Infant Microbiota Research Articles

Maternal group B Streptococcus decreases infant length and alters the early-life microbiome: a prospective cohort study

Background Maternal colonization with Group B Streptococcus (GBS) disrupts the vaginal microbiota, potentially affecting infant microbiota assembly and growth. While the gut microbiota’s importance in infant growth is recognized, the specific effects of maternal GBS on growth remain unclear. This study aimed to explore the effects of maternal vaginal GBS during pregnancy on early infant growth, microbiome, and metabolomics. Methods We recruited and classified 453 pregnant women from southern China into GBS or healthy groups based on GBS vaginal colonization. Their infants were categorized as GBS-exposed or GBS-unexposed groups. We comprehensively analyzed infant growth, gut microbiota, and metabolites during early life, along with maternal vaginal microbiota during pregnancy, using 16S rDNA sequencing and targeted metabolomics. Results GBS-exposed infants exhibited lower length-for-age z-scores (LAZ) than GBS-unexposed infants, especially at 2 months. Altered gut microbiota and metabolites in GBS-exposed infants correlated with growth, mediating the impact of maternal GBS on infant LAZ. Changes in the vaginal microbiota of the GBS group during the third trimester correlated with infant LAZ. Additionally, differences in neonatal gut microbiota, metabolites, and vaginal microbiota during pregnancy were identified between infants with overall LAZ<-1 within 8 months after birth and their counterparts, enhancing the discriminatory power of fundamental data for predicting the occurrence of LAZ<-1 during the first 8 months of life. Conclusions GBS exposure is associated with decreased infant length growth, with altered microbiota and metabolites potentially mediating the effects of maternal GBS on offspring length growth, offering potential targets for predicting and addressing growth impairment.

Galacto-oligosaccharides alone and combined with lactoferrin impact the Kenyan infant gut microbiota and epithelial barrier integrity during iron supplementation in vitro

Aim: Iron supplementation to African weaning infants was associated with increased enteropathogen levels. While cohort studies demonstrated that specific prebiotics inhibit enteropathogens during iron supplementation, their mechanisms remain elusive. Here, we investigated the in vitro impact of galacto-oligosaccharides (GOS) and iron-sequestering bovine lactoferrin (bLF) alone and combined on the gut microbiota of Kenyan infants during low-dose iron supplementation. Methods: Different doses of iron, GOS, and bLF were first screened during batch fermentations (n = 3), and the effect of these factors was studied on microbiota community structure and activity in the new Kenyan infant continuous intestinal PolyFermS model. The impact of different fermentation treatments on barrier integrity, enterotoxigenic Escherichia coli (ETEC) infection, and inflammatory response was assessed using a transwell co-culture of epithelial and immune cells. Results: A dose-dependent increase in short-chain fatty acid (SCFA) production, Bifidobacterium and Lactobacillus /Leuconostoc /Pediococcus (LLP) growth was detected with GOS alone and combined with bLF during iron supplementation in batches. This was confirmed in the continuous PolyFermS model, which also showed a treatment-induced inhibition of opportunistic pathogens C. difficile and C. perfringens . In all tests, supplementation of iron alone and combined with bLF did not have a significant effect on microbiota composition and activity. We observed a strengthening of the epithelial barrier and a decrease in cell death and pro-inflammatory response during ETEC infection with microbiota fermentation supernatants from iron + GOS, iron + bLF, and iron + GOS + bLF treatments compared to iron alone. Conclusion: Overall, beneficial effects on infant gut microbiota were shown using advanced in vitro models for GOS alone and combined with bLF during low-dose iron supplementation.

The effect of complementary foods on the colonic microbiota of weaning infants: a systematic review.

The transition from breastmilk to solid foods (weaning) is a decisive stage for the development of the colonic microbiota. However, little is known about how complementary foods influence the composition and function of the colonic microbiota in infants. This systematic review collected evidence of the effect of individual foods on the fecal microbiota of weaning infants (4-12 months old) using five databases: PubMed, CENTRAL, Scopus, Web of Science, and ScienceDirect. A total of 3625 records were examined, and seven randomized clinical trials met the review's eligibility criteria. Altogether, 983 participants were enrolled, and plant-based foods, meats, and dairy products were used as interventions. Wholegrain cereal increased the fecal abundance of the order Bacteroidales in the two included studies. Pureed beef increased the fecal abundances of the genus Bacteroides and the Clostridium XIVa group, as well as microbial richness in two of the three included studies. However, the conclusions of this review are limited by the small number of studies included. No conclusions could be drawn about the impact of complementary foods on fecal metabolites. Further clinical trials assessing the effect of dietary interventions on both fecal microbial composition and function are needed to fill this knowledge gap in infant nutrition.

Characteristics of gut microbiota of premature infants in the early postnatal period and their relationship with intraventricular hemorrhage

BackgroundStudies have shown correlations between gut microbiota and neurocognitive function, but little was known about the early postnatal gut microbiota and intraventricular hemorrhage (IVH). We aimed to explore the characteristics of gut microbiota in premature infants and their relationship with IVH, further exploring potential therapeutic targets.MethodsPremature infants delivered at Peking University First Hospital from February 2023 to August 2023 were recruited as a cohort. Feces samples were collected on postnatal days 1, 3, and 5. Premature infants were divided into normal, mild IVH, and severe IVH groups based on cranial ultrasound. 16S rRNA amplicon sequencing technology was used to determine the fecal microbiota, and the results were analyzed.ResultsThirty-eight premature infants were enrolled. There was a significant difference in alpha and beta diversity among the three groups. The relative abundance of E. coli and A. muciniphila was different among the three groups. Further random forest analysis indicated that S. lutetiensis, L. mirabilis, and N. macacae can effectively distinguish premature infants with IVH. Finally, the phylogenetic investigation of communities by reconstruction of unobserved states2 (PICRUSt2) functional gene analysis predicted significant differences in energy metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, and membrane transport between normal and severe IVH groups.ConclusionsThe gut microbiota in the early postnatal period of premature infants is closely associated with the IVH status. As age increases, the differences in gut microbiota of premature infants with different degrees of IVH continue to increase, and the trend of changes with severity of IVH becomes more and more obvious. E. coli, A. muciniphila, S. lutetiensis, L. mirabilis, N. macacae, G. haemolysans, and S. oralis can effectively distinguish between IVH infants and normal premature infants. The results indicate that gut microbiota is expected to provide effective therapeutic targets for the diagnosis and treatment of IVH.

Comparison of nasal microbiota between preterm and full-term infants in early life.

The respiratory microbiota influences infant immune system maturation. Little is known about how perinatal, physiological, and environmental exposures impact the nasal microbiota in preterm infants after discharge, or nasal microbiota differences between preterm and healthy full-term infants. Nasal swabs (from 136 preterm and 299 full-term infants at mean postmenstrual age of 45 weeks from the prospective Basel-Bern Infant Lung Development cohort) were analyzed by 16S-rRNA gene amplification and sequencing (Illumina MiSeq). Associations were tested with multivariable linear regression and principal coordinate analysis. Presence of older siblings in preterm infants was associated with β-diversity (PERMANOVA p = 0.001) and an increased abundance of Moraxella and Haemophilus. The nasal microbiota of preterm infants exhibited a distinct composition compared to that of full-term infants (PERMANOVA, R2 = 0.014, p = 0.001), characterized by a reduced abundance of the Moraxella and Dolosigranulum genera (ANCOM-BC, p < 0.05). Our results indicate that, despite both infant groups having similar nasal microbiota patterns, there are some disparities which suggest that prematurity influences the initial microbiota colonization. In preterm infants the presence of older siblings had an effect on the nasal microbiota, whereas perinatal and early postnatal factors did not show significant effects. Presence of older siblings affected the nasal microbiota of preterm infants. This study demonstrated that microbiota composition differs between full-term and preterm infants, with a lower abundance of Moraxella and Dolosigranulum in preterm infants. Examining the differences in nasal microbiota between preterm and full-term infants may contribute to understanding the trajectory of the bacterial component of the nasal microbiota of preterm infants.

Early nasal microbiota and subsequent respiratory tract infections in infants with cystic fibrosis

BackgroundRespiratory tract infections (RTIs) drive lung function decline in children with cystic fibrosis (CF). While the respiratory microbiota is clearly associated with RTI pathogenesis in infants without CF, data on infants with CF is scarce. We compared nasal microbiota development between infants with CF and controls and assessed associations between early-life nasal microbiota, RTIs, and antibiotic treatment in infants with CF.MethodsWe included 50 infants with CF and 30 controls from two prospective birth cohorts followed throughout the first year of life. We collected 1511 biweekly nasal swabs and analyzed the microbiota after amplifying the V3–V4 region of the 16S rRNA gene. We conducted structured weekly interviews to assess respiratory symptoms and antibiotic treatment. We calculated generalized additive mixed models and permutational analysis of variance.ResultsHere, we show that the nasal microbiota is already altered before the first RTI or antibiotic treatment in infants with CF. Microbiota diversity differs between infants with CF and controls following RTIs and/or antibiotic treatment. CF infants with lower α-diversity have a higher number of subsequent RTIs.ConclusionsEarly nasal microbiota alterations may reflect predisposition or predispose to RTIs in infants with CF, and further change after RTIs and antibiotic treatment. This highlights the potential of targeting the nasal microbiota in CF-related RTI management, while also questioning current practices in the era of novel modulator therapies.

Brain injury in premature infants may be related to abnormal colonization of early gut microbiome.

Premature infants are more prone to brain injuries owing to incomplete nervous system development and poor adaptation outside the mother's body. Without timely intervention, premature infants with brain injuries often develop intellectual disabilities, causing significant burdens on families and the society. Multiple studies have shown that gut dysbiosis can affect the nervous system, and vice versa. This study aimed to explore the changes in gut microbiota of typical premature infants and those with brain injuries on the third and seventh days after birth using 16S rRNA technology. Fecal samples from typical premature infants (non-brain injury group, n = 17) and those with brain injuries (brain injury group, n = 21) were collected on days 1, 3, and 7 after birth for 16S rRNA sequencing. Alpha diversity analysis was used to evaluate the diversity of gut microbiome. LEfSe and DESeq2 were used to analyze of the microorganisms' characteristics and differentiate the microorganisms between the two groups. At the phylum level, Firmicutes, Proteobacteria, and Actinobacteria were the dominant flora in both groups. At the genus level, the proportion of Enterococcus in fecal samples of the brain injury group was higher than that of the non-brain injury group on day three after birth; however, the opposite was observed on day seven. Rothia and Lactobacillales were characteristic bacteria of the non-brain injury group on days three and seven after birth, whereas Enterococcus and Bifidobacteria were characteristic bacteria of the brain injury group on days three and seven after birth, respectively. Three days after birth, the Shannon and Simpson indices of the non-brain injury group were significantly higher than those of the brain injury group. Premature infants with brain injuries have a unique gut microbiota that is different from that of typical premature infants, indicating correlation between brain injuries and gut microbiota.

SOME POTENTIAL PREREQUISITES FOR THE FORMATION OF THE GUT MICROBIOTA IN PREMATURE BABIES: PART III

Abnormal microbial colonization of the gut from birth in newborns aff ects growth, development, and health, leading to short- and long-term adverse eff ects. The microbiota of preterm infants diff ers from that of term infants. This is because preterm infants and their mothers have more complicated prenatal and postnatal health conditions and anatomically- functional immaturity of organs and systems depending on gestational age. Maternal conditions, antibiotics, type of feeding, and use of probiotics can signifi cantly aff ect the gut microbiota of preterm infants in the early neonatal period; however, these eff ects decrease with age. Although some factors and processes are diffi cult to intervene or avoid, understanding the potential factors and determinants will help to develop timely strategies to promote a healthy gut microbiota in preterm infants. This review discusses potential determinants of gut microbial colonization in preterm infants, the underlying mechanisms, and recommendations for addressing adverse eff ects.

Association of toll-like receptors with the airway-intestinal microbiota and pneumonia development in preterm infants - A case control study

BackgroundThe prevention and treatment of pneumonia and lung injury in preterm infants are major challenges for pediatricians worldwide. Few studies have analyzed the composition of bacterial colonies in the airway and intestine and their relationship with toll-like receptors (TLRs) as it relates to pneumonia in preterm infants. MethodsThis study included 70 infants born at 32–35 weeks gestation. Oral-tracheal aspirates at the time of birth, first-pass meconium, and serum specimens were collected. Bacterial deoxyribonucleic acid (DNA) was extracted from the Oral-tracheal aspirates and meconium, and 16S ribosomal ribonucleic acid (rRNA) genes were amplified and sequenced. The levels of TLR2 and TLR4 were analyzed using an enzyme-linked immunosorbent assay. Preterm infants were classified into non-pneumonia (A) and pneumonia (B) groups according to their clinical manifestations. ResultsSignificant differences in the alpha and beta diversities were observed between the two groups. Infants with pneumonia had less bacterial diversity in the airways and intestinal flora at birth than those without pneumonia. The three most predominant phyla in the airways at birth were Proteobacteria, Firmicutes, and Actinobacteria. The levels of TLR2 and TLR4 in oral-tracheal aspirates were higher in infants with pneumonia than in those without pneumonia, although serum TLR2 and TLR4 levels did not differ between the groups. Streptococcus in the oral tracheal aspirate was negatively correlated with TLR2 and TLR4 levels, and Ureaplasma in the oral-tracheal aspirate was negatively correlated with TLR4 levels in the airway. ConclusionReduced perinatal microbiota diversity is associated with the levels of TLR2 and TLR4, and may also have a significant impact on the development of pneumonia.

Impact of non-invasive ventilation on microbial colonisation patterns in preterm infants: a single-centre study.

The objective of this study is to assess the relationship between non-invasive ventilation (NIV) and the colonisation of oral and nasal microbiota in preterm infants within the neonatal intensive care unit (NICU). A prospective cohort study. The NICU of Zhejiang University Children's Hospital. Patients include preterm infants with a gestational age of 28-35 weeks, enrolled within the first 24 hours of life. Infants were categorised based on respiratory support: NIV, which included nasal continuous positive airway pressure, nasal intermittent positive pressure ventilation or high-flow nasal cannula; and no respiratory support, defined as room air or low-flow nasal cannula at ≤2 L/min. The primary outcome was the colonisation of oral and nasal microbiota at 5 days post birth, measured by colony-forming units per millilitre (CFU/mL), with colonisation defined as bacterial growth >103 CFU/mL. The study included 100 preterm infants, with 50 in each group. Nasal microbial colonisation was observed in 56% (28/50) of the NIV group, significantly higher than the 28% in the no respiratory support group. No significant differences were found in oral colonisation. Adjusted binary logistic regression showed an association between NIV and increased risk of nasal colonisation (adjusted OR=2.91, 95% CI 1.12 to 7.58, p=0.028). NIV in preterm infants was linked to a higher risk of nasal microbial colonisation. This finding suggests the need for further research and consideration of infection control strategies in the NICU.

Interactions between the human milk oligosaccharide 2'-fucosyllactose and Bifidobacterium longum subspecies infantis in influencing systemic immune development and function in piglets.

The oligosaccharide 2'-fucosyllactose (2'-FL) is a predominant component of human milk, serving as a prebiotic for gut microbiota and influencing immune development in infants. Bifidobacterium longum subspecies infantis (B. infantis) is a commensal bacterium found in breastfed infants. Both 2'-FL and a specific strain of B. infantis, Bi-26™, are commercially available. This study investigates the potential synbiotic relationship between 2'-FL and Bi-26™ on immune development. Two-day-old piglets (n = 53) were randomized in a 2 × 2 design, receiving either a commercial milk replacer ad libitum without (CON) or with 1.0 g/L 2'-FL (FL). Piglets in each diet were further randomized to receive either glycerol stock alone or Bi-26™ (109 CFU) (BI and FLBI) orally once daily. On postnatal day (PND) 34/35, animals were euthanized, and blood was collected for serum cytokine analysis. Additionally, peripheral blood mononuclear cells (PBMCs) were isolated for ex vivo stimulation and flow cytometry analysis. Serum and ex vivo cytokines were analyzed using a multivariate model. All other outcomes were analyzed using a two-way ANOVA, considering prebiotic and probiotic fixed effects. The significance level was set at a p value <0.05, with trends reported for 0.05 < p < 0.1. Immune cell populations in PBMCs were unaffected by the experimental treatment. However, serum interleukin (IL)-1RA, IL-1β, IL-12, and IL-18 were all higher (p < 0.05) in the FL group than in the CON group. In isolated PBMCs, lipopolysaccharide (LPS) stimulation resulted in higher IL-1RA and a trend for higher IFN-γ secretion in the FL group vs. the CON group. 2'-FL stimulates a balanced cytokine profile in healthy piglets without changing immune cell populations. When immune cells are stimulated ex vivo with LPS, 2'-FL primes T-cells for a proinflammatory response, which is moderated by co-administration of Bi-26™.

Reduce, reinforce, and replenish: safeguarding the early-life microbiota to reduce intergenerational health disparities.

Socioeconomic (SE) disparity and health inequity are closely intertwined and associated with cross-generational increases in the rates of multiple chronic non-communicable diseases (NCDs) in North America and beyond. Coinciding with this social trend is an observed loss of biodiversity within the community of colonizing microbes that live in and on our bodies. Researchers have rightfully pointed to the microbiota as a key modifiable factor with the potential to ease existing health inequities. Although a number of studies have connected the adult microbiome to socioeconomic determinants and health outcomes, few studies have investigated the role of the infant microbiome in perpetuating these outcomes across generations. It is an essential and important question as the infant microbiota is highly sensitive to external forces, and observed shifts during this critical window often portend long-term outcomes of health and disease. While this is often studied in the context of direct modulators, such as delivery mode, family size, antibiotic exposure, and breastfeeding, many of these factors are tied to underlying socioeconomic and/or cross-generational factors. Exploring cross-generational socioeconomic and health inequities through the lens of the infant microbiome may provide valuable avenues to break these intergenerational cycles. In this review, we will focus on the impact of social inequality in infant microbiome development and discuss the benefits of prioritizing and restoring early-life microbiota maturation for reducing intergenerational health disparities.

The role of early life factors and green living environment in the development of gut microbiota in infancy: Population-based cohort study

ObjectiveEarly life microbial exposure influences the composition of gut microbiota. We investigated how early life factors, and the green living environment around infants’ homes, influence the development of gut microbiota during infancy by utilizing data from the Steps to Healthy Development follow-up study (the STEPS study). MethodsThe gut microbiota was analyzed at early (∼3 months, n = 959), and late infancy (∼13 months, n = 984) using 16S rRNA amplicon sequencing, and combined with residential green environment, measured as (1) Normalized Difference Vegetation Index, (2) Vegetation Cover Diversity, and (3) Naturalness Index within a 750 m radius. We compared gut microbiota diversity and composition between early and late infancy, identified significant individual and family level early life factors influencing gut microbiota, and determined the role of the residential green environment measures on gut microbiota development. ResultsAlpha diversity (t-test, p < 0.001) and beta diversity (PERMANOVA, R2 = 0.095, p < 0.001) differed between early and late infancy. Birth mode was the strongest contributor to the gut microbiota community composition in early infancy (PERMANOVA, R2 = 0.005, p < 0.01) and the presence of siblings in late infancy (PERMANOVA, R2 = 0.007, p < 0.01). Residential green environment showed no association with community composition, whereas time spend outdoors did (PERMANOVA, R2 = 0.002, p < 0.05). Measures of greenness displayed a statistically significant association with alpha diversity during early infancy, not during late infancy (glm, p < 0.05). In adjusted analysis, the associations remained only with the Naturalness Index, where higher human impact on living environment was associated with decreased species richness (glm, Observed richness, p < 0.05). ConclusionsThe role of the residential green environment to the infant gut microbiota is especially important in early infancy, however, other early life factors, such as birth mode and presence of sibling, had a more significant effect on the overall community composition.

Characteristics of intestinal microbiota in the acute phase of Kawasaki disease in infants and children

To study the composition, abundance, and functional profiles of the intestinal microbiota in infants and young children with Kawasaki disease (KD) during the acute phase, and to explore the potential role of intestinal microbiota in the pathogenesis of KD. Six children aged 0-3 years with acute KD admitted to the Department of Cardiology, Children's Hospital Affiliated to Capital Institute of Pediatrics from July to October 2021 were prospectively included as the KD group. Six age- and sex-matched healthy children who underwent physical examinations at the hospital during the same period were selected as the healthy control group. Metagenomics sequencing was used to detect and compare the differences in the microflora structure and functional profiles of fecal samples between the two groups. There were significant differences in the structural composition and diversity of intestinal microbiota between the two groups (P<0.05). Compared with the healthy control group, the abundance of Listeria_monocytogenes (family Listeriaceae and genus Listeria), Bifidobacterium_rousetti, Enterococcus_avium, and Enterococcus_hirae was significantly higher in the intestinal microbiota in the KD group (|LDA|>2.0, P<0.05). The steroid degradation and apoptosis pathways were significantly upregulated in the KD group compared with the healthy control group, while the Bacterial_secretion_system, Sulfur_metabolism, Butanoate_metabolism, Benzoate_degradation, β-alanine metabolism, and α-linolenic acid pathways were significantly downregulated (|LDA|>2, P<0.05). There are significant differences in the structure and diversity of intestinal microbiota between children aged 0-3 years with acute KD and healthy children, suggesting that disturbances in intestinal microbiota occur during the acute phase of KD. In particular, Listeria_monocytogenes, Enterococcus_avium, and Enterococcus_hirae may be involved in the pathogenesis of KD through steroid degradation and apoptosis pathways.

Comparison of intestinal and pharyngeal microbiota in preterm infants on the first day of life and the characteristics of pharyngeal microbiota in infants delivered by cesarean section or vaginally.

This study aimed to explore the distribution of intestinal and pharyngeal microbiota on the first day of life in preterm infants and compare the composition of microbiota in infants delivered by cesarean section or vaginally. This study included 44 late preterm infants with a gestational age of 34-36 + 6 weeks. Stool and throat swab samples were collected from the preterm infants on the first day of life. The infants were divided into cesarean section and vaginal delivery groups. Illumina NovaSeq high-throughput sequencing technology was used to sequence the V3-V4 hypervariable region of the 16S rRNA gene of all bacteria in the samples. Venn diagram was used to identify shared operational taxonomic units (OTUs) in the intestines and pharynges. Microbial analysis was conducted at the phylum and genus levels, and α and β diversity comparisons were performed. (1) Gestational age may have significantly affected the microbial colonization of the intestines and pharynges of preterm infants on the first day after birth (p ≤ 0.001). (2) More OTUs were detected in the pharynx than in the intestines, both have a total of 819 shared OTUs. Proteobacteria, Firmicutes, and Bacteroidota were the dominant phyla in both. At the genus level, Streptococcus had a lower relative abundance in stool samples (0.5%) compared to throat samples (0.5% vs. 22.2%, p = 0.003). 3) The relative abundance of Streptococcus in pharyngeal samples was 26.2% in the cesarean section group much higher than the 3.8% in the vaginal delivery group (p = 0.01). The early postnatal period is a critical time for the establishment of an infant's microbiota. Gestational age at birth may influence microbial colonization, while birth weight, gender, and mode of delivery do not. The intestinal and pharyngeal microbiota composition of preterm infants on the first day after birth showed high similarity, but larger samples are needed for further validation.

Microbiota, metabolic profiles and immune biomarkers in infants receiving formula with added bovine milk fat globule membrane: a randomized, controlled trial.

Few studies have evaluated the effects of milk fat globule membrane (MFGM) on microbiota and immune markers in early infant nutrition. In this double-blind randomized study, infants (7-18 days of age) received either bovine milk-based infant formula (Control) or similar formula with an added source (5 g/L) of bovine MFGM (INV-MFGM) for 60 days. A reference group received mother's own human milk over the same period (HM). Oral and stool samples were collected (Baseline and Day 60) to evaluate microbiota, immune markers, and metabolites. At Day 60, stool bacterial diversity and richness were higher in formula groups vs HM, as were Bifidobacterium bifidum and B. catenulatum abundance. Compared to HM, stool pH was higher in Control, while acetate, propionate, isovalerate, and total short- and branched-chain fatty acids were higher in INV-MFGM. Butyrate and lactate increased for INV-MFGM from baseline to Day 60. No group differences in oral microbiota or immune markers (α- and β-defensin, calprotectin, or sIgA) were detected, although sIgA increased over time in all study groups. Added bovine MFGM in infant formula modulated stool microbiota and short- and branched-chain fatty acids compared to human milk; changes were modest relative to control formula. Overall, distinct patterns of stool metabolites and microbiota development were observed based on early nutrition. ClinicalTrials.gov, identifier NCT04059666.

Relationship between infant gastrointestinal microorganisms and maternal microbiome within 6 months of delivery.

To investigate the association between the microbiota in mothers and gut microbiota in infants from 0 to 6 months, the microbiotas in infant feces, maternal feces, and breast milk were determined by 16S rRNA gene sequencing. The contribution of each maternal microbiome to the infant was assessed using fast expectation-maximization for microbial source tracking calculations. The levels of short-chain fatty acids (SCFAs) and secretory immunoglobulin A (sIgA) in the feces of infants were also determined using gas chromatography and IDK-sIgA ELISA to gain a more comprehensive understanding of the infant gut microbiome. The results of this study showed that in addition to Firmicutes (E1) and Bifidobacterium (E2), the dominant microorganisms of the intestinal microbiota of infants aged 0-6 months include Proteobacteria, which is different from previous findings. Acetic acid, the most abundant SCFA in the infant gut, was positively correlated with Megasphaera (P < 0.01), whereas sIgA was positively correlated with Bacteroides (P < 0.05) and negatively correlated with Klebsiella and Clostridium_XVIII (P < 0.05). The maternal gut microbiota contributed more to the infant gut microbiota (43.58% ± 11.13%) than the breast milk microbiota, and significant differences were observed in the contribution of the maternal microbiota to the infant gut microbiota based on the delivery mode and feeding practices. In summary, we emphasize the key role of maternal gut health in the establishment and succession of infant gut microbiota.IMPORTANCEThis study aims to delineate the microbial connections between mothers and infants, leveraging the fast expectation-maximization for microbial source tracking methodology to quantify the contribution of maternal microbiota to the constitution of the infant's gut microbiome. Concurrently, it examines the correlations between the infant gut microbiota and two distinctive biomolecules, namely short-chain fatty acids (SCFAs) and secretory immunoglobulin A (sIgA). The findings indicate that the maternal gut microbiota exerts a greater influence on the infant's gut microbial composition than does the microbiota present in breast milk. Infants born via vaginal delivery and receiving mixed feeding display gut microbiota profiles more similar to their mothers'. Notably, the SCFA acetate displays positive associations with beneficial bacteria and inverse relationships with potentially harmful ones within the infant's gut. Meanwhile, sIgA positively correlates with Bacteroides species and negatively with potentially pathogenic bacteria. By delving into the transmission dynamics of maternal-infant microbiota, exploring the impacts of metabolic byproducts within the infant's gut, and scrutinizing how contextual factors such as birthing method and feeding practices affect the correlation between maternal and infant microbiota, this research endeavors to establish practical strategies for optimizing early-life gut health management in infants. Such insights promise to inform targeted interventions that foster healthier microbial development during the critical first 6 months of life.

Comparative Study of Prebiotics for Infants Using a Fecal Culture System: Insights into Responders and Non-Responders

Background: The gut microbiota of breast-fed infants is dominated by infant-type human-residential bifidobacteria (HRB) that contribute to infant health; thus, it is crucial to develop infant formulas that promote the establishment of a gut microbiota enriched with infant-type HRB, closely resembling that of breastfed infants. Methods: We compared various non-digestible prebiotic oligosaccharides and their combinations using a fecal culture system to explore which candidates could promote the growth of all infant-type HRB and rarely yield non-responders. The analysis included lactulose (LAC), raffinose (RAF), galactooligosaccharides (GOS), and short- and long-chain fructooligosaccharides. Fecal samples were collected from seven infants aged 1.5–10.2 months and cultured with each oligosaccharide individually or their combinations. Results: No single oligosaccharide effectively promoted the growth of all infant-type HRB, although GOS promoted the growth of HRB other than Bifidobacterium longum subsp. longum. Only the LAC/RAF/GOS group evenly and effectively promoted the growth of all infant-type HRB. Accordingly, acetate production was higher in fecal cultures supplemented with GOS or LAC/RAF/GOS than in the other cultures, suggesting that it is a superior combination for all infant-type HRB and rarely yields non-responders. Conclusions: This study can aid in developing infant formulas that help align the gut microbiota of formula-fed infants with that of breastfed infants.

Some oral microbiota in complete cleft infants in comparison with normal infants.

To compare caries-related microorganisms and candida in complete cleft infants with normal palate infants. The case-control study was conducted from April 2021 to January 2022 at the College of Dentistry, University of Baghdad, Baghdad, Iraq, and comprised infants with age ranging from 1 day to 4 months. They were divided into complete cleft group A and control group B. Group A was subdivided into those with class III Veau's palatal classification, and the rest with class IV Veau's palatal classification. Samples were taken using oral swab which were subjected to colony morphology, gram staining and biochemical testing. Data was analysed using SPSS 21. Of the 52 subjects, 26(50%) were in each of the 2 groups. The subgroups of group A had 13(50%) patients each. The counting and colonisation of streptococcus mutans, lactobacilli and candida albicans were significantly higher in group A than in group B (p<0.05). The difference between the subgroups of group A was not significant (p>0.05). Infants with cleft palate were more susceptible to dental caries and oral infection than those with normal palate.

Faecal microbiota and cytokine profiles of rural Cambodian infants linked to diet and diarrhoeal episodes

The gut microbiota of infants in low- to middle-income countries is underrepresented in microbiome research. This study explored the faecal microbiota composition and faecal cytokine profiles in a cohort of infants in a rural province of Cambodia and investigated the impact of sample storage conditions and infant environment on microbiota composition. Faecal samples collected at three time points from 32 infants were analysed for microbiota composition using 16S rRNA amplicon sequencing and concentrations of faecal cytokines. Faecal bacterial isolates were subjected to whole genome sequencing and genomic analysis. We compared the effects of two sample collection methods due to the challenges of faecal sample collection in a rural location. Storage of faecal samples in a DNA preservation solution preserved Bacteroides abundance. Microbiota analysis of preserved samples showed that Bifidobacterium was the most abundant genus with Bifidobacterium longum the most abundant species, with higher abundance in breast-fed infants. Most infants had detectable pathogenic taxa, with Shigella and Klebsiella more abundant in infants with recent diarrhoeal illness. Neither antibiotics nor infant growth were associated with gut microbiota composition. Genomic analysis of isolates showed gene clusters encoding the ability to digest human milk oligosaccharides in B. longum and B. breve isolates. Antibiotic-resistant genes were present in both potentially pathogenic species and in Bifidobacterium. Faecal concentrations of Interlukin-1alpha and vascular endothelial growth factor were higher in breast-fed infants. This study provides insights into an underrepresented population of rural Cambodian infants, showing pathogen exposure and breastfeeding impact gut microbiota composition and faecal immune profiles.