Browsing by Author "Magne, Fabien"

Now showing 1 - 4 of 4
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    Amerindian ancestry proportion as a risk factor for inflammatory bowel diseases: results from a Latin American Andean cohort
    (2023) Pérez Jeldres, Tamara De Lourdes; Magne, Fabien; Ascui, Gabriel; Alvares, Danilo; Orellana, Matias; Álvarez Lobos Manuel Marcelo; Hernández Rocha, Cristián Antonio; Azocar, Lorena; Aguilar, Nataly; Espino, Alberto; Estela, Ricardo; Escobar, Sergio; Zazueta, Alejandra; Baez, Pablo; Silva, Veronica; de la Vega, Andres; Arriagada, Elizabeth; Pávez Ovalle, Carolina Denisse; Diaz-Asencio, Alejandro; Travisany, Dante; Miquel Poblete, Juan Francisco; Villablanca, Eduardo J.; Kronenberg, Mitchell; Bustamante, Maria Leonor
    Background and aimsLatin American populations remain underrepresented in genetic studies of inflammatory bowel diseases (IBDs). Most genetic association studies of IBD rely on Caucasian, African, and Asian individuals. These associations have yet to be evaluated in detail in the Andean region of South America. We explored the contribution of IBD-reported genetic risk variants to a Chilean cohort and the ancestry contribution to IBD in this cohort.MethodsA total of 192 Chilean IBD patients were genotyped using Illumina's Global Screening Array. Genotype data were combined with similar information from 3,147 Chilean controls. The proportions of Aymara, African, European, and Mapuche ancestries were estimated using the software ADMIXTURE. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for gender, age, and ancestry proportions. We also explored associations with previously reported IBD-risk variants independently and in conjunction with genetic ancestry.ResultsThe first and third quartiles of the proportion of Mapuche ancestry in IBD patients were 24.7 and 34.2%, respectively, and the corresponding OR was 2.30 (95%CI 1.52-3.48) for the lowest vs. the highest group. Only one variant (rs7210086) of the 180 reported IBD-risk SNPs was associated with IBD risk in the Chilean cohort (adjusted P = 0.01). This variant is related to myeloid cells.ConclusionThe type and proportion of Native American ancestry in Chileans seem to be associated with IBD risk. Variants associated with IBD risk in this Andean region were related to myeloid cells and the innate immune response.
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    Evaluating the Capacity of Human Gut Microorganisms to Colonize the Zebrafish Larvae (Danio rerio)
    (2018) Valenzuela, María José; Caruffo, Mario; Herrera, Yoani; Medina, Daniel A.; Coronado, Máximo; Feijoo, Carmen G.; Muñoz, Salomé; Garrido Cortés, Daniel; Troncoso, Miriam; Figueroa, Guillermo; Toro, Magaly; Reyes Jara, Angélica; Magne, Fabien; Navarrete, Paola
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    Genotype Prevalence of Lactose Deficiency, Vitamin D Deficiency, and the Vitamin D Receptor in a Chilean Inflammatory Bowel Disease Cohort: Insights from an Observational Study
    (MDPI, 2023) Pérez Jeldres, Tamara De Lourdes; Bustamante, M. Leonor; Segovia-Melero, Roberto; Aguilar, Nataly; Magne, Fabien; Ascui, Gabriel; Uribe, Denisse; Azocar, Lorena; Hernández Rocha, Cristián Antonio; Estela, Ricardo; Silva, Veronica; De La Vega, Andres; Arriagada, Elizabeth; Gonzalez, Mauricio; Onetto, Gian-Franco; Escobar, Sergio; Baez, Pablo; Zazueta, Alejandra; Pávez Ovalle Carolina Denisse; Miquel Poblete, Juan Francisco; Álvarez Lobos Manuel Marcelo
    Lactose intolerance (LI) and vitamin D deficiency (VDD) have been linked to inflammatory bowel disease (IBD). We conducted an observational study in 192 Chilean IBD patients to investigate the prevalence of a specific gene variant (LCT-13910 CC genotype) associated with LI and the prevalence of VDD/Vitamin D Receptor (VDR) gene variants. Blood samples were analyzed using Illumina's Infinium Global Screening Array. The LCT-13910 CC genotype was found in 61% of IBD patients, similar to Chilean Hispanic controls and lower than Chilean Amerindian controls. The frequency of the LCT-13910-C allele in Chilean IBD patients (0.79) was comparable to the general population and higher than Europeans (0.49). Regarding VDR and VDD variants, in our study, the rs12785878-GG variant was associated with an increased risk of IBD (OR = 2.64, CI = 1.61-4.32; p-value = 0.001). Sixty-one percent of the Chilean IBD cohort have a genetic predisposition to lactose malabsorption, and a significant proportion exhibit genetic variants associated with VDD/VDR. Screening for LI and VDD is crucial in this Latin American IBD population.
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    Impact of pomegranate peel extract on gut microbiota composition and metabolic health parameters in high-fat diet-fed mice
    (2024) Duarte, Lissette; Bustamante, Andrés; Orellana, Juan Francisco; Valenzuela, Rodrigo; Magne, Fabien; Fuentes, Jocelyn; Speisky, Hernán; Echeverria Gonzalez, Francisca Cecilia
    Background: Gut microbiota (GM) plays a crucial role in obesity pathophysiology and is heavily influenced by dietary factors. Polyphenols have shown a positive effect in preventing and treating obesity, which is blunted in the absence of GM. Pomegranate peel, known for its high content of polyphenols (ellagitannins), has been found to exhibit favorable metabolic effects in obesity. Interestingly, ellagitannins are metabolized by the action of GM. However, the specific impact of pomegranate peel extract (PPE) on GM and metabolism remains unclear.Objective: to evaluate the effect of a PPE (microencapsulated or not) on the composition of GM in high-fat diet (HFD)-fed mice and analyze its association with metabolic parameters.Methods: Male C57BL/6J mice (n = 40) were randomly distributed into five groups: control diet (CD), HFD, HFD + inulin (IN), HFD + PPE (50 mg/kg/d of total polyphenols; TP), and HFD + MPPE (50 mg/kg/d TP), for 14 weeks. Liver and serum antioxidant status were assessed. GM composition, further relative abundances, and biodiversity were calculated from cecal content samples. The bacterial community clustering was analyzed using a canonical-correlation analysis (CCA). GM parameters and metabolic outcomes were evaluated for correlation (Spearman’s correlation), p < 0.05.Results: PPE and MPPE showed increased energy expenditure, reduced liver arachidonic acid content, elevated antioxidant capacity, and higher GM alpha diversity compared to HFD alone.Conclusion: PPE, regardless of encapsulation, ameliorated metabolic alterations induced by HFD, potentially through modulation of GM. These findings provide data on the therapeutic potential of PPE in managing obesityrelated metabolic dysfunction.