive value (67%), accuracy (71.4%), and area under the ROC curve (0.708) acceptable in predicting EC.

Conclusion

This study showed that FC levels can be elevated in patients with EC, which is easily corrected with a targeted elimination of food allergens.

The Impact of Dietary Fiber as a Prebiotic on Inflammation in Children with Obesity

Background: Obesity is associated with dysbiosis, contributing to inflammation and insulin resistance. Inulin might reduce inflammation by manipulating intestinal microbiota. Objective: We aimed to determine the effects of inulin supplementation on inflammation and assess the relationships of inflammatory cytokines with adiposity and insulin resistance in obese Thai children. Design: Obese Thai children ages 7−15 years were randomly assigned to inulin (intervention), maltodextrin (placebo), and dietary fiber advice groups. All participants received monthly follow-up and identical advice on lifestyle modification for six visits. Body composition was evaluated using bioelectrical impedance analysis. IL-1β, IL-6, TNF-α, and fecal calprotectin were analyzed by ELISA technique at baseline and the final visit. Spearman correlation was used to assess the associations between inflammation and other clinical outcome variables. Results: A total of 155 obese children completed the study (mean age: 10.4 ± 2.2 years, 59% male). All groups showed a significant decrease in BMI z-score, fat mass index (FMI), percent body fat, and trunk FMI. A generalized estimating equation (GEE) model showed significantly decreased IL-1β and TNF-α of 34.8% and 25.8%, (p < 0.0001) but increased IL-6 (21.5%, p = 0.006) in all groups. There were no significant differences in inflammatory cytokines and fecal calprotectin between groups. Mean IL-6 was higher in obese children with acanthosis nigricans (p = 0.048). Only IL-6 was positively correlated with body fat percentage and FMI (r = 0.29, p = 0.008 and r = 0.25, p = 0.049, respectively). Conclusions: Intensive behavioral modification and frequent follow-up visits were effective methods to reduce BMI and adiposity leading to decreased inflammatory cytokines. The additional benefits of inulin on inflammation could not be demonstrated due to the Hawthorne effect. Among the three cytokines, IL-6 was the most likely mediator relating FM and insulin resistance at baseline; therefore, it could be used as a surrogate marker of inflammation in obese children who are at risk for insulin resistance and metabolic syndrome.

Association between Fecal Calprotectin and Mucosal Healing in Pediatric Patients with Crohn's Disease Who Have Achieved Sustained Clinical Remission with Anti-Tumor Necrosis Factor Agents

Background/Aims

Although mucosal healing (MH) is acknowledged as the treatment target in the treat-to-target era, there are limitations on repeated endoscopic examinations, especially in pediatric patients. We aimed to investigate whether fecal calprotectin (FC) could serve as a surrogate marker for the assessment of MH in pediatric patients with Crohn’s disease (CD) who have achieved sustained clinical remission (CR) while treated with anti-tumor necrosis factor (TNF) agents.

Methods

This multicenter retrospective cross-sectional study included pediatric CD patients who had sustained a CR for at least 6 months with anti-TNF agents and who simultaneously underwent ileocolonoscopy and FC tests during follow-up. MH was defined as the absence of any ulcer on ileocolonoscopy.

Results

A total of 131 patients were included in this study. MH was observed in 87 patients (66.7%). The FC level was significantly lower in patients with MH than in those without MH (median 49.0 mg/kg vs 599.0 mg/kg; p<0.001). According to the multivariate logistic regression analysis, FC was the only factor associated with MH (odds ratio, 0.62; 95% confidence interval [CI], 0.52 to 0.73; p<0.001). According to the receiver operating characteristic curve analysis, the optimal cutoff value for FC for the association with MH was <140 mg/kg (area under the curve 0.890, 95% CI 0.829 to 0.951, sensitivity 78.2%, specificity 88.6%, p<0.001).

Conclusions

FC was associated with MH in pediatric patients with CD who had achieved a sustained CR for at least 6 months with anti-TNF agents. In these patients, FC can be used to stratify patients and guide decisions regarding ileocolonoscopy in the treat-to-target era.

The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

OBJECTIVES

The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children.

METHODS

A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors.

RESULTS

A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9.

CONCLUSIONS

Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schönlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.

Association of clinical characteristics and lifestyle factors with fecal S100/calgranulin concentrations in healthy dogs

Background

Fecal S100/calgranulin (S100A12 and calprotectin) concentrations are useful markers of gastrointestinal inflammation in dogs. In people, fecal S100/calgranulin concentrations are affected by age, obesity, diet and other lifestyle factors. Knowledge about the effects of such factors on fecal S100/calgranulin concentrations in dogs is currently scarce.

Objective

To evaluate the association between several factors and fecal S100/calgranulin concentrations in a large cohort of healthy adult dogs.

Methods

Single‐spot fecal samples from 181 healthy pet dogs and data derived from a standard questionnaire served to evaluate the effect of age, sex, reproductive status, body weight and body condition, breed type and size, vaccination, endoparasite treatment, diet, environment and travel history on fecal S100/calgranulin concentrations and the fecal calgranulin ratio (fCalR).

Results

Univariate analysis showed a significant association of reproductive status (in female dogs) and breed size with fecal S100A12, fecal calprotectin and fCalR. Breed type was linked to fecal S100A12 concentrations and fCalR; recent vaccination (particularly with a vaccine against canine parvovirus) to fCalR. In multivariate models, breed size was linked to fecal S100A12 and calprotectin concentrations, and recent vaccination affected S100A12 concentrations.

Conclusions

Breed size, recent vaccination and reproductive status in female dogs can affect fecal S100/calgranulin concentrations, and these biomarkers should be interpreted in light of those confounding factors. The utility of reference intervals for fecal canine S100/calgranulin concentrations might be improved through stratification by sex/reproductive status and breed size. Fecal canine S100/calgranulin concentrations are not confounded by age, body condition, deworming, diet, environment or travel history.

The Increased Levels of Fecal Calprotectin in Children With Active Enthesitis Related Arthritis and MRI Signs of Sacroiliitis: The Results of a Single Center Cross-Sectional Exploratory Study in Juvenile Idiopathic Arthritis Patients

Enthesitis related arthritis (ERA) is a specific subtype of juvenile idiopathic arthritis (JIA), often regarded as an undifferentiated form of juvenile spondyloarthritis (jSpA). While gut is increasingly recognized as origin and/or target of inflammation in adult onset spondyloarthritis (SpA), the incidence of gut involvement in ERA patients is largely unknown. The aim of this study was to measure the concentration of fecal calprotectin (fCAL), a surrogate marker of gut inflammation, in patients with different subtypes of JIA, as well as to correlate the results with various demographic, clinical, laboratory, imaging, and treatment characteristics. The cross-sectional exploratory study involving 71 patients with ERA, other forms of JIA and children complaining musculoskeletal symptoms was therefore conducted. Along with fCAL assessment, a detailed clinical and laboratory examination was performed, including the calculation of a composite disease activity scores. Moreover, MRI of the sacroiliac joints was performed in all ERA and other patients complaining of low back pain. The median concentration of fCAL was highest in ERA patients (33.2 mg/kg, p = 0.02), with a significant difference between those with inactive and active disease (20.0 vs. 57.4, p = 0.01), as well as those with and without MRI signs of sacroiliitis (22.6 vs. 54.3, p = 0.04). The fCAL did not differ depending on the NSAID use (23 vs. 20, p = 0.18), although weak correlation was observed with the treatment duration (r = 0.25, p = 0.03). In conclusion, our findings indicate that a parallel inflammation in musculoskeletal system and gut can occur not just in adults with SpA, but in children with ERA as well.

Fecal calprotectin in the pediatric population: a 2020 update

Calprotectin is a calcium and zinc-binding protein, formed by a hetero complex of S100A8 and S100A9 proteins, which belong to the S-100 protein family consisting in more than 20 different proteins with a tissue-specific expression pattern. This protein is secreted extracellularly from stimulated neutrophils or released by cell disruption or death. The presence of calprotectin in feces quantitatively relates to neutrophil migration toward the gastrointestinal (GI) tract; thus, it represents a useful marker of intestinal inflammation. Fecal calprotectin (FC) has been proven largely useful for determining the inflammatory origin of GI symptoms differentiating between organic and non-organic diseases. Indeed, increased FC levels are also seen in gastroenteritis, microscopic colitis, polyps, malignancies and cystic fibrosis. To date, there are many evidences regarding usefulness in the detection of fecal calprotectin for the management of gastrointestinal disorders, both in children and adults but, especially in the pediatric population, still clear indications for its use are lacking. Its incorporation in primary care reduces the risk of missing an organic disease and facilitates the indication for expensive and invasive investigations as colonoscopy. We herein review and discuss the last evidence on the usefulness of FC in children, with its current indications and future prospective.

Normal fecal calprotectin levels in healthy children are higher than in adults and decrease with age

Background/Objectives

The paediatric reference range of fecal calprotectin (FC) has not been decisively established and previous studies show a wide within-age variability, suggesting that other factors like anthropometric data or type of feeding can influence FC. Our aims were to establish the normal levels of FC in healthy children grouped by age and analyze whether sex, gestational age, birth weight, type of delivery, type of feeding, or anthropometric data influence FC values.

Methods

This multicentre, cross-sectional, and observational study enrolled healthy donors under 18 years of age who attended their Primary Health Care Centre for their routine Healthy Child Program visits. The exclusion criteria were: (i) immunodeficiency, (ii) autoimmune or (iii) gastrointestinal disease; (iv) medication usage; (v) gastrointestinal symptoms; or (vi) positive finding in the microbiological study.

Results

We enrolled 395 subjects, mean age was 4.2 years (range 3 days to 16.9 years), and 204 were male. The median FC was 77.0 mcg/g (interquartile range 246). A negative correlation between age and FC was observed (Spearman's rho = -0.603, P<0.01), and none of the other factors analyzed were found to influence FC levels.

Conclusions

Normal FC values in healthy children (particularly in infants) are higher than those considered to be altered in adults and show a negative correlation with age. It is necessary to reconsider the upper limits of FC levels for paediatric patients according to age, with further studies required to determine other factors that influence FC during infancy.

The role of fecal calprotectin in pediatric disease

Fecal calprotectin (FC) is a calcium- and zinc-binding protein of the S100 family, mainly expressed by neutrophils and released during inflammation. FC became an increasingly useful tool both for gastroenterologists and for general practitioners for distinguishing inflammatory bowel disease (IBD) from irritable bowel syndrome. Increasing evidences support the use of this biomarker for diagnosis, follow-up and evaluation of response to therapy of several pediatric gastrointestinal diseases, ranging from IBD to nonspecific colitis and necrotizing enterocolitis. This article summarizes the current literature on the use of FC in clinical practice.

A Study of Fecal Calprotectin in Obese Children and Adults

BACKGROUND

Obesity is a complex, medical condition causally contributing to many chronic diseases and a number of efforts have been made to find the associated markers for novel prevention and treatment of obesity. Our study was to evaluate the relationship between gut immune response and obesity and overweight with use of fecal calprotectin (FC) both in adult and children groups.

METHODS

Fecal samples were obtained from 74 subjects: 14 non-obese and overweight children (PN), 13 obese and overweight children (PO), 20 non-obese and overweight adults (AN), and 27 obese and overweight adults (AO). FC was measured using a commercial Legend Max quantitative enzyme-linked immunosorbent assay (BioLegend). Mann-Whitney U-test was used for statistical analysis.

RESULTS

Median FC concentration was 7.9 μg/g (range, 1.9-28.9 μg/g) for PN, 5.0 μg/g (range, 2.6-29.6 μg/g) for PO, 9.5 μg/g (range, 0.8-28.9 μg/g) for AN, and 10.0 μg/g (range, 1.6-25.6 μg/g) for AO, respectively. In both adults and children age groups, the FC showed no statistically significant difference between AO and AN or PO and PN. However, FC showed statistically significant difference (P<0.05) between AO and PO while not significant between AN and PN.

CONCLUSION

FC level in AO was significantly higher than that in PO, suggestive of different pathophysiologic mechanism between children obesity and adults obesity.

Efficacy of an Anthocyanin and Prebiotic Blend on Intestinal Environment in Obese Male and Female Subjects

Background

Anthocyanins and prebiotics impact overall health and wellness, likely through modulation of the microbiota and the intestinal ecosystem.

Objectives

An 8-week open-label study in male and female volunteers with uncomplicated obesity was designed to study the efficacy of an anthocyanin and prebiotic blend in modulating intestinal microbiota and intestinal inflammation.

Results

After 8 weeks of daily supplementation, participants had a significant decrease in Firmicutes (p < 0.001) and Actinobacteria (p < 0.001) and a significant increase in Bacteroidetes (p < 0.001). Bowel habits were improved as evidenced by reductions in the severity of bloating (p < 0.05), gas (p=0.035), and abdominal pain (p=0.015) as well as significant improvements in stool consistency (p < 0.05). Finally, a nonsignificant decrease in the inflammatory marker fecal calprotectin was seen (p=0.107). The supplement was safe and well tolerated.

Conclusions

The results suggest that regular consumption of the anthocyanin-prebiotic blend positively modulated the intestinal ecosystem and provided insights into the mechanisms of action and its impact on health benefits.

The Vampire Study: Significant elevation of faecal calprotectin in healthy volunteers after 300 ml blood ingestion mimicking upper gastrointestinal bleeding

Background

Faecal calprotectin correlates with histological and clinical activity in inflammatory bowel disease. Gastrointestinal bleeding might also increase faecal calprotectin levels, erroneously implying intestinal inflammation; however, this possibility has not been systematically assessed.

Methods

Sixteen healthy volunteers without gastrointestinal disease and normal faecal calprotectin baseline values ingested their own blood twice, either by drinking or via nasogastric tube. Quantities of 100 ml and 300 ml blood were ingested in a randomised order, with a 28-day wash-out period. Faecal calprotectin, faecal occult blood test, and the occurrence of melaena were assessed. Faecal calprotectin ≥ 50 µg/g was considered elevated.

Results

Melaena was reported by all healthy volunteers after 300 ml and by 11/15 healthy volunteers (71%) after 100 ml blood ingestion. One day after ingestion of 300 ml blood, 8/16 faecal calprotectin tests were positive compared to 1/16 at baseline (p = 0.016). Faecal calprotectin levels above > 200 µg/g were rarely observed. There was a trend for faecal calprotectin test positivity also after ingestion of 100 ml.

Conclusion

Ingestion of blood resulted in an increase in faecal calprotectin-positive tests. Gastrointestinal bleeding should be considered as a potential cause of mild faecal calprotectin elevation > 50 µg/g; however, increased faecal calprotectin above > 250-300 µg/g, the established cut-off for relevant intestinal inflammation in patients with inflammatory bowel disease, is rare.