Early infancy dysbiosis in food protein-induced enterocolitis syndrome: A prospective cohort study.

BACKGROUND: The microbiome associations of food protein-induced enterocolitis syndrome (FPIES) are understudied. We sought to prospectively define the clinical features of FPIES in a birth cohort, and investigate for the evidence of gut dysbiosis. METHODS: We identified children diagnosed with FPIES in the Gastrointestinal Microbiome and Allergic Proctocolitis Study, a healthy infant cohort. Children were assessed and stools were collected at each well child visit. The clinical features of the children with FPIES were summarized. Stool microbiome was analyzed using 16S rRNA sequencing comparing children with and without FPIES. RESULTS: Of the 874 children followed up for 3 years, 8 FPIES cases (4 male) were identified, yielding a cumulative incidence of 0.92%. The most common triggers were oat and rice (n = 3, each) followed by milk (n = 2). The children with FPIES were more likely to have family history of food allergy (50% vs. 15.9% among unaffected, p = .03). The average age of disease presentation was 6 months old. During the first 6 months of life, stool from children with FPIES contained significantly less Bifidobacterium adolescentis, but more pathobionts, including Bacteroides spp. (especially Bacteroides fragilis), Holdemania spp., Lachnobacterium spp., and Acinetobacter lwoffii. The short-chain fatty acid (SCFA)-producing Bifidobacterium shunt was expressed significantly less in the stool from FPIES children. CONCLUSIONS: In this cohort, the cumulative incidence over the 3-year study period was 0.92%. During the first 6 months of life, children with FPIES had evidence of dysbiosis and SCFA production pathway was expressed less in their stool, which may play an important role in the pathogenesis of FPIES.

Longitudinal assessment of early growth in children with IgE- and non-IgE-mediated food allergy in a healthy infant cohort.

BACKGROUND: There are conflicting associations reported between food allergies (FAs) and poor growth, with some indication that children with multiple FAs are at highest risk. OBJECTIVE: We analyzed longitudinal weight-for-length (WFL) trajectories from our healthy cohort to evaluate growth in children with IgE-mediated FAs and food protein-induced allergic proctocolitis (FPIAP), a non-IgE-mediated FA. METHODS: Our observational cohort of 903 healthy newborn infants was prospectively enrolled to evaluate the development of FAs. Longitudinal mixed effects modeling was used to compare differences in WFL among children with IgE-FA and FPIAP, compared with unaffected children, through age 2. RESULTS: Among the 804 participants who met inclusion criteria, FPIAP cases had significantly lower WFL than unaffected controls during active disease, which resolved by 1 year of age. In contrast, children with IgE-FA had significantly lower WFL than unaffected controls after 1 year. We also found that children with IgE-FA to cow's milk had significantly lower WFL over the first 2 years of age. Children with multiple IgE-FAs had markedly lower WFL over the first 2 years of age. CONCLUSION: Children with FPIAP have impaired growth during active disease in the first year of age which resolves, whereas children with IgE-FA, particularly those with multiple IgE-FA, have impaired growth more prominently after the first year of age. It may be appropriate to focus nutritional assessment and interventions accordingly during these higher risk periods in these patient populations.

Food aversion and poor weight gain in food protein-induced enterocolitis syndrome: A retrospective study.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a form of non-IgE-mediated gastrointestinal food allergy. Insufficient data exist in regard to gastrointestinal history and outcome, particularly comorbidity, family history, food aversion, and poor body weight gain. OBJECTIVE: We sought to identify the gastrointestinal outcomes and related risk factors in FPIES. METHODS: We analyzed the clinical features and gastrointestinal outcomes of patients with FPIES retrospectively at 4 hospitals in Boston. RESULTS: Two hundred three patients with FPIES were identified, including 180 only with acute FPIES, 8 with chronic FPIES, and 15 with both. Oat (34.5%), rice (29.6%), and cow's milk (19.2%) were the most common food triggers. The prevalence rates of personal history with allergic proctocolitis (23.2%) and family history with inflammatory bowel diseases (9.4%) and celiac disease (7.3%) were higher than those in the general population. Compared with patients with FPIES with 1 or 2 food triggers, the risk of developing food aversion increased in cases triggered by 3 or more foods (adjusted odds ratio, 3.07; 95% CI, 1.38-6.82; P = .006). The risk of poor body weight gain increased in FPIES triggered by cow's milk (adjusted odds ratio, 3.41; 95% CI, 1.21-9.63; P = .02) and banana (adjusted odds ratio, 7.63; 95% CI, 2.10-27.80; P = .002). CONCLUSIONS: Gastrointestinal comorbidities and family history were common in patients with FPIES. Patients with FPIES with 3 or more triggers were at risk of food aversion. Patients with FPIES with cow's milk and banana as triggers were at risk of poor body weight gain.

Demonstration of binding of neuronal calcium sensor-1 to the cav2.1 p/q-type calcium channel.

In neurons, entry of extracellular calcium (Ca(2+)) into synaptic terminals through Cav2.1 (P/Q-type) Ca(2+) channels is the driving force for exocytosis of neurotransmitter-containing synaptic vesicles. This class of Ca(2+) channel is, therefore, pivotal during normal neurotransmission in higher organisms. In response to channel opening and Ca(2+) influx, specific Ca(2+)-binding proteins associate with cytoplasmic regulatory domains of the P/Q channel to modulate subsequent channel opening. Channel modulation in this way influences synaptic plasticity with consequences for higher-level processes such as learning and memory acquisition. The ubiquitous Ca(2+)-sensing protein calmodulin (CaM) regulates the activity of all types of mammalian voltage-gated Ca(2+) channels, including the P/Q class, by direct binding to specific regulatory motifs. More recently, experimental evidence has highlighted a role for additional Ca(2+)-binding proteins, particularly of the CaBP and NCS families in the regulation of P/Q channels. NCS-1 is a protein found from yeast to humans and that regulates a diverse number of cellular functions. Physiological and genetic evidence indicates that NCS-1 regulates P/Q channel activity, including calcium-dependent facilitation, although a direct physical association between the proteins has yet to be demonstrated. In this study, we aimed to determine if there is a direct interaction between NCS-1 and the C-terminal cytoplasmic tail of the Cav2.1 α-subunit. Using distinct but complementary approaches, including in vitro binding of bacterially expressed recombinant proteins, fluorescence spectrophotometry, isothermal titration calorimetry, nuclear magnetic resonance, and expression of fluorescently tagged proteins in mammalian cells, we show direct binding and demonstrate that CaM can compete for it. We speculate about how NCS-1/Cav2.1 association might add to the complexity of calcium channel regulation mediated by other known calcium-sensing proteins and how this might help to fine-tune neurotransmission in the mammalian central nervous system.

Factors influencing age of common allergen introduction in early childhood.

Objectives: We evaluated factors influencing the timing of allergen introduction in the U.S., including updated peanut introduction guidelines. Study design: The Gastrointestinal Microbiome and Allergic Proctocolitis (GMAP) study is a prospective observational cohort in suburban Massachusetts. Infants' caregivers enrolled between 2014 and 2017, and they reported when they introduced common allergens to their child. Multivariable linear and survival regression analyses were used to examine factors influencing time of introduction of allergens. Results: By 9 months, children old enough to be potentially affected by NIAID's 2017 peanut introduction guidelines were more often introduced to peanut than children enrolled well before guidelines publication [54% vs. 42%, OR: 1.63, CI: (1.03, 2.57), P = 0.03]. At any given time, Black children were 73% [HR: 0.27, CI: (0.11, 0.69), P = 0.006] less likely to be introduced to peanut as early as White children. Asian children were, respectively, 36% [HR: 0.64, CI: (0.47, 0.86), P = 0.003] and 26% [HR: 0.74, CI: (0.55, 0.97), P = 0.03] less likely to be introduced to peanut and egg as early as White children. A first child was 27% [HR: 1.27, CI: (1.04, 1.56), P = 0.02] more likely to have been introduced to peanut earlier than a non-first child. There was no association between age of introduction and sex, gestational age, family history of food allergy, or other allergic comorbidities. Conclusion: Updated introduction guidelines, race, and birth order all influenced earlier introduction of peanut. Further studies to evaluate current practices for allergen introduction with a focus on potential disparities are needed.

EasyMap - An Interactive Web Tool for Evaluating and Comparing Associations of Clinical Variables and Microbiome Composition.

One of the most common tasks in microbiome studies is comparing microbial profiles across various groups of people (e.g., sick vs. healthy). Routinely, researchers use multivariate linear regression models to address these challenges, such as linear regression packages, MaAsLin2, LEfSe, etc. In many cases, it is unclear which metadata variables should be included in the linear model, as many human-associated variables are correlated with one another. Thus, multiple models are often tested, each including a different set of variables, however the challenge of selecting the metadata variables in the final model remains. Here, we present EasyMap, an interactive online tool allowing for (1) running multiple multivariate linear regression models, on the same features and metadata; (2) visualizing the associations between microbial features and clinical metadata found in each model; and (3) comparing across the various models to identify the critical metadata variables and select the optimal model. EasyMap provides a side-by-side visualization of association results across the various models, each with additional metadata variables, enabling us to evaluate the impact of each metadata variable on the associated feature. EasyMap's interface enables filtering associations by significance, focusing on specific microbes and finding the robust associations that are found across multiple models. While EasyMap was designed to analyze microbiome data, it can handle any other tabular data with numeric features and metadata variables. EasyMap takes the common task of multivariate linear regression to the next level, with an intuitive and simple user interface, allowing for wide comparisons of multiple models to identify the robust microbial feature associations. EasyMap is available at http://yassour.rcs.huji.ac.il/easymap.

Longitudinal disease-associated gut microbiome differences in infants with food protein-induced allergic proctocolitis.

BACKGROUND: Complex interactions between the gut microbiome and immune cells in infancy are thought to be part of the pathogenesis for the marked rise in pediatric allergic diseases, particularly food allergies. Food protein-induced allergic proctocolitis (FPIAP) is commonly the earliest recognized non-immunoglobulin E (IgE)-mediated food allergy in infancy and is associated with atopic dermatitis and subsequent IgE-mediated food allergy later in childhood. Yet, a large prospective longitudinal study of the microbiome of infants with FPIAP, including samples prior to symptom onset, has not been done. RESULTS: Here, we analyzed 954 longitudinal samples from 160 infants in a nested case-control study (81 who developed FPIAP and 79 matched controls) from 1 week to 1 year of age by 16S rRNA ribosomal gene sequencing as part of the Gastrointestinal Microbiome and Allergic Proctocolitis (GMAP) study. We found key differences in the microbiome of infants with FPIAP, most strongly a higher abundance of a genus of Enterobacteriaceae and a lower abundance of a family of Clostridiales during the symptomatic period. We saw some of these significant taxonomic differences even prior to symptom onset. There were no consistent longitudinal differences in richness or stability diversity metrics between infants with FPIAP and healthy controls. CONCLUSIONS: This study is the first to identify differences in the infant gut microbiome in children who develop FPIAP, some even before they develop symptoms, and provides a foundation for more mechanistic investigation into the pathogenesis of FPIAP and subsequent food allergic diseases in childhood. Video abstract.

Characterization of the blood microbiota in children with Celiac disease.

Celiac Disease (CD) is an autoimmune disorder triggered by gluten ingestion that can develop in genetically predisposed individuals. Alterations in the gut microbiota have been suggested to contribute to development of autoimmune conditions including CD. Recent work suggests the existence of a blood microbiota. Evidence that alterations in the blood microbiota potentially influence the development of chronic immune based diseases is increasing. However, there is no published literature regarding the blood microbiota in children, including those with CD. This study aimed to characterize the diversity and taxonomic composition of the blood microbiota of children with CD compared to controls. Whole blood samples were collected from children with active CD, CD in remission, and control subjects and 16S rRNA sequencing was utilized to analyze the blood microbiota. We found 16s rRNA present throughout all pediatric blood samples, providing evidence for the presence of a pediatric blood microbiota. We found significant differences in beta diversity and in abundance of certain taxa (Campylobacterales order, Odoribacteraceae and Helicobacteraceae families, Odoribacter genus and species, and Bacteroides acidifaciens species) between subjects with active CD and controls. These taxa have been previously reported to be associated with immune response and gut-inflammatory diseases. We did not find significant differences between subjects with active and remission CD or between remission CD and controls. Conclusions: We provide evidence for a pediatric blood microbiota and identified higher beta diversity and alterations in the composition of blood microbiota in subjects with active CD compared to controls.

Prospective Assessment of Pediatrician-Diagnosed Food Protein-Induced Allergic Proctocolitis by Gross or Occult Blood.

BACKGROUND: Food protein-induced allergic proctocolitis (FPIAP) is an early and common manifestation of food allergy, yet its epidemiology and relationship to other allergic diseases remain unclear. OBJECTIVE: To prospectively define the incidence of FPIAP as it is being diagnosed clinically in the community and to identify factors associated with its development. METHODS: A total of 1003 of 1162 eligible serial healthy newborn infants recruited from a single suburban pediatrics practice were followed prospectively for the diagnosis of FPIAP. Investigators reviewed each case to confirm prespecified inclusion criteria, including documented gross or occult blood in the stool. RESULTS: A total of 903 infants were analyzed (46% females, 89% term, 32% caesarian-section, 9% neonatal antibiotics); 153 cases met inclusion criteria, a cumulative incidence of 17%, while 63 (7%) had gross blood. Infants initially fed both breast milk and formula were 61% less likely to develop FPIAP compared with those exclusively formula-fed (hazard ratio, 0.39; P = .005). Breast milk and formula at any point during the first 4 months were also associated with lower risk compared with exclusive formula or exclusive breast milk (hazard ratio, 0.44; P = .005; hazard ratio, 0.62; P = .0497). Eczema (odds ratio, 1.5; 95% confidence interval, 1.1- 2.2; P = .02) or a first-degree relative with food allergies (odds ratio, 1.9; 95% confidence interval, 1.2-2.8; P = .005) were among risk factors for FPIAP development. CONCLUSIONS: The prospectively defined incidence of FPIAP when diagnosed clinically by community pediatricians without challenge is markedly higher than published estimates. Combination feeding of formula and breast milk is associated with the lowest rate of FPIAP in this population.

The Relationship Between Mock Boards and Clinical Board Examinations in Dental Hygiene Education.

Research on the effectiveness of clinical mock boards for future oral health professionals is conflicting and limited. Despite this, U.S. dental hygiene programs rely on clinical mock board experiences as essential components for preparing students for their clinical board examinations. Differences in programs' mock board characteristics may relate to board exam outcomes. The validity and reliability of mock boards can be questioned when deviations from exam criteria and procedures are made and grading mechanisms are not consistent. The aim of this study was to determine which mock board characteristics were critical in preparing students by exploring the relationships between programs' dental hygiene, local anesthesia, and restorative mock boards and their 2013-14 candidates' performance on the corresponding three Western Regional Examining Board (WREB) licensure exams. Of the 23 U.S. dental hygiene education programs in four states invited to participate, 15 agreed to do so, and 13 consented to have WREB provide their programs' test result data. The mock board coordinators provided data on characteristics of their programs' mock boards with an online questionnaire distributed in 2014. Scores calculated from the responses were compared to performance of the programs' candidates on the corresponding WREB exam. Of the 45 questionnaires (on three exams each x 15 programs), 33 were completed (73.3%). Significant relationships were found between candidates' WREB exam results and the mock boards' intensity scores, remediation, multiple experiences, and examiner calibration scores. The results of this study provide fundamental information about mock board characteristics that may assist educators in facilitating experiences to more effectively prepare students for these high-stakes exams.

Identification of key structural elements for neuronal calcium sensor-1 function in the regulation of the temperature-dependency of locomotion in C. elegans.

BACKGROUND: Intracellular Ca2+ regulates many aspects of neuronal function through Ca2+ binding to EF hand-containing Ca2+ sensors that in turn bind target proteins to regulate their function. Amongst the sensors are the neuronal calcium sensor (NCS) family of proteins that are involved in multiple neuronal signalling pathways. Each NCS protein has specific and overlapping targets and physiological functions and specificity is likely to be determined by structural features within the proteins. Common to the NCS proteins is the exposure of a hydrophobic groove, allowing target binding in the Ca2+-loaded form. Structural analysis of NCS protein complexes with target peptides has indicated common and distinct aspects of target protein interaction. Two key differences between NCS proteins are the size of the hydrophobic groove that is exposed for interaction and the role of their non-conserved C-terminal tails. RESULTS: We characterised the role of NCS-1 in a temperature-dependent locomotion assay in C. elegans and identified a distinct phenotype in the ncs-1 null in which the worms do not show reduced locomotion at actually elevated temperature. Using rescue of this phenotype we showed that NCS-1 functions in AIY neurons. Structure/function analysis introducing single or double mutations within the hydrophobic groove based on information from characterised target complexes established that both N- and C-terminal pockets of the groove are functionally important and that deletion of the C-terminal tail of NCS-1 did not impair its ability to rescue. CONCLUSIONS: The current work has allowed physiological assessment of suggestions from structural studies on the key structural features that underlie the interaction of NCS-1 with its target proteins. The results are consistent with the notion that full length of the hydrophobic groove is required for the regulatory interactions underlying NCS-1 function whereas the C-terminal tail of NCS-1 is not essential. This has allowed discrimination between two potential modes of interaction of NCS-1 with its targets.

Bang! Month-scale eruption triggering at Santorini volcano.

The time lag between intrusion of fresh, hot magma and an ensuing eruption is of critical importance in both understanding the triggering and mitigating the consequences of volcanic eruptions. This work looks at material erupted during 1925-28 at the Nea Kameni volcanic center in Santorini, Greece, to determine this time scale. By exploiting Fe-Mg diffusion in olivine crystals, we constrained the intrusion-to-eruption time lag to between 3 and 10 weeks. These techniques have potential application at many volcanic centers; previously erupted material can be used to calibrate records of the short-time scale processes common to many volcanic centers.