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1.
ACS Nano ; 18(2): 1504-1515, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38112538

ABSTRACT

Protein post-translational modifications (PTMs) play a crucial role in countless biological processes, profoundly modulating protein properties on both spatial and temporal scales. Protein PTMs have also emerged as reliable biomarkers for several diseases. However, only a handful of techniques are available to accurately measure their levels, capture their complexity at a single molecule level, and characterize their multifaceted roles in health and disease. Nanopore sensing provides high sensitivity for the detection of low-abundance proteins, holding the potential to impact single-molecule proteomics and PTM detection, in particular. Here, we demonstrate the ability of a biological nanopore, the pore-forming toxin aerolysin, to detect and distinguish α-synuclein-derived peptides bearing single or multiple PTMs, namely, phosphorylation, nitration, and oxidation occurring at different positions and in various combinations. The characteristic current signatures of the α-synuclein peptide and its PTM variants could be confidently identified by using a deep learning model for signal processing. We further demonstrate that this framework can quantify α-synuclein peptides at picomolar concentrations and detect the C-terminal peptides generated by digestion of full-length α-synuclein. Collectively, our work highlights the advantage of using nanopores as a tool for simultaneous detection of multiple PTMs and facilitates their use in biomarker discovery and diagnostics.


Subject(s)
Deep Learning , Nanopores , alpha-Synuclein/chemistry , Protein Processing, Post-Translational , Peptides/chemistry
2.
Nat Commun ; 14(1): 2175, 2023 04 18.
Article in English | MEDLINE | ID: mdl-37072397

ABSTRACT

Proteins are essential molecular building blocks of life, responsible for most biological functions as a result of their specific molecular interactions. However, predicting their  binding  interfaces remains a challenge. In this study, we present a geometric transformer that acts directly on atomic coordinates labeled only with element names. The resulting model-the Protein Structure Transformer, PeSTo-surpasses the current state of the art in predicting protein-protein interfaces and can also predict and differentiate between interfaces involving nucleic acids, lipids, ions, and small molecules with high confidence. Its low computational cost enables processing high volumes of structural data, such as molecular dynamics ensembles allowing for the discovery of interfaces that remain otherwise inconspicuous in static experimentally solved structures. Moreover, the growing foldome provided by de novo structural predictions can be easily analyzed, providing new opportunities to uncover unexplored biology.


Subject(s)
Deep Learning , Protein Binding , Proteins/metabolism , Molecular Dynamics Simulation , Computational Biology/methods
3.
J Allergy Clin Immunol ; 149(2): 650-658.e5, 2022 02.
Article in English | MEDLINE | ID: mdl-34224785

ABSTRACT

BACKGROUND: Tolerance development is an important clinical outcome for infants with cow's milk allergy. OBJECTIVE: This multicenter, prospective, randomized, double-blind, controlled clinical study (NTR3725) evaluated tolerance development to cow's milk (CM) and safety of an amino acid-based formula (AAF) including synbiotics (AAF-S) comprising prebiotic oligosaccharides (oligofructose, inulin) and probiotic Bifidobacterium breve M-16V in infants with confirmed IgE-mediated CM allergy. METHODS: Subjects aged ≤13 months with IgE-mediated CM allergy were randomized to receive AAF-S (n = 80) or AAF (n = 89) for 12 months. Stratification was based on CM skin prick test wheal size and study site. After 12 and 24 months, CM tolerance was evaluated by double-blind, placebo-controlled food challenge. A logistic regression model used the all-subjects randomized data set. RESULTS: At baseline, mean ± SD age was 9.36 ± 2.53 months. At 12 and 24 months, respectively, 49% and 62% of subjects were CM tolerant (AAF-S 45% and 64%; AAF 52% and 59%), and not differ significantly between groups. During the 12-month intervention, the number of subjects reporting at least 1 adverse event did not significantly differ between groups; however, fewer subjects required hospitalization due to serious adverse events categorized as infections in the AAF-S versus AAF group (9% vs 20%; P = .036). CONCLUSIONS: After 12 and 24 months, CM tolerance was not different between groups and was in line with natural outgrowth. Results suggest that during the intervention, fewer subjects receiving AAF-S required hospitalization due to infections.


Subject(s)
Amino Acids/administration & dosage , Immune Tolerance , Infant Formula , Milk Hypersensitivity/immunology , Double-Blind Method , Female , Humans , Infant , Infant Formula/adverse effects , Infant, Newborn , Male , Prospective Studies , Synbiotics/administration & dosage
4.
Chimia (Aarau) ; 76(1-2): 145-150, 2022 Feb 23.
Article in English | MEDLINE | ID: mdl-38069760

ABSTRACT

moleculARweb (https://molecularweb.epfl.ch) began as a website for education and outreach in chemistry and structural biology through augmented reality (AR) content that runs in the web browsers of regular devices like smartphones, tablets, and computers. Here we present two evolutions of moleculARweb's Virtual Modeling Kits (VMK), tools where users can build and view molecules, and explore their mechanics, in 3D AR by handling the molecules in full 3D with custom-printed cube markers (VMK 2.0) or by moving around a simulated scene with mouse or touch gestures (VMK 3.0). Upon simulation the molecules experience visually realistic torsions, clashes, and hydrogen-bonding interactions that the user can manually switch on and off to explore their effects. Moreover, by manually tuning a fictitious temperature the users can accelerate conformational transitions or 'freeze' specific conformations for careful inspection in 3D. Even some phase transitions and separations can be simulated. We here showcase these and other features of the new VMKs connecting them to possible specific applications to teaching and self-learning of concepts from general, organic, biological and physical chemistry; and in assisting with small tasks in molecular modelling for research. Last, in a short discussion section we overview what future developments are needed for the 'dream tool' for the future of chemistry education and work.

5.
Front Mol Biosci ; 8: 686086, 2021.
Article in English | MEDLINE | ID: mdl-34381813

ABSTRACT

Post-translational modifications (PTMs) within the first 17 amino acids (Nt17) of the Huntingtin protein (Htt) have been shown to inhibit the aggregation and attenuate the toxicity of mutant Htt proteins in vitro and in various models of Huntington's disease. Here, we expand on these studies by investigating the effect of methionine eight oxidation (oxM8) and its crosstalk with lysine 6 acetylation (AcK6) or threonine 3 phosphorylation (pT3) on the aggregation of mutant Httex1 (mHttex1). We show that M8 oxidation delays but does not inhibit the aggregation and has no effect on the final morphologies of mHttex1aggregates. The presence of both oxM8 and AcK6 resulted in dramatic inhibition of Httex1 fibrillization. Circular dichroism spectroscopy and molecular dynamics simulation studies show that PTMs that lower the mHttex1 aggregation rate (oxM8, AcK6/oxM8, pT3, pT3/oxM8, and pS13) result in increased population of a short N-terminal helix (first eight residues) in Nt17 or decreased abundance of other helical forms, including long helix and short C-terminal helix. PTMs that did not alter the aggregation rate (AcK6) of mHttex1 exhibit a similar distribution of helical conformation as the unmodified peptides. These results show that the relative abundance of N- vs. C-terminal helical conformations and long helices, rather than the overall helicity of Nt17, better explains the effect of different Nt17 PTMs on mHttex1; thus, explaining the lack of correlation between the effect of PTMs on the overall helicity of Nt17 and mHttex1 aggregation in vitro. Taken together, our results provide novel structural insight into the differential effects of single PTMs and crosstalk between different PTMs in regulating mHttex1 aggregation.

6.
Cell Commun Signal ; 19(1): 78, 2021 07 20.
Article in English | MEDLINE | ID: mdl-34284799

ABSTRACT

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and ß-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and ß-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.


Subject(s)
Receptors, Adrenergic, alpha-1/genetics , Receptors, Adrenergic, beta-1/genetics , Urologic Diseases/genetics , Urologic Neoplasms/genetics , Adrenergic beta-Antagonists/therapeutic use , Epithelial-Mesenchymal Transition/drug effects , Humans , Male , Prostate/metabolism , Prostate/pathology , Signal Transduction/drug effects , Tumor Microenvironment/genetics , Urinary Tract/metabolism , Urinary Tract/pathology , Urologic Diseases/pathology , Urologic Neoplasms/pathology
7.
Nutrients ; 13(1)2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33451130

ABSTRACT

We determined the nutritional adequacy and overall quality of the diets of adult patients with eosinophilic esophagitis (EoE). Dietary intakes stratified by sex and age were compared to Dietary Reference Values (DRV). Overall diet quality was assessed by two independent Diet-Quality-Indices scores, the PANDiet and DHD-index, and compared to age- and gender-matched subjects from the general population. Lastly, food and nutrient intakes of EoE patients were compared to intakes of the general population. Saturated fat intake was significantly higher and dietary fiber intake significantly lower than the DRV in both males and females. In males, the DRV were not reached for potassium, magnesium, selenium, and vitamins A and D. In females, the DRV were not reached for iron, sodium, potassium, selenium, and vitamins A, B2, C and D. EoE patients had a significantly lower PANDiet and DHD-index compared to the general population, although the relative intake (per 1000 kcal) of vegetables/fruits/olives was significantly higher (yet still up to 65% below the recommended daily amounts) and alcohol intake was significantly lower compared to the general Dutch population. In conclusion, the composition of the habitual diet of adult EoE patients has several pro-inflammatory and thus unfavorable immunomodulatory properties, just as the general Dutch population, and EoE patients had lower overall diet quality scores than the general population. Due to the observational character of this study, further research is needed to explore whether this contributes to the development and progression of EoE.


Subject(s)
Diet , Eosinophilic Esophagitis/diet therapy , Eosinophilic Esophagitis/epidemiology , Nutritive Value , Adult , Comorbidity , Diet/methods , Diet/standards , Energy Intake , Female , Humans , Male , Middle Aged , Netherlands/epidemiology , Nutrition Surveys
8.
Sci Adv ; 6(50)2020 Dec.
Article in English | MEDLINE | ID: mdl-33298438

ABSTRACT

Digital data storage is a growing need for our society and finding alternative solutions than those based on silicon or magnetic tapes is a challenge in the era of "big data." The recent development of polymers that can store information at the molecular level has opened up new opportunities for ultrahigh density data storage, long-term archival, anticounterfeiting systems, and molecular cryptography. However, synthetic informational polymers are so far only deciphered by tandem mass spectrometry. In comparison, nanopore technology can be faster, cheaper, nondestructive and provide detection at the single-molecule level; moreover, it can be massively parallelized and miniaturized in portable devices. Here, we demonstrate the ability of engineered aerolysin nanopores to accurately read, with single-bit resolution, the digital information encoded in tailored informational polymers alone and in mixed samples, without compromising information density. These findings open promising possibilities to develop writing-reading technologies to process digital data using a biological-inspired platform.

9.
Immun Inflamm Dis ; 8(1): 93-105, 2020 03.
Article in English | MEDLINE | ID: mdl-32031763

ABSTRACT

BACKGROUND: Amino acid-based formulas (AAFs) are used for the dietary management of cow's milk allergy (CMA). Whether AAFs have the potential to prevent the development and/or symptoms of CMA is not known. OBJECTIVE: The present study evaluated the preventive effects of an amino acid (AA)-based diet on allergic sensitization and symptoms of CMA in mice and aimed to provide insight into the underlying mechanism. METHODS: C3H/HeOuJ mice were sensitized with whey protein or with phosphate-buffered saline as sham-sensitized control. Starting 2 weeks before sensitization, mice were fed with either a protein-based diet or an AA-based diet with an AA composition based on that of the AAF Neocate, a commercially available AAF prescribed for the dietary management of CMA. Upon challenge, allergic symptoms, mast cell degranulation, whey-specific immunoglobulin levels, and FoxP3+ cell counts in jejunum sections were assessed. RESULTS: Compared to mice fed with the protein-based diet, AA-fed mice had significantly lower acute allergic skin responses. Moreover, the AA-based diet prevented the whey-induced symptoms of anaphylaxis and drop in body temperature. Whereas the AA-based diet had no effect on the levels of serum IgE and mucosal mast cell protease-1 (mMCP-1), AA-fed mice had significantly lower serum IgG2a levels and tended to have lower IgG1 levels (P = .076). In addition, the AA-based diet prevented the whey-induced decrease in FoxP3+ cells. In sham-sensitized mice, no differences between the two diets were observed in any of the tested parameters. CONCLUSION: This study demonstrates that an AA-based diet can at least partially prevent allergic symptoms of CMA in mice. Differences in FoxP3+ cell counts and serum levels of IgG2a and IgG1 may suggest enhanced anti-inflammatory and tolerizing capacities in AA-fed mice. This, combined with the absence of effects in sham-sensitized mice indicates that AAFs for the prevention of food allergies may be an interesting concept that warrants further research.


Subject(s)
Amino Acids/administration & dosage , Anaphylaxis/prevention & control , Milk Hypersensitivity/prevention & control , Whey Proteins/immunology , Administration, Oral , Allergens , Animals , Cattle , Chymases/metabolism , Dietary Supplements , Disease Models, Animal , Female , Immunoglobulin E/blood , Immunoglobulin G/blood , Mast Cells/metabolism , Mice , Mice, Inbred C3H , Milk Hypersensitivity/complications
11.
Clin Transl Allergy ; 9: 27, 2019.
Article in English | MEDLINE | ID: mdl-31164972

ABSTRACT

BACKGROUND: Altered gut microbiota is implicated in cow's milk allergy (CMA) and differs markedly from healthy, breastfed infants. Infants who suffer from severe CMA often rely on cow's milk protein avoidance and, when breastfeeding is not possible, on specialised infant formulas such as amino-acid based formulas (AAF). Herein, we report the effects of an AAF including specific synbiotics on oral and gastrointestinal microbiota of infants with non-IgE mediated CMA with reference to healthy, breastfed infants. METHODS: In this prospective, randomized, double-blind controlled study, infants with suspected non-IgE mediated CMA received test or control formula. Test formula was AAF with synbiotics (prebiotic fructo-oligosaccharides and probiotic Bifidobacterium breve M-16V). Control formula was AAF without synbiotics. Healthy, breastfed infants were used as a separate reference group (HBR). Bacterial compositions of faecal and salivary samples were analysed by 16S rRNA-gene sequencing. Faecal analysis was complemented with the analysis of pH, short-chain fatty acids (SCFAs) and lactic acids. RESULTS: The trial included 35 test subjects, 36 controls, and 51 HBR. The 16S rRNA-gene sequencing revealed moderate effects of test formula on oral microbiota. In contrast, the gut microbiota was substantially affected across time comparing test with control. In both groups bacterial diversity increased over time but was characterised by a more gradual increment in test compared to control. Compositionally this reflected an enhancement of Bifidobacterium spp. and Veillonella sp. in the test group. In contrast, the control-fed infants showed increased abundance of adult-like species, mainly within the Lachnospiraceae family, as well as within the Ruminococcus and Alistipes genus. The effects on Bifidobacterium spp. and Lachnospiraceae spp. were previously confirmed through enumeration by fluorescent in situ hybridization and were shown for test to approximate the proportions observed in the HBR. Additionally, microbial activity was affected as evidenced by an increase of l-lactate, a decrease of valerate, and reduced concentrations of branched-chain SCFAs in test versus control. CONCLUSIONS: The AAF including specific synbiotics effectively modulates the gut microbiota and its metabolic activity in non-IgE mediated CMA infants bringing it close to a healthy breastfed profile.Trial registration Registered on 1 May 2013 with Netherlands Trial Register Number NTR3979.

13.
Clin Transl Allergy ; 9: 5, 2019.
Article in English | MEDLINE | ID: mdl-30651972

ABSTRACT

BACKGROUND: Here we report follow-up data from a double-blind, randomized, controlled multicenter trial, which investigated fecal microbiota changes with a new amino acid-based formula (AAF) including synbiotics in infants with non-immunoglobulin E (IgE)-mediated cow's milk allergy (CMA). METHODS: Subjects were randomized to receive test product (AAF including fructo-oligosaccharides and Bifidobacterium breve M-16V) or control product (AAF) for 8 weeks, after which infants could continue study product until 26 weeks. Fecal percentages of bifidobacteria and Eubacterium rectale/Clostridium coccoides group (ER/CC) were assessed at 0, 8, 12, and 26 weeks. Additional endpoints included stool markers of gut immune status, clinical symptoms, and safety assessments including adverse events and medication use. RESULTS: The trial included 35 test subjects, 36 controls, and 51 in the healthy reference group. Study product was continued by 86% and 92% of test and control subjects between week 8-12, and by 71% and 80%, respectively until week 26. At week 26 median percentages of bifidobacteria were significantly higher in test than control [47.0% vs. 11.8% (p < 0.001)], whereas percentages of ER/CC were significantly lower [(13.7% vs. 23.6% (p = 0.003)]. Safety parameters were similar between groups. Interestingly use of dermatological medication and reported ear infections were lower in test versus control, p = 0.019 and 0.011, respectively. Baseline clinical symptoms and stool markers were mild (but persistent) and low, respectively. Symptoms reduced towards lowest score in both groups. CONCLUSION: Beneficial effects of this AAF including specific synbiotics on microbiota composition were observed over 26 weeks, and shown suitable for dietary management of infants with non-IgE-mediated CMA.Trial Registration NTR3979.

15.
Nutr Res ; 58: 95-105, 2018 10.
Article in English | MEDLINE | ID: mdl-30340819

ABSTRACT

The conditionally essential amino acid glycine functions as inhibitory neurotransmitter in the mammalian central nervous system. Moreover, it has been shown to act as an anti-inflammatory compound in animal models of ischemic perfusion, post-operative inflammation, periodontal disease, arthritis and obesity. Glycine acts by binding to a glycine-gated chloride channel, which has been demonstrated on neurons and immune cells, including macrophages, polymorphonuclear neutrophils and lymphocytes. The present study aims to evaluate the effect of glycine on allergy development in a cow's milk allergy model. To this end, C3H/HeOuJ female mice were supplemented with glycine by oral gavage (50 or 100 mg/mouse) 4 hours prior to sensitization with cow's milk whey protein, using cholera toxin as adjuvant. Acute allergic skin responses and anaphylaxis were assessed after intradermal allergen challenge in the ears. Mouse mast cell protease-1 (mMCP-1) and whey specific IgE levels were detected in blood collected 30 minutes after an oral allergen challenge. Jejunum was dissected and evaluated for the presence of mMCP-1-positive cells by immunohistochemistry. Intake of glycine significantly inhibited allergy development in a concentration dependent manner as indicated by a reduction in; acute allergic skin response, anaphylaxis, serum mMCP-1 and serum levels of whey specific IgE. In addition, in-vitro experiments using rat basophilic leukemia cells (RBL), showed that free glycine inhibited cytokine release but not cellular degranulation. These findings support the hypothesis that the onset of cow's milk allergy is prevented by the oral intake of the amino acid glycine. An adequate intake of glycine might be important in the improvement of tolerance against whey allergy or protection against (whey-induced) allergy development.


Subject(s)
Anaphylaxis/prevention & control , Glycine/therapeutic use , Immune Tolerance/drug effects , Milk Hypersensitivity/prevention & control , Milk/immunology , Skin Diseases/prevention & control , Whey Proteins/immunology , Administration, Oral , Allergens , Animals , Cattle , Cell Line, Tumor , Cells , Chymases/blood , Cytokines/metabolism , Dietary Supplements , Disease Models, Animal , Female , Glycine/metabolism , Glycine/pharmacology , Immunoglobulin E/blood , Jejunum/drug effects , Jejunum/metabolism , Mice, Inbred C3H , Milk Hypersensitivity/complications , Milk Hypersensitivity/metabolism , Rats , Skin/immunology
16.
Pediatr Res ; 83(3): 677-686, 2018 03.
Article in English | MEDLINE | ID: mdl-29155807

ABSTRACT

BackgroundPrebiotics and probiotics (synbiotics) can modify gut microbiota and have potential in allergy management when combined with amino-acid-based formula (AAF) for infants with cow's milk allergy (CMA).MethodsThis multicenter, double-blind, randomized controlled trial investigated the effects of an AAF-including synbiotic blend on percentages of bifidobacteria and Eubacterium rectale/Clostridium coccoides group (ER/CC) in feces from infants with suspected non-IgE-mediated CMA. Feces from age-matched healthy breastfed infants were used as reference (healthy breastfed reference (HBR)) for primary outcomes. The CMA subjects were randomized and received test or control formula for 8 weeks. Test formula was a hypoallergenic, nutritionally complete AAF including a prebiotic blend of fructo-oligosaccharides and the probiotic strain Bifidobacterium breve M-16V. Control formula was AAF without synbiotics.ResultsA total of 35 (test) and 36 (control) subjects were randomized; HBR included 51 infants. At week 8, the median percentage of bifidobacteria was higher in the test group than in the control group (35.4% vs. 9.7%, respectively; P<0.001), whereas ER/CC was lower (9.5% vs. 24.2%, respectively; P<0.001). HBR levels of bifidobacteria and ER/CC were 55% and 6.5%, respectively.ConclusionAAF including specific synbiotics, which results in levels of bifidobacteria and ER/CC approximating levels in the HBR group, improves the fecal microbiota of infants with suspected non-IgE-mediated CMA.


Subject(s)
Amino Acids/chemistry , Gastrointestinal Microbiome , Infant Formula , Milk Hypersensitivity/therapy , Synbiotics , Animals , Cattle , Clostridium , Double-Blind Method , Eubacterium , Female , Humans , Immunoglobulin E , Infant , Male , Milk , Milk Hypersensitivity/immunology , Treatment Outcome
17.
J Pediatr Gastroenterol Nutr ; 65(3): 346-349, 2017 09.
Article in English | MEDLINE | ID: mdl-28604516

ABSTRACT

Data on the mineral status of infants with cow's milk allergy (CMA) consuming an amino acid-based formula (AAF) have not been published. The present study aims to assess mineral status of term infants age 0 to 8 months diagnosed with CMA receiving an AAF for 16 weeks. Serum concentrations of calcium, phosphorus, chloride, sodium, potassium, magnesium, and ferritin were determined in 82 subjects at baseline and in 66 subjects after 16 weeks on AAF using standard methods and evaluated against age-specific reference ranges. In addition to this, individual estimated energy and mineral intakes were compared to Adequate Intakes defined by the European Food Safety Authority and the US Institute of Medicine. The results of this study show that the AAF was effective in providing an adequate mineral status in infants with CMA. The vast majority of infants aged 0 to 6 months (formula only) and aged 6 to 12 months (formula and complementary foods) had adequate mineral intakes.


Subject(s)
Amino Acids , Infant Formula , Milk Hypersensitivity/diet therapy , Minerals/blood , Nutritional Status , Trace Elements/blood , Biomarkers/blood , Double-Blind Method , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Male , Milk Hypersensitivity/blood , Prospective Studies , Synbiotics
18.
Am J Gastroenterol ; 112(7): 1061-1071, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28417991

ABSTRACT

OBJECTIVES: The esophageal mucosal integrity is impaired in eosinophilic esophagitis (EoE) and it has been suggested that the duodenal permeability is increased. The absence of food allergens may restore the integrity. The aims of this study were to assess duodenal permeability in EoE and to evaluate the effect of an elemental diet on the esophageal and duodenal integrity. METHODS: In this prospective study 17 adult EoE patients and 8 healthy controls (HC) were included. Esophageal biopsy specimens were sampled before and after 4 weeks of elemental diet to measure eosinophil counts and gene expression of tight junction and barrier integrity proteins. Esophageal and duodenal impedance were measured by electrical tissue impedance spectroscopy and Ussing chambers were used to measure transepithelial resistance (TER) and transepithelial molecule flux. Small intestinal permeability was measured using a test, measuring lactulose/mannitol (L/M) ratios. RESULTS: In EoE patients, the esophageal but not the duodenal integrity was impaired, compared with HC. We observed no significant difference between L/M ratios of HC and EoE patients. After diet, eosinophil counts decreased significantly, which was paralleled by normalization of esophageal impedance and transepithelial molecule flux. The esophageal TER improved significantly, but did not reach values seen in HC. Esophageal expression of genes encoding for barrier integrity proteins filaggrin and desmoglein-1 was impaired at baseline and restored after diet. CONCLUSIONS: An elemental diet restores esophageal integrity, suggesting that it is at least partly secondary to allergen exposure. Duodenal integrity seems not to be affected in EoE, and possibly plays a minor role in its pathophysiology.


Subject(s)
Eosinophilic Esophagitis/diet therapy , Eosinophilic Esophagitis/pathology , Esophagus/pathology , Food, Formulated , Intestinal Mucosa/pathology , Intestine, Small/pathology , Adult , Biopsy , Case-Control Studies , Electric Impedance , Endoscopy, Digestive System , Female , Filaggrin Proteins , Humans , Male , Middle Aged , Prospective Studies , Real-Time Polymerase Chain Reaction , Treatment Outcome
19.
Immun Inflamm Dis ; 4(2): 155-165, 2016 06.
Article in English | MEDLINE | ID: mdl-27933160

ABSTRACT

To support dietary management of severe cow's milk allergic infants, a synbiotic mixture of non-digestible oligosaccharides and Bifidobacterium breve M-16V (B. breve) was designed from source materials that are completely cow's milk-free. It was investigated whether this specific synbiotic concept can reduce an established food allergic response in a research model for hen's egg allergy. Mice were orally sensitized once a week for 5 weeks to ovalbumin (OVA) using cholera toxin (CT) as an adjuvant. Non-sensitized mice received CT in PBS only. Sensitized mice were fed a control diet or a diet enriched with short-chain- (scFOS) and long-chain fructo-oligosaccharides (lcFOS), B. breve or scFOSlcFOS + B. breve for 3 weeks starting after the last sensitization. Non-sensitized mice received the control diet. Anaphylactic shock symptoms, acute allergic skin responses and serum specific IgE, mMCP-1 and galectin-9 were measured upon OVA challenge. Activated Th2-, Th1-cells and regulatory T-cells were quantified in spleen and mesenteric lymph nodes (MLN) and cytokine profiles were analyzed. Short chain fatty acids (SCFA) were measured in ceacal samples. The acute allergic skin response was reduced in mice fed the scFOSlcFOS + B. breve diet compared to mice fed any of the other diets. A reduction in mast cell degranulation (mMCP-1) and anaphylactic shock symptoms was also observed in these mice. Unstimulated splenocyte cultures produced increased levels of IL10 and IFNg in mice fed the scFOSlcFOS + B. breve diet. Correspondingly, increased percentages of activated Th1 cells were observed in the spleen. Allergen-specific re-stimulation of splenocytes showed a decrease in IL5 production. In summary; post-sensitization administration of scFOSlcFOS + B. breve was effective in reducing allergic symptoms after allergen challenge. These effects coincided with changes in regulatory and effector T-cell subsets and increases in the SCFA propionic acid. These results suggest immune modulatory benefits of dietary intervention with a unique combination of scFOSlcFOS + B. breve in established food allergy. Whether these effects translate to human applications is subject for ongoing clinical studies.


Subject(s)
Bifidobacterium breve , Food Hypersensitivity/therapy , Oligosaccharides/therapeutic use , Animals , Cattle , Chickens , Disease Models, Animal , Female , Food Hypersensitivity/immunology , Humans , Infant , Mice , Mice, Inbred BALB C , Ovalbumin , Synbiotics
20.
Pediatr Allergy Immunol ; 26(4): 316-22, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25845680

ABSTRACT

BACKGROUND: Children with cow's milk allergy (CMA) are at risk for inadequate nutritional intake and growth. Dietary management of CMA, therefore, requires diets that are not only hypoallergenic but also support adequate growth in this population. This study assessed growth of CMA infants when using a new amino acid-based formula (AAF) with prebiotics and probiotics (synbiotics) and evaluated its safety in the intended population. METHODS: In a prospective, randomized, double-blind controlled study, full-term infants with diagnosed CMA received either an AAF (control; n = 56) or AAF with synbiotics (oligofructose, long-chain inulin, acidic oligosaccharides, Bifidobacterium breve M-16V) (test; n = 54) for 16 wk. Primary outcome was growth, measured as weight, length and head circumference. Secondary outcomes included allergic symptoms and stool characteristics. RESULTS: Average age (±SD) of infants at inclusion was 4.5 ± 2.4 months. Both formulas equally supported growth according to WHO 2006 growth charts and resulted in similar increases of weight, length and head circumference. At week 16, differences (90% CI) in Z-scores (test-control) were as follows: weight 0.147 (-0.10; 0.39, p = 0.32), length -0.299 (-0.69; 0.09, p = 0.21) and head circumference 0.152 (-0.15; 0.45, p = 0.40). Weight-for-age and length-for-age Z-scores were not significantly different between the test and control groups. Both formulas were well tolerated and reduced allergic symptoms; the number of adverse events was not different between the groups. CONCLUSIONS: This is the first study that shows that an AAF with a specific synbiotic blend, suitable for CMA infants, supports normal growth and growth similar to the AAF without synbiotics. This clinical trial is registered as NCT00664768.


Subject(s)
Child Development , Infant Formula/administration & dosage , Infant Nutrition Disorders/prevention & control , Milk Hypersensitivity/immunology , Synbiotics/administration & dosage , Amino Acids/administration & dosage , Double-Blind Method , Female , Humans , Infant , Infant Formula/statistics & numerical data , Infant, Newborn , Male , Prospective Studies , Synbiotics/statistics & numerical data
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