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1.
Artigo em Inglês | MEDLINE | ID: mdl-32150651

RESUMO

BACKGROUND: Perinatal childhood exposures, including probiotic supplementation, may affect epigenetic modifications and impact on immune maturation and allergy development. The aim of this study was to assess the effects of pre- and postnatal Lactobacillus reuteri supplementation on DNA methylation in relation to immune maturation and allergy development. METHODS: DNA methylation patterns were investigated for allergy-related T helper subsets using a locus-specific method and at a genome-wide scale using the Illumina 450K array. From a randomised, double-blind, placebo-controlled allergy prevention trial with pre- and postnatal probiotic supplementation, CD4+ T helper cells were obtained at birth (from cord blood), and 12 and 24 months of age (total (placebo/probiotics); locus-specific method: CB = 32 (17/15), 12 months = 24 (9/15), 24 months = 35 (15/20); Illumina: CB = 19 (10/9), 12 months = 10 (6/4), 24 months = 19(11/8)). RESULTS: Comparing probiotics to placebo, the greatest genome-wide differential DNA methylation was observed at birth, where the majority of sites were hypomethylated, indicating transcriptional accessibility in the probiotic group. Bioinformatic analyses, including network analyses, revealed a module containing 91 genes, enriched for immune-related pathways such as chemotaxis, PI3K-Akt, MAPK and TGF-ß signalling. A majority of the module genes were associated with atopic manifestations (OR = 1.43, P = 2.4 × 10-6 ), and a classifier built on this model could predict allergy development (AUC = 0.78, P = 3.0 × 10e-3 ). Pathways such as IFN-γ signalling and T-cell activation were more hypermethylated at birth compared with later in life in both intervention groups over time, in line with DNA methylation patterns in the IFNG locus obtained by the locus-specific methodology. CONCLUSION: Maternal L. reuteri supplementation during pregnancy alters DNA methylation patterns in CD4+ T cells towards enhanced immune activation at birth, which may affect immune maturation and allergy development.

2.
Immunol Cell Biol ; 98(1): 79-87, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31680329

RESUMO

γδ T cells are unconventional T cells that function on the border of innate and adaptive immunity. They are suggested to play important roles in neonatal and infant immunity, although their phenotype and function are not fully characterized in early childhood. We aimed to investigate γδ T cells in relation to age, prematurity and cytomegalovirus (CMV) infection. Therefore, we used flow cytometry to characterize the γδ T-cell compartment in cord blood and peripheral blood cells from 14-day-, 2-year- and 5-year-old children, as well as in peripheral blood samples collected at several time points during the first months of life from extremely premature neonates. γδ T cells were phenotypically similar at 2 and 5 years of age, whereas cord blood was divergent and showed close proximity to γδ T cells from 14-day-old neonates. Interestingly, 2-year-old children and adults showed comparable Vδ2+ γδ T-cell functionality toward both microbial and polyclonal stimulations. Importantly, extreme preterm birth compromised the frequencies of Vδ1+ cells and affected the functionality of Vδ2+ γδ T cells shortly after birth. In addition, CMV infection was associated with terminal differentiation of the Vδ1+ compartment at 2 years of age. Our results show an adult-like functionality of the γδ T-cell compartment already at 2 years of age. In addition, we demonstrate an altered γδ T-cell phenotype early after birth in extremely premature neonates, something which could possible contribute to the enhanced risk for infections in this vulnerable group of children.

3.
J Immunol ; 204(1): 68-77, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31801814

RESUMO

Extremely preterm neonates are particularly susceptible to infections, likely because of severely impaired immune function. However, little is known on the composition of the T cell compartment in early life in this vulnerable population. We conducted a comprehensive phenotypic flow cytometry-based longitudinal analysis of the peripheral conventional T cell compartment of human extremely low gestational age neonates (ELGAN) with extremely low birth weight (ELBW; <1000 g) participating in a randomized placebo-controlled study of probiotic supplementation. PBMCs from ELGAN/ELBW neonates were collected at day 14, day 28, and postmenstrual week 36. Comparisons were made with full-term 14-d-old neonates. Total CD4+ and CD8+ T cell frequencies were markedly lower in the preterm neonates. The reduction was more pronounced among the CD8+ population, resulting in an increased CD4/CD8 ratio. The preterm infants were also more Th2 skewed than the full-term infants. Although the frequency of regulatory T cells seemed normal in the ELGAN/ELBW preterm neonates, their expression of the homing receptors α4ß7, CCR4, and CCR9 was altered. Notably, ELGAN/ELBW infants developing necrotizing enterocolitis before day 14 had higher expression of CCR9 in CD4+T cells at day 14. Chorioamnionitis clearly associated with reduced T regulatory cell frequencies and functional characteristics within the preterm group. Finally, probiotic supplementation with Lactobacillus reuteri did not impose any phenotypic changes of the conventional T cell compartment. In conclusion, notable immaturities of the T cell compartment in ELGAN/ELBW neonates may at least partially explain their increased susceptibility to severe immune-mediated morbidities.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31736150

RESUMO

BACKGROUND: Early colonization with a diverse microbiota seems to play a crucial role for appropriate immune maturation during childhood. Breastmilk microbiota is one important source of microbes for the infant, transferred together with maternal IgA antibodies. We previously observed that allergy development during childhood was associated with aberrant IgA responses to the gut microbiota already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breastfed infants. OBJECTIVE: To determine the microbial composition and IgA-coated bacteria in breastmilk in relation to allergy development in children participating in an intervention trial with pre- and post-natal Lactobacillus reuteri supplementation. METHODS: A combination of flow cytometric cell sorting and 16S rRNA gene sequencing was used to characterize the bacterial recognition patterns by IgA in breastmilk samples collected one month post-partum from 40 mothers whose children did or did not develop allergic and asthmatic symptoms during the first 7 years of age. RESULTS: The milk fed to children developing allergic manifestations had significantly lower bacterial richness, when compared to the milk given to children that remained healthy. Probiotic treatment influenced the breastmilk microbiota composition. However, the proportions of IgA-coated bacteria, the total bacterial load and the patterns of IgA-coating were similar in breastmilk between mothers of healthy children and those developing allergies. CONCLUSION: Consumption of breastmilk with a reduced microbial richness in the first month of life may play an important role in allergy development during childhood.

5.
Lakartidningen ; 1162019 Oct 08.
Artigo em Sueco | MEDLINE | ID: mdl-31593284

RESUMO

Preterm delivery in Sweden constitutes 5.7 % of all deliveries, which is among the lowest rates in the world. There has not been any increase in the proportion of iatrogenic preterm deliveries during the last decades.The main hypothesis concerning the causality of preterm delivery is still that of the ascending infection from the vagina to the uterus and inflammation resulting in contractions, rupture of membranes and delivery. The mechanisms behind parturition at term are still elusive and this is also true for preterm delivery. The genetic contribution to preterm delivery is about 25-30 %. The first genes that are associated with preterm delivery and gestational duration have recently been published. Huge progress has been made in care of preterm born infants. Sweden has among the lowest rates of mortality and morbidity in the world, especially in the lowest gestational weeks. New modes of care, family-centered care and hospital-assisted home care, have empowered the parents and reduced the cost for care.


Assuntos
Nascimento Prematuro , Corioamnionite , Deficiências do Desenvolvimento/epidemiologia , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/epidemiologia , Gravidez , Resultado da Gravidez , Nascimento Prematuro/economia , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/etiologia , Fatores de Risco , Suécia/epidemiologia
6.
Lakartidningen ; 1162019 Oct 08.
Artigo em Sueco | MEDLINE | ID: mdl-31593285

RESUMO

The recently documented high survival of extremely preterm infants in Sweden is related to a high degree of centralization of pre- and postnatal care and to recently issued national consensus guidelines providing recommendations for perinatal care at 22-24 gestational weeks. The prevalence of major neonatal morbidity remains high and exceeded 60 % in a recent study of extremely preterm infants born at < 27 gestational weeks delivered in Sweden in 2014-2016 and surviving to 1 year of age. Damage to immature organ systems inflicted during the neonatal period causes varying degrees of functional impairment with lasting effects in the growing child. There is an urgent need for evidence-based novel interventions aiming to prevent neonatal morbidity with a subsequent improvement of long-term outcome.


Assuntos
Lactente Extremamente Prematuro , Doenças do Prematuro , Nascimento Prematuro , Displasia Broncopulmonar/epidemiologia , Displasia Broncopulmonar/fisiopatologia , Displasia Broncopulmonar/prevenção & controle , Serviços Centralizados no Hospital , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/epidemiologia , Hemorragia Cerebral/fisiopatologia , Hemorragia Cerebral/prevenção & controle , Ventrículos Cerebrais/irrigação sanguínea , Ventrículos Cerebrais/diagnóstico por imagem , Enterocolite Necrosante/epidemiologia , Enterocolite Necrosante/fisiopatologia , Enterocolite Necrosante/prevenção & controle , Feminino , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/fisiopatologia , Doenças do Prematuro/prevenção & controle , Assistência Perinatal/organização & administração , Gravidez , Nascimento Prematuro/mortalidade , Retinopatia da Prematuridade/sangue , Retinopatia da Prematuridade/epidemiologia , Retinopatia da Prematuridade/fisiopatologia , Retinopatia da Prematuridade/prevenção & controle , Taxa de Sobrevida , Suécia/epidemiologia
7.
JAMA ; 321(12): 1188-1199, 2019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30912837

RESUMO

Importance: Since 2004-2007, national guidelines and recommendations have been developed for the management of extremely preterm births in Sweden. If and how more uniform management has affected infant survival is unknown. Objective: To compare survival of extremely preterm infants born during 2004-2007 with survival of infants born during 2014-2016. Design, Setting and Participants: All births at 22-26 weeks' gestational age (n = 2205) between April 1, 2004, and March 31, 2007, and between January 1, 2014, and December 31, 2016, in Sweden were studied. Prospective data collection was used during 2004-2007. Data were obtained from the Swedish pregnancy, medical birth, and neonatal quality registries during 2014-2016. Exposures: Delivery at 22-26 weeks' gestational age. Main Outcomes and Measures: The primary outcome was infant survival to the age of 1 year. The secondary outcome was 1-year survival among live-born infants who did not have any major neonatal morbidity (specifically, without intraventricular hemorrhage grade 3-4, cystic periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity stage 3-5, or severe bronchopulmonary dysplasia). Results: During 2004-2007, 1009 births (3.3/1000 of all births) occurred at 22-26 weeks' gestational age compared with 1196 births (3.4/1000 of all births) during 2014-2016 (P = .61). One-year survival among live-born infants at 22-26 weeks' gestational age was significantly lower during 2004-2007 (497 of 705 infants [70%]) than during 2014-2016 (711 of 923 infants [77%]) (difference, -7% [95% CI, -11% to -2.2%], P = .003). One-year survival among live-born infants at 22-26 weeks' gestational age and without any major neonatal morbidity was significantly lower during 2004-2007 (226 of 705 infants [32%]) than during 2014-2016 (355 of 923 infants [38%]) (difference, -6% [95% CI, -11% to -1.7%], P = .008). Conclusions and Relevance: Among live births at 22-26 weeks' gestational age in Sweden, 1-year survival improved between 2004-2007 and 2014-2016.


Assuntos
Mortalidade Infantil/tendências , Lactente Extremamente Prematuro , Deficiências do Desenvolvimento/epidemiologia , Feminino , Viabilidade Fetal , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Doenças do Prematuro/epidemiologia , Terapia Intensiva Neonatal , Masculino , Estudos Prospectivos , Natimorto/epidemiologia , Taxa de Sobrevida , Suécia/epidemiologia
8.
Acta Paediatr ; 108(1): 62-69, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29999201

RESUMO

AIM: This study evaluated if oral supplementation with the probiotic bacterium Lactobacillus reuteri DSM 17938 improved enteral feeding tolerance and growth rates in extremely low birthweight (ELBW) infants. METHOD: A randomised, double-blind, placebo-controlled trial comprising 134 ELBW (<1000 g) infants born before gestational week 28 + 0. Daily supplementation of L. reuteri (1.25 × 108 bacteria/day) or placebo started within 3 days and continued until gestational week 36 + 0. Primary outcome was feeding tolerance and secondary outcome growth rate calculated as z-score development. RESULTS: Feeding tolerance was similar in the probiotic and placebo group. Time to full enteral feeds was 15 days in both groups. The z-score of the head circumference decreased in both groups from birth to day 28 of life, but it decreased less in the L. reuteri group compared to the placebo group: -1.2 SD (95% CI: -1.4 to -1.0) versus -1.7 SD (95% CI: -2.0 to -1.5; p = 0.001). Other growth parameters were similar in the study groups. CONCLUSION: Lactobacillus reuteri did not reduce time to reach full enteral feeds in ELBW infants. The L. reuteri supplemented infants, however, had a better growth rate of the head during the first month of life.

9.
Mol Nutr Food Res ; 63(3): e1800658, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30407734

RESUMO

SCOPE: Necrotizing enterocolitis (NEC) is a leading cause of morbidity and death in preterm infants, occurring more often in formula-fed than breastfed infants. Studies in both rats and humans show that human milk oligosaccharides (HMOs) lower the incidence of NEC, but the mechanism underlying such protection is currently unclear. METHODS AND RESULTS: By extracting HMOs from pooled human breastmilk, the impact of HMOs on the intestinal mucin levels in a murine model of NEC are investigated. To confirm the results, the findings are validated by exposing human intestinal epithelial cells and intestinal organoids to HMOs and evaluated for mucin expression. HMO-gavage to pups increases Muc2 levels and decreases intestinal permeability to macromolecular dextran. HMO-treated cells have increased Muc2 expression, decreased bacterial attachment and dextran permeability during challenge by enteric pathogens. To identify the mediators involved in HMO induction of mucins, it is demonstrated that HMOs directly induce the expression of chaperone proteins including protein disulfide isomerase (PDI). Suppression of PDI activity removes the protective effects of HMOs on barrier function in vitro as well as NEC protection in vivo. CONCLUSIONS: Taken together, the results provide insights to the possible mechanisms by which HMOs protect the neonatal intestine through upregulation of mucins.


Assuntos
Enterocolite Necrosante/prevenção & controle , Leite Humano/química , Mucina-2/genética , Oligossacarídeos/farmacologia , Animais , Animais Recém-Nascidos , Células CACO-2 , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Enterocolite Necrosante/metabolismo , Células Caliciformes/efeitos dos fármacos , Humanos , Mucosa Intestinal/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Mucina-2/análise , Isomerases de Dissulfetos de Proteínas/fisiologia
10.
Nutrients ; 10(10)2018 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-30347801

RESUMO

Difference in human milk oligosaccharides (HMO) composition in breast milk may be one explanation why some preterm infants develop necrotizing enterocolitis (NEC) despite being fed exclusively with breast milk. The aim of this study was to measure the concentration of 15 dominant HMOs in breast milk during the neonatal period and investigate how their levels correlated to NEC, sepsis, and growth in extremely low birth weight (ELBW; <1000 g) infants who were exclusively fed with breast milk. Milk was collected from 91 mothers to 106 infants at 14 and 28 days and at postmenstrual week 36. The HMOs were analysed with high-performance anion-exchange chromatography with pulsed amperometric detection. The HMOs diversity and the levels of Lacto-N-difucohexaose I were lower in samples from mothers to NEC cases, as compared to non-NEC cases at all sampling time points. Lacto-N-difucohexaose I is only produced by secretor and Lewis positive mothers. There were also significant but inconsistent associations between 3'-sialyllactose and 6'-sialyllactose and culture-proven sepsis and significant, but weak correlations between several HMOs and growth rate. Our results suggest that the variation in HMO composition in breast milk may be an important factor explaining why exclusively breast milk fed ELBW infants develop NEC.


Assuntos
Enterocolite Necrosante/etiologia , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Leite Humano/química , Oligossacarídeos/efeitos adversos , Oligossacarídeos/classificação , Humanos , Recém-Nascido , Oligossacarídeos/química
11.
ISME J ; 12(9): 2292-2306, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29899505

RESUMO

Information on how the oral microbiome develops during early childhood and how external factors influence this ecological process is scarce. We used high-throughput sequencing to characterize bacterial composition in saliva samples collected at 3, 6, 12, 24 months and 7 years of age in 90 longitudinally followed children, for whom clinical, dietary and health data were collected. Bacterial composition patterns changed through time, starting with "early colonizers", including Streptococcus and Veillonella; other bacterial genera such as Neisseria settled after 1 or 2 years of age. Dental caries development was associated with diverging microbial composition through time. Streptococcus cristatus appeared to be associated with increased risk of developing tooth decay and its role as potential biomarker of the disease should be studied with species-specific probes. Infants born by C-section had initially skewed bacterial content compared with vaginally delivered infants, but this was recovered with age. Shorter breastfeeding habits and antibiotic treatment during the first 2 years of age were associated with a distinct bacterial composition at later age. The findings presented describe oral microbiota development as an ecological succession where altered colonization pattern during the first year of life may have long-term consequences for child´s oral and systemic health.


Assuntos
Bactérias/isolamento & purificação , Cárie Dentária/microbiologia , Microbiota , Boca/microbiologia , Antibacterianos/uso terapêutico , Aleitamento Materno , Criança , Pré-Escolar , Parto Obstétrico , Fenômenos Ecológicos e Ambientais , Humanos , Lactente , Estudos Longitudinais , Saliva/microbiologia , Streptococcus/isolamento & purificação
12.
J Pediatr ; 200: 104-110.e1, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29731360

RESUMO

OBJECTIVE: To explore the prevalence of hyperglycemia and the associations between nutritional intakes, hyperglycemia, insulin treatment, and mortality in extremely preterm infants. STUDY DESIGN: Prospectively collected data from the Extremely Preterm Infants in Sweden Study (EXPRESS) was used in this study and included 580 infants born <27 gestational weeks during 2004-2007. Available glucose measurements (n = 9850) as well as insulin treatment and nutritional data were obtained retrospectively from hospital records for the first 28 postnatal days as well as 28- and 70-day mortality data. RESULTS: Daily prevalence of hyperglycemia >180 mg/dL (10 mmol/L) of up to 30% was observed during the first 2 postnatal weeks, followed by a slow decrease in its occurrence thereafter. Generalized additive model analysis showed that increasing parenteral carbohydrate supply with 1 g/kg/day was associated with a 1.6% increase in glucose concentration (P < .001). Hyperglycemia was associated with more than double the 28-day mortality risk (P < .01). In a logistic regression model, insulin treatment was associated with lower 28- and 70-day mortality when given to infants with hyperglycemia irrespective of the duration of the hyperglycemic episode (P < .05). CONCLUSIONS: Hyperglycemia is common in extremely preterm infants throughout the first postnatal month. Glucose infusions seem to have only a minimal impact on glucose concentrations. In the EXPRESS cohort, insulin treatment was associated with lower mortality in infants with hyperglycemia. Current practices of hyperglycemia treatment in extremely preterm infants should be reevaluated and assessed in randomized controlled clinical trials.


Assuntos
Glicemia/metabolismo , Ingestão de Energia , Hiperglicemia/tratamento farmacológico , Lactente Extremamente Prematuro , Insulina/uso terapêutico , Nutrientes/farmacologia , Nutrição Parenteral/métodos , Feminino , Seguimentos , Humanos , Hiperglicemia/sangue , Hiperglicemia/epidemiologia , Hipoglicemiantes/uso terapêutico , Incidência , Recém-Nascido , Doenças do Prematuro , Masculino , Estudos Prospectivos , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Suécia/epidemiologia
14.
Nestle Nutr Inst Workshop Ser ; 88: 107-115, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28346927

RESUMO

The complex and diverse intestinal microbiome is recognized as important in promoting human health. An altered gut microflora, referred to as dysbiosis, is increasingly recognized as having an etiologic role in a variety of conditions, including functional gastrointestinal disorders: colic in infants and irritable bowel syndrome in older children. Probiotics are defined as live microorganisms that, if ingested in sufficient amounts, restore microbial homeostasis and have a benefit on health. Randomized controlled trials indicate that probiotics can be effective in a variety of intestinal conditions, including colic and irritable bowel syndrome. Probiotics may promote gut microbial diversity, but timing of the intervention appears crucial. Strain-specific effects on colonization resistance, epithelial barrier integrity, modulation of signal transduction, impacts on innate and adaptive immune responses, and effects on visceral hyperalgesia likely explain the observed variability in various probiotic strains. In the future, probiotics are likely to be chosen for use in a defined clinical setting based on underlying mechanism(s) of action. The precise component of the probiotic agent mediating observed effects is the subject of current research. Unresolved issues relate to optimal dosages, timing of ingestion, single versus combination formulations, maintenance of viability in storage, and the merits of employing probiotic-derived products.


Assuntos
Gastroenteropatias/microbiologia , Microbioma Gastrointestinal/fisiologia , Animais , Bifidobacterium , Criança , Cólica/microbiologia , Cólica/terapia , Disbiose , Fezes/microbiologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/imunologia , Humanos , Lactente , Recém-Nascido , Síndrome do Intestino Irritável/microbiologia , Lactobacillus , Probióticos/uso terapêutico
15.
J Allergy Clin Immunol ; 139(3): 1017-1025.e14, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27531072

RESUMO

BACKGROUND: Although a reduced gut microbiota diversity and low mucosal total IgA levels in infancy have been associated with allergy development, IgA responses to the gut microbiota have not yet been studied. OBJECTIVE: We sought to determine the proportions of IgA coating together with the characterization of the dominant bacteria, bound to IgA or not, in infant stool samples in relation to allergy development. METHODS: A combination of flow cytometric cell sorting and deep sequencing of the 16S rDNA gene was used to characterize the bacterial recognition patterns by IgA in stool samples collected at 1 and 12 months of age from children staying healthy or having allergic symptoms up to 7 years of age. RESULTS: The children with allergic manifestations, particularly asthma, during childhood had a lower proportion of IgA bound to fecal bacteria at 12 months of age compared with healthy children. These alterations cannot be attributed to differences in IgA levels or bacterial load between the 2 groups. Moreover, the bacterial targets of early IgA responses (including coating of the Bacteroides genus), as well as IgA recognition patterns, differed between healthy children and children with allergic manifestations. Altered IgA recognition patterns in children with allergy were observed already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breast-fed children. CONCLUSION: An aberrant IgA responsiveness to the gut microbiota during infancy precedes asthma and allergy development, possibly indicating an impaired mucosal barrier function in allergic children.


Assuntos
Fezes/microbiologia , Microbioma Gastrointestinal , Hipersensibilidade/imunologia , Hipersensibilidade/microbiologia , Imunoglobulina A/imunologia , Bactérias/isolamento & purificação , Carga Bacteriana , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
16.
Adv Nutr ; 7(5): 928-37, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27633108

RESUMO

Necrotizing enterocolitis (NEC) is a devastating intestinal disease in preterm infants characterized by barrier disruption, intestinal microbial dysbiosis, and persistent inflammation of the colon, which results in high mortality rates. Current strategies used to manage this disease are not sufficient, although the use of human breast milk reduces the risk of NEC. Mother's milk is regarded as a fundamental nutritional source for neonates, but pasteurization of donor breast milk affects the composition of bioactive compounds. Current research is evaluating the benefits and potential pitfalls of adding probiotics and prebiotics to pasteurized milk so as to improve the functionality of the milk and thereby reduce the burden of illness caused by NEC. Probiotics (live micro-organisms that confer health to the host) and prebiotics (nondigestible oligosaccharides that stimulate the growth of healthy bacteria) are functional foods known to mediate immune responses and modulate microbial populations in the gut. Clinical research shows strain- and compound-specific responses when probiotics or prebiotics are administered in conjunction with donor breast milk for the prevention of NEC. Despite ongoing controversy surrounding optimal treatment strategies, randomized controlled studies are now investigating the use of synbiotics to reduce the incidence and severity of NEC. Synbiotics, a combination of probiotics and prebiotics, have been proposed to enhance beneficial health effects in the intestinal tract more than either agent administered alone. This review considers the implications of using probiotic-, prebiotic-, and synbiotic-supplemented breast milk as a strategy to prevent NEC and issues that could be encountered with the preparations.


Assuntos
Enterocolite Necrosante/prevenção & controle , Leite Humano , Prebióticos , Probióticos , Simbióticos , Bactérias , Humanos , Leite Humano/química , Leite Humano/microbiologia , Neonatologia , Oligossacarídeos
18.
J Allergy Clin Immunol ; 136(5): 1378-86.e1-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26014812

RESUMO

BACKGROUND: Although immune responses directed against antigens from the intestinal microbiota are observed in certain diseases, the normal human adaptive immune response to intestinal microbiota is poorly defined. OBJECTIVE: Our goal was to assess the adaptive immune response to the intestinal microbiota present in 143 healthy adults and compare this response with the response observed in 52 children and their mothers at risk of having allergic disease. METHODS: Human serum was collected from adults and children followed from birth to 7 years of age, and the serum IgG response to a panel of intestinal microbiota antigens was assessed by using a novel protein microarray. RESULTS: Nearly every subject tested, regardless of health status, had serum IgG that recognized a common set of antigens. Seroreactivity to the panel of antigens was significantly lower in atopic adults. Healthy infants expressed the highest level of IgG seroreactivity to intestinal microbiota antigens. This adaptive response developed between 6 and 12 months of age and peaked around 2 years of age. Low IgG responses to certain clusters of microbiota antigens during infancy were associated with allergy development during childhood. CONCLUSIONS: There is an observed perturbation of the adaptive response to antigens from the microbiota in allergic subjects. These perturbations are observable even in childhood, suggesting that optimal stimulation of the adaptive immune system by the microbiota might be needed to prevent certain immune-mediated diseases.


Assuntos
Antígenos de Bactérias/imunologia , Microbioma Gastrointestinal/imunologia , Hipersensibilidade/imunologia , Intestinos/imunologia , Imunidade Adaptativa , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Intestinos/microbiologia , Masculino , Análise em Microsséries
19.
Pediatr Res ; 77(1-2): 214-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25310761

RESUMO

Limited microbial exposure is suggested to underlie the increase of allergic diseases in affluent countries, and bacterial diversity seems to be more important than specific bacteria taxa. Prospective studies indicate that the gut microbiota composition during the first months of life influences allergy development, and support the theory that factors influencing the early maturation of the immune system might be important for subsequent allergic disease. However, recent research indicates that microbial exposure during pregnancy may be even more important for the preventative effects against allergic disease. This review gives a background of the epidemiology, immunology, and microbiology literature in this field. It focuses on possible underlying mechanisms such as immune-regulated epigenetic imprinting and bacterial translocation during pregnancy, potentially providing the offspring with a pioneer microbiome. We suggest that a possible reason for the initial exposure of bacterial molecular patterns to the fetus in utero is to prime the immune system and/or the epithelium to respond appropriately to pathogens and commensals after birth.


Assuntos
Epigênese Genética/imunologia , Trato Gastrointestinal/microbiologia , Hipersensibilidade/epidemiologia , Hipersensibilidade/imunologia , Hipersensibilidade/microbiologia , Microbiota , Efeitos Tardios da Exposição Pré-Natal/microbiologia , Feminino , Humanos , Modelos Biológicos , Gravidez
20.
Clin Transl Allergy ; 4: 21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25002964

RESUMO

BACKGROUND: Mice models indicate that intact Toll like receptor (TLR) signaling may be essential for the allergy protective effects of diverse bacterial exposure observed in clinical trials and epidemiological studies. Probiotic supplementation with Lactobacillus reuteri from pregnancy week 36 and to the infant through the first year of life decreased the prevalence of IgE-associated eczema at two years (ClinicalTrials.gov NCT01285830). The effect of this supplementation on innate immune responses to bacterial products and the expression of associated TLRs were explored. METHODS: Blood mononuclear cells were collected at birth, 6, 12 and 24 months from 61 infants and cultured with TLR2, 4 and 9 ligands. Cytokine and chemokine secretion was determined as well as TLR2, 4 and 9 mRNA expression. RESULTS: Probiotic supplementation was associated with decreased LTA (lipoteichoic acid) induced CCL4, CXCL8, IL-1ß and IL-6 responses at 12 months and decreased CCL4 and IL-1ß secretion at 24 months. TLR2 mRNA expression was not affected by probiotic treatment. CONCLUSIONS: Decreased responses to TLR2, the main receptor for LTA from Gram positive bacteria, in probiotic treated children seem to be dependent on factors downstream of TLR mRNA expression.

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