Person: Fernández Álvarez, Leonides
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First Name
Leonides
Last Name
Fernández Álvarez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Farmacia Galénica y Tecnología Alimentaria
Area
Tecnología de los Alimentos
Identifiers
19 results
Search Results
Now showing 1 - 10 of 19
Item Immunomodulation of the Vaginal Ecosystem by Ligilactobacillus salivarius CECT 30632 Improves Pregnancy Rates among Women with Infertility of Unknown Origin or Habitual Abortions(Nutrients, 2023) Fernández Álvarez, Leonides; Castro Navarro, Irma; Arroyo Rodríguez, Rebeca; Alba Rubio, Claudio; Beltrán, David; Rodríguez Gómez, Juan MiguelIn this study, the probiotic potential of Ligilactobacillus salivarius CECT 30632 was assessed, including properties specifically related with gynecological targets. This strain displayed co-aggregative and antimicrobial activity against a wide spectrum of vaginal pathogens while being respectful with the growth of vaginal lactobacilli. The strain produced a high concentration of lactic acid and displayed α-amylase activity when assayed in vitro. It showed a noticeable survival rate after exposition to conditions similar to those present in the human digestive tract and was adhesive to both vaginal and intestinal cells. Subsequently, their capacity to increase pregnancy rates among women with habitual abortion or infertility of unknown origin was studied. Administration of L. salivarius CECT 30632 (~9 log10 CFU) daily for a maximum of six months to these women was safe and led to a successful pregnancy rate of 67.5% (80% and 55% for women with repetitive abortion and infertile women, respectively). Significant differences in Nugent score, vaginal pH, and vaginal concentrations of lactobacilli, TGF-β, and VEFG were observed when the samples collected before the intervention were compared with those collected after the treatment among those women who got pregnant. Therefore, this strain can modulate the vaginal ecosystem and lead to better fertility outcomes.Item Bacteriological and Immunological Profiling of Meconium and Fecal Samples from Preterm Infants: A Two-Year Follow-Up Study(Nutrients, 2017) Gómez, Marta; Moles, Laura; Espinosa-Martos, Irene; Bustos, Gerardo; de Vos, Willem; Fernández Álvarez, Leonides; Rodríguez Gómez, Juan Miguel; Fuentes, Susana; Jiménez Quintana, Esther AntoniaAn abnormal colonization pattern of the preterm gut may affect immune maturation and exert a long-term influence on the intestinal bacterial composition and host health. However, follow-up studies assessing the evolution of the fecal microbiota of infants that were born preterm are very scarce. In this work, the bacterial compositions of fecal samples, obtained from sixteen 2-year-old infants were evaluated using a phylogenetic microarray; subsequently, the results were compared with those obtained in a previous study from samples of meconium and feces collected from the same infants while they stayed in the neonatal intensive care unit (NICU). In parallel, the concentration of a wide range of cytokines, chemokines, growth factors and immunoglobulins were determined in meconium and fecal samples. Globally, a higher bacterial diversity and a lower interindividual variability were observed in 2-year-olds’ feces, when compared to the samples obtained during their first days of life. Hospital-associated fecal bacteria, that were dominant during the NICU stay, seemed to be replaced, two years later, by genera, which are usually predominant in the healthy adult microbiome. The immune profile of the meconium and fecal samples differed, depending on the sampling time, showing different immune maturation statuses of the gut.Item Application of Ligilactobacillus salivarius CECT5713 to Achieve Term Pregnancies in Women with Repetitive Abortion or Infertility of Unknown Origin by Microbiological and Immunological Modulation of the Vaginal Ecosystem(Nutrients, 2021) Fernández Álvarez, Leonides; Castro Navarro, Irma; Arroyo Rodríguez, Rebeca; Alba Rubio, Claudio; Beltrán, David; Rodríguez, Juan M.In this study, the cervicovaginal environment of women with reproductive failure (repetitive abortion, infertility of unknown origin) was assessed and compared to that of healthy fertile women. Subsequently, the ability of Ligilactobacillus salivarius CECT5713 to increase pregnancy rates in women with reproductive failure was evaluated. Vaginal pH and Nugent score were higher in women with reproductive failure than in fertile women. The opposite was observed regarding the immune factors TGF-β 1, TFG-β 2, and VEFG. Lactobacilli were detected at a higher frequency and concentration in fertile women than in women with repetitive abortion or infertility. The metataxonomic study revealed that vaginal samples from fertile women were characterized by the high abundance of Lactobacillus sequences, while DNA from this genus was practically absent in one third of samples from women with reproductive failure. Daily oral administration of L. salivarius CECT5713 (~9 log10 CFU/day) to women with reproductive failure for a maximum of 6 months resulted in an overall successful pregnancy rate of 56%. The probiotic intervention modified key microbiological, biochemical, and immunological parameters in women who got pregnant. In conclusion, L. salivarius CECT5713 has proved to be a good candidate to improve reproductive success in women with reproductive failure.- Project number: 236
Item Desarrollo de una práctica integral sobre el diseño, elaboración y comercialización de un alimento obtenido por fermentación a escala semi-industrial(2020) Fernández Álvarez, Manuela; Gilabert Santos, Juan Antonio; García De Fernando Minguillón, Gonzalo Doroteo; Selgas Cortecero, María Dolores; Fernández Álvarez, Leonides; Cabeza Briales, María Concepción; Orgaz Martín, Belén; Guerrero Moreno, Andrés; Lucas López, Juan Raúl; Marty Poncini, Lorena; Estebas Elizo, Víctor JuanEste documento contiene la memoria final del proyecto de innovación docente "Desarrollo de una práctica integral sobre el diseño, elaboración y comercialización de un alimento obtenido por fermentación a escala semi-industrial", llevado a cabo en el curso 2018-19. En la memoria se describen los resultados obtenidos en el desarrollo de este proyecto, cuyo objetivo ha sido implementar una práctica para que los estudiantes del Grado en Ciencia y Tecnología de los Alimentos llevaran a cabo el diseño y la elaboración de cerveza en condiciones similares a las reales en la industria alimentaria. El proyecto se ha incluido dentro de las actividades de la asignatura optativa "Tecnología Enológica y de Otras Bebidas Alcohólicas", que se imparte en el cuarto curso del Grado. Item Physiological Translocation of Lactic Acid Bacteria during Pregnancy Contributes to the Composition of the Milk Microbiota in Mice(Nutrients, 2017) Andrés Leo, Javier de; Jiménez Quintana, Esther Antonia; Chico-Calero, Isabel; Fresno, Manuel; Fernández Álvarez, Leonides; Rodríguez Gómez, Juan MiguelThe human milk microbiota is a complex and diverse ecosystem that seems to play a relevant role in the mother-to-infant transmission of microorganisms during early life. Bacteria present in human milk may arise from different sources, and recent studies suggest that at least some of them may be originally present in the maternal digestive tract and may reach the mammary gland through an endogenous route during pregnancy and lactation. The objective of this work was to elucidate whether some lactic acid bacteria are able to translocate and colonize the mammary gland and milk. For this purpose, two lactic acid bacteria strains (Lactococcus lactis MG1614 and Lactobacillus salivarius PS2) were transformed with a plasmid containing the lux genes; subsequently, the transformed strains were orally administered to pregnant mice. The murine model allowed the visualization, isolation, and Polymerase Chain Reaction (PCR)-detection of the transformed bacteria in different body locations, including mammary tissue and milk, reinforcing the hypothesis that physiological translocation of maternal bacteria during pregnancy and lactation may contribute to the composition of the mammary and milk microbiota.Item Nasal and Fecal Microbiota and Immunoprofiling of Infants With and Without RSV Bronchiolitis(Frontiers in Microbiology, 2021) Alba Rubio, Claudio; Aparicio, Marina; González-Martínez, Felipe; González-Sánchez, María Isabel; Pérez-Moreno, Jimena; Toledo del Castillo, Blanca; Rodríguez Gómez, Juan Miguel; Rodríguez-Fernández, Rosa; Fernández Álvarez, LeonidesBronchiolitis associated with the respiratory syncytial virus (RSV) is the leading cause of hospitalization among infants aged < 1 year. The main objective of this work was to assess the nasal and fecal microbiota and immune profiles in infants with RSV bronchiolitis, and to compare them with those of healthy infants. For this purpose, a total of 58 infants with RSV-positive bronchiolitis and 17 healthy infants (aged < 18 months) were recruited in this case-control study, which was approved by the Ethics Committee of the Hospital Gregorio Marañón. Nasal and fecal samples were obtained and submitted to bacterial microbiota analysis by 16S rDNA sequencing and to analysis of several immune factors related to inflammatory processes. Nasal samples in which Haemophilus and/or Moraxella accounted for > 20% of the total sequences were exclusively detected among infants of the bronchiolitis group. In this group, the relative abundances of Staphylococcus and Corynebacterium were significantly lower than in nasal samples from the control group while the opposite was observed for those of Haemophilus and Mannheimia. Fecal bacterial microbiota of infants with bronchiolitis was similar to that of healthy infants. Significant differences were obtained between bronchiolitis and control groups for both the frequency of detection and concentration of BAFF/TNFSF13B and sTNF.R1 in nasal samples. The concentration of BAFF/TNFSF13B was also significantly higher in fecal samples from the bronchiolitis group. In conclusion, signatures of RSV-associated bronchiolitis have been found in this study, including dominance of Haemophilus and a high concentration of BAFF/TNFSF13B, IL-8 and sTNF.R1 in nasal samples, and a high fecal concentration of BAFF/TNFSF13B.Item The Microbiota of the Human Mammary Ecosystem(Frontiers in Cellular and Infection Microbiology, 2020) Fernández Álvarez, Leonides; Pannaraj, Pia S.; Rautava, Samuli; Rodríguez Gómez, Juan MiguelHuman milk contains a dynamic and complex site-specific microbiome, which is not assembled in an aleatory way, formed by organized microbial consortia and networks. Presence of some genera, such as Staphylococcus, Streptococcus, Corynebacterium, Cutibacterium (formerly known as Propionibacterium), Lactobacillus, Lactococcus and Bifidobacterium, has been detected by both culture-dependent and culture-independent approaches. DNA from some gut-associated strict anaerobes has also been repeatedly found and some studies have revealed the presence of cells and/or nucleic acids from viruses, archaea, fungi and protozoa in human milk. Colostrum and milk microbes are transmitted to the infant and, therefore, they are among the first colonizers of the human gut. Still, the significance of human milk microbes in infant gut colonization remains an open question. Clinical studies trying to elucidate the question are confounded by the profound impact of non-microbial human milk components to intestinal microecology. Modifications in the microbiota of human milk may have biological consequences for infant colonization, metabolism, immune and neuroendocrine development, and for mammary health. However, the factors driving differences in the composition of the human milk microbiome remain poorly known. In addition to colostrum and milk, breast tissue in lactating and non-lactating women may also contain a microbiota, with implications in the pathogenesis of breast cancer and in some of the adverse outcomes associated with breast implants. This and other open issues, such as the origin of the human milk microbiome, and the current limitations and future prospects are addressed in this review.Item Microbiological and Immunological Markers in Milk and Infant Feces for Common Gastrointestinal Disorders: A Pilot Study(Nutrients, 2020) Aparicio, Marina; Alba Rubio, Claudio; Rodríguez Gómez, Juan Miguel; Fernández Álvarez, LeonidesThe objective of this pilot study was to assess the fecal microbiome and different immunological parameters in infant feces and maternal milk from mother–infant pairs in which the infants were suffering from different gastrointestinal disorders (colic, non-IgE-mediated cow milk protein allergy (CMPA), and proctocolitis). A cohort of 30 mother–infant pairs, in which the infants were diagnosed with these gastrointestinal disorders or included as healthy controls, were recruited. Bacterial composition of infant feces and breast milk was determined by metataxonomic sequencing. Immunological compounds were quantified using multiplexed immunoassays. A higher abundance of Eggerthellaceae, Lachnospiraceae and Peptostreptococcaceae, and lower abundance of Bifidobacterium and higher abundance of Rothia were registered in fecal samples from the CMPA group. Eggerthellaceae was also significantly more abundant in milk samples of the CMPA group. There were no differences in the concentration of immunological compounds in infant fecal samples between the four groups. In contrast, differences were found in the concentration and/or frequency of compounds related to acquired immunity and granulocyte colony stimulating factor (GCSF) in breast milk samples. In conclusion, a few microbial signatures in feces may explain part of the difference between CMPA and other infants. In addition, some milk immunological signatures have been uncovered among the different conditions addressed in this pilot study.Item Interactions between human milk oligosaccharides, microbiota and immune factors in milk of women with and without mastitis(Scientific Reports, 2022) Castro Navarro, Irma; García Carral, Cristina; Furst, Annalee; Khwajazada, Sadaf; Janneiry, García; Arroyo Rodríguez, Rebeca; Ruiz, Lorena; Rodríguez Gómez, Juan Miguel; Bode, Lars; Fernández Álvarez, LeonidesLactational mastitis is an excellent target to study possible interactions between HMOs, immune factors and milk microbiota due to the infectious and inflammatory nature of this condition. In this work, microbiological, immunological and HMO profiles of milk samples from women with (MW) or without (HW) mastitis were compared. Secretor status in women (based on HMO profile) was not associated to mastitis. DFLNH, LNFP II and LSTb concentrations in milk were higher in samples from HW than from MW among Secretor women. Milk from HW was characterized by a low bacterial load (dominated by Staphylococcus epidermidis and streptococci), high prevalence of IL10 and IL13, and low sialylated HMO concentration. In contrast, high levels of staphylococci, streptococci, IFNγ and IL12 characterized milk from MW. A comparison between subacute (SAM) and acute (AM) mastitis cases revealed differences related to the etiological agent (S. epidermidis in SAM; Staphylococcus aureus in AM), milk immunological profile (high content of IL10 and IL13 in SAM and IL2 in AM) and milk HMOs profile (high content of 3FL in SAM and of LNT, LNnT, and LSTc in AM). These results suggest that microbiological, immunological and HMOs profiles of milk are related to mammary health of women.Item High Temperature Short Time Pasteurization System for Donor Milk in a Human Milk Bank Setting(Frontiers in Microbiology, 2018) Escuder Vieco, Diana; Espinosa-Martos, Irene; Rodríguez Gómez, Juan Miguel; Corzo, Nieves; Montilla, Antonia; Siegfried, Pablo; Fernández Álvarez, Leonides; Pallas Alonso, Carmen Rosa; Andrea Gomez-ZavagliaDonor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min). Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST) pasteurization has been proposed as an alternative for a better preservation of some of the biological components of human milk although, at present, there is no equipment available to perform this treatment under the current conditions of a human milk bank. In this work, the specific needs of a human milk bank setting were considered to design an HTST equipment for the continuous and adaptable (time-temperature combination) processing of donor milk. Microbiological quality, activity of indicator enzymes and indices for thermal damage of milk were evaluated before and after HTST treatment of 14 batches of donor milk using different temperature and time combinations and compared to the results obtained after Holder pasteurization. The HTST system has accurate and simple operation, allows the pasteurization of variable amounts of donor milk and reduces processing time and labor force. HTST processing at 72°C for, at least, 10 s efficiently destroyed all vegetative forms of microorganisms present initially in raw donor milk although sporulated Bacillus sp. survived this treatment. Alkaline phosphatase was completely destroyed after HTST processing at 72 and 75°C, but γ-glutamil transpeptidase showed higher thermoresistance. Furosine concentrations in HTST-treated donor milk were lower than after Holder pasteurization and lactulose content for HTST-treated donor milk was below the detection limit of analytical method (10 mg/L). In conclusion, processing of donor milk at 72°C for at least 10 s in this HTST system allows to achieve the microbiological safety objectives established in the milk bank while having a lower impact regarding the heat damage of the milk.