Browsing by Author "Bastos-Amador, P."
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- Aflatoxin B1 and early life gut microbiota: preliminary results under earlyMYCO projectPublication . Silva, I.; Duarte, E.L.; Bastos-Amador, P.; Ferreira, M.; Alvito, P.; Assunção, R.; Salvador, C.; Caldeira, A.TAflatoxin B1 (AFB1) produces acute or chronic deleterious health effects in humans and animals. Still, long-term effects derived from initial exposure in early-life, a critical period for colonization and development of gut microbiota, has not been fully evaluated, . particularly, effects on gut microbiota and immunity system. This study, performed under the earlyMYCO project, investigated the impact of maternal exposure to AFB1 on early-life microbiota in a mouse model. Females were fed jelly pellets containing 400 µg/kg AFB1 diluted in DMSO (treated animals n=6) or DMSO vehicle alone (control group n=6) during pregnancy and lactation. Faeces from the offspring were collected immediately after weaning and faecal DNA was extracted and purified. Bacterial taxa diversity and relative abundance were assessed by High-Throughput Sequencing performed in an Illumina Miseq® sequencer, targeting the V3 and V4 regions of the 16S rRNA gene. Operational taxonomic units (OTUs) were determined by clustering reads to 16S reference databases. A hundred and twenty-four (N=124) bacterial genera were found in both groups, 5 were only present in AFB1 treated group and 27 exclusively in control groups. A hundred and fifty-one (N=151) bacterial species were common to both groups, 15 species exclusively found in AFB1 litters and 34 species were exclusively found in control litters. Although present in both groups, Akkermansia muciniphila and Bacteroides acidifaciens were significantly higher in controls. A. muciniphila colonizes the intestinal tract in childhood and regulates mucus thickness, intestinal barrier integrity and is involved in immune modulation. B. acidifaciens participates in the metabolism of lipids and sugars and activates some cytokines and immune cell receptors. Sulfidogenic bacteria, recently related to inflammatory bowel disease, such as Desulfovibrio piger and Bilophila wadsworthia were exclusivly found in the treated litters. Early-life gut microbiome triggers the gut immune defences, but is far less stable than the adult microbiome. These preliminary results open an extensive field to further investigate the association between mycotoxins and microbiome, as the latest is increasingly recognized as a major player in a wide spectrum of diseases.
- Early-life exposure to aflatoxin B1 and associated effects on gut microbiota: preliminary results under earlyMYCO projectPublication . Silva, I.; Duarte, E.; Bastos-Amador, P.; Ferreira, M.; Assunção, R.; Salvador, C.; Caldeira, A.Aflatoxin B1 (AFB1) produces acute or chronic deleterious health effects in humans and animals. Still, long-term effects derived from initial exposure in early life, a critical period for colonization and development of gut microbiota, has not been fully evaluated. Particularly, aflatoxins could impair gut microbiota and immunity settlement, as they have been proven to cross the placental barrier and can be found in breast milk. We investigated the impact of maternal exposure to AFB1 on early-life microbiota in a mouse model. Females were fed jelly pellets containing 400 µg/kg AFB1 diluted in DMSO (treated animals n=6) or DMSO vehicle alone (control group n=6) during pregnancy and lactation. Faeces from the offspring of both treated and control females were collected immediately after weaning and faecal DNA was extracted and purified. Bacterial taxa diversity and relative abundance were assessed by High-Throughput Sequencing performed in an Illumina Miseq® sequencer, targeting the V3 and V4 regions of the 16S rRNA gene. Operational taxonomic units (OTUs) were determined by clustering reads to 16S reference databases. A hundred and twenty-four (N=124) bacterial genera were found in both groups, 5 were only present in AFB1 treated group and 27 exclusively in control groups. A hundred and fifty-one (N=151) bacterial species were common to both groups, 15 species exclusively found in AFB1 litters and 34 species were exclusively found in control litters. To assess abundance and characterize species diversity and evenness, Shannon diversity index was calculated but no significant differences were found between groups. Although present in both groups, Akkermansia muciniphila and Bacteroides acidifaciens were significantly higher in controls. A. muciniphila colonizes the intestinal tract in childhood and regulates mucus thickness, intestinal barrier integrity and is involved in immune modulation. B. acidifaciens participates in the metabolism of lipids and sugars and activates some cytokines and immune cell receptors. Sulfidogenic bacteria recently related to inflammatory bowel disease such as Desulfovibrio piger and Bilophila wadsworthia were exclusivly found in the treated litters. Early-life gut microbiome is paramount to trigger the gut immune defences, but is far less stable than the adult microbiome. Moreover, previous work identified aflatoxins intake as a potential health hazard in Portuguese children. These preliminary results open an extensive field to further investigate the association between mycotoxins and microbiome, as the latest is increasingly recognized as a major player in a wide spectrum of diseases.
- Early-life exposure to MYCOtoxins and its impact on health – a case studyPublication . Alvito, P.; Assunção, R.; Bastos-Amador, P.; de Boevre, M.; Duarte, E.; Martins, C.; Serrenho, i.; Silva, I.; Visintin, L.; Ferreira, M.Considering the potential impact on health and the scarce data available regarding early-life exposure to mycotoxins, earlyMYCO project (early-life exposure to MYCOtoxins and its impact on health) proposed to answer key questions: are pregnant women and infants until six months exposed to mycotoxins? Is this exposure a health threat? Does this early-life exposure influence the intestinal immune system development? Which is the burden derived from the exposure to mycotoxins? The earlyMYCO pilot study enrolled 19 pairs of mother and children, with a loss to follow-up ranging between 11% and 47% for different moments of observation. The mycotoxins’ biomarkers detected were AFB1, OTA, DON and bZEL in urine samples (mother and children), and AFB1, aZEL, FB1, FB2 and FB3 in breast milk samples. Food consumption data revealed that foods consumed more frequently during the week were bread, dairy products, non-alcoholic drinks (tea and coffee), animal products (meat and fish) and pasta. Regarding infants, 22% were fed with infant formula and 78% were exclusively breastfed. Considering the exposure levels, a low risk of mothers’ exposure to the main mycotoxins analyzed is expected, since urine samples did not reveal detectable levels of these compounds; however, infants’ urine samples presented a DON mean value of 14.8 ng/mL (corresponding to 148.0 μg/kg bw/day through reverse dosimetry), which could represent a risk for this population group. Notably, maternal exposure to AFB1 promoted an increase of overall T cell population, while it also resulted in a selective reduction of cytokine-producing innate lymphoid cells group 2 (ILC2) population in intestine of the progeny. These alterations were associated with decreased expression of Reg3b and Reg3g by the intestinal mucosa of progeny. Thus, these results indicate that maternal exposure to mycotoxins impacts the development of offspring intestinal immune system. An in vitro approach using intestinal cell lines Caco-2 and Caco-2/HT29-MTX models exposed to AFB1 during 24h, confirmed the deleterious effects of AFB1 on intestinal membrane integrity and its effect on mucus layer. To assess the impact of AFB1 on early-life microbiota, faeces from litters of AFB1 treated female mice and controls were assessed by metagenomics. Although the overall diversity (Shannon diversity index) of the microbiome wasn’t affected between groups, the microbiome composition varied between AFB1 and control faecal samples (Bray–Curtis dissimilarity index). In particular, some beneficial species were diminished in the litters from AFB1 treated females. Results emphasized the need for assessing the prenatal and lactation exposure to mycotoxins.
- How maternal exposure to aflatoxin B1 impacts the development of progeny intestinal immune system?Publication . Bastos-Amador, P.; Duarte, E.L.; Alvito, P.; Assunção, R.; Ferreira, M.
- How maternal exposure to aflatoxin B1 impacts the development of progeny intestinal immune system?Publication . Bastos-Amador, P.; Duarte, E.L.; Alvito, P.; Assunção, R.; Ferreira, M.Exposure to toxic contaminants during early-life is associated with the development of diseases. Individuals are exposed to mycotoxins since early stages of life[1]. However how maternal exposure to mycotoxins influences the development and function of the offspring’s immune system remains largely unexplored. Recently, we showed that in utero maternal exposure to micronutrients is critical for the development of the immune system, which sets long term immunity if the progeny[2]. Here we show that presence of aflatoxin B1 in the diet of pregnant murine females affects the development and function of the intestinal immune system. Notably, maternal exposure to AFB1 promoted an increase of overall T cell population, while it also resulted in a selective reduction of cytokine-producing innate lymphoid cells group 2 (ILC2) population in intestine of the progeny. These alterations were associated with decreased expression of Reg3b, Reg3g and Fut2 by the intestinal mucosa of progeny. Thus, these results indicate that maternal exposure to mycotoxins impacts the development of offspring intestinal immune system. ILC2 are critical in intestinal epithelial repair, whether mice exposed to AFB1 display defective tissue damage response needs to be investigated. Also FUT2-dependent fucosylation is key in host–commensal symbiosis suggesting alterations in the intestinal microbiota. Our work reveals that maternal exposure to dietary contaminants such as mycotoxins alters the normal development of intestinal immune system framework of the progeny and may have impact in their immune function.