Infant Microbiota Research Articles

Isolation, purification and characterization of bioactive surfactant from the probiotic bacterium Lactobacillus casei NM512 isolated from infant microbiota

Background Lactobacillus casei NM512 was previously isolated from the feces of breast-fed infants and has great potential for probiotic treatment of diseases that are based on immune deregulation. These strains fulfill the main criteria required for safe human consumption and could therefore be useful in pharmaceutical and therapeutic preparations. However, further studies are needed to evaluate and decipher the in vivo activities of the isolated strains with regard to their immunomodulatory function. Objective This work aims to isolate, identify and characterize the bioactive surfactant component from the probiotic bacterium L. casei NM512. Materials and methods The isolation of the surfactant from L. casei NM512 was performed after incubation the strain for 72 h at 37°C with shaking at 120 rpm. The surfactant extracted from cells by acid precipitation. A combination of different methods (TLC, FT-IR, NMR, and GC mass) was used to analyze the composition of the isolated surfactant. The surfactant was also investigated for its antimicrobial activity using the well agar diffusion method, antioxidant ability targeting the DPPH free radical, Cytotoxicity ability using MTT assay, and anti- inflammatory activity was done by determination the inhibition of nitric oxide (NO) production in RAW 264.7 macrophages. Results and conclusion The obtained data show that the surfactant is a mixture of carbohydrates, lipids and proteins with glycolipopeptide nature that expressed remarkable antibacterial and antioxidant activities. Furthermore the isolated surfactant showed safety by keeping the cell viability and anti-inflammatory activity. Here we introduce a novel biosurfactant for medical and pharmaceutical purposes.

The composition of the maternal breastmilk microbiota influences the microbiota network structure during early infancy.

Human breastmilk (BM) is important for microbiome maturation in infants across different body sites. Streptococcus and Staphylococcus are considered universally predominant genera in the BM microbiota. However, whether the differential abundance of Streptococcus and Staphylococcus in BM can differentially affect microbiome maturation in infants remains unclear. We recruited exclusively breastfeeding mothers from among the donors of the human milk bank established at National Cheng-Kung University Hospital. The donor mothers provided 35 BM samples at three months (3M; before introducing children to complementary feeding) and 23 BM samples at six months (6M; after introducing children to complementary feeding) postpartum. At both time points, samples from different body sites, including nasal swabs, oral swabs and stool, were collected from the mothers and their infants. Maternal BMI was inversely associated with coagulase-negative Staphylococcus (CoNS) abundance in breastmilk. Staphylococcus caprae representation in BM CoNS showed a negative correlation with Streptococcus abundance. Network analysis revealed that infants fed Staphylococcus-dominated BM had better gut and nasal microbiota networks than infants fed Streptococcus-abundant BM during early infancy. Our work suggests that maternal metabolic status plays a crucial role in Staphylococcus/Streptococcus competition in BM, which in turn can impact the development of the infant microbiota. Our microbiota co-occurrence network analysis might serve as a helpful bioinformatic tool to monitor microbiota maturation during early infancy.

Impact of milk secretor status on the fecal metabolome and microbiota of breastfed infants

ABSTRACT Maternal secretor status has been shown to be associated with the presence of specific fucosylated human milk oligosaccharides (HMOs), and the impact of maternal secretor status on infant gut microbiota measured through 16s sequencing has previously been reported. None of those studies have confirmed exclusive breastfeeding nor investigated the impact of maternal secretor status on gut microbial fermentation products. The present study focused on exclusively breastfed (EBF) Indonesian infants, with exclusive breastfeeding validated through the stable isotope deuterium oxide dose-to-mother (DTM) technique, and the impact of maternal secretor status on the infant fecal microbiome and metabolome. Maternal secretor status did not alter the within-community (alpha) diversity, between-community (beta) diversity, or the relative abundance of bacterial taxa at the genus level. However, infants fed milk from secretor (Se+) mothers exhibited a lower level of fecal succinate, amino acids and their derivatives, and a higher level of 1,2-propanediol when compared to infants fed milk from non-secretor (Se-) mothers. Interestingly, for infants consuming milk from Se+ mothers, there was a correlation between the relative abundance of Bifidobacterium and Streptococcus, and between each of these genera and fecal metabolites that was not observed in infants receiving milk from Se- mothers. Our findings indicate that the secretor status of the mother impacts the gut microbiome of the exclusively breastfed infant.

Effects of Maternal Stress on Breast Milk Production and the Microbiota of Very Premature Infants.

Perinatal stress experienced by mothers of very premature newborns may influence the mother's milk and the infant's intestinal microbiota. This prospective study of mothers of very preterm infants fed with mother's own milk (MOM) was carried out in a tertiary hospital over a 2-year period. The assessment of maternal stress in 45 mothers of 52 very preterm newborns using the parental stress scale (PSS:NICU) revealed an inverse relationship between stress and MOM production in the first days of life (p = 0.012). The greatest contributor to stress was the one related to the establishment of a mother-child bond. Maternal stress was lower in mothers in whom the kangaroo method was established early (p = 0.011) and in those with a higher educational level (p = 0.032). Levels of fecal calprotectin (FC) decreased with the passage of days and were directly correlated with birthweight (p = 0.044). FC levels 7 days post-delivery were lower in newborns that received postnatal antibiotics (p = 0.027). High levels of maternal stress resulted in progressive decreases and increases in the proportions of Firmicutes and Proteobacteria species, respectively, over 15 days post-delivery, both in MOM and in fecal samples from premature newborns. These findings underscore the importance of recognizing and appropriately managing maternal stress in neonatal units, given its marked influence on both the microbiota of maternal milk and the intestinal microbiota of premature newborns.

Effect of Probiotic Supplementation on the Gut Microbiota Composition of Infants Delivered by Cesarean Section: An Exploratory, Randomized, Open-label, Parallel-controlled Trial.

Infants born via cesarean section (CS) are at an increased risk of immune-related diseases later in life, potentially due to altered gut microbiota. Recent research has focused on the administration of probiotics in the prevention of gut microbiota dysbiosis in neonates delivered by CS. This study was performed to investigate the effects of probiotic supplementation on the gut microbiota of CS-delivered infants. Thirty full-term neonates delivered by CS were randomized into the intervention (supplemented orally with a probiotic containing Bifidobacterium longum, Lactobacillus acidophilus, and Enterococcus faecalis for 2weeks) and control groups. Stool samples were collected at birth and 2weeks and 42days after birth. The composition of the gut microbiota was analyzed using 16S rRNA sequencing technology. The applied bacterial strains were abundant in the CS-delivered infants supplemented with probiotics. Probiotics increased the abundance of some beneficial bacteria, such as Bacteroides, Acinetobacter, Veillonella, and Faecalibacterium. Low colonization of Klebsiella, a potentially pathogenic bacterium, was observed in the intervention group. Our results showed that probiotics supplemented immediately after CS enriched the gut microbiota composition and altered the pattern of early gut colonization. registration number NCT05086458.

Seeding the Infant Gut in Early Life-Effects of Maternal and Infant Seeding with Probiotics on Strain Transfer, Microbiota, and Gastrointestinal Symptoms in Healthy Breastfed Infants.

We investigated the effects of two dosing regimens of two multi-strain probiotic products on the gut microbiota of breastfed infants, including the transfer of the dosed strains and clinical outcomes. In forty-seven dyads, infants were either exposed through maternal intake (MS) of Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12, Lacticaseibacillus rhamnosus LGG, and Bifidobacterium longum subsp. infantis Bifin02 from gestational week thirty-three until four weeks after birth (n = 24) or dosed directly (IS) with the same strains except for LA-5 starting within 24 h after birth until day 28 (n = 23). Infant stool samples were collected on day 0, 14, 28, and 42 after birth. Gastrointestinal symptoms were assessed by parents using an electronic diary. Microbiota composition was determined using 16S rRNA sequencing, and strain recovery was analyzed by qPCR. Notably, 100% of the IS infants were colonized with Bifin02 after 14 days as opposed to only 25% of the MS infants. Mean stool frequency was significantly lower in IS infants compared to MS infants and IS infants had softer stools on day 14, 28, and 42. A significantly steeper slope of progression of inconsolable crying and fussing was observed in MS infants compared to IS infants. In conclusion, direct infant seeding induced a faster increase in fecal bifidobacteria abundancy and Bifin02 recovery compared to dosed through the maternal intake.

Gut, oral, and nasopharyngeal microbiota dynamics in the clinical course of hospitalized infants with respiratory syncytial virus bronchiolitis.

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and hospitalization in infants worldwide. The nasopharyngeal microbiota has been suggested to play a role in influencing the clinical course of RSV bronchiolitis, and some evidence has been provided regarding oral and gut microbiota. However, most studies have focused on a single timepoint, and none has investigated all three ecosystems at once. Here, we simultaneously reconstructed the gut, oral and nasopharyngeal microbiota dynamics of 19 infants with RSV bronchiolitis in relation to the duration of hospitalization (more or less than 5 days). Fecal samples, oral swabs, and nasopharyngeal aspirates were collected at three timepoints (emergency room admission, discharge and six-month follow-up) and profiled by 16S rRNA amplicon sequencing. Interestingly, all ecosystems underwent rearrangements over time but with distinct configurations depending on the clinical course of bronchiolitis. In particular, infants hospitalized for longer showed early and persistent signatures of unhealthy microbiota in all ecosystems, i.e., an increased representation of pathobionts and a depletion of typical age-predicted commensals. Monitoring infant microbiota during RSV bronchiolitis and promptly reversing any dysbiotic features could be important for prognosis and long-term health.

The contribution of maternal oral, vaginal, and gut microbiota to the developing offspring gut

There is limited understanding of how the microbiota colonizing various maternal tissues contribute to the development of the neonatal gut microbiota (GM). To determine the contribution of various maternal microbiotic sites to the offspring microbiota in the upper and lower gastrointestinal tract (GIT) during early life, litters of mice were sacrificed at 7, 9, 10, 11, 12, 14, and 21 days of age, and fecal and ileal samples were collected. Dams were euthanized alongside their pups, and oral, vaginal, ileal, and fecal samples were collected. This was done in parallel using mice with either a low-richness or high-richness microbiota to assess the consistency of findings across multiple microbial compositions. Samples were analyzed using 16S rRNA amplicon sequencing. The compositional similarity between pup and dam samples were used to determine the contribution of each maternal source to the composition of the neonate fecal and ileal samples at each timepoint. As expected, similarity between neonate and maternal feces increased significantly over time. During earlier time-points however, the offspring fecal and ileal microbiotas were closer in composition to the maternal oral microbiota than other maternal sites. Prominent taxa contributed by the maternal oral microbiota to the neonate GM were supplier-dependent and included Lactobacillus spp., Streptococcus spp., and a member of the Pasteurellaceae family. These findings align with the microbial taxa reported in infant microbiotas, highlighting the translatability of mouse models in this regard, as well as the dynamic nature of the GM during early life.

Early-life gut microbiota and neurodevelopment in preterm infants: a narrative review.

Infants born preterm are at a high risk of both gut microbiota (GM) dysbiosis and neurodevelopmental impairment. While the link between early dysbiosis and short-term clinical outcomes is well established, the relationship with long-term infant health has only recently gained interest. Notably, there is a significant overlap in the developmental windows of GM and the nervous system in early life. The connection between GM and neurodevelopment was first described in animal models, but over the last decade a growing body of research has also identified GM features as one of the potential mediators for human neurodevelopmental and neuropsychiatric disorders. In this narrative review, we provide an overview of the developing GM in early life and its prospective relationship with neurodevelopment, with a focus on preterm infants. Animal models have provided evidence for emerging pathways linking early-life GM with brain development. Furthermore, a relationship between both dynamic patterns and static features of the GM during preterm infants' early life and brain maturation, as well as neurodevelopmental outcomes in early childhood, was documented. Future human studies in larger cohorts, integrated with studies on animal models, may provide additional evidence and help to identify predictive biomarkers and potential therapeutic targets for healthy neurodevelopment in preterm infants.

Baseline azithromycin resistance in the gut microbiota of preterm born infants

BackgroundMacrolides, including azithromycin, are increasingly used in preterm-born infants to treat Ureaplasma infections. The baseline carriage of macrolide resistance genes in the preterm stool microbiota is unknown.ObjectivesIdentify carriage of azithromycin resistant bacteria and the incidence of macrolide resistant genes.MethodsAzithromycin resistant bacteria were isolated from serial stool samples obtained from preterm infants (≤32 weeks’ gestation) by culturing aerobically/anaerobically, in the presence/absence of azithromycin. Using quantitative PCR, we targeted 6 common macrolide resistance genes (erm(A), erm(B), erm(C), erm(F), mef(A/E), msr(A)) in DNA extracted from selected bacteria resistant to azithromycin.ResultsFrom 89 stool samples from 37 preterm-born infants, 93.3% showed bacterial growth in aerobic or anaerobic conditions. From the 280 azithromycin resistant isolates that were identified, Staphylococcus (75%) and Enterococcus (15%) species dominated. Macrolide resistance genes were identified in 91% of resistant isolates: commonest were erm(C) (46% of isolates) and msr(A) (40%). Multiple macrolide resistance genes were identified in 18% of isolates.ConclusionMacrolide resistance is common in the gut microbiota of preterm-born infants early in life, most likely acquired from exposure to the maternal microbiota. It will be important to assess modulation of macrolide resistance, if macrolide treatment becomes routine in the management of preterm infants.Impact StatementAzithromycin resistance is present in the stool microbiota in the first month of life in preterm infants91% of azithromycin resistant bacteria carried at least one of 6 common macrolide resistant genesIncreasing use of macrolides in the preterm population makes this an important area of study

Sources of gut microbiota variation in a large longitudinal Finnish infant cohort.

Although the infant gut microbiota has been extensively studied, comprehensive assessment on the microbiota determinants including technical variables has not been performed in large infant cohorts. We studied the effect of 109 variables on the 16S rRNA gene amplicon-based gut microbiota profiles of infants sampled longitudinally from three weeks to two years of life in the Finnish HELMi birth cohort. Spot faecal samples from both parents were included for intra-family analyses, totalling to 7657 samples from 985 families that were evaluated for beta-diversity patterns using permutational multivariate analysis on Bray-Curtis distances, and differential abundance testing and alpha-diversity for variables of interest. We also assessed the effect of different taxonomic levels and distance methods. In time point-specific models, the largest share of variation explained, up to 2-6%, were seen in decreasing order for the DNA extraction batch, delivery mode and related perinatal exposures, defecation frequency and parity/siblings. Variables describing the infant gastrointestinal function were continuously important during the first two years, reflecting changes in e.g., feeding habits. The effect of parity/siblings on infant microbiota was modified by birth mode and exposure to intrapartum antibiotics, exemplifying the tight interlinkage of perinatal factors relevant for infant microbiota research. In total, up to 19% of the biological microbiota variation in the infant gut could be explained. Our results highlight the need to interpret variance partitioning results in the context of each cohort's characteristics and microbiota processing. Our study provides a comprehensive report of key factors associated with infant gut microbiota composition across the two first years of life in a homogenous cohort. The study highlights possible important future research areas and confounding factors to be considered. This research was supported by Business Finland, Academy of Finland, Foundation for Nutrition Research and the Doctoral Program in Microbiology and Biotechnology, University of Helsinki, Finland.

The impact of neonatal intensive care unit antibiotics on gut bacterial microbiota of preterm infants: a systematic review

Preterm infants encounter an unnatural beginning to life, with housing in neonatal intensive care units (NICUs) where they are exposed to antibiotics. Although the effectiveness of antibiotics in infection control is well established, the short- and long-term unintended effects on the microbiota of preterm infants receiving antibiotic treatment are yet to be quantified. Our aim was to investigate the unintended consequences of NICU antibiotics on preterm infants’ gut microbiota. We searched three electronic databases—Embase, PubMed, and Scopus—for records from 2010 to October 2022. Eligibility criteria included intervention and observational studies that collected stool samples and analyzed microbiota data on the effect of antibiotics on the gut microbiota of preterm infants using 16S rRNA sequencing. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the quality of the studies was judged using the Cochrane Collaboration Tool for assessing risk of bias (RoB2) for clinical trials, while non-randomized studies were assessed using the Newcastle–Ottawa Scale (NOS). The initial searches yielded 7,605 papers, of which 21 were included in the review. The selected studies examined 3,669 stool samples that were collected longitudinally from 878 preterm infants in seven different countries. Preterm infants exposed to antibiotics had a reduced bacterial diversity, an increased relative abundance of pathogenic bacteria such as Enterobacteriaceae, and a decrease or absence of symbiotic bacteria such as Bifidobacterium spp., which have been shown to assist in immunity development. Antibiotic discontinuation restored diversity, with variances linked to the antibiotic spectrum and treatment duration in some but not all cases. Breastfeeding confounded the association between antibiotic use and dysbiosis. Intriguingly, the reduction of γ-aminobutyric acid (GABA), a crucial neurotransmitter for early brain development, was linked to the depletion of Veillonella spp. Despite the apparent benefits of using antibiotics on preterm infants, we conclude that they should be used only when absolutely necessary and for a short period of time. Mothers’ milk is recommended to hasten the restoration of disrupted microbiota.

Assessing the impact of pregnancy and birth factors on the maternal and infant microbiota.

Background: The microbiota acquired at birth is known to play an intimate role in later life health and disease and has been shown to be affected by the mode of birth. There has been recent interest in microbiota correction by maternal vaginal seeding in Cesarean section-born infants; however, the safety of this practice has been debated. The aim of this study was to assess how other factors, such as timing of sampling, maternal obesity, vaginal Group B Streptococcus colonization (GBS), and antibiotic exposure, affect the maternal and infant microbiota. Methods: Maternal vaginal and saliva samples were collected at three time periods: 35-37 weeks gestation (prenatal), within 24-36 hours after birth (birth), and at ~6 weeks postpartum. Infant saliva and stool samples were collected at ~6 weeks postpartum. 16S rRNA amplicon sequencing was utilized to assess the taxonomic and inferred functional compositions of the bacterial communities from both mothers and infants. Results: Samples from 36 mothers and 32 infants were obtained. Gestational age, breastfeeding, mode of birth, and gravidity were associated with taxonomic alterations in the infant samples, while obesity, antibiotic use, and GBS status were not. Maternal samples were predominantly affected by time, whereby significant alterations including increased microbial diversity were seen at birth and persisted to 6 weeks postpartum. Conclusion: This study provides information on the relationship between health and delivery factors and changes in vaginal and infant microbiota. These results may better direct clinicians and mothers in optimizing the infant microbiota towards health during infancy and later life.

Stability and heterogeneity in the antimicrobiota reactivity of human milk-derived immunoglobulin A.

Immunoglobulin A (IgA) is secreted into breast milk and is critical for both protecting against enteric pathogens and shaping the infant intestinal microbiota. The efficacy of breast milk-derived maternal IgA (BrmIgA) is dependent upon its specificity; however, heterogeneity in BrmIgA binding ability to the infant microbiota is not known. Using a flow cytometric array, we analyzed the reactivity of BrmIgA against bacteria common to the infant microbiota and discovered substantial heterogeneity between all donors, independent of preterm or term delivery. Surprisingly, we also observed intradonor variability in the BrmIgA response to closely related bacterial isolates. Conversely, longitudinal analysis showed that the antibacterial BrmIgA reactivity was relatively stable through time, even between sequential infants, indicating that mammary gland IgA responses are durable. Together, our study demonstrates that the antibacterial BrmIgA reactivity displays interindividual heterogeneity but intraindividual stability. These findings have important implications for how breast milk shapes the development of the preterm infant microbiota and protects against necrotizing enterocolitis.

Probiotic supplementation modifies the gut microbiota profile of very low birth weight preterm infants during hospitalization

Probiotic supplementation is increasingly being given to very low birth weight (VLBW) preterm infants. This preliminary observational study aimed to investigate the effects of multiple-strain probiotics on the gut microbiota of VLBW preterm infants. We collected meconium and stool samples on days 14, 30, and 60 after birth from 49 VLBW infants with a gestational age of <32 weeks. The infants were divided into the probiotics (n=24) and control (n=25) groups. The microbial composition and diversity in the gut of the two groups were analyzed using 16S rRNA gene sequencing. The relative abundance of Bifidobacterium and Lactobacillus was significantly higher in the probiotics group than in the control group on days 14, 30, and 60 (Bifidobacterium: p=0.002, p<0.0001, and p<0.0001, respectively; Lactobacillus: p=0.012, p<0.0001, and p<0.0001, respectively). The control group exhibited a significantly higher proportion of participants with a low abundance (<1%) of Bifidobacterium or Lactobacillus on days 14, 30, and 60 than those in the probiotic group. Moreover, the probiotics group exhibited a significantly lower abundance of Klebsiella on days 14 and 30 (2.4% vs. 11.6%, p=0.037; and 7.9% vs. 16.6%, p=0.032, respectively) and of Escherichia-Shigella on day 60 than the control group (6.1% vs. 12.3%, p=0.013). Beta diversity analysis revealed that the microbiota profile was clearly divided into two groups on days 30 and 60 (p=0.001). Probiotic supplementation significantly increased the relative abundance of Bifidobacterium and Lactobacillus and inhibited the growth of potential pathogens. Furthermore, probiotic supplementation led to a distinct gut microbiota profile. Further research is needed to identify probiotic strains that exert significant influence on the gut microbiome and their long-term health implications in preterm infants.

Alterations in the intestinal microbiota of preterm infants with neurodevelopmental impairments: a prospective cohort study

To investigate the difference in intestinal microbiota between preterm infants with neurodevelopmental impairment (NDI) and those without NDI. In this prospective cohort study, the preterm infants who were admitted to the neonatal intensive care unit of Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from September 1, 2019 to September 30, 2021 were enrolled as subjects. According to the assessment results of Gesell Developmental Scale at the corrected gestational age of 1.5-2 years, they were divided into two groups: normal (n=115) and NDI (n=100). Fecal samples were collected one day before discharge, one day before introducing solid food, and at the corrected gestational age of 1 year. High-throughput sequencing was used to compare the composition of intestinal microbiota between groups. Compared with the normal group, the NDI group had a significantly higher Shannon diversity index at the corrected gestational age of 1 year (P<0.05). The principal coordinate analysis showed a significant difference in the composition of intestinal microbiota between the two groups one day before introducing solid food and at the corrected gestational age of 1 year (P<0.05). Compared with the normal group, the NDI group had a significantly higher abundance of Bifidobacterium in the intestine at all three time points, a significantly higher abundance of Enterococcus one day before introducing solid food and at the corrected gestational age of 1 year, and a significantly lower abundance of Akkermansia one day before introducing solid food (P<0.05). There are significant differences in the composition of intestinal microbiota between preterm infants with NDI and those without NDI. This study enriches the data on the characteristics of intestinal microbiota in preterm infants with NDI and provides reference for the microbiota therapy and intervention for NDI in preterm infants.

Early-life differences in the gut microbiota composition and functionality of infants at elevated likelihood of developing autism spectrum disorder

Evidence from cross-sectional human studies, and preliminary microbial-based intervention studies, have implicated the microbiota-gut-brain axis in the neurobiology of autism spectrum disorder (ASD). Using a prospective longitudinal study design, we investigated the developmental profile of the fecal microbiota and metabolome in infants with (n = 16) and without (n = 19) a family history of ASD across the first 36 months of life. In addition, the general developmental levels of infants were evaluated using the Mullen Scales of Early Learning (MSEL) test at 5 and 36 months of age, and with ADOS-2 at 36 months of age. At 5 months of age, infants at elevated-likelihood of ASD (EL) harbored less Bifidobacterium and more Clostridium and Klebsiella species compared to the low-likelihood infants (LL). Untargeted metabolic profiling highlighted that LL infants excreted a greater amount of fecal γ-aminobutyric acid (GABA) at 5 months, which progressively declined with age. Similar age-dependent patterns were not observed in the EL group, with GABA being consistently low across all timepoints. Integrated microbiome-metabolome analysis showed a positive correlation between GABA and Bifidobacterium species and negative associations with Clostridium species. In vitro experiments supported these observations demonstrating that bifidobacteria can produce GABA while clostridia can consume it. At the behavioral level, there were no significant differences between the EL and LL groups at 5 months. However, at 36 months of age, the EL group had significantly lower MSEL and ADOS-2 scores compared to the LL group. Taken together, the present results reveal early life alterations in gut microbiota composition and functionality in infants at elevated-likelihood of ASD. These changes occur before any behavioral impairments can be detected, supporting a possible role for the gut microbiota in emerging behavioral variability later in life.

Validation of a batch cultivation protocol for fecal microbiota of Kenyan infants

BackgroundThe combination of cultivation studies with molecular analysis approaches allows characterization of the complex human gut microbiota in depth. In vitro cultivation studies of infants living in rural sub-Saharan Africa are scarce. In this study, a batch cultivation protocol for Kenyan infant fecal microbiota was validated.MethodsFresh fecal samples were collected from 10 infants living in a rural area of Kenya. Samples were transported under protective conditions and subsequently prepared for inoculation within less than 30 h for batch cultivation. A diet-adapted cultivation medium was used that mimicked the daily intake of human milk and maize porridge in Kenyan infants during weaning. 16 S rRNA gene amplicon sequencing and HPLC analyses were performed to assess the composition and metabolic activity, respectively, of the fecal microbiota after 24 h of batch cultivation.ResultsHigh abundance of Bifidobacterium (53.4 ± 11.1%) and high proportions of acetate (56 ± 11% of total metabolites) and lactate (24 ± 22% of total metabolites) were detected in the Kenyan infant fecal microbiota. After cultivation started at an initial pH 7.6, the fraction of top bacterial genera (≥ 1% abundant) shared between fermentation and fecal samples was high at 97 ± 5%. However, Escherichia-Shigella, Clostridium sensu stricto 1, Bacteroides and Enterococcus were enriched concomitant with decreased Bifidobacterium abundance. Decreasing the initial pH to 6.9 lead to higher abundance of Bifidobacterium after incubation and increased the compositional similarity of fermentation and fecal samples. Despite similar total metabolite production of all fecal microbiota after cultivation, inter-individual differences in metabolite profiles were apparent.ConclusionsProtected transport and batch cultivation in host and diet adapted conditions allowed regrowth of the top abundant genera and reproduction of the metabolic activity of fresh Kenyan infant fecal microbiota. The validated batch cultivation protocol can be used to study the composition and functional potential of Kenyan infant fecal microbiota in vitro.

Long Duration of Oral Care Using Mother's Own Milk Influences Oral Microbiota and Clinical Outcomes in Very-low-birthweight Infants: Randomized Controlled Trial.

Several studies have focused on the clinical outcomes of oral care using colostrum for a limited time (2-5 days) in very-low-birthweight (VLBW) infants. However, the effect of long-term mother's own milk (MOM) on the clinical outcomes and oral microbiota of VLBW infants remains unknown. In this randomized controlled trial, VLBW neonates were randomly assigned to oral care by MOM or sterile water (SW) groups until they started oral feeding. The primary outcome was oral microbiota composition including alpha and beta diversity, relative abundance, and linear discriminant analysis effect size (LEfSe). The secondary outcomes were various morbidities and mortality. The baseline characteristics of the two groups did not differ (63 neonates, MOM group, n = 30, oral care 22 days; SW group, n = 33, oral care 27 days). There was no significant difference in alpha and beta diversities between the groups before and after the intervention. The MOM group had a significantly lower rate of clinical sepsis than the SW group (47% vs. 76%, risk ratio = 0.62, 95% CI: 0.40-0.97). The relative abundance of Bifidobacterium bifidum and Faecalibacterium were maintained after MOM care, especially in neonates without clinical sepsis, but decreased after SW care. LEfSe showed that neonates in the MOM and SW groups with clinical sepsis had the highest abundance of Pseudomonas and Gammaproteobacteria, respectively, compared with neonates without sepsis. A longer duration of oral care using MOM in VLBW infants sustains healthy bacteria and decreases the risk of clinical sepsis.

Influence of Early Life Factors, including breast milk Composition, on the Microbiome of Infants Born to Mothers with and without Inflammatory Bowel Disease.

Herein we analysed the influence of early life factors, including breast milk composition, on the development of the intestinal microbiota of infants born to mothers with and without IBD. The MECONIUM [Exploring MEChanisms Of disease traNsmission In Utero through the Microbiome] study is a prospective cohort study consisting of pregnant women with or without IBD and their infants. Longitudinal stool samples were collected from babies and analysed using 16s rRNA sequencing and faecal calprotectin. Breast milk proteomics was profiled using Olink inflammation panel. We analysed gut microbiota of 1034 faecal samples from 294 infants [80 born to mothers with and 214 to mothers without IBD]. Alpha diversity was driven by maternal IBD status and time point. The major influencers of the overall composition of the microbiota were mode of delivery, feeding, and maternal IBD status. Specific taxa were associated with these exposures, and maternal IBD was associated with a reduction in Bifidobacterium. In 312 breast milk samples [91 from mothers with IBD], mothers with IBD displayed lower abundance of proteins involved in immune regulation, such as thymic stromal lymphopoietin, interleukin-12 subunit beta, tumour necrosis factor-beta, and C-C motif chemokine 20, as compared with control mothers [adjusted p = 0.0016, 0.049, 0.049, and 0.049, respectively], with negative correlations with baby´s calprotectin, and microbiome at different time points. Maternal IBD diagnosis influences microbiota in their offspring during early life. The proteomic profile of breast milk of women with IBD differs from that of women without IBD, with distinct time-dependent associations with baby's gut microbiome and feacal calprotectin.