Impact of perinatal factors on the maternal- neonatal microbiota and influence on health outcomes

Tesis por compendio[EN] The importance of the microbiota for host health and disease is now widely appreciated. Microbial communities that inhabit the human body have been proposed as an essential aspect of the hypothesis focused on the developmental origin of health and disease (DOHaD), suggesting that altered microbial exposure during infancy could play a role in the risk of some immune-based diseases, such as obesity, allergy development or T2 diabetes mellitus. Indeed, associational studies have related perinatal factors that could disrupt neonatal microbial colonization, such as antibiotic intake, Csection and formula feeding, to these diseases later in life. Some authors have suggested that the interaction between the initial microbiome and the developing immune system could be crucial for a correct maturation of the latter. However, the exact molecular mechanisms that regulate the host−microbiome interconnection during this period are still unknown. Furthermore, despite the importance of maternal microbiota on initial neonatal microbial seeding, data concerning the effect of these perinatal factors on maternal microbiota are still scarce. Objectives: The general aim of the thesis was to to ascertain the impact of perinatal factors, such as mode and place of delivery, antibiotic use, maternal diet and gestational age on maternal-neonatal microbiota composition and their implications on health outcomes. Subjects: Participants in this study were part of a larger longitudinal cohort study conducted in the Mediterranean area, between 2015 and 2019. Mothers were enrolled in the Hospital Universitario y Politécnico La Fe, Hospital Clinico Universitario de Valencia, primary health-care units from Valencia and CEIC-Parc de Salut MAR. In this thesis, faecal samples at birth, 7 and 31 days were used as well as the saliva, amniotic fluid and placenta samples from a subset of participants. Methods: Next-generation sequencing targeting the V3−V4 region of the 16S rRNA gene was performed to assess the microbiota composition at each time point. Enzymelinked immunosorbent assay and Luminex assay were used for the determination of the molecular hormonal, metabolic and immune status of the participants and/or cellular models. Quantitative polymerase chain reaction (PCR) and reverse transcription PCR were also performed in a quantitative measurement of microbiota composition and for the assessment of gene expression in placental tissue and cellular models, respectively. The culture of different cell lines, including intestinal epithelial cells (Caco-2), mucusproducer cells (LSTH-17) and monocyte-like cells (THP-1), were used for the in vitro assays. Results and conclusion: Maternal microbiota at delivery was influenced by several perinatal factors, including immune status of amniotic cavity, diet during gestation and delivery mode. Maternal consumption of fat was positively related to Firmicutes spp. while carbohydrates, fibre and polyunsaturated fatty acids (PUFA) intakes were associated with higher relative abundance of Bacteroidetes and Proteobacteria levels. Some of these relations were also reflected in the neonatal microbiota at delivery. Indeed, children born by C-section and from mothers with higher fat intakes showed higher body mass index (BMI) index z-scores than those born from mothers with higher fibre consumption. Two bacterial profiles were found during the study. The first one was composed of health-related bacteria with short-chain fatty acids (SCFA) production activity, such as Roseburia, Faecalibacterium, Blautia, Lachnospira or Bacteroides genera. This group was associated with a distinct amniotic cytokine profile characterized by higher concentrations of IL-2, IL-5, IL-17 and TNF-α. Indeed, salivary cortisol concentration also showed positive relations with some of these genera independently of the delivery mode. The other group was characterized by Finegoldia, Peptoniphilus, Anaeroaoccus, Porphyromonas and Campylobacter genera. Those were associated with another amniotic cytokine profile dominated by IL-4, IL-13, IL-18, and IL-10 cytokines and more highly represented in mothers who had undergone a Csection. Some of these genera were negatively associated with salivary cortisol concentration. Thus, our results suggested that amniotic fluid immune status and cortisol concentration were related to maternal microbiota at delivery with implications also in neonatal microbiota. Furthermore, we described the effect of mode and place of birth in the microbial colonization evolution during the first month of life, showing that neonates born by Csection had a distinct microbial pattern and higher BMI index z-scores than vaginalborn infants, both at home and hospital. We proposed an in vitro molecular mechanism by which the differences observed in C-section-born neonates in terms of microbiota composition would promote a shift in immune system maturation through the lack of immune stimulation observed in these samples compared with those from vaginal-born infants, especially those from the home birth group. Thus, disruptions in the colonization process during the first month of life could have long-lasting consequences through an alteration of immune system development during this period.[ES] El gran impacto del microbioma humano sobre la salud del huésped es ampliamente conocido. Se cree que las comunidades microbianas que habitan el cuerpo humano serían un aspecto fundamental en la hipótesis promulgada sobre el posible origen de la enfermedad durante el desarrollo (DOHad) sugiriendo que alteraciones en la exposición microbiana durante la infancia podrían estar implicadas en el mayor riesgo de algunas enfermedades de base inmunológica como la obesidad, la alergia o la diabetes mellitus de tipo II. Además, se han encontrado relaciones significativas entre este tipo de enfermedades con algunos factores perinatales que se han descrito como disruptores del proceso de colonización, como la cesárea, el uso de antibióticos o la alimentación mediante leche de formula. Algunos autores sugieren que la interacción entre la microbiota inicial y el sistema inmunológico que está desarrollándose sería crucial para una correcta maduración de este. Sin embargo, los mecanismos exactos que mediarían en esta relación huésped-microbiota durante este periodo todavía se desconocen. Además, a pesar de la importancia de la microbiota materna para el inicio del proceso de colonización, todavía es escasa la información sobre como los diferentes factores perinatales afectan a la microbiota materna. Objetivos: El objetivo general de esta tesis fue definir el impacto de los diferentes factores perinatales como el tipo de parto, el uso de antibióticos, la dieta materna o la edad gestacional en la composición de la microbiota materno-neonatal y sus posibles implicaciones para la salud. Participantes: Los participantes del presente análisis son parte de un estudio longitudinal de cohorte desarrollado en el área mediterránea entre 2015 y 2019. Las madres fueron reclutadas en el Hospital Universitario y Politécnico de la Fe, el Hospital Clínico Universitario de Valencia, centros de atención primaria de la ciudad de Valencia y el CEIC-Parc de Salut MAR. En el presente trabajo se utilizaron las muestras fecales recogidas al parto, a los 7 y 31 días, así como las muestras de saliva, líquido amniótico y placenta de un grupo reducido de participantes. Métodos: Se utilizaron técnicas de secuenciación de nueva generación dirigidas a la región V3-V4 del gen 16S rRNA para la determinación de la composición de la microbiota de cada muestra a los tiempo estudiados. Además, el ensayo por inmunoadsorción ligado a enzimas y la técnica Luminex fueron usadas para la determinación de moléculas relacionadas con el estado hormonal, metabólico e inmune de las muestras y/o de los ensayos celulares. La PCR cuantitativa y la de transcripción reversa fueron usadas para realizar una medida cuantitativa de la composición microbiana y de la expresión de algunos genes seleccionados en las muestras de placenta y modelos celulares, respectivamente. EL cultivo de diferentes líneas celulares, como líneas epiteliales (Caco-2), productoras de moco (LSTH-17) y líneas similares a macrófagos (THP-1) fueron utilizadas en los ensayos in vitro. Resultados y conclusión: La microbiota materna al parto estuvo influenciada por diversos factores perinatales, incluyendo el estado inmunológico de la cavidad amniótica, la dieta durante el embarazo y el tipo de parto. El consumo materno de grasa estuvo positivamente relacionado con Fimicutes spp. Mientras que el consumo de carbohidratos, fibra y ácidos grasos poliinsaturados fueron asociados con mayores abundancias relativas de los filos Bacteroidetes y Proteobacteria. Algunas de estas relaciones fueron observadas también en la microbiota neonatal. Además, los niños nacidos por cesárea y de madres con altos consumos de grasa mostraron mayores IMC (índice de masa corporal) z-scores que aquellos que nacieron de madres consumidoras de fibra. Dos patrones microbianos fueron encontrados a lo largo de todos los análisis. El primero de ellos estaba compuesto por especies asociadas a la salud y productoras de SCFA como los géneros Roseburia, Faecalibacterium, Blautia, Lachnospira o Bacteroides. Este grupo estuvo asociado a un perfil de citoquinas caracterizado por IL2, IL-5, IL-17 y TNF-α. Los niveles de cortisol en saliva estuvieron positivamente correlacionados con algunos de estos géneros independientemente del tipo de parto. El otro patrón microbiano estuvo caracterizado por los géneros Finegoldia, Peptoniphilus, Anaeroaoccus, Porphyromonas y Campylobacter. Estos estuvieron relacionados con un perfil de citoquinas en la cavidad amniótica dominados por la presencia de IL-4, IL-13, IL-18 y IL-10 y con el parto por cesárea. Además, algunos de estos géneros estuvieron negativamente correlacionados con los niveles de cortisol en saliva. Así, nuestros resultados sugieren que el ambiente inmunológico de la cavidad uterina y la concentración de cortisol estuvieron relacionados con la composición de la microbiota materna al parto con implicaciones para la microbiota neonatal. Además, describimos el efecto del tipo de parto y el lugar en el proceso de colonización durante el primer mes de vida mostrando que los niños nacidos por cesárea tienen un perfil diferencial de microbiota y mayores IMC z-scores que los niños nacidos de forma vaginal, tanto en el hospital como en casa. En nuestra investigación, hemos propuesto un mecanismo molecular por el cual las diferencias en la composición microbiana de los niños nacidos por cesárea podrían provocar una alteración en la maduración del sistema inmunológico mediante la falta de imnunoestimulación observada estas muestras comparadas con aquellas obtenidas de los niños nacidos por parto vaginal, especialmente de aquellos nacidos en casa. Así, las alteraciones en el proceso de colonización durante el primer mes de vida podrían tener consecuencias a largo plazo en la salud infantil debido a una alteración del desarrollo del sistema inmunológico durante este periodo.[CA] El gran impacte del microbioma humà sobre la salut humana del hoste és amplament reconegut. Es creu que les comunitats microbianes que habiten el cos humà serien un aspecte fonamental en la hipòtesi promulgada sobre el possible origen de la malaltia durant el desenvolupament (coneguda com DOHad) suggerint que alteracions en l’exposició microbiana al llarg de la infància podrien estar implicades en el augment del risc a patir algunes malalties amb base immunològica com són l’obesitat, l’al·lèrgia o la diabetis mellitus tipus II. Així mateix, s’han trobat relacions significatives entre aquest tipus de malalties amb alguns factors perinatals que s’han descrit com disruptors del procés de colonització, com la cesària, l’ús d’antibiòtics o l’alimentació mitjançant llet de fórmula. Alguns autors suggereixen que la interacció entre la microbiota inicial i el sistema immunològic que estaria desenvolupant-se seria crucial per a una correcta maduració d’aquest últim. No obstant això, els mecanismes exactes que mediten en aquesta relació hoste-microbiota durant aquest període encara es desconeixen. A pesar de la importància de la microbiota materna en l’inici del procés de colonització, encara és escassa la informació sobre els diferents factors perinatals que afecten a la microbiota materna. Objectius: L’objectiu general d’aquesta tesi fou definir l’impacte dels diferents factors perinatals com el tipus de part, l’ús d’antibiòtics, la dieta materna o l’edat gestacional en la composició de la microbiota materno-neoantal i les possibles implicacions sobre la salut. Participants: Els participants del present anàlisi són part d’un estudi longitudinal de cohort de l’àrea mediterrània entre el 2015 i 2019. Les mares van ser reclutades en l’Hospital Universitari i Politècnic La Fe, l’Hospital Clínic Universitari de València, centres d’atenció primària de la ciutat de València i el CEIC-Pac de Salut Mar de Catalunya. En el present treball s’utilitzaren les mostres fecals recollides al part, als 7 i als 31 dies, així com les mostres de saliva, líquid amniòtic i placenta. Mètodes: S’utilitzaren tècniques de seqüenciació de nova generació dirigides a la regió V3-V4 del gen 16S rRNA per a la determinació de la composició de la microbiota de cada mostra als temps estudiats. Així mateix, l’assaig per immune adsorció lligat a enzims i la tècnica Luminex foren utilitzades per a la determinació de molècules relacionades amb l’estat hormonal, metabòlic e immunològic de les mostres i/o els assajos cel·lulars. La PCR quantitativa i la de transcripció en mode revers foren utilitzades per a realitzar una mesura quantitativa de la composició de la microbiota i de l’expressió d’alguns gens seleccionats en les mostres de placenta i models cel·lulars, respectivament. El cultiu de diferents tipus cel·lulars, com tipus epitelials (Caco-2), productors de moc (LSTH-17) i línies similars a macròfags (THP-1) foren utilitzades en els assajos in vitro. Resultats i conclusió: La microbiota materna en el moment del part va estar influenciada per diversos factors perinatals, incloent l’estat immunològic de la cavitat amniòtica, la dieta durant l’embaràs i el tipus de part. El consum matern de greix es va vore associat amb Fimicutes spp. Pel contrari, el consum de carbohidrats, fibra i àcids grassos poliinsaturades es van veure relacionats amb majors abundàncies relatives dels phylum Bacteroidetes i Proteobacteria. Algunes d’aquestes relacions foren també observades en la microbiota neonatal. Tan mateix, els nounats nascuts per cesària i de mares consumidores de greixos van mostrar majors índexs de massa corporal (IMC) zscores que els nonats nascuts de mares consumidores de fibra. Dos patrons microbians es trobaren al llarg de totes les anàlisis. La primera d’elles va estar composta per espècies associades amb la salut i productes d’àcids grassos de cadena curta (SCFA), com són els gèneres Rosburia, Faecalibacterium, Blautia, Lachnospira o Bacteroides. Aquest grup va estar associat a un perfil de citocines caracteritzat per interleucines (IL)-2, IL-5, IL-17 i TNF-alpha. Els nivells de cortisol en saliva al part estigueren positivament correlacionats amb alguns d’aquests grups , independentment del tipus de part. L’altre patró microbià estava caracteritzat per els gèneres Finegoldia, Peptoniphilus, Anaeroccocus, Porphyromonas i Campylobacter. Aquests grups foren relacionats amb el part per cesària i un perfil de citoquines en la cavitat amniòtica dominat per la presència de IL-4, IL-13, IL.18 i IL-10. A més, alguns d’aquests gèneres estigueren negativament relacionats amb els nivells de cortisol en saliva en el moment del part. Així, els nostres resultats suggereixen que l’ambient immunològic de la cavitat uterina i la concentració de cortisol tenien una relació amb la composició de la microbiota materna al part amb implicacions per a la microbiota neonatal. Tan mateix, descrivim l’efecte del tipus de part i el lloc de naixement (hospital vs. casa) en el procés de colonització durant el primer mes de vida, mostrant que els nonats nascuts per cesària tenien un perfil diferencial de microbiota i majors índexs de massa corporal (IMC) z-scores que aquells nonats nascuts de forma vaginal, tant a l’hospital com a casa. En la nostra investigació, hem proposat un mecanisme molecular pel qual les diferències en la composició microbiana podrien provocar una alteració en la maduració del sistema immunològic mitjançant una manca de inmuno-estimulació, observada en les mostres obtingudes dels nounats nascuts per cesària, especialment si es compara amb aquells nascuts a casa. Així, les alteracions en el procés de colonització, durant el primer mes de vida podrien tenir conseqüències a llarg termini en la salut infant debut a alteracions en el desenvolupament del sistema immunològic durant el període.Selma Royo, M. (2020). Impact of perinatal factors on the maternal- neonatal microbiota and influence on health outcomes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153159TESISCompendi

Evaluación de la actividad estrogénica (RYA) de aguas contaminadas con compuestos derivados de la industria del corcho, tratadas con Foto-fenton

[EN] The concern about the increasing number of toxic compounds found in the environment is increasing. Among these compounds are pharmaceuticals, drugs of abuse, personal care products, steroids and hormones, surfactants and perfluorinated compounds, among others. These compounds are incorporated into the environment by industrial and agricultural activity and municipal waste disposal. One of the main sources of contaminants are emerging effluents of wastewater treatment plants, because in many cases there isn’t achieved a complete elimination thereof. That is why, today, new technologies are being developed to achieve complete elimination of these substances. In this research, artificially contaminated waters with eight compounds related to the cork industry (gallic acid, ellagic acid, protocatechuic acid, vanillic acid, sinapic acid, siringic acid, tannic acid and 2,4-dinitrofenol) and subjected to advanced oxidation processes (photo-Fenton) for different times, have been evaluated from the ecotoxicological point of view by testing RYA (Recombinant Yeast Assay) that evaluates estrogenic activity in the wastewater. This assay is based on a recombinant strain of the yeast Saccharomyces cerevisiae. The estrogenic potential of the samples were detected by fluorescence emission after treatment. Ecotoxicological evaluation of water samples contaminated by assay RYA demonstrates a increased toxicity at 20 min of treatment of the waters, due to the appearance of intermediate compounds which are more toxic than the original pollutants, so it is necessary to extend the treatment time in the advanced oxidation processes, in order to reduce the toxicity of contaminated waters.[ES] La preocupación por el creciente número de compuestos tóxicos detectados en el medio ambiente va en aumento. Entre éstos se encuentran productos farmacéuticos, drogas de abuso, productos de cuidado personal, esteroides y hormonas, agentes tensioactivos y compuestos perfluorados, entre otros. Estos compuestos son incorporados al medio ambiente por actividad industrial y agrícola y eliminación de desechos municipales, provocando efectos adversos en los organismos vivos. Uno de los efectos más preocupantes es de disrupción endocrina. Una de las principales fuentes de contaminantes son los efluentes de las plantas de tratamiento de aguas residuales, ya que, en muchos casos, no se consigue una eliminación completa de los mismos. Es por ello que, actualmente, se están desarrollando nuevas tecnologías para conseguir una completa eliminación de este tipo de sustancias (Procesos de Oxidación Avanzada). En este trabajo de investigación, aguas artificialmente contaminadas con ocho compuestos relacionados con la industria del corcho (ácidos gálico, tánico, elágico, protocatecuico, valínico, siríngico y sinápico y el 2,4-dinitrofenol) y sometidas a un Proceso de Oxidación Avanzada (Foto- Fenton) van a ser evaluadas mediante el ensayo RYA (Recombinant Yeast Assay) determinando la actividad estrogénica de dichas aguas. Este ensayo está basado en una cepa recombinante de la levadura Saccharomyces cerevisiae. El potencial estrogénico de la muestras se detecta mediante emisión de fluorescencia, previo tratamiento de las muestras. La evaluación mediante el ensayo RYA demuestra un aumento de la toxicidad a los 20 min de tratamiento de las aguas, debido a la aparición de compuestos intermedios que son más tóxicos que los contaminantes originales, por lo que es necesario alargar los tiempos de tratamiento en los procesos de oxidación avanzada, con el fin de reducir la toxicidad de las aguas contaminadas.Selma Royo, M. (2014). Evaluación de la actividad estrogénica (RYA) de aguas contaminadas con compuestos derivados de la industria del corcho, tratadas con Foto-fenton. http://hdl.handle.net/10251/40437.Archivo delegad

Impact of “chemical cocktails” exposure in shaping mice gut microbiota and the role of selenium supplementation combining metallomics, metabolomics, and metataxonomics

Biological systems are exposed to a complex environment in which pollutants can interact through synergistic or antagonistic mechanisms, but limited information is available on the combined effects. To this end, conventional and antibiotic-treated (Abx) mice models were fed regular rodent or selenium (Se) supplemented diets and exposed to a “chemical cocktail” (CC) including metals and pharmaceuticals. Metallomics, metabolomics, and metataxomics were combined to delve into the impact on gut microbiota, plasma selenoproteome, metabolome,and arsenic metabolization. At the molecular level, Se decreased the concentration of the antioxidant glutathione peroxidase in plasma and increased the arsenic methylation rate, possibly favoring its excretion, but not in the Abx and also plasma metabolomes of Abx, and Abx-Se were not differentiated. Moreover, numerous associations were obtained between plasma selenoproteins and gut microbes. Se-supplementation partially antagonizes the gut microbiota alteration caused by Abx, and slightly by CC, but strongly altered profiles were observed in CCAbx- Se, suggesting synergistic deleterious effects between pollutants, Abx and Se. Moreover, although CC and Abx changed gut microbiota, several common taxa were enriched in CC-Abx and control mice, indicating possible synergistic effects. Our results suggest a potential beneficial impact of supplementation, but mediated by gut microbes being reversed in their absence.Biological systems are exposed to a complex environment in which pollutants can interact through synergistic or antagonistic mechanisms, but limited information is available on the combined effects. To this end, conventional and antibiotic-treated (Abx) mice models were fed regular rodent or selenium (Se) supplemented diets and exposed to a “chemical cocktail” (CC) including metals and pharmaceuticals. Metallomics, metabolomics, and metataxomics were combined to delve into the impact on gut microbiota, plasma selenoproteome, metabolome, and arsenic metabolization. At the molecular level, Se decreased the concentration of the antioxidant glutathione peroxidase in plasma and increased the arsenic methylation rate, possibly favoring its excretion, but not in the Abx and also plasma metabolomes of Abx, and Abx-Se were not differentiated. Moreover, numerous associations were obtained between plasma selenoproteins and gut microbes. Se-supplementation partially antagonizes the gut microbiota alteration caused by Abx, and slightly by CC, but strongly altered profiles were observed in CC-Abx-Se, suggesting synergistic deleterious effects between pollutants, Abx and Se. Moreover, although CC and Abx changed gut microbiota, several common taxa were enriched in CC-Abx and control mice, indicating possible synergistic effects. Our results suggest a potential beneficial impact of supplementation, but mediated by gut microbes being reversed in their absence.This work was supported by the projects: PG2018–096608-B-C21 from the Spanish Ministry of Science and Innovation (MICIN). Generaci´on del Conocimiento. MCIN/ AEI /10.13039/501100011033/ FEDER “Una manera de hacer Europa’’, UHU-1256905 and UHU- 202009 from the FEDER Andalusian Operative Program 2014–2020 (Ministry of Economy, Knowledge, Business and Universities, Regional Government of Andalusia, Spain). The authors are grateful to FEDER (European Community) for financial support, Grant UNHU13–1E-1611. Funding for open access charge: Universidad de Huelva / CBUA. The authors would like to acknowledge the support from The Ram´on Areces Foundation (ref. CIVP19A5918)

Mice brain metabolomics after the exposure to a “chemical cocktail” and selenium supplementation through the gut-brain axis

Several environmental pollutants have been shown to damage brain and affect gut microbiota. Limited evidence is available about the impact of “chemical cocktails” (CC) of xenobiotics on brain metabolome and their possible influence in the gut-brain crosstalk. To this end, BALB/c mice were exposed to heavy metals (As, Hg, Cd) and pharmaceuticals (diclofenac and flumequine) under regular rodent diet or supplemented with selenium (Se). Selenium, an antioxidant well-known for its antagonism against the neurotoxicity of several pollutants, modulated several brain metabolic impairments caused by CC (e.g., brain levels of the excitatory amino acid N-acetyl aspartic acid) by influencing mainly the metabolisms of purine, glycosylate and dicarboxylate, glutamate, glycerophospholipid, alanine and aspartate. Numerous associations were obtained between brain metabolites and gut microbes and they changed after Se-supplementation (e.g., Lactobacillus was positively associated with a brain ceramide, phosphoserine, phosphocholine, vitamin D3 derivative, fatty acids, malic acid, amino acids, and urea after the exposure, but not after Se-supplementation). Our results showed numerous evidences about the impact of CC on brain metabolome, the potential role of Se as an antagonist and their impact on the gut-brain axis. Further research is needed to understand the complex mechanism of action implied on CC-brain-microbiota interactions.This work was supported by the projects: PG2018–096608-B-C21 and PID2021-123073NB-C21 from the Spanish Ministry of Science and Innovation (MICIN). Generación del Conocimiento. MCI/AEI/ FEDER “Una manera de hacer Europa”, UHU-1256905 and UHU-202009 from the FEDER Andalusian Operative Program 2014–2020 (Ministry of Economy, Knowledge, Business and Universities, Regional Government of Andalusia, Spain). The authors are grateful to FEDER (European Community) for financial support, Grant UNHU13–1E-1611. CPM thanks MICIN for a predoctoral grant (ref. PRE2019–091650). Funding for open access charge: Universidad de Huelva / CBUA. The authors would like to acknowledge the support from The Ramón Areces Foundation (ref. CIVP19A5918)

Untargeted Gut Metabolomics to Delve the Interplay between Selenium Supplementation and Gut Microbiota

El selenio (Se) es un oligoelemento con funciones importantes para la salud debido a las propiedades antioxidantes de las selenoproteínas. Para analizar la interacción entre Se y la microbiota intestinal, se determinaron los perfiles metabolómicos intestinales en ratones convencionales (C) y con microbiota empobrecida (Abx) después de la suplementación con Se (Abx-Se) mediante metabolómica no dirigida, utilizando una multiplataforma analítica basada en GC-MS y UHPLC-QTOF-MS (MassIVE ID MSV000087829). El perfil de la microbiota intestinal se realizó mediante la secuenciación del amplicón del gen 16S rRNA. Se encontraron diferencias significativas en los niveles de aproximadamente el 70 % de los metabolitos intestinales determinados, incluidos los acilos grasos, los glicerolípidos, los glicerofosfolípidos y los esteroides, en Abx-Se en comparación con Abx, y solo el 30 % fue diferente entre Abx-Se y C, lo que sugiere un efecto importante de la suplementación con Se en el metabolismo de los ratones Abx. A nivel de género, el análisis de correlación mostró fuertes asociaciones entre los metabolitos y los perfiles bacterianos intestinales. Asimismo, una mayor abundancia de Lactobacillus spp., un género potencialmente beneficioso enriquecido tras la suplementación con Se, se asoció con niveles más altos de lípidos de prenol, fosfatidilgliceroles (C-Se), esteroides y diterpenoides (Abx-Se), y también con niveles más bajos de ácidos grasos (Abx-Se). Por lo tanto, observamos una interacción crucial entre la ingesta de Se-microbiota-metabolitos, aunque se necesitan más estudios para aclarar los mecanismos específicos. Este es el primer estudio sobre la metabolómica intestinal no dirigida después del agotamiento de la microbiota y la suplementación con Se.Selenium (Se) is an essential trace element with important health roles due to the antioxidant properties of selenoproteins. To analyze the interplay between Se and gut microbiota, gut metabolomic profiles were determined in conventional (C) and microbiota depleted mice (Abx) after Se-supplementation (Abx-Se) by untargeted metabolomics, using an analytical multiplatform based on GC-MS and UHPLC-QTOF-MS (MassIVE ID MSV000087829). Gut microbiota profiling was performed by 16S rRNA gene amplicon sequencing. Significant differences in the levels of about 70% of the gut metabolites determined, including fatty acyls, glycerolipids, glycerophospholipids, and steroids, were found in Abx-Se compared to Abx, and only 30% were different between Abx-Se and C, suggesting an important effect of Se-supplementation on Abx mice metabolism. At genus level, the correlation analysis showed strong associations between metabolites and gut bacterial profiles. Likewise, higher abundance of Lactobacillus spp., a potentially beneficial genus enriched after Se-supplementation, was associated with higher levels of prenol lipids, phosphatidylglycerols (C-Se), steroids and diterpenoids (Abx-Se), and also with lower levels of fatty acids (Abx-Se). Thus, we observed a crucial interaction between Se intake–microbiota–metabolites, although further studies to clarify the specific mechanisms are needed. This is the first study about untargeted gut metabolomics after microbiota depletion and Se-supplementation.This work was supported by the projects PG2018-096608-B-C21 f from the Spanish Ministry of Science and innovation (MCIN). Generación del Conocimiento. MCIN/ AEI /10.13039/501100011033/ FEDER “Una manera de hacer Europa” and UHU-1256905 from the FEDER Andalusian Operative Program 2014–2020 (Ministry of Economy, Knowledge, Business and Universities, Regional Government of Andalusia, Spain). Authors would like to acknowledge the support from The Ramón Areces Foundation (ref CIVP19A5918). Authors are grateful to FEDER (European Community) for financial support, Grant UNHU13-1X10-1611. Funding for open access charge: Universidad de Huelva / CBU

The Breast Milk Immunoglobulinome

Breast milk components contribute to the infant's immune development and protection, and among other immune factors, immunoglobulins (Igs) are the most studied. The presence of IgA in milk has been known for a long time; however, less information is available about the presence of other Igs such as IgM, IgG, and their subtypes (IgG1, IgG2, IgG3, and IgG4) or even IgE or IgD. The total Ig concentration and profile will change during the course of lactation; however, there is a great variability among studies due to several variables that limit establishing a clear pattern. In this context, the aim of this review was firstly to shed light on the Ig concentration in breast milk based on scientific evidence and secondly to study the main factors contributing to such variability. A search strategy provided only 75 studies with the prespecified eligibility criteria. The concentrations and proportions found have been established based on the intrinsic factors of the study¿such as the sampling time and quantification technique¿as well as participant-dependent factors, such as lifestyle and environment. All these factors contribute to the variability of the immunoglobulinome described in the literature and should be carefully addressed for further well-designed studies and data interpretation

The role of selenium in shaping mice brain metabolome and selenoproteome through the gut-brain axis by combining metabolomics, metallomics, gene expression, and amplicon sequencing

Selenium (Se) is a trace element crucial for human health. Recently, the impact of Se supplementation on gut microbiota has been pointed out as well as its influence on the expression of certain selenoproteins and gut metabolites. This study aims to elucidate the link between Se supplementation, brain selenoproteins and brain metabolome as well as the possible connection with the gut-brain axis. To this end, an in vivo study with 40 BALB/c mice was carried out. The study included conventional ( n = 20) and mice model with microbiota depleted by antibiotics ( n = 20) under a regular or Se supplemented diet. Brain selenoproteome was determined by a transcriptomic/gene expression profile, while brain metabolome and gut microbiota profiles were accomplished by untargeted metabolomics and amplicon sequencing, respectively. The total content of Se in brain was also determined. The selenoproteins genes Dio and Gpx isoenzymes, SelenoH, SelenoI, SelenoT, SelenoV, and SelenoW and 31 metabolites were significantly altered in the brain after Se supplementation in conventional mice, while 11 selenoproteins and 26 metabolites were altered in microbiota depleted mice. The main altered brain metabolites were related to glyoxylate and dicarboxylate metabolism, amino acid metabolism, and gut microbiota that have been previously related with the gut-brain axis ( e.g., members of Lachnospiraceae and Ruminococcaceae families ). Moreover, specific associations were determined between brain selenoproteome and metabolome, which correlated with the same bacteria, suggesting an intertwined mechanism. Our results demonstrated the effect of Se on brain metabolome through specific selenoproteins gene expression and gut microbiota.This work was supported by the projects: PG2018-096608-B- C21 and PID2021-123073NB-C21 from the Spanish Ministry of Science and Innovation (MICIN) . Generación del Conocimiento . MCIN/ AEI /10.13039/50110 0 011033/ FEDER “Una manera de hacer Europa”, UHU-1256905 and UHU-202009 from the FEDER Andalusian Operative Program 2014-2020 (Ministry of Economy, Knowledge, Business and Universities, Regional Government of Andalusia, Spain). S.R.A. thanks the Spanish Ministry of Science and Innovation for a PhD scholarship ( BES-2016-076364 ). The authors are grateful to FEDER (European Community) for financial support, Grant UNHU13-1E-1611 . The authors would like to acknowledge the support from The Ramón Areces Foundation (ref. CIVP19A5918 ). Funding for open access charge: Universidad de Huelva / CBUA

Nasopharyngeal microbiota profiling of pregnant women with SARS-CoV-2 infection.

We aimed to analyze the nasopharyngeal microbiota profles in pregnant women with and without SARS-CoV-2 infection, considered a vulnerable population during COVID-19 pandemic. Pregnant women were enrolled from a multicenter prospective population-based cohort during the frst SARS-CoV-2 wave in Spain (March-June 2020 in Barcelona, Spain) in which the status of SARSCoV-2 infection was determined by nasopharyngeal RT–PCR and antibodies in peripheral blood. Women were randomly selected for this cross-sectional study on microbiota. DNA was extracted from nasopharyngeal swab samples, and the V3-V4 region of the 16S rRNA of bacteria was amplifed using region-specifc primers. The diferential abundance of taxa was tested, and alpha/beta diversity was evaluated. Among 76 women, 38 were classifed as positive and 38 as negative for SARS-CoV-2 infection. All positive women were diagnosed by SARS-CoV-2 IgG and IgM/IgA antibodies, and 14 (37%) also had a positive RT–PCR. The overall composition of the nasopharyngeal microbiota difer in pregnant women with SARS-CoV-2 infection (positive SARS-CoV-2 antibodies), compared to those without the infection (negative SARS-CoV-2 antibodies) (p = 0.001), with a higher relative abundance of the Tenericutes and Bacteroidetes phyla and a higher abundance of the Prevotellaceae family. Infected women presented a diferent pattern of microbiota profling due to beta diversity and higher richness (observed ASV< 0.001) and evenness (Shannon index < 0.001) at alpha diversity. These changes were also present in women after acute infection, as revealed by negative RT–PCR but positive SARS-CoV-2 antibodies, suggesting a potential association between SARS-CoV-2 infection and long-lasting shift in the nasopharyngeal microbiota. No signifcant diferences were reported inmild vs. severe cases. This is the frst study on nasopharyngeal microbiota during pregnancy. Pregnant women with SARS-CoV-2 infection had a diferent nasopharyngeal microbiota profle compared to negative cases

Galectins-1, -3 and -9 Are Present in Breast Milk and Have a Role in Early Life Development

Galectins (Gal) are a family of conserved soluble proteins with high affinity for β-galactoside structures. They have been recognized as important proteins for successful pregnancy. However, little is known about their presence in breast milk and their role in early infancy. Gal-1, -3 and -9 concentrations were evaluated by Multiplex immunoassays in mother-infant pairs from the MAMI cohort in maternal plasma (MP) (n = 15) and umbilical cord plasma (UCP) (n = 15) at birth and in breast milk samples (n = 23) at days 7 and 15 postpartum. Data regarding mother and infant characteristics were collected. Gal-9 was present in a lower concentration range than Gal-1 and Gal-3 in plasma, specifically in UCP. A major finding in the current study is that Gal-1, -3 and -9 were detected for the first time in all the transitional breast milk samples and no differences were found when comparing the two breastfeeding time points. Finally, Gal levels were associated with some maternal and infant characteristics, such as gestational age, pregnancy weight gain, maternal diet, the gender, infant growth and infant infections. In conclusion, Gal levels seem to be involved in certain developmental aspects of early life. Keywords: galectin; breast milk; umbilical cord plasma; maternal plasm