bluuebunny/crossref_metadata_2025_split huggingface dataset:
A18 EARLY LIFE EXPOSURE TO PARENTAL CROHN'S DISEASE IS ASSOCIATED WITH GUT MICROBIAL COMPOSITION AND FUNCTION, GUT PERMEABILITY AND INCREASED RISK OF FUTURE CROHN'S DISEASE
Authors: Bushra M , Shao J , Qiu L , Olivera P A , Leibovitzh H , Xue M , Neustaeter A , Xu W , Espin-Garcia O , Aumais G , Huynh H , Panaccione R , Steinhart H , Cino M , Mack D , Marshall J , Ropeleski M , Bitton A , Jacobson K , Mcgrath J , Yerushalmi B , Abreu M , Bernstein C , Radford-Smith G , Lees C , Turner D , Silverberg M , Turpin W , Croitoru K , Lee S 
Published: February 2024

Abstract

Background
Previous studies show that offspring of persons with Crohn’s disease (CD) have a 7-fold higher risk of incident CD than the general population. Newborns of women with CD (vs healthy women) have altered stool microbiome composition and elevated fecal calprotectin (FCP). The perinatal period (pregnancy and first year postpartum) is critical for the development of the gut microbiome and immune system.

Aims
We investigated whether perinatal exposure to parental CD (compared to exposure later in life) has an impact on offspring’s gut barrier function, microbiome composition, and risk of future CD.

Methods
We assessed 1252 healthy offspring of persons with CD who were recruited in the CCC-GEM Project. We classified offspring into "perinatally exposed (pregnancy and first year postpartum)" vs "exposed later in life" to parental CD diagnosis. We measured baseline FCP and urinary fractional excretion ratio of lactulose to mannitol (marker of intestinal permeability, LMR). Fecal microbiome composition was determined by 16S rRNA gene sequencing. Microbiome function was imputed by PICRUSt2 (q value defined as false discovery rate-adjusted p&lt;0.05). Multivariable regression and Cox proportional-hazards analyses were used to assess if peri-natal exposure to parental CD is associated with LMR, FCP, altered microbial composition, and future CD onset.

Results
Offspring exposed to a CD parent perinatally had a 4.7-fold higher risk (aHR 95%CI 1.3-17.5) of developing CD compared to those exposed to a parent who developed CD later in life (11/586 vs 3/666). LMR was significantly higher in the offspring exposed to parental CD perinatally (p=0.003), while no significant difference was observed for FCP at recruitment (p=0.94). Five bacterial taxa were significantly increased in the perinatally exposed group (q&lt;0.05). The microbial functions such as glycine amidinotransferase, serine protein kinase and cyanophycin synthase were significantly increased in the perinatally exposed group (q&lt;0.05).

Conclusions
Offspring exposed to parental CD perinatally had a higher risk of developing CD than those exposed to parental CD later in life. Early life exposure to parental CD was associated with higher baseline LMR, altered bacterial taxa and functional capacities. Environmental exposure during the perinatal period may determine the offspring’s risk of developing CD.

Funding Agencies
CAG, CCC, CIHRCanada Research Chair
A19 THE IMPACT OF FOOD INSECURITY ON ADHERENCE TO A GLUTEN-FREE DIET IN THE ADULT CELIAC DISEASE POPULATION ATTENDING A DEDICATED CELIAC CLINIC
Authors: Leong R , Tandon S , Khaouli M , Blom J , Daca R , Verdu E , Armstrong D , Pinto-Sanchez M 
Published: February 2024

Abstract

Background
A strict gluten-free diet (GFD) is currently the only treatment for celiac disease (CeD), but a GFD can be inconvenient and expensive. CeD patients who are food insecure (FI) face threats to GFD adherence, overall health, and quality of life.

Aims
To evaluate the prevalence of FI in patients with CeD attending a dedicated Adult Celiac Disease Clinic (ACDC) at an academic hospital and to examine the relationship between FI and GFD adherence, quality of life and various gastrointestinal symptoms.

Methods
Patients were invited to participate in the CeD registry when they attended the ACDC; those who agreed to participate then provided verbal and signed consent. Patients had the option to complete the CeD registry forms in the clinic on an iPad or at home using a card with a QR code and a unique ID to access the online CeD registry. The CeD registry uses REDCap (v. 11.1, 2021, US) and includes six validated questionnaires (Celiac Diet Adherence Test (CDAT), Celiac Disease Quality of Life Questionnaire (CD QoL), Celiac Symptom Index (CSI), Gastrointestinal Symptom Rating Scale (GSRS), Hospital Anxiety and Depression Scale (HADS), and Household Food Security Survey Module (HFSSM)). Continuous data are expressed as mean (SD), and categorical data as proportions of patients. The chi-squared test with Fisher correction and t-test were used to assess differences between groups.

Results
A total of 653 patients attended the ACDC from November 2, 2022, to September 20, 2023, and 411 patients were invited to participate in this study. Of them, 204 completed the CeD registry. Food insecurity was identified in 16% of CeD patients, of whom 11 (5%) were marginally FI, 16 (8%) were moderately FI, and 7 (3%) were severely FI. Compared to CeD patients who are food secure, a greater proportion of FI CeD patients reported nonadherence to GFD (26/34 vs 70/170; p&lt;0.001), reduced QoL (32/34 vs 98/170; p&lt;0.001), greater anxiety (27/34 vs 84/170; p=0.001) and greater depression (13/34 vs 26/170; p=0.004) compared with normal values. CeD patients with FI also reported lower QoL [61.0(14.9) vs 49.6(16.7); p=0.001] and increased gastrointestinal symptoms [GSRS 37.7(14.7) vs 29.0(12.8); p=0.001] compared with food secure CeD patients.

Conclusions
Food insecurity is common in patients with CeD and is associated with significantly worse adherence to treatment, symptom control, and quality of life. There is an important need for programs and societal measures to abolish food insecurity and ensure adequate access to treatment for patients with CeD.

Funding Agencies
TRIANGLE Summer Studentship
A20 FECAL MICROBIOTA TRANSPLANTATION FORMULATIONS DO NOT AFFECT BACTERIAL VIABILITY OR TREATMENT OUTCOMES IN RECURRENT C. DIFFICILE INFECTION
Authors: Chan L , Franz R , McDougall C , Wong K , Kao D 
Published: February 2024

Abstract

Background
Fecal microbiota transplantation (FMT) is the most effective therapy for recurrent Clostridioides difficile infections (rCDI) with multiple RCTs showing efficacy of 80-90%. Frozen FMT is a commonly used formulation but requires storage at -80°C, creating barriers to storage and transportation. More recently, lyophilized FMT (LFMT) has shown promise as an alternative formulation, but little data exists as to how bacterial viability may be affected compared to fresh or frozen FMT by different storage temperatures and duration, and real-world outcome data is sparse. As such, this study aims to evaluate the viability and efficacy of LFMT compared to fresh and frozen FMT.

Aims
To 1) compare bacterial viability in 3 FMT formulations: fresh, frozen and lyophilization, at varying storage temperatures and duration, and 2) correlate different formulations with treatment outcomes.

Methods
We compared bacterial viability using flow cytometry to determine the proportion of live vs dead bacteria on fresh, frozen and lyophilized donor stool samples stored at different temperatures (-80°C for frozen, -80°C and +4°C for LFMT) and duration (up to 12 months). We then retrospectively examined treatment success rates in rCDI patients who received fresh, frozen or LFMT at the University of Alberta since inception of the FMT program in 2012. Success is defined as no recurrence of CDI 8 weeks after receiving a single FMT treatment.

Results
Compared to fresh FMT (20% live cells), the proportions of live cells in frozen formulation stored at -80°C and lyophilized formulations stored at -80°C and 4°C did not diminish over time for up to 12 months as shown in Figure 1. Between 2013-2022, outcome data was available in 503 rCDI patients with baseline characteristics and treatment outcomes shown in Table 1. A logistic regression analysis comparing LFMT to frozen FMT resulted in an odds ratio of 0.14, indicating that success rate of LFMT is 14% higher than frozen FMT.

Conclusions
Our study showed that LFMT stored at either -80°C or 4°C over 12 months did not result in diminished bacterial viability compared with frozen FMT. Furthermore, treatment success rate following LFMT in rCDI patients was not lower than with frozen FMT. This finding has implication for stool banks and FMT programs as LFMT can be stored and shipped at 4°C, facilitating use in outpatient settings.
Table 1. Baseline characteristics and success rates of rCDI patients who received fresh, frozen or LFMT.

Figure 1. Proportions of live cells in frozen FMT stored at -80°C, LFMT stored at -80°C and 4°C, at 1, 3, 6, 9 and 12 months.

Funding Agencies
None
A26 BIOLOGICAL CHARACTERIZATION OF THE INTERACTION BETWEEN SIRT1 AND HNF4Α2 IN INTESTINAL EPITHELIAL CELLS
Authors: Herrera Pulido J A , Jones C , Boudreau F 
Published: February 2024

Abstract

Background
Colorectal cancer (CRC) is the third most common cancer in Canada. HNF4A locus is amplified in CRC, while additional reports suggest that hepatocyte nuclear factor 4 alpha (HNF4α) is associated with increased proliferation and disease development. This dual role as a tumor suppressor or oncoprotein might be due to the production of 12 spliced isoforms with structural differences and variable tissue expression. It suggests distinct functions for each isoform according to their specific interaction complexes. However, little is known about the nature of these protein complexes and their biological functions during intestinal physiopathology. Recently, using a BioID2 and mass spectrometry approach, our laboratory showed a possible interaction between HNF4α2 and sirtuin 1 (SIRT1) in intestinal epithelial cells from a colon carcinoma (HCT116). HNF4α2 is one of the most potent isoforms in the control of transcriptional activity of multiple intestinal epithelial genes related to regulating cell death, angiogenesis, apoptosis, response to injury, and response to drugs, among others.

Aims
To characterize the possible interaction between HNF4α2 and SIRT1 in intestinal epithelial cells at the biological level.

Methods
We performed SIRT1 knockdown using shRNAs in HCT116 cells expressing the HNF4α2 isoform in an inducible manner by doxycycline (DOX). Subsequently, we conducted a proximity ligation assay to validate the interaction between HNF4α2 and SIRT1 in HCT116 cells. Additionally, protein purification was performed to validate their physical interaction through EMSA. A transcriptome analysis was carried out using RNA-seq to define the biological processes involved in the interaction between the two proteins.

Results
We observed an interaction signal between HNF4α2 and SIRT1 in HCT116 cells, similar to that observed for IRFBB2, whose interaction with HNF4α2 has been previously validated. This signal decreased when cells were treated with shRNA for SIRT1 and was not observed in cells not induced by DOX. EMSA analyses revealed a direct interaction signal between HNF4α2 and SIRT1. RNA-seq analyses showed a loss in the regulation of over 95% of genes targeted by HNF4α2 when cells were treated with shRNA for SIRT1. An enrichment analysis for GO annotations using ShyniGO v. 0.77 software showed an enrichment of genes for biological processes such as apoptosis, inflammation, cell migration, cell invasion, cell death, and various cancer-related signaling pathways.

Conclusions
SIRT1 displays physical interaction with HNF4α2 and significantly affects the transcriptional regulation of this isoform in the context of epithelial cells. Their interaction is involved in processes related to intestinal inflammation and cancer progression. Pharmacological targeting of SIRT1 could represent a viable strategy in treating CRC and other intestinal diseases

Funding Agencies
CIHRNSERC
A34 DEVELOPING A NOVEL MOUSE MODEL TO ELUCIDATE MECHANISMS OF ORAL TOLERANCE IN EARLY LIFE
Authors: FitzPatrick R D , Cartwright R A , Gatti D M , Reynolds L 
Published: February 2024

Abstract

Background
Oral tolerance is the active suppression of immune responses to antigens that are first encountered in the gastrointestinal tract. When this process fails, food allergies can arise. Food allergies affect up to 6% of Canadian children underlining the need for a thorough understanding of how oral tolerance develops in childhood. Despite this, tolerance has historically been studied using adult rodent models instead of focusing on more physiologically relevant early-life time points.

Aims
Our research aims to develop a robust mouse model to elucidate mechanisms of oral tolerance development in early life and we hypothesize that the mesenteric lymph nodes are a major site of food antigen-specific T cell development in early life.

Methods
Prior to weaning, actively suckling mouse pups were orally gavaged with ovalbumin (OVA), an egg white component and common food allergen or water as a control. Following a series of systemic challenges with OVA, circulating antibody levels were quantified by ELISA to measure the development of oral tolerance to OVA. Additionally, splenocytes isolated from tolerized and control mice were stimulated in vitro with exogenous OVA and cytokines were quantified in culture supernatants via a cytometric bead array assay to assess the suppression of T cell responses to OVA in tolerized mice. One week following oral OVA exposure flow cytometry was used to characterize the expansion of T cell populations in the mesenteric lymph nodes, spleen and thymus.

Results
Mice orally gavaged with OVA in early life show reduced systemic antibody production after subsequent challenges with OVA, compared to mice not orally exposed to OVA. We determined the minimum dosage of OVA required to confer tolerance in these mice and confirmed the validity of this model in both male and female C57BL/6 and BALB/c mice. Further, we detected an active suppression of IL-5 production, a cytokine indicative of a Type 2 immune response, in OVA-stimulated splenocyte cultures isolated from mice tolerized to OVA. We found a significant increase in the frequency of CD4 T cells in the mesenteric lymph nodes just 1-week following oral OVA exposure.

Conclusions
We have developed a robust mouse model of oral tolerance where mice are directly exposed to OVA in an early life period while they are still actively ingesting breastmilk, and their mucosal immune system and intestinal microbiota composition are under significant development. To date, our data suggests that the gut draining mesenteric lymph nodes may be a site of food antigen-specific T cell expansion in early life.

Funding Agencies
CIHRTRIANGLE
A39 DEVELOPMENTALLY REGULATED CECAL CONTENT MICRO-RNAS CORRELATE WITH MATURING MICROBIOTA GENES AND FUNCTIONS IN JUVENILE MICE
Authors: Cuinat C , Taibi A , Tremblay J , Gargari G , Guglielmetti S , Tompkins T , Comelli E 
Published: February 2024

Abstract

Background
The gut microbiome establishment in early life is critical to life-long health and influenced by the maternal gut ecosystem. MicroRNAs (miRNAs) have emerged as a new player in host-microbiota interaction due to their regulatory effect on bacterial genes. We previously found that maternal supplementation with a probiotic mix of Lacticaseibacillus rhamnosus R0011 and Lactobacillus helveticus R0052 supported the maturation of microbial metabolic activity and altered the cecal content miRNA profile in juvenile mice.

Aims
To investigate the relationship between cecal content miRNAs and inferred microbiota genes and functions in early life and identify potential miRNA-bacterial gene targets.

Methods
We generated 16S rRNA gene sequencing and NanoString nCounter® data from the cecal content of 14, 21, and 36-days-old C57BL/6 mice born to dams receiving or not probiotic-supplemented water since preconception. Taxa contributions to bacterial enzyme-encoding genes and pathways were inferred with PICRUSt2. Time or group-altered genes, pathways, and miRNAs were identified with DESeq2. Spearman correlations were performed between miRNAs and bacterial genes or pathways (n= 3-5 male offspring/PND/group) and significant correlations (q ampersand:003C 0.05) were visualized with NAViGaTOR. Potential miRNA binding sites on bacterial genes were investigated using the ViennaRNA Package.

Results
Time-associated miR-433 positively correlated with two time-altered genes involved in the TCA and glyoxylate cycles. Group-associated miR-691 was positively correlated with genes related to tRNA charging pathway, pyruvate fermentation to acetate and lactate, and amino acids biosynthesis. Additionally, miR-691 was negatively correlated with six group-altered genes involved in myo-inositol degradation. We identified potential miRNA binding sites (total free energy of binding ampersand:003C -10 kcal/mol) for miR-691 with genes involved in pyruvate fermentation, lysine biosynthesis, and myo-inositol degradation, and for miR-433 with genes annotated to the TCA and glyoxylate cycles.

Conclusions
Host miRNAs correlate with bacterial pathways and genes maturing during the weaning transition, highlighting their potential to regulate microbial metabolic activity. Maternal probiotics supplementation may accelerate the development of microbial metabolic pathways through epigenetic mechanisms, independently of weaning dietary shift. Correlations identified include energy production pathways and may become clinical targets in infants with delayed maturation of the intestinal ecosystem.

Funding Agencies
NSERC
A42 A HIGH SALT DIET INCREASES ELASTOLYTIC ACTIVITY AND WORSENS COLITIS IN GNOTOBIOTIC MICE
Authors: Hann A , Bording Jorgensen M , Santiago Badenas A , Constante M , Jackson K , Bercik P , Galipeau H , Verdu E 
Published: February 2024

Abstract

Background
Recent evidence has linked ultra-processed foods, which are high in salt, to increased risk of inflammatory bowel disease (IBD). A high salt diet (HSD) was also shown to be colitogenic in specific pathogen-free mice, in part, through modulation of the microbiota. We recently described high microbial proteolytic activity (PA) in feces from IBD patients, that when transferred to germ-free mice, increased acute colitis severity. However, the drivers of high microbial PA are unknown.

Aims
To determine whether HSD increases proteolytic activity, thereby exacerbating colitis.

Methods
Adult germ-free (GF) C57BL/6 mice were colonized with feces from a patient with UC in flare (n=13). Mice were fed either a control diet (CD; 7004, Teklad) or a HSD (7004 supplemented with 4% NaCl) plus 1% NaCl in drinking water. Three weeks following colonization, chronic colitis was induced in half of the mice by three cycles (five days each; 2.0%, 1.5% and 1.5%, respectively) of DSS in drinking water with a five-day wash-out period between cycles. Fecal PA and predicted microbial protease profiles were measured before colitis induction. Weight loss and disease activity (e.g., occult blood in feces and stool consistency) was evaluated for the duration of colitis and microscopic colitis was evaluated at endpoint.

Results
In mice colonized with UC microbiota, a HSD increased elastolytic activity (p=.03 versus CD) and induced a unique predicted protease and peptidase profile. After colitis induction, mice consuming a HSD lost more weight than mice consuming the CD (p=.0001) and had higher disease activity (p=.0004). Additionally, HSD induced more severe microscopic colitis scores compared with the CD (p=.0001).

Conclusions
These results raise the hypothesis that a HSD drives microbial proteolytic activity of IBD microbiota. However, whether this shift is causally associated with the worsening of colitis remains unclear. Mechanistic insight underlying this HSD-microbial proteolytic function could lead to specific dietary modifications or anti-proteolytic therapies for IBD in patients with proteolytic-driven inflammation.

Funding Agencies
CCC, CIHR
A47 A PRELIMINARY ANALYSIS OF THE CROHN'S DISEASE THERAPEUTIC INTERVENTION TRIAL (CD-TDI) IN MILD-TO-MODERATE CROHN'S DISEASE
Authors: Haskey N , Bruno A , Ramay H , Munazza Y , Taylor L M , Ohland C , McCoy K , Ma C , Ghosh S , Veniamin S , Dieleman L , Raman M 
Published: February 2024

Abstract

Background
Studies show a diet-CD remission link, yet a lack of clinical trials exists. The CD Therapeutic Dietary Intervention (CD-TDI) is an evidence-based dietary regimen based on the principles of the Mediterranean diet and incorporates insights from our pilot data as well as the scientific literature about mitigating inflammation through diet in CD.

Aims
To explore the efficacy of the CD-TDI compared with conventional management (CM) to induce clinical and biochemical remission in patients with active, mild-to-moderate luminal CD.

Methods
Participants (n=28) were randomly assigned (2:1 ratio) to either CD-TDI (n=16) or conventional management (CM) (n=12) for 13 weeks. Stool and blood samples were collected at the start and end of the 13 weeks, and fecal bacteriome was analyzed by 16S rRNA.

Results
At baseline, fecal calprotectin (FCP) or C-reactive protein (CRP) levels were not significantly different. By W13, the CD-TDI group's FCP decreased (△ -113±237 µg/g), whereas the CM group experienced an increase (△ 337±1224 µg/g) (p=0.04). CD-TDI significantly reduced CRP (1.0 mg/L, IQR: 0.6-2.4) compared to the CM (4.5 mg/L, IQR: 2.6-13.0, p=0.007). In the CD-TDI group, zonulin decreased (-43 vs. +26, p=0.04) and increased in the CM group (-43 vs. +26, p=0.04), respectively. Lipopolysaccharide-binding protein (LBP) significantly increased in the CM group compared to CD-TDI (CD-TDI = 17 vs. CM = 26; p=0.03). Differential abundance analysis identified a higher abundance of Lachnospiraceae, Selenomonadaceae, Sutterella spp., and Akkermansia muciniphila in the CD-TDI group, whereas Collinsella intestinalis was more prevalent in the CM group.

Conclusions
The CD-TDI demonstrated a reduction in markers of inflammation and intestinal permeability in patients with mild-to-moderately active CD, along with alterations in the composition of bacterial taxa. These initial findings strongly indicate that CD-TDI holds promise for alleviating the inflammatory burden in CD patients and warrants further exploration as a valuable adjunctive therapy.

Funding Agencies
Crohn's Colitis Foundation of America; IMAGINE