Relationship between intestinal permeability and calprotectin concentration in gut lavage fluid

Design and rationale for the SIB trial: a randomized parallel comparison of semaglutide versus placebo on intestinal barrier function in type 2 diabetes mellitus

Objective

To describe the rationale and design of the SIB trial, an interventional clinical trial testing the hypothesis that subcutaneous (s.c.) once-weekly semaglutide can improve intestinal permeability and reduce systemic inflammation in participants with type 2 diabetes (T2D) and obesity.

Methods

SIB (NCT04979130) is an investigator-initiated, single-center randomized, double-blinded, placebo-controlled clinical study being conducted at the University of Colorado Anschutz Medical Campus. The primary objective of this novel trial is to test the hypothesis that subcutaneous (s.c.) once-weekly semaglutide could improve intestinal permeability and reduce systemic inflammation in participants with T2D and obesity. Eligible participants had a diagnosis of type 2 diabetes, elevated body mass index, and evidence of systemic inflammation. Participants were randomized 1:1 to s.c. semaglutide or placebo. Participants were assessed for intestinal permeability and markers of inflammation at baseline, mid-study, and at the end of the study. Efficacy assessments were based on the analysis of the following: lactulose:mannitol ratio test, serum lipopolysaccharide-binding protein (LBP), fecal calprotectin, inflammatory biomarkers (IL-6, TNF, IL-1, IL-8, hs-CRP), and HbA1c. All participants who enrolled in the trial provided written informed consent after having received written and oral information on the trial. The risks of semaglutide use were minimized by administration according to FDA-labeled use and close monitoring for adverse events.

Discussion

SIB is the first study to examine the effects of GLP-1 receptor agonists on intestinal permeability in humans and will provide important data on their impact on systemic inflammation and intestinal permeability in the setting of T2D and obesity.

Elevated Fecal Calprotectin Accompanied by Intestinal Neutrophil Infiltration and Goblet Cell Hyperplasia in a Murine Model of Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system caused by myelin-specific autoreactive T cells. We previously demonstrated intestinal barrier disruption and signs of inflammation in experimental autoimmune encephalomyelitis (EAE), a model of MS. Fecal calprotectin is a disease activity biomarker in inflammatory bowel diseases, released by neutrophils in response to inflammation. We aimed to further investigate EAE manifestations in the gastrointestinal tract and to determine whether calprotectin is a useful biomarker of intestinal inflammation in EAE. Calprotectin was analyzed in feces, cecal contents, and plasma of EAE mice. Infiltrating neutrophils and goblet cells were investigated in different parts of the gastrointestinal tract before the onset of neurological symptoms and during established disease. We found increased calprotectin levels in feces, cecal content, and plasma preceding EAE onset that further escalated during disease progression. Increased neutrophil infiltration in the intestinal tissue concomitant with IL-17 expression and myeloperoxidase activity was found to correlate well with clinical activity. Increased goblet cells in the intestine, similar to irritable bowel syndrome (IBS), were also observed. The results suggest calprotectin as a good biomarker of gastrointestinal inflammation in EAE and the potential of this model as a useful animal model for IBS.

Increased dietary vitamin D3 and calcium partially alleviate heat stress symptoms and inflammation in lactating Holstein cows independent of dietary concentrations of vitamin E and selenium

Twelve multiparous Holstein cows (42.2 ± 5.6 kg of milk/d; 83 ± 27 d in milk) were used in a split-plot design testing the effects of mineral and vitamin supplementation on the time course of animal performance, metabolism, and inflammation markers during heat stress. The main plot was the average concentrations of dietary vitamin E and Se (adequate: 11.1 IU/kg of vitamin E and 0.55 mg/kg of Se, and high: 223 IU/kg of vitamin E and 1.8 mg/kg of Se, respectively). Within each plot, cows were randomly assigned to (1) heat stress (HS) with adequate concentrations of vitamin D₃ and Ca (1,012 IU/kg and 0.73%, respectively), (2) HS with high concentrations of vitamin D₃ and Ca (HS+D₃/Ca; 3,764 IU/kg and 0.97%, respectively), or (3) pair-feeding (PF) in thermoneutrality with adequate concentrations of vitamin D₃ and Ca (1,012 IU/kg and 0.73% Ca) in a Latin square design with 14-d periods and 7-d washouts. The highest rectal temperature was recorded at 1700 h for HS (39.4°C; mean of d 1 to 14), being 1.2 and 0.8°C greater than for PF and HS+D₃/Ca, respectively. Respiratory rate and water intake were higher in HS (73 breaths/min and 115 L/d, respectively) relative to PF (28 breaths/min and 76 L/d). Heat stress decreased dry matter intake progressively, reaching a nadir on d 5 to 7 (33% reduction) and was not different between treatments. Milk yield decreased progressively in all treatments, but remained greater in PF relative to HS from d 3 to 14 (10%), whereas HS and HS+D₃/Ca were not different. Milk fat, protein, and lactose concentrations and yields were lower in HS relative to PF from d 3 to 14, but not different between HS and HS+D₃/Ca. Relative to PF, preprandial insulin concentrations were increased in HS, whereas plasma nonesterified fatty acids were decreased on d 7 and 14. Plasma lipopolysaccharide-binding protein concentrations increased in HS cows on d 7 and 14, respectively, relative to PF, whereas they were reduced in HS + D₃/Ca on d 14. Plasma C-reactive protein, tumor necrosis factor-α, and fecal calprotectin were increased in HS relative to both PF and HS+D₃/Ca on d 7 and 14. Rectal temperature was positively associated with plasma lipopolysaccharide-binding protein (r = 0.72), tumor necrosis factor-α (r = 0.74), C-reactive protein (r = 0.87), and with milk somatic cells (r = 0.75). Plasma 8-hydroxy-2-deoxyguanosine concentrations presented a 3-way interaction, where 8-hydroxy-2-deoxyguanosine was lower in HS than in PF on d 7 and 14, and lower in HS+D₃/Ca relative to HS on d 14 in the adequate vitamin E and Se treatment, but no effects were observed in the high vitamin E and Se group. Plasma superoxide dismutase concentrations increased over time, and were higher in HS relative to PF on d 14, whereas HS+D₃/Ca was similar to HS. Heat stress markedly reduced milk production and milk components while increasing markers of leaky gut and inflammation. In contrast, vitamin D₃ and Ca supplementation reduced hyperthermia (d 7-14), markers of leaky gut, and inflammation independent of dietary concentrations of vitamin E and Se.

Analysis of correlations between gut microbiota, stool short chain fatty acids, calprotectin and cardiometabolic risk factors in postmenopausal women with obesity: a cross-sectional study

BACKGROUND

Microbiota and its metabolites are known to regulate host metabolism. In cross-sectional study conducted in postmenopausal women we aimed to assess whether the microbiota, its metabolites and gut barrier integrity marker are correlated with cardiometabolic risk factors and if microbiota is different between obese and non-obese subjects.

METHODS

We analysed the faecal microbiota of 56 obese, postmenopausal women by means of 16S rRNA analysis. Stool short chain fatty acids, calprotectin and anthropometric, physiological and biochemical parameters were correlates to microbiome analyses.

RESULTS

Alpha-diversity was inversely correlated with lipopolysaccharide (Rho = - 0.43, FDR P (Q) = 0.004). Bray-Curtis distance based RDA revealed that visceral fat and waist circumference had a significant impact on metabolic potential (P = 0.003). Plasma glucose was positively correlated with the Coriobacteriaceae (Rho = 0.48, Q = 0.004) and its higher taxonomic ranks, up to phylum (Actinobacteria, Rho = 0.46, Q = 0.004). At the metabolic level, the strongest correlation was observed for the visceral fat (Q < 0.15), especially with the DENOVOPURINE2-PWY, PWY-841 and PWY0-162 pathways. Bacterial abundance was correlated with SCFAs, thus some microbiota-glucose relationships may be mediated by propionate, as indicated by the significant average causal mediation effect (ACME): Lachnospiraceae (ACME 1.25, 95%CI (0.10, 2.97), Firmicutes (ACME 1.28, 95%CI (0.23, 3.83)) and Tenericutes (ACME - 0.39, 95%CI (- 0.87, - 0.03)). There were significant differences in the distribution of phyla between this study and Qiita database (P < 0.0001).

CONCLUSIONS

Microbiota composition and metabolic potential are associated with some CMRF and fecal SCFAs concentration in obese postmenopausal women. There is no unequivocal relationship between fecal SCFAs and the marker of intestinal barrier integrity and CMRF. Further studies with appropriately matched control groups are warranted to look for causality between SCFAs and CMRF.

Trends of fecal calprotectin levels and associations with early life experience in preterm infants

Background

Preterm infants are at risk for severe infections due to their immature immune systems. Factors such as early life pain/stress experiences and feeding may influence immune activation and maturation of immune systems. However, the underlying mechanism remains unclear. Fecal calprotectin (FCP) is a noninvasive surrogate biomarker of mucosal inflammation in the gastrointestinal tract and has been used in detecting intestinal inflammation in specific pediatric gastrointestinal disorders.

Objective

To describe the longitudinal trajectory of FCP levels in preterm infants and investigate the contributing factors that are associated with FCP levels.

Design

A longitudinal study design was used.

Settings

Preterm infants were recruited from 2 neonatal intensive care units (NICU) of a children's medical center in the North-eastern US.

Methods

Preterm infants were followed during their first 4 weeks of NICU hospitalization. Stool samples were collected twice per week to quantify the FCP levels. Cumulative pain/stress experiences and feeding types were measured daily. A linear mixed-effect model was used to examine the associations between FCP levels and demographic and clinical characteristics, cumulative pain/stress, and feeding over time.

Results

Forty-nine preterm infants were included in the study. Infants' FCP levels varied largely with a mean of 268.7±261.3 µg/g and increased over time. Preterm infants experienced an average of 7.5±5.0 acute painful procedures and 15.3±20.8 hours of chronic painful procedures per day during their NICU stay. The mean percentage of mother's own milk increased from the first week (57.1±36.5%) to the fourth week (60.7±38.9%) after birth. Elevated FCP concentration was associated with acute and cumulative (chronic) pain/stress levels, mother's own milk, non-White race, and higher severity of illness score.

Conclusions

FCP levels were elevated in preterm infants with wide interindividual and intraindividual variations. Cumulative pain/stress during the NICU hospitalization, feeding, race, and health status may influence FCP concentrations in early life that may be associated with inflammatory gut processes.

Does a single exposure to social defeat render rats more vulnerable to chemically induced colitis than brief inescapable foot-shocks?

All mammals are to different degrees exposed to stressors being physical or social, which may affect health and well-being. Stressful and traumatic situations have direct effects on immune responses that may alter susceptibility to developing somatic illnesses. In animal research, different types of stressors have been investigated in studying the effect on bowel disorders, some stressors being more or less of environmental origin. We aimed, therefore, to explore whether a more natural stressor would differ from a stressor of more unnatural characteristics on dextran sulphate sodium (DSS) induced colitis in adult rats. Specifically, whether social stress within a single social defeat (SD) paradigm would be a more potent stressor than brief inescapable foot-shocks (IFS) in causing elevated faecal granulocyte marker protein (GMP), and crypt- and inflammation scores in colonic tissue. Three groups of male Wistar rats were used; socially defeated rats; inescapable foot-shock rats; and comparison rats. Main findings showed no difference between the groups on GMP levels. However, there was a significant difference on inflammation and crypt scores for the distal part of colon, detected through histology, where socially defeated rats were more susceptible. A single SD seems to be more adverse than inescapable foot-shock on DSS induced colitis, but further studies are recommended to validate a broader range of different outcomes comparing two such different rodent stress models.

Women with type 1 diabetes exhibit a progressive increase in gut Saccharomyces cerevisiae in pregnancy associated with evidence of gut inflammation

AIMS

Studies of the gut microbiome have focused on its bacterial composition. We aimed to characterize the gut fungal microbiome (mycobiome) across pregnancy in women with and without type 1 diabetes.

METHODS

Faecal samples (n = 162) were collected from 70 pregnant women (45 with and 25 without type 1 diabetes) across all trimesters. Fungi were analysed by internal transcribed spacer 1 amplicon sequencing. Markers of intestinal inflammation (faecal calprotectin) and intestinal epithelial integrity (serum intestinal fatty acid binding protein; I-FABP), and serum antibodies to Saccharomyces cerevisiae (ASCA) were measured.

RESULTS

Women with type 1 diabetes had decreased fungal alpha diversity by the third trimester, associated with an increased abundance of Saccharomyces cerevisiae that was inversely related to the abundance of the anti-inflammatory butyrate-producing bacterium Faecalibacterium prausnitzii. Women with type 1 diabetes had higher concentrations of calprotectin, I-FABP and ASCA.

CONCLUSIONS

Women with type 1 diabetes exhibit a shift in the gut mycobiome across pregnancy associated with evidence of gut inflammation and impaired intestinal barrier function. The relevance of these findings to the higher rate of pregnancy complications in type 1 diabetes warrants further study.

Efficacy of probiotics for managing infantile colic due to their anti-inflammatory properties: a meta-analysis and systematic review

BACKGROUND

Infantile colic (IC) is excessive crying in otherwise healthy children. Despite vast research efforts, its etiology remains unknown.

PURPOSE

Most treatments for IC carry various side effects. The collection of evidence may inform researchers of new strategies for the management and treatment of IC as well as new clues for understanding its pathogenesis. This review and meta-analysis aimed to evaluate the efficacy and possible mechanisms of probiotics for mananaging IC.

METHODS

Ten papers met the study inclusion and exclusion criteria, and the meta-analysis was conducted using Review Manager (RevMan) software and a random-effects model.

RESULTS

This meta-analysis revealed that probiotics are effective for treating infantile colic, while the review showed that this efficacy may be due to their anti-inflammatory effects.

CONCLUSION

Probiotics may be an important treatment option for managing infantile colic due to their anti-inflammatory properties.

Type 1 diabetes in pregnancy is associated with distinct changes in the composition and function of the gut microbiome

BACKGROUND

The gut microbiome changes in response to a range of environmental conditions, life events and disease states. Pregnancy is a natural life event that involves major physiological adaptation yet studies of the microbiome in pregnancy are limited and their findings inconsistent. Pregnancy with type 1 diabetes (T1D) is associated with increased maternal and fetal risks but the gut microbiome in this context has not been characterized. By whole metagenome sequencing (WMS), we defined the taxonomic composition and function of the gut bacterial microbiome across 70 pregnancies, 36 in women with T1D.

RESULTS

Women with and without T1D exhibited compositional and functional changes in the gut microbiome across pregnancy. Profiles in women with T1D were distinct, with an increase in bacteria that produce lipopolysaccharides and a decrease in those that produce short-chain fatty acids, especially in the third trimester. In addition, women with T1D had elevated concentrations of fecal calprotectin, a marker of intestinal inflammation, and serum intestinal fatty acid-binding protein (I-FABP), a marker of intestinal epithelial damage.

CONCLUSIONS

Women with T1D exhibit a shift towards a more pro-inflammatory gut microbiome during pregnancy, associated with evidence of intestinal inflammation. These changes could contribute to the increased risk of pregnancy complications in women with T1D and are potentially modifiable by dietary means. Video abstract.

Chromogranin A regulates gut permeability via the antagonistic actions of its proteolytic peptides

AIM

A "leaky" gut barrier has been implicated in the initiation and progression of a multitude of diseases, for example, inflammatory bowel disease (IBD), irritable bowel syndrome and celiac disease. Here we show how pro-hormone Chromogranin A (CgA), produced by the enteroendocrine cells, and Catestatin (CST: hCgA_352-372 ), the most abundant CgA-derived proteolytic peptide, affect the gut barrier.

METHODS

Colon tissues from region-specific CST-knockout (CST-KO) mice, CgA-knockout (CgA-KO) and WT mice were analysed by immunohistochemistry, western blot, ultrastructural and flowcytometry studies. FITC-dextran assays were used to measure intestinal barrier function. Mice were supplemented with CST or CgA fragment pancreastatin (PST: CgA_250-301 ). The microbial composition of cecum was determined. CgA and CST levels were measured in blood of IBD patients.

RESULTS

Plasma levels of CST were elevated in IBD patients. CST-KO mice displayed (a) elongated tight, adherens junctions and desmosomes similar to IBD patients, (b) elevated expression of Claudin 2, and (c) gut inflammation. Plasma FITC-dextran measurements showed increased intestinal paracellular permeability in the CST-KO mice. This correlated with a higher ratio of Firmicutes to Bacteroidetes, a dysbiotic pattern commonly encountered in various diseases. Supplementation of CST-KO mice with recombinant CST restored paracellular permeability and reversed inflammation, whereas CgA-KO mice supplementation with CST and/or PST in CgA-KO mice showed that intestinal paracellular permeability is regulated by the antagonistic roles of these two peptides: CST reduces and PST increases permeability.

CONCLUSION

The pro-hormone CgA regulates the intestinal paracellular permeability. CST is both necessary and sufficient to reduce permeability and primarily acts by antagonizing PST.

The gut microbiota is associated with the small intestinal paracellular permeability and the development of the immune system in healthy children during the first two years of life

BACKGROUND

The intestinal barrier plays an important role in the defense against infections, and nutritional, endocrine, and immune functions. The gut microbiota playing an important role in development of the gastrointestinal tract can impact intestinal permeability and immunity during early life, but data concerning this problem are scarce.

METHODS

We analyzed the microbiota in fecal samples (101 samples in total) collected longitudinally over 24 months from 21 newborns to investigate whether the markers of small intestinal paracellular permeability (zonulin) and immune system development (calprotectin) are linked to the gut microbiota. The results were validated using data from an independent cohort that included the calprotectin and gut microbiota in children during the first year of life.

RESULTS

Zonulin levels tended to increase for up to 6 months after childbirth and stabilize thereafter remaining at a high level while calprotectin concentration was high after childbirth and began to decline from 6 months of life. The gut microbiota composition and the related metabolic potentials changed during the first 2 years of life and were correlated with zonulin and calprotectin levels. Faecal calprotectin correlated inversely with alpha diversity (Shannon index, r = - 0.30, FDR P (Q) = 0.039). It also correlated with seven taxa; i.a. negatively with Ruminococcaceae (r = - 0.34, Q = 0.046), and Clostridiales (r = - 0.34, Q = 0.048) and positively with Staphylococcus (r = 0.38, Q = 0.023) and Staphylococcaceae (r = 0.35, Q = 0.04), whereas zonulin correlated with 19 taxa; i.a. with Bacillales (r = - 0.52, Q = 0.0004), Clostridiales (r = 0.48, Q = 0.001) and the Ruminococcus (torques group) (r = 0.40, Q = 0.026). When time intervals were considered only changes in abundance of the Ruminococcus (torques group) were associated with changes in calprotectin (β = 2.94, SE = 0.8, Q = 0.015). The dynamics of stool calprotectin was negatively associated with changes in two MetaCyc pathways: pyruvate fermentation to butanoate (β = - 4.54, SE = 1.08, Q = 0.028) and Clostridium acetobutylicum fermentation (β = - 4.48, SE = 1.16, Q = 0.026).

CONCLUSIONS

The small intestinal paracellular permeability, immune system-related markers and gut microbiota change dynamically during the first 2 years of life. The Ruminococcus (torques group) seems to be especially involved in controlling paracellular permeability. Staphylococcus, Staphylococcaceae, Ruminococcaceae, and Clostridiales, may be potential biomarkers of the immune system. Despite observed correlations their clear causation and health consequences were not proven. Mechanistic studies are required.

Intestinal Mucosal Wound Healing and Barrier Integrity in IBD-Crosstalk and Trafficking of Cellular Players

The intestinal epithelial barrier is carrying out two major functions: restricting the entry of potentially harmful substances while on the other hand allowing the selective passage of nutrients. Thus, an intact epithelial barrier is vital to preserve the integrity of the host and to prevent development of disease. Vice versa, an impaired intestinal epithelial barrier function is a hallmark in the development and perpetuation of inflammatory bowel disease (IBD). Besides a multitude of genetic, molecular and cellular alterations predisposing for or driving barrier dysintegrity in IBD, the appearance of intestinal mucosal wounds is a characteristic event of intestinal inflammation apparently inducing breakdown of the intestinal epithelial barrier. Upon injury, the intestinal mucosa undergoes a wound healing process counteracting this breakdown, which is controlled by complex mechanisms such as epithelial restitution, proliferation and differentiation, but also immune cells like macrophages, granulocytes and lymphocytes. Consequently, the repair of mucosal wounds is dependent on a series of events including coordinated trafficking of immune cells to dedicated sites and complex interactions among the cellular players and other mediators involved. Therefore, a better understanding of the crosstalk between epithelial and immune cells as well as cell trafficking during intestinal wound repair is necessary for the development of improved future therapies. In this review, we summarize current concepts on intestinal mucosal wound healing introducing the main cellular mediators and their interplay as well as their trafficking characteristics, before finally discussing the clinical relevance and translational approaches to therapeutically target this process in a clinical setting.

Correlation between Fecal Calprotectin Levels in Meconium and Vitamin D Levels in Cord Blood: Association with Intestinal Distress

We aimed to investigate the correlation between vitamin D status in cord blood and fecal calprotectin concentrations in meconium, and also find their association with intestinal distress symptoms during the first two weeks of life. Two hundred and twenty-eight newborns were enrolled in the study who were delivered at Kyungpook National University Children’s Hospital between July 2016 and August 2017. The first passed meconium samples were collected for fecal calprotectin analysis. Intestinal distress involved infants with necrotizing enterocolitis (NEC) and other feeding interruption signs. The median gestational age of the population was 37.0 (34.3–38.4) weeks, and the median birth weight was 2635 (2100–3268) g. The median fecal calprotectin levels in meconium were 134.1 (55.6–403.2) μg/g (range: 11.5–2000 μg/g) and the median 25-hydroxyvitamin D (25-OHD) concentrations in cord blood were 21.0 (15.5–28.8) ng/mL. Sixty infants (26.3%) had intestinal distress, including four patients (1.8%) diagnosed as having NEC. Higher fecal calprotectin concentrations (398.2 (131.8–900.2) μg/g vs. 105.6 (39.4–248.5) μg/g, p < 0.001) and lower 25-OHD levels (17.9 (12.8–22.1) ng/mL vs. 23.2 (17.2–33.0) ng/mL, p < 0.001) were found in infants with intestinal distress compared to infants without intestinal distress. The cut-off value was set at 359.8 μg/g with a sensitivity of 0.53 and a specificity of 0.82 for the development of intestinal distress in the first two weeks of life. Serum 25-OHD levels in cord blood were inversely correlated with fecal calprotectin concentrations in meconium.

Does Human Milk Fortifier Affect Intestinal Inflammation in Preterm Infants?

Background: Fecal calprotectin, a recognized marker of intestinal inflammation, is derived from neutrophil migration to a site of inflammation. Introduction of bovine-based human milk fortifier containing intact protein in preterm infants is associated with an increase in fecal calprotectin suggestive of intestinal inflammation. Newer fortifiers contain protein hydrolysates in place of intact protein. Objective: To measure fecal calprotectin in human milk-fed preterm infants before and after human milk fortification using a fortifier containing hydrolyzed protein. Methods: Serial stool samples were collected from 24 infants beginning at the first week to 60 days postnatal age. To compare the effect of human milk fortification, samples collected before and after fortification were compared. Infant demographics, diet, postnatal morbidities, and maternal characteristics were recorded. Results: A total of 401 stool samples were collected from 24 study infants who had a birth weight of 993 ± 277 g (mean ± standard deviation), gestational age 27.5 ± 2.8 weeks, and fortifier initiation at 14 days. Median fecal calprotectin before and after fortification were similar. Calprotectin levels were not correlated with birth weight or gestational age but were inversely correlated with postnatal age (p = 0.005), use of fortifier (p < 0.001), receipt of antibiotics antenatally (p = 0.007) and postnatally (p = 0.008). After adjusting for postnatal age, calprotectin levels were significantly lower following receipt of fortifier (p < 0.001) and postnatal antibiotics (p < 0.001). Conclusions: The feeding of protein hydrolysate-containing human milk fortifiers does not appear to be associated with increases in a marker of intestinal inflammation.

Role for diet in normal gut barrier function: developing guidance within the framework of food-labeling regulations

A reduction in intestinal barrier function is currently believed to play an important role in pathogenesis of many diseases, as it facilitates passage of injurious factors such as lipopolysaccharide, peptidoglycan, whole bacteria, and other toxins to traverse the barrier to damage the intestine or enter the portal circulation. Currently available evidence in animal models and in vitro systems has shown that certain dietary interventions can be used to reinforce the intestinal barrier to prevent the development of disease. The relevance of these studies to human health is unknown. Herein, we define the components of the intestinal barrier, review available modalities to assess its structure and function in humans, and review the available evidence in model systems or perturbations in humans that diet can be used to fortify intestinal barrier function. Acknowledging the technical challenges and the present gaps in knowledge, we provide a conceptual framework by which evidence could be developed to support the notion that diet can reinforce human intestinal barrier function to restore normal function and potentially reduce the risk for disease. Such evidence would provide information on the development of healthier diets and serve to provide a framework by which federal agencies such as the US Food and Drug Administration can evaluate evidence linking diet with normal human structure/function claims focused on reducing risk of disease in the general public.

Pathogenic Autoreactive T and B Cells Cross-React with Mimotopes Expressed by a Common Human Gut Commensal to Trigger Autoimmunity

Given the immense antigenic load present in the microbiome, we hypothesized that microbiota mimotopes can be a persistent trigger in human autoimmunity via cross-reactivity. Using antiphospholipid syndrome (APS) as a model, we demonstrate cross-reactivity between non-orthologous mimotopes expressed by a common human gut commensal, Roseburia intestinalis (R. int), and T and B cell autoepitopes in the APS autoantigen β₂-glycoprotein I (β₂GPI). Autoantigen-reactive CD4⁺ memory T cell clones and an APS-derived, pathogenic monoclonal antibody cross-reacted with R. int mimotopes. Core-sequence-dependent anti-R. int mimotope IgG titers were significantly elevated in APS patients and correlated with anti-β₂GPI IgG autoantibodies. R. int immunization of mice induced β₂GPI-specific lymphocytes and autoantibodies. Oral gavage of susceptible mice with R. int induced anti-human β₂GPI autoantibodies and autoimmune pathologies. Together, these data support a role for non-orthologous commensal-host cross-reactivity in the development and persistence of autoimmunity in APS, which may apply more broadly to human autoimmune disease.

Serial fecal calprotectin in the prediction of necrotizing enterocolitis in preterm neonates

PURPOSE

To investigate whether serial measurements of fecal calprotectin concentrations enable us to identify infants who will develop NEC prior to development of symptoms.

METHODS

Prospective matched case-control study including 100 high-risk neonates. High risk includes 1) gestational age (GA) ≤30 weeks, 2) birth-weight (BW) ≤1000 g, 3) GA 30-32 weeks and BW ≤1250 g, 4) born from a mother who received indomethacin for tocolysis. We matched every NEC subject with three controls for birth weight and gestational age. Fecal calprotectin was measured twice a week from day one until five weeks after birth or until NEC development. We analyzed differences in fecal calprotectin between NEC subjects and controls in the week preceding NEC onset and course of fecal calprotectin within subjects who developed NEC.

RESULTS

Of 100 included patients, ten (median GA 27.5 weeks [24.6-29.4], BW 1010 g [775-1630]) developed NEC. The median calprotectin concentration in all samples combined was 332 μg/g [<40-8230] μg/g feces. There were no differences between NEC subjects and controls, with a wide variation in both groups. In NEC subjects, there was no intraindividual rise in calprotectin before clinical symptoms occurred.

CONCLUSIONS

There are high concentrations and wide interindividual variations in calprotectin in preterm infants during the first weeks of life. Wide intraindividual variation further precludes the serial use of fecal calprotectin in the early detection or prediction of NEC in high risk infants.

LEVEL OF EVIDENCE

III.

Assessing intestinal permeability in Crohn's disease patients using orally administered 52Cr-EDTA

Background

Intestinal permeability can be assessed by monitoring renal excretion of orally administered radioactively ⁵¹Cr-labeled ethylenediaminetetraacetic acid (⁵¹Cr-EDTA). Although considered safe, patient participation in using radio-labeled tracers is low. Here, we used orally administered ⁵²Cr-EDTA as non-radioactive alternative to assess intestinal permeability in CD and analyzed the association with disease activity, disease location and gut microbial dysbiosis.

Materials and methods

60 CD patients with low (n = 25) and increased (n = 35) fecal calprotectin levels (cut-off: 100 μg/g feces) ingested 20 mL ⁵²Cr-EDTA (20 mmol/L) solution whereafter 24-h urine was collected. Urinary ⁵²Cr-EDTA concentrations were quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Fecal Enterobacteriaceae and Faecalibacterium prausnitzii were quantified using FISH. Correlations between urinary ⁵²Cr-EDTA excretion and other parameters were established using nonparametric Spearman’s correlation coefficients (ρ).

Results

CD patients with increased fecal calprotectin levels (> 100 μg/g) demonstrated an elevated urinary ⁵²Cr-EDTA/creatinine ratio (772 vs. 636 μmol/mol, P = 0.132). Patients with primarily colonic disease showed the highest ⁵²Cr-EDTA excretion. Importantly, a positive correlation was observed for the urinary ⁵²Cr-EDTA/creatinine ratio and fecal calprotectin levels (ρ = 0.325, P < 0.05). Finally, urinary ⁵²Cr-EDTA/creatinine ratio negatively correlated with the relative abundance of Faecalibacterium prausnitzii (ρ = -0.221, P = 0.092), while positively correlating with Enterobacteriaceae (ρ = 0.202, P = 0.126).

Conclusions

Orally administered and renal excreted ⁵²Cr-EDTA may be used to assess intestinal permeability in CD and correlates with fecal calprotectin levels and bacterial species relevant to CD. This test may improve non-invasive detection of disease exacerbations and help monitor disease activity.

Fecal Calprotectin and Eosinophil-derived Neurotoxin in Healthy Children Between 0 and 12 Years

OBJECTIVES

In young children, the use of fecal calprotectin (fCP) as a biomarker is limited because reference values have not been widely accepted up to now. Moreover, reference values for fecal eosinophil-derived neurotoxin (fEDN) in children have not been established. The aim of the present study was to investigate fCP and fEDN levels in young healthy children to establish reference values.

METHODS

Stool samples were obtained from healthy children ages 0 to 12 years. fCP and fEDN levels were analyzed using the EliA Calprotectin 2 assay (Phadia AB) and a novel research assay (on the ImmunoCAP platform), respectively.

RESULTS

In the 174 included children (87 boys), 95th Percentile values ranged from 1519 mg/kg at 0 months to 54.4 mg/kg at 144 months for fCP and from 9.9 mg/kg at 0 months to 0.2 mg/kg at 144 months for fEDN. There was a statistically significant association between age and fCP concentrations (P < 0.001) and age and fEDN concentrations (P < 0.001). We also found a statistically significant association between fEDN and fCP concentrations (rho = 0.52, P < 0.001). According to our results, we provide a nomogram and we suggest 3 different age groups for evaluation of fCP and fEDN concentrations, the 95th percentile being respectively 910.3 and 7.4 mg/kg for 0-12 months, 285.9 and 2.9 mg/kg for >1 to 4 years, and 54.4 and 0.2 mg/kg for >4 to 12 years.

DISCUSSION

By using an improved analytical method, we have confirmed that young healthy children have higher fCP concentrations than healthy adults. We, for the first time, report reference values for fEDN concentrations in a pediatric population. The proposed nomograms and reference values for fCP and fEDN are aimed at facilitating the applicability of biomarkers for both neutrophil- and eosinophil-mediated intestinal inflammation in children in clinical practice.

Systemic symptoms in irritable bowel syndrome: An investigative study on the role of enterocyte disintegrity, endotoxemia and inflammation

Irritable bowel syndrome (IBS) is often accompanied by extra-intestinal symptoms, including fatigue and musculoskeletal pain. The present study aimed to investigate whether these symptoms were associated with markers of enterocyte disintegrity, endotoxemia and inflammation. Patients with IBS were recruited consecutively from our outpatient clinic (n=94) and compared with a group of healthy controls (n=20). Habitual symptoms were assessed using the IBS Severity Scoring System, the Fatigue Impact Scale and Visual Analogue Scales for measuring musculoskeletal pain. A lactulose challenge test was performed to induce post-prandial symptoms, and blood samples were obtained prior to and 90 min following lactulose ingestion to determine levels of intestinal fatty acid binding protein (iFABP), lipopolysaccharide (LPS), the LPS co-receptor soluble cluster of differentiation (sCD) 14, monocyte chemoattractant protein-1 (MCP-1) and calprotectin. Habitual symptom scores were high among the included patients, and lactulose ingestion induced significantly more symptoms in the patient group compared with the healthy control group (P=0.0001). Serum levels of iFABP were reduced in IBS patients compared with healthy controls, prior to and following lactulose ingestion (P=0.0002 and P=0.0001, respectively). Following lactulose ingestion, iFABP levels decreased in IBS patients (P=0.0001) and in healthy controls (P=0.02). Fasting levels of LPS, sCD14, MCP-1 and calprotectin were not significantly different between IBS patients and healthy controls. However, following lactulose ingestion, LPS levels increased in healthy controls (P=0.03), whereas MCP-1 levels decreased in IBS patients (P=0.008). Intestinal and extra-intestinal symptom severities were not correlated with levels of circulating biomarkers. No assessed biomarker in the present study appeared to be associated with symptom development in IBS patients. However, the implications of the low levels of iFABP observed require further investigation.

Extra-intestinal symptoms in patients with irritable bowel syndrome: related to high total IgE levels and atopic sensitization?

Objective We have previously found that high levels of total IgE, but not atopic sensitization, was a significant predictor for functional gastrointestinal (GI) symptoms. In this study, we aimed to assess the prevalence of extra-intestinal symptoms in IBS patients, and explore their relation to total IgE levels and atopic sensitization. Materials and methods Seventy-one patients with functional GI complaints were included. Severity of GI symptoms, fatigue and musculoskeletal pain was evaluated using the following questionnaires: IBS-Severity Scoring System (IBS-SSS), Fatigue Impact Scale (FIS), FibroFatigue Scale (FFS), and Visual Analog Scales (VAS) for musculoskeletal pain. Levels of total IgE and specific IgE-antibodies were analyzed. Results Fatigue and musculoskeletal pain were demonstrated in 78.9 and 43.7% of the patients, respectively. IBS-SSS scores were significantly correlated with fatigue scores and musculoskeletal pain. Patients with fatigue and musculoskeletal pain had significantly higher IBS-SSS scores than patients without fatigue and musculoskeletal pain. Total IgE levels were significantly higher in IBS patients compared to a healthy control group from a previous study. However, neither total IgE nor atopic sensitization was significantly associated with extra-intestinal symptoms. Conclusions IBS, fatigue, and musculoskeletal pain were significantly associated. Total IgE levels were higher in IBS patients than healthy controls, but not related to intestinal or extra-intestinal symptom severity. Atopy was not associated with any of the co-morbidities. Thus, the clinical significance of high IgE levels in IBS remains unclear and further studies are warranted to explore a common underlying mechanism for the co-morbid triad of IBS, fatigue, and musculoskeletal pain.

Influence of Breed Size, Age, Fecal Quality, and Enteropathogen Shedding on Fecal Calprotectin and Immunoglobulin A Concentrations in Puppies During the Weaning Period

Background

Fecal calprotectin and immunoglobulin A (IgA) are markers of intestinal inflammation and immunity in adult dogs.

Hypothesis

Fecal calprotectin and IgA concentrations in puppies are not influenced by fecal moisture in puppies but by enteropathogen shedding.

Animals

Three hundred and twenty‐four puppies.

Methods

Fecal consistency was assessed by gross examination. Fecal moisture was evaluated before and after lyophilization. Canine parvovirus and coronavirus were detected in feces by qPCR and qRT‐PCR respectively. Giardia intestinalis antigen was quantified by ELISA. The standard McMaster flotation technique was used to detect eggs and oocysts in feces. Fecal calprotectin and IgA concentrations were quantified by in‐house radioimmunoassays.

Results

For each marker (IgA and calprotectin), a strong positive correlation was observed between concentration in fresh feces and concentration in fecal dry matter. 75.6% of the puppies were found to be infected by at ≥1 of the enteropathogens evaluated. Fecal calprotectin concentration was significantly influenced by age (P = .001), with higher concentrations in younger puppies, but not by viral (P = .863) or parasitic infection (P = .791). Fecal IgA concentration was significantly influenced by enteropathogen shedding (P = .01), with a lower fecal IgA concentration in puppies shedding at ≥1 enteropathogen compared to puppies without any enteropathogen shedding, but not by age.

Conclusions

Fecal calprotectin and IgA are of no diagnostic value to detect presence of enteropathogens in clinically healthy puppies or puppies with abnormal feces, but could help to better understand the maturation of digestive tract.

What is known about the mechanisms of dietary influences in Crohn's disease?

Much has been written about the role of diet and risk for Crohn's disease (CD). However, the evidence is contradictory. Recent evidence has pointed to fiber playing an important role along with the possibility that dietary fat and overnutrition also have a role. Diet has a clearer place in disease modification, with some diets used in the treatment of CD. The lack of clarity stems from a poor understanding of the mechanisms underlying the relationship between diet and CD. Gut permeability is likely to play a key role in the risk for CD. Mechanisms whereby diet can affect gut permeability, including the effects of the gut microbiota, are reviewed. Modification of disease behavior is likely to be influenced by additional mechanisms, including recognition of complex food antigens. As with many other chronic diseases, a surrogate marker of CD risk would greatly aid evaluation of the dietary factors involved. Formal measures of gut permeability are too cumbersome for large-scale use, but fecal calprotectin may be a convenient measure of this. There are only preliminary data on the effect of diet and microbiota composition on fecal calprotectin and these require further investigation.

Rectal effluent as a research tool

Studies of localized secretions are generally superior to those of blood because they contain higher concentrations of molecules specific to the organ of interest. A common method used to analyze localized secretions is lavage. The flow of fluid over the lining of a cavity picks up both cells and soluble factors, and the effluent can be collected for study. Gastrointestinal (GI) lavage is easily and noninvasively performed by the administration of gut lavage solutions such as those routinely given to patients prior to colonoscopy, with GI lavage fluid being the copious, watery rectal effluent subsequently induced. Residual effluent is currently suctioned from the colon and discarded during colonoscopy. With millions of routine colonoscopies performed per year, GI lavage fluid is a rich and largely untapped resource for basic and clinical research. Rectal effluent can also be easily collected in a toilet receptacle without need for a colonoscopy. Rectal effluent generated in this manner has been used to study diarrheal disease, mucosal immunology, inflammatory bowel disease, celiac disease, and cancer. It is often referred to as gut lavage, colon lavage, GI lavage, or whole gut lavage fluid, which makes it challenging to locate previous studies in the literature and there are currently no comprehensive reviews of its use as a research tool. This review attempts to fill this void by discussing previous applications of rectal effluent in research and the methods that have been developed for its collection, stabilization, and analysis.

Fecal calprotectin is an effective diagnostic tool that differentiates inflammatory from functional intestinal disorders

BACKGROUND

The clinical pictures of functional gastrointestinal disorders and inflammatory diseases can be quite similar leading to inappropriate and expensive investigations. Objective. To investigate fecal calprotectin (FC) diagnostic performance in different gastrointestinal conditions.

MATERIAL AND METHODS

Stool specimens of 66 outpatients referred for colonoscopy were collected for further FC determination. Diagnostic accuracy was assessed by the area under the curve (AUC). Sensitivity (Se), specificity (Sp), positive (PPV), and negative predictive values (NPV) were calculated according to the presence of inflammation and the main final diagnosis.

RESULTS

Histological inflammation was found in 45 (68%) patients: 24 had a diagnosis of inflammatory bowel disease (IBD) while 21 reported miscellaneous conditions (5 microscopic colitis, 2 eosinophilic colitis, and 14 nonspecific chronic colitis). The diagnosis in the 21 (32%) patients without inflammation was irritable bowel syndrome (IBS). Median FC values were 268 µg/g (95% CI, 151-343) and 49 µg/g (95% CI, 23-101) in patients with and without inflammation, respectively (p = 0.0001). AUC value of FC was 0.811 (Se = 68.9%, Sp = 71.4%, PPV = 83.8%, and NPV = 56.3% with a cutoff value of 100 µg/g) for discriminating between patients with and without inflammation and 0.931 (Se = 87.5%, Sp = 90.5%, PPV = 91.3%, and NPV = 86.4% with a cutoff value of 150 µg/g) for discriminating between patients with IBS and IBD. Using the cutoff value recommended by the manufacturer (50 µg/g), we found Se =100%, Sp =52.4%, PPV =70.6%, and NPV =100% for the diagnosis of IBD.

CONCLUSIONS

FC appears to be a reliable noninvasive biomarker of intestinal inflammation useful to improve the appropriateness of colonoscopy requests.

Review article: intestinal barrier dysfunction and central nervous system disorders--a controversial association

BACKGROUND

Central nervous system (CNS) development and physiopathology are greatly affected by environmental stimuli. The intestinal barrier restricts the entrance of toxins, pathogens, and antigens while modulating the expression of various neuroactive compounds. The existence of a rich gut-to-brain communication raises the possibility that intestinal barrier alterations may take part in the pathophysiology of CNS disorders.

AIM

To review evidence associating intestinal barrier dysfunction with the development of CNS disorders.

METHODS

Literature search was conducted on PubMed using the following terms: intestinal barrier, intestinal permeability, central nervous system, mental disorders, schizophrenia, autism, stress, anxiety, depression, and neurodegeneration.

RESULTS

Clinical and animal model studies of the association between intestinal barrier and schizophrenia, autism spectrum disorders, neurodegenerative diseases or depression were reviewed. The majority of reports concentrated on schizophrenia and autism spectrum disorders. About half of these described increased intestinal permeability/mucosal damage in patients compared with healthy controls, with up to 43% of children with autism spectrum disorders and up to 35% of schizophrenia patients displaying abnormally high urinary excretion of the sugars used as permeability markers. However, another substantial group of studies did not find such differences. In autism spectrum disorders, some reports show that the use of diets such as the gluten-free casein-free diet may contribute to the normalisation of lactulose/mannitol ratio, but to date there is no adequately controlled study showing improvement in behavioural symptoms following these dietary interventions.

CONCLUSIONS

Evidence of altered intestinal permeability in individuals suffering from CNS disorders is limited and cannot be regarded as proven. Moreover the efficacy of targeting gut barrier in the management of neurological and behavioural aspects of CNS disorders has not yet been established, and needs further investigation.

Comparison of the different kinds of feeding on the level of fecal calprotectin

BACKGROUND

Controversial results have been reported on the effect of type of feeding on the level of fecal calprotectin in infants.

OBJECTIVE

To assess fecal calprotectin levels in breast fed or nonbreast fed healthy infants.

DESIGN

A study was conducted to compare fecal calprotectin in infants who were exclusively breastfed compared to those who were not breastfed in Shanghai, China. Stool samples were collected and analyzed, and the fecal calprotectin concentration was determined using a commercially available enzyme-linked immunosorbent assay. The infant's weight and length were measured. Parents were asked to fill in a brief questionnaire, with questions about several clinical and sociodemographic factors.

SUBJECTS

This study included 105 healthy infants aged 0-5 months.

RESULTS

Stool samples were obtained from 105 healthy infants (63 boys, 42 girls) with a median age of 2.86 months (range 1-5.88). The median fecal calprotectin concentration was significantly higher in breast fed infants (377μg/g, range 35-937μg/g) than that in nonbreast fed ones (233μg/g, range 37-895μg/g) (p=0.001). A correlation was found that from 0 to 5 months, fecal calprotectin was negatively and significantly associated with age in both two kinds of feeding (breast fed: Spearman's rho -0.346, p=0.010; nonbreast fed: Spearman's rho -0.478, p<0.001).

CONCLUSIONS

Our findings show that the kind of feeding influences the fecal calprotectin concentration and breast fed infants have higher levels than nonbreast fed ones in the first months of life. This may represent that human milk influences the gut mucosa by immunomodulating factors.

Fecal calprotectin concentration in neonatal necrotizing enterocolitis

PURPOSE

Among the many factors associated with acute intestinal mucosal infection, numerous studies have proposed the usefulness of fecal calprotectin. The aim of this study was to evaluate the usefulness of fecal calprotectin in the diagnosis of necrotizing enterocolitis (NEC).

METHODS

We collected 154 stool samples from 16 very low birth weight and premature newborns at the Konyang University Hospital neonatal intensive care unit or neonatal nursery. The stool samples were collected using the Calprest device, and the fecal calprotectin level was measured with the BÜHLMANN Calprotectin enzyme-linked immunosorbent assay kit.

RESULTS

Fecal calprotectin levels were significantly higher in the NEC group than in the non-NEC group (P=0.02). There was a significant positive linear relationship between the fecal calprotectin level and number of days after birth (P=0.00) in the gestational age <26 weeks group. There was a significant negative linear relationship between the calprotectin level and number of days after birth (P=0.03) in the gestational age ≥26 weeks and <30 weeks group. There was no difference in the calprotectin levels according to the type and method of feeding between the NEC and non-NEC groups.

CONCLUSION

Fecal calprotectin levels were significantly increased in premature infants with NEC. The fecal calprotectin test is a noninvasive, easy, and useful tool for the diagnosis of NEC.

Indication of immune activation in patients with perceived food hypersensitivity

Majority of the patients with perceived food hypersensitivity have irritable bowel syndrome (IBS), and a significant proportion of IBS patients also attribute their gastrointestinal complaints to food items. Different factors such as disturbed intestinal fermentation, enteric dysmotility, post-infectious changes and altered microbial flora in the colon as well as psychological disturbances likely play a role in the pathophysiology and symptoms generation in patients with food hypersensitivity. In addition, a number of studies in these patient groups indicate that local, systemic and mucosal immune systems are activated. The question now is no longer intestinal immune activation, but how the immune system is activated in these patients. In the following review, the potential pathogenetic role of the immune system and evidence of immune activation are reported in patients with perceived food hypersensitivity.

Effect of age, gestation and lactation on faecal IgA and calprotectin concentrations in dogs

Faecal calprotectin and IgA have been suggested as non-invasive markers of gut health. Faecal calprotectin is a marker of intestinal inflammation in adults, whereas IgA has been suggested as a marker of intestinal immunity. The purpose of the present study was to evaluate the effect of gestation, lactation and age on faecal concentrations of these biomarkers. Thirty puppies, nineteen pregnant or lactating bitches and eighty-nine healthy control adult dogs were included in the study. Faeces were collected from the fourth week of gestation until the eighth week of lactation in pregnant and lactating bitches, and between 4 and 9 weeks of age in puppies. Faeces from the eighty-nine healthy control adult dogs were also collected. Faecal calprotectin and IgA concentrations were measured. Faecal calprotectin concentrations in control dogs were significantly lower than faecal calprotectin concentrations in puppies between 4 and 6 weeks of age (P < 0·001) or between 7 and 9 weeks of age (P = 0·004). Puppies between 4 and 6 weeks of age had significantly higher faecal IgA concentrations compared with puppies between 7 and 9 weeks of age (P = 0·001). Bitches during their second month of lactation had significantly lower faecal IgA concentrations compared with their first month of lactation (P = 0·049). Faecal calprotectin and IgA have been suggested as non-invasive and easily measured biomarkers of gut health in adults. However, the present study underlines that faecal IgA and calprotectin concentrations vary markedly depending of physiologic factors such as gestation, lactation and age. These factors need to be considered when these faecal biomarkers are used for evaluation of intestinal immunity or inflammation.

Gastrointestinal permeability in patients with irritable bowel syndrome assessed using a four probe permeability solution

BACKGROUND

Abnormal gastrointestinal permeability has been linked to irritable bowel syndrome (IBS). The lactulose-to-mannitol ratio is traditionally used to assess small intestine permeability while sucralose and sucrose are used to assess colonic and gastric permeability respectively. We used a single 4-probe test solution to assess permeability throughout the gastrointestinal tract in IBS patients and healthy controls by measuring the recovery of the probes in urine after ingestion using a modified liquid chromatography mass spectrometry protocol.

METHODS

Fasting participants (N=59) drank a permeability test solution (100ml: sucralose, sucrose, mannitol, and lactulose). Urine was collected over a 5-h period and kept frozen until analysis. Urinary sugar concentrations were measured using a liquid chromatography/triple quadruple mass spectrometer.

RESULTS

Colonic permeability was significantly lower in IBS patients when compared to healthy controls (p=0.011). Gastric and small intestinal permeability did not significantly differ between the groups.

CONCLUSIONS

The study demonstrates the clinical potential of this non-invasive method for assessing alterations in gastrointestinal permeability in patients with IBS.

Subjective food hypersensitivity: assessment of enterochromaffin cell markers in blood and gut lavage fluid

BACKGROUND

Food hypersensitivity is commonly suspected, but seldom verified. Patients with subjective food hypersensitivity suffer from both intestinal and extraintestinal health complaints. Abnormalities of the enterochromaffin cells may play a role in the pathogenesis. The aim of this study was to investigate enterochromaffin cell function in patients with subjective food hypersensitivity by measuring serum chromogranin A (CgA) and 5-hydroxytryptamine (5-HT, serotonin) in gut lavage fluid.

METHODS

Sixty-nine patients with subjective food hypersensitivity were examined. Twenty-three patients with inflammatory bowel disease and 35 healthy volunteers were included as comparison groups. CgA was measured in serum by enzyme-linked immunosorbent assay. Gut lavage fluid was obtained by administering 2 L of polyethylene glycol solution intraduodenally. The first clear fluid passed per rectum was collected and 5-HT was analyzed by liquid chromatography tandem mass spectrometry.

RESULTS

Serum levels of CgA were significantly lower in patients with subjective food hypersensitivity than in healthy controls (P = 0.04). No differences were found in 5-HT levels in gut lavage fluid between patients with subjective food hypersensitivity and the control groups. There was no correlation between serum CgA and gut lavage 5-HT.

CONCLUSION

Decreased blood levels of CgA suggest neuroendocrine alterations in patients with subjective food hypersensitivity. However, 5-HT levels in gut lavage fluid were normal.

Effect of neutral and acidic oligosaccharides on fecal IL-8 and fecal calprotectin in preterm infants

The gastrointestinal inflammatory response may play a role in the susceptibility of preterm infants for infections. We previously reported a trend toward lower endogenous infection morbidity after enteral supplementation of neutral and acidic oligosaccharides (SC GOS/LC FOS/AOS). We hypothesize that enteral supplementation of prebiotics may decrease infectious morbidity by reducing intestinal inflammation. Therefore, we aimed to determine the effect of enteral supplementation of prebiotics on intestinal inflammation, as measured by fecal IL-8 (f-IL-8) and calprotectin (f-calprotectin), in preterm infants. In a randomized controlled trial, infants with a GA <32 wk and/or birth weight <1,500 g received enteral supplementation of prebiotics or placebo (maltodextrin) between d 3 and 30 of life. F-IL-8 and f-calprotectin was assessed at baseline, d 7, 14, and 30 of life. In total, 113 infants were included. Baseline patient and nutritional characteristics were not different in the SC GOS/LC FOS/AOS (n = 55) and the placebo group (n = 58). Enteral supplementation of prebiotics had no effect on f-IL-8 and f-calprotectin. F-IL-8 and f-calprotectin were strongly correlated at all time points (p < 0.001). In conclusion, enteral supplementation of prebiotics (SC GOS/LC FOS/AOS) does not affect f-IL-8 and f-calprotectin levels in preterm infants.

Faecal calprotectin concentrations in apparently healthy children aged 0-12 years in urban Kampala, Uganda: a community-based survey

Background

Calprotectin is a calcium and zinc binding protein, abundant in neutrophils and is extremely stable in faeces. Faecal calprotectin is used as a non-specific marker for gastrointestinal inflammation. It has a good diagnostic precision to distinguish between irritable bowel syndrome and inflammatory bowel disease. Studies have established normal concentrations in healthy children; all these studies have been performed in high-income countries. The objective of this study was to determine the concentration of faecal calprotectin in apparently healthy children aged 0-12 years in urban Kampala, Uganda.

Method

We tested 302 apparently healthy children aged, age 0-12 years (162 female, 140 male) in urban Kampala, Uganda. The children were recruited consecutively by door-to-door visits. Faecal calprotectin was analyzed using a quantitative enzyme-linked immunosorbent assay. Faeces were also tested for Helicobacter pylori (H. pylori) antigen, for growth of enteropathogens and microscopy was performed to assess protozoa and helminths. A short standardized interview with socio-demographic information and medical history was obtained to assess health status of the children.

Results

In the different age groups the median faecal calprotectin concentrations were 249 mg/kg in 0 < 1 year (n = 54), 75 mg/kg in 1 < 4 years (n = 89) and 28 mg/kg in 4 < 12 years (n = 159). There was no significant difference in faecal calprotectin concentrations and education of female caretaker, wealth index, gender, habits of using mosquito nets, being colonized with H. pylori or having other pathogens in the stool.

Conclusion

Concentrations of faecal calprotectin among healthy children, living in urban Ugandan, a low-income country, are comparable to those in healthy children living in high-income countries. In children older than 4 years, the faecal calprotectin concentration is low. In healthy infants faecal calprotectin is high. The suggested cut-off concentrations in the literature can be used in apparently healthy Ugandan children. This finding also shows that healthy children living under poor circumstances do not have a constant inflammation in the gut. We see an opportunity to use this relatively inexpensive test for further understanding and investigations of gut inflammation in children living in low-income countries.

Faecal calprotectin in term and preterm neonates

OBJECTIVES

The aim of this review was to examine the characteristics of the faecal calprotectin assay in neonates and the evidence for its use as a noninvasive marker of intestinal illnesses during the neonatal period.

METHODS

Bibliographic searches were performed in the MEDLINE electronic database up to February 2010 looking for the following words (all fields): "infants" or "neonates" and "calprotectin." Twenty studies, in which 1180 neonates were enrolled, were selected.

RESULTS

During the neonatal period, calprotectin levels are characterized by significantly higher values in both healthy full-term and preterm infants during their first year of life compared with reference values established for children and adults. No difference was observed according to gestational age or birth weight, whereas a higher faecal calprotectin level was detected during intestinal distress in neonates with either inflammatory or patent digestive alterations. Despite high interindividual variations, cutoff levels are proposed to identify infants with a high risk of intestinal illnesses.

CONCLUSIONS

Compared with adults and children, healthy full-term and preterm neonates have high calprotectin levels. The measurement of calprotectin levels in faeces can be a promising noninvasive clinical screening test for intestinal distress in neonates.

Fecal calprotectin concentration in celiac disease

GOALS

We aimed to determine fecal calprotectin (FC) concentration and its relation with histopathologic findings of children with celiac disease (CD) and to observe the probable alterations under gluten-free diet (GFD).

BACKGROUND

As FC is regarded as a marker of inflammation in the gastrointestinal tract, we hypothesized that it might be increased in untreated CD.

STUDY

The study included 29 newly diagnosed patients with CD (mean age: 6.6+/-0.6 y) and sex and age-matched 10 healthy children. All of the children with CD admitted to the hospital were classical form who has chronic diarrhea and failure to thrive. The degree of mucosal damage was graded according to the modified Marsh criteria. FC concentration was determined by enzyme-linked immunosorbent assay method on admission and after 1 year of GFD.

RESULTS

Mean FC concentration of children with CD on admission and of healthy children were 13.40+/-8.5 and 4.3+/-3.3 mg/L, respectively (P=0.004). FC concentration under GFD was 4.6+/-2.7 mg/L and there was a significant statistical difference between untreated patients and those under GFD for 1 year (P=0.001). There was no statistical difference between FC concentration of those under GFD and healthy children (P=0.8). Mean FC concentrations of children with total-villous atrophy and partial-villous atrophy were significantly different (13.8+/-9.3 mg/L vs. 3.7+/-1.8 mg/L, P=0.005).

CONCLUSIONS

It was found that FC concentration is increased in childhood CD, related to the severity of histopathologic findings and responsive to GFD. The pathogenetic mechanism by which FC is increased in CD should be investigated in further studies.

Intestinal B cell-activating factor: an indicator of non-IgE-mediated hypersensitivity reactions to food?

BACKGROUND

Medically confirmed hypersensitivity reactions to food are usually IgE-mediated. Non-IgE-mediated reactions are not only seldom recognized but also more difficult to diagnose.

AIM

To examine B cell-activating factor (BAFF) in serum and gut lavage fluid of patients with self-reported food hypersensitivity, and to study its relationship to atopic disease.

METHODS

Gut lavage fluid was obtained from 60 and serum from another 17 patients with self-reported food hypersensitivity. Twenty healthy volunteers served as controls, gut lavage fluid was obtained in all, serum from 11 of 20. The patients were divided into atopic and non-atopic subgroups. BAFF was measured by ELISA in both serum and gut lavage fluid.

RESULTS

B cell-activating factor levels in serum and gut lavage fluid were significantly higher in patients than in controls (P < 0.03 and P < 0.002 respectively). Non-atopic patients had significantly higher levels of BAFF in serum than both atopic patients (P < 0.05) and controls (P < 0.05). There was no significant correlation between serum levels of BAFF and IgE.

CONCLUSIONS

The results suggest that BAFF might be a new mediating mechanism in food hypersensitivity reactions. Significantly higher levels in non-atopic compared with atopic patients, and no correlation between BAFF and IgE, suggest that BAFF might be involved particularly in non-IgE-mediated reactions.

Fecal calprotectin excretion in preterm infants during the neonatal period

BACKGROUND

Fecal calprotectin has been proposed as a non-invasive marker of intestinal inflammation in inflammatory bowel disease in adults and children. Fecal calprotectin levels have been reported to be much higher in both healthy full-term and preterm infants than in children and adults.

OBJECTIVE

To determine the time course of fecal calprotectin (f-calprotectin) excretion in preterm infants from birth until hospital discharge and to identify factors influencing f-calprotectin levels in the first weeks of life, including bacterial establishment in the gut.

METHODOLOGY

F-calprotectin was determined using an ELISA assay in 147 samples obtained prospectively from 47 preterm infants (gestational age, and birth-weight interquartiles 27-29 weeks, and 880-1320 g, respectively) at birth, and at 2-week intervals until hospital discharge.

PRINCIPAL FINDINGS

Although median f-calprotectin excretion was 138 microg/g, a wide range of inter- and intra-individual variation in f-calprotectin values (from day 3 to day 78) was observed (86% and 67%, respectively). In multivariate regression analysis, f-calprotectin correlated negatively with ante and per natal antibiotic treatment (p = 0.001), and correlated positively with the volume of enteral feeding (mL/kg/d) (p = 0.009), the need to interrupt enteral feeding (p = 0.001), and prominent gastrointestinal colonization by Clostridium sp (p = 0.019) and Staphylococcus sp (p = 0.047).

CONCLUSION

During the first weeks of life, the high f-calprotectin values observed in preterm infants could be linked to the gut bacterial establishment.

Anxiety and depression in patients with self-reported food hypersensitivity

OBJECTIVE

Self-reported food hypersensitivity (SFH) is common. Psychological factors are assumed to be associated. We assessed anxiety and depression in SFH patients, using both questionnaires and interview.

METHODS

Consecutive patients (n=130) and randomly selected healthy volunteers (n=75) completed the Hospital Anxiety and Depression Scale (HADS), the neuroticism scale of the Eysenck Personality Questionnaire (EPQ-N) and the General Health Questionnaire (GHQ). Seventy-six of the patients were also interviewed by use of the Mini International Neuropsychiatric Interview and the Montgomery-Aasberg Depression Rating Scale. All patients underwent extensive allergological, gastroenterological and dietary examinations.

RESULTS

According to interviews, 57% of patients fulfilled the DSM-IV criteria for at least one psychiatric disorder. Anxiety disorders (34%) and depression (16%) predominated. According to questionnaires, patients scored significantly higher than controls on all psychometric scales except for depression (HADS). We also found an underreporting of depression in HADS compared with interviews (2.5% vs. 16%, P=.001). Food hypersensitivity was rarely confirmed by provocation tests (8%). Eighty-nine percent of the patients had irritable bowel syndrome.

CONCLUSIONS

Anxiety and depression are common in patients with IBS-like complaints self-attributed to food hypersensitivity. Anxiety disorders predominate. In this setting, depression may be underreported by HADS.

Pro- and prebiotic supplementation induces a transient reduction in hemoglobin concentration in infants

OBJECTIVES

: Regarding safety, we investigated the effect of prenatal probiotic and 6 months of pro- and prebiotic supplementation of infants on their hematologic values at 6 months and 2 years and factors affecting these values.

PATIENTS AND METHODS

: In a prospective randomized controlled probiotic intervention trial in infants at high risk for allergy, we obtained blood samples consecutively from 98 infants at 6 months and from 658 children at 2 years to measure hematologic values. We collected fecal samples at 3 and 6 months to measure immunologic development by calprotectin, alpha-1-antitrypsin, tumor necrosis factor-alpha, and immunoglobulin A.

RESULTS

: At 6 months, infants in the probiotic group had significantly lower hemoglobin (Hb) values than did the placebo group, mean (SD): 119.8 g/L (6.3) versus 123.3 g/L (8.4), P = 0.025. Adjustment for factors that might affect Hb values (breast-feeding duration, solid-food introduction, and sex), revealed no need for adjustment. A significant negative correlation emerged between Hb values at 6 months and fecal calprotectin at age 3 months r = -0.301, P = 0.009, which was affected neither by breast-feeding, sex, nor study group. At 2 years, hematologic values in both groups became similar.

CONCLUSIONS

: Probiotics cause a gut mucosal inflammation with decreased Hb values during intervention, corrected after halting the supplementation.

Effects of Bifidobacterium lactis Bb12 supplementation on body weight, fecal pH, acetate, lactate, calprotectin, and IgA in preterm infants

Preterm infants are prone to abnormal bacterial colonization of the intestine with ensuing adverse health effects. To examine whether the oral application of Bifidobacterium lactis Bb12 (probiotic) may improve selected indicators of health status in preterm infants, a double blind, placebo controlled randomized clinical study was performed on 69 preterm infants (<37 gestation wk). Weight gain was defined as the primary outcome measure. In antibiotic-treated infants, probiotic supplementation resulted in a higher body weight compared with placebo (p < 0.001). In the probiotic group, the fecal pH was significantly lower than in the placebo group. The fecal concentrations of acetate and lactate were 42 and 38% higher, respectively, in the probiotic group than in the placebo group. Fecal calprotectin was lower in the probiotic group (p = 0.041), while fecal IgA was higher in this group compared with the placebo group (p = 0.021).

Use of atorvastatin as an anti-inflammatory treatment in Crohn's disease

BACKGROUND AND PURPOSE

Experimental and clinical investigations have revealed that statins can downregulate both acute and chronic inflammatory processes. Whether statins express anti-inflammatory activities in the treatment of Crohn's disease is unknown.

EXPERIMENTAL APPROACH

Ten patients were given 80 mg atorvastatin once daily for 13 weeks and then followed up for 8 weeks after the treatment. The anti-inflammatory effects of statin were assessed by measuring levels of plasma C-reactive protein (CRP), soluble (s) CD14, tumour necrosis factor (TNF)-alpha, sTNFRI and II, CCL2 and 8 and the mucosal inflammation by faecal calprotectin. Circulating monocytes were subgrouped and their chemokine receptor expression of CCR2 and CX(3)CR1 were analysed.

KEY RESULTS

In 8 of 10 patients, atorvastatin treatment reduced CRP (P=0.008) and sTNFRII (P=0.064). A slight decrease in plasma levels of sCD14, TNF-alpha and sTNFRI was observed in 7/10 patients and faecal calprotectin was reduced in 8/10 patients. We also observed that the treatment diminished expression of CCR2 and CX(3)CR1 on monocyte populations (P=0.014). At the follow-up visit, 8 weeks after the atorvastatin treatment was terminated, CRP levels had returned to those seen before the treatment.

CONCLUSIONS AND IMPLICATIONS

Our findings imply that atorvastatin therapy reduces inflammation in patients with Crohn's disease and, therefore, encourage further investigations of statin-mediated protective effects in inflammatory bowel diseases.

Fecal calprotectin is useful in predicting disease relapse in pediatric inflammatory bowel disease

BACKGROUND

Fecal calprotectin (FC) has been proposed as a noninvasive surrogate marker to determine the degree of intestinal inflammation and predicting relapse in patients with inflammatory bowel disease (IBD). The aim was to compare FC levels in IBD and healthy controls, to correlate FC levels with clinical disease activity, and to assess whether FC levels can be used to predict clinical relapse in children with IBD.

METHODS

Enzyme-linked immunosorbent assay (ELISA) determined levels of FC were measured in more than 1 stool samples (n) from 32 IBD patients (n = 97) and from 34 healthy controls (n = 37). Disease activity was assessed by the Harvey-Bradshaw index in Crohn's disease (CD) and by Physician's Global Assessment (PGA) in both CD and ulcerative colitis (UC). Clinical events were recorded up to 9 months following stool collection in CD patients. Wilcoxon rank sum test and Fisher's exact tests were used to compare FC levels in IBD patients and in control. Kaplan-Meyer analysis was used to determine a risk of clinical relapse in relation to FC levels.

RESULTS

The IBD group had higher FC levels (range 17-7500 g/g) compared with control (16-750 g/g, P < 0.0001). FC levels were higher during relapse (CD, 3214 +/- 2186; UC, 2819 +/- 1610) compared to remission (CD, 1373 +/- 1630; UC, 764 +/- 869; P < 0.0001). Among those with clinical relapse, 90% had FC levels more than 400 mug/g in CD. Eighty-nine percent of CD encounters with FC levels less than 400 mug/g remained in clinical remission.

CONCLUSIONS

FC levels differentiate active IBD from controls. Among children with CD and in remission, FC levels may be useful in predicting impending clinical relapse.

Metabolic and inflammatory faecal markers in collagenous colitis

OBJECTIVES

To evaluate the excretion of the inflammatory and metabolic faecal markers calprotectin, lactoferrin, and short-chain fatty acids in symptomatic and quiescent collagenous colitis.

METHODS

Faecal samples from 21 patients with active collagenous colitis, 12 patients retested in remission, and 13 controls were analysed. Calprotectin was determined using an enzyme-linked immunosorbent assay. Lactoferrin was estimated by a latex agglutination test. Short-chain fatty acids were determined by steam distillation followed by gas-liquid chromatography.

RESULTS

Calprotectin was increased in patients with active collagenous colitis [80 microg/g (6.25-1899)] (median and range) compared with patients with quiescent collagenous colitis [26 microg/g (6.25-340)], P=0.025 and controls [6.25 microg/g (6.25-99)], P=0.002. Eight patients (38%) with active collagenous colitis had normal levels of calprotectin. Lactoferrin was detected in one patient only. Concentrations of total short-chain fatty acids did not differ in patients with active collagenous colitis compared with quiescent collagenous colitis or controls (P=0.75), whereas concentrations of the branched-chain fatty acids were decreased in patients with active collagenous colitis versus controls (P<0.005). In-vitro incubations demonstrated increased ratios of acetate in patients with active and quiescent collagenous colitis compared with controls (P<0.05), with a corresponding decrease in branched-chain fatty acids ratios (P<0.05).

CONCLUSION

Faecal calprotectin was increased in collagenous colitis; however, increased excretion was not a universal finding limiting the use of calprotectin as an inflammatory marker in collagenous colitis. Faecal lactoferrin was almost undetectable. Luminal fermentative conditions are altered in collagenous colitis. Fermentative alterations could be secondary to changes in substrate availability and intestinal transit time.

Intestinal permeability and irritable bowel syndrome

Based on a systematic PubMed search, this short review addresses why intestinal permeability may be important in the pathobiology of irritable bowel syndrome (IBS), the evidence of abnormal permeability in patients with IBS, and the pros and cons of the different probe molecules available to assess intestinal permeability. While a subgroup of patients with IBS appears to have evidence of increased intestinal permeability, improvements in the methods and validation are key to further research in this field in order to better understand intestinal barrier functions in IBS.