Effect of Breastmilk Microbiota and Sialylated Oligosaccharides on the Colonization of Infant Gut Microbial Community and Fecal Metabolome

Human milk microbiota and oligosaccharides in colostrum and mature milk: comparison and correlation

Background

The interaction between the human breast milk microbiota and human milk oligosaccharides (HMOs) plays a crucial role in the healthy growth and development of infants. We aimed to clarify the link between the breast milk microbiota and HMOs at two stages of lactation.

Methods

The microbiota and HMOs of 20 colostrum samples (C group, 1-5 days postpartum) and 20 mature milk samples (S group, 42 days postpartum) collected from postpartum mothers were analyzed using 16S rRNA gene high-throughput sequencing and high-performance liquid chromatography-tandem mass spectrometry.

Result

The total average HMO content was significantly higher in the C group than in the S group (6.76 ± 1.40 g/L vs. 10.27 ± 2.00 g/L, p < 0.05). Among the HMOs, the average values of 2'-fucosyllactose (2'-FL, 1.64 ± 1.54 g/L vs. 3.03 ± 1.79 g/L), 3'-sialyllactose (3'-SL, 0.10 ± 0.02 g/L vs. 0.21 ± 0.06), 6'-SL (0.22 ± 0.09 g/L vs. 0.33 ± 0.11 g/L), and lacto-N-triaose 2 (LNT2, 0.03 ± 0.01 g/L vs. 0.16 ± 0.08 g/L) were significantly lower in the S group than in the C group (p < 0.05), while that of 3'-FL was significantly higher in the S group than in the C group (1.35 ± 1.00 g/L vs. 0.41 ± 0.43 g/L, p < 0.05). The diversity and structure of the microbiota in the S and C groups were also significantly different (p < 0.05). Comparative analysis of the microbial communities revealed that Proteobacteria and Firmicutes were the most abundant phyla, in both groups, with the keystone species (Serratia, Streptococcus and Staphylococcus) of breast milk closely interacting with HMOs, including 3'-SL, 6'-SL, and LNT2. In PICRUSt2 functional prediction analysis, the S group exhibited significant reduction in the expression of genes involved in several infectious disease pathways.

Discussion

Our findings support the recognition of human milk as a synbiotic comprising beneficial bacteria and prebiotic HMOs.

Dietary modulation of human milk bioactives is associated with maternal FUT2 secretor phenotype: an exploratory analysis of carotenoids and polyphenol metabolites

Introduction

Maternal diet modifies profiles of human milk oligosaccharides (HMOs), carotenoids, and polyphenols in human milk (HM). However, substantial variability in profiles exists between women, highlighting the complexity of non-dietary factors modulating these profiles. The objective of this study was to carry out a secondary analysis exploring the effect of maternal diet on HM carotenoids and polyphenols and relationships between dietary modulation of HM bioactives (carotenoids, polyphenols, and oligosaccharides) and maternal α1,2-fucosyltransferase 2 (FUT2) secretor phenotype.

Methods

In this pilot study, 16 exclusively breastfeeding women with obesity were enrolled between 4 and 5 months postpartum. The women were provided a 4-week meal plan consistent with the 2020 Dietary Guidelines for Americans (DGA). HM was collected for 24 h at baseline and post-intervention. Maternal FUT2 secretor phenotype was determined by 2'-fucosyllactose concentration in HM (non-secretor: < 100 nmol/ml; secretor: ≥100 nmol/ml). Concentrations of carotenoids and HMOs were determined by LC and polyphenol metabolites by UPLC-MS/MS.

Results

Thirteen women completed the study (6 secretors, 7 non-secretors). The change in HM concentrations of the HMOs lacto-N-tetraose (LNT, p = 0.007), lacto-N-fucopentaose II (LNFP II, p = 0.02), difucosyllacto-N-tetraose (DFLNT, p = 0.003), and disialyllacto-N-tetraose (DSLNT, p = 0.003) and polyphenol metabolites 4-hydroxybenzoic acid (4-HBA, p = 0.08) and ferulic acid (p = 0.02) over the intervention time frame was differentially associated with maternal secretor status. 4-HBA and ferulic acid positively correlated with HMOs LNT and DSLNT (rrm = 0.82-0.90, p = 0.03-0.06) for secretors but not for non-secretors. Only secretors demonstrated a negative correlation between 4-HBA and DFLNT (rrm = -0.94, p = 0.001).

Discussion

The influence of maternal diet on composition of HMOs and polyphenol metabolites in HM differs based on maternal secretor status. Consideration of non-dietary factors is needed to evaluate differences in response of HM bioactives to dietary modulation.

Human milk oligosaccharide composition is affected by season and parity and associates with infant gut microbiota in a birth mode dependent manner in a Finnish birth cohort

BACKGROUND

Human milk oligosaccharides (HMOs), their determinants, infant gut microbiota and health are under extensive research; however, seldom jointly addressed. Leveraging data from the HELMi birth cohort, we investigated them collectively, considering maternal and infant secretor status.

METHODS

HMO composition in breastmilk collected 3 months postpartum (n = 350 mothers) was profiled using high-performance liquid chromatography. Infant gut microbiota taxonomic and functional development was studied at 3, 6, and 12 months (n = 823 stool samples) via shotgun metagenomic sequencing, focusing on HMO metabolism via glycoside hydrolase (GH) analysis. Maternal and infant secretor statuses were identified through phenotyping and genotyping, respectively. Child health, emphasizing allergies and antibiotics as proxies for infectious diseases, was recorded until 2 years.

FINDINGS

Mother's parity, irritable bowel syndrome, gestational diabetes, and season of milk collection associated with HMO composition. Neither maternal nor infant secretor status associated with infant gut microbiota, except for a few taxa linked to individual HMOs. Analysis stratified for birth mode revealed distinct patterns between the infant gut microbiota and HMOs. Child health parameters were not associated to infant or maternal secretor status.

INTERPRETATION

This comprehensive exploration unveils intricate links between secretor genotype, maternal factors, HMO composition, infant microbiota, and child health. Understanding these nuanced relationships is paramount for refining strategies to optimize early life nutrition and its enduring impact on long-term health.

FUNDING

Sweet Crosstalk EU H2020 MSCA ITN, Academy of Finland, Mary and Georg C. Ehrnrooth Foundation, Päivikki and Sakari Sohlberg Foundation, and Tekes.

Human Milk Composition Is Associated with Maternal Body Mass Index in a Cross-Sectional, Untargeted Metabolomics Analysis of Human Milk from Guatemalan Mothers

Background

Maternal overweight and obesity has been associated with poor lactation performance including delayed lactogenesis and reduced duration. However, the effect on human milk composition is less well understood.

Objectives

We evaluated the relationship of maternal BMI on the human milk metabolome among Guatemalan mothers.

Methods

We used data from 75 Guatemalan mothers who participated in the Household Air Pollution Intervention Network trial. Maternal BMI was measured between 9 and <20 weeks of gestation. Milk samples were collected at a single time point using aseptic collection from one breast at 6 mo postpartum and analyzed using high-resolution mass spectrometry. A cross-sectional untargeted high-resolution metabolomics analysis was performed by coupling hydrophilic interaction liquid chromatography (HILIC) and reverse phase C18 chromatography with mass spectrometry. Metabolic features associated with maternal BMI were determined by a metabolome-wide association study (MWAS), adjusting for baseline maternal age, education, and dietary diversity, and perturbations in metabolic pathways were identified by pathway enrichment analysis.

Results

The mean age of participants at baseline was 23.62 ± 3.81 y, and mean BMI was 24.27 ± 4.22 kg/m2. Of the total metabolic features detected by HILIC column (19,199 features) and by C18 column (11,594 features), BMI was associated with 1026 HILIC and 500 C18 features. Enriched pathways represented amino acid metabolism, galactose metabolism, and xenobiotic metabolic metabolism. However, no significant features were identified after adjusting for multiple comparisons using the Benjamini-Hochberg false discovery rate procedure (FDRBH < 0.2).

Conclusions

Findings from this untargeted MWAS indicate that maternal BMI is associated with metabolic perturbations of galactose metabolism, xenobiotic metabolism, and xenobiotic metabolism by cytochrome p450 and biosynthesis of amino acid pathways. Significant metabolic pathway alterations detected in human milk were associated with energy metabolism-related pathways including carbohydrate and amino acid metabolism.This trial was registered at clinicaltrials.gov as NCT02944682.

Linking human milk oligosaccharide metabolism and early life gut microbiota: bifidobacteria and beyond

SUMMARYHuman milk oligosaccharides (HMOs) are complex, multi-functional glycans present in human breast milk. They represent an intricate mix of heterogeneous structures which reach the infant intestine in an intact form as they resist gastrointestinal digestion. Therefore, they confer a multitude of benefits, directly and/or indirectly, to the developing neonate. Certain bifidobacterial species, being among the earliest gut colonizers of breast-fed infants, have an adapted functional capacity to metabolize various HMO structures. This ability is typically observed in infant-associated bifidobacteria, as opposed to bifidobacteria associated with a mature microbiota. In recent years, information has been gleaned regarding how these infant-associated bifidobacteria as well as certain other taxa are able to assimilate HMOs, including the mechanistic strategies enabling their acquisition and consumption. Additionally, complex metabolic interactions occur between microbes facilitated by HMOs, including the utilization of breakdown products released from HMO degradation. Interest in HMO-mediated changes in microbial composition and function has been the focal point of numerous studies, in recent times fueled by the availability of individual biosynthetic HMOs, some of which are now commonly included in infant formula. In this review, we outline the main HMO assimilatory and catabolic strategies employed by infant-associated bifidobacteria, discuss other taxa that exhibit breast milk glycan degradation capacity, and cover HMO-supported cross-feeding interactions and related metabolites that have been described thus far.

Distinguishable Influence of the Delivery Mode, Feeding Pattern, and Infant Sex on Dynamic Alterations in the Intestinal Microbiota in the First Year of Life

The delivery mode, the feeding pattern and infant sex significantly influence the development of the infant gut flora. However, the extent to which these factors contribute to the establishment of the gut microbiota at different stages has rarely been studied. The factors that play a dominant role in determining microbial colonization of the infant gut at specific time points are unknown. The purpose of this study was to assess the different contributions of the delivery mode, the feeding pattern and infant sex to the composition of the infant gut microbiome. Here, 213 fecal samples from 55 infants at five ages (0, 1, 3, 6, and 12 months postpartum) were collected, and the composition of the gut microbiota via 16S rRNA sequencing was analyzed. The results showed that the average relative abundances of four genera, Bifidobacterium, Bacteroides, Parabacteroides, and Phascolarctobacterium, were increased in vaginally delivered infants versus cesarean section-delivered infants, while those of ten genera, such as Salmonella and Enterobacter, were reduced. The relative proportions of Anaerococcus and Peptostreptococcaceae were higher in exclusive breastfeeding than in combined feeding, while those of Coriobacteriaceae, Lachnospiraceae and Erysipelotrichaceae were lower. The average relative abundances of two genera, Alistipes and Anaeroglobus, were increased in male infants compared with female infants, whereas those of the phyla Firmicutes and Proteobacteria were reduced. During the first year of life, the average UniFrac distances revealed that the individual difference in the gut microbial composition in vaginally delivered infants was greater than that in cesarean section-delivered infants (P < 0.001) and that infants who received combined feeding had greater individual microbiota differences than exclusively breastfed infants (P < 0.01). The delivery mode, infant sex, and the feeding pattern were the dominant factors determining colonization of the infant gut microbiota at 0 months, from 1 to 6 months, and at 12 months postpartum, respectively. This study demonstrated for the first time that infant sex accounted for the dominant contribution to infant gut microbial development from 1 to 6 months postpartum. More broadly, this study effectively established the extent to which the delivery mode, the feeding pattern and infant sex contribute to the development of the gut microbiota at various time points during the first year of life.

Foodomics-Based Approaches Shed Light on the Potential Protective Effects of Polyphenols in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and progressive inflammatory disorder affecting the gastrointestinal tract (GT) caused by a wide range of genetic, microbial, and environmental factors. IBD is characterized by chronic inflammation and decreased gut microbial diversity, dysbiosis, with a lower number of beneficial bacteria and a concomitant increase in pathogenic species. It is well known that dysbiosis is closely related to the induction of inflammation and oxidative stress, the latter caused by an imbalance between reactive oxygen species (ROS) production and cellular antioxidant capacity, leading to cellular ROS accumulation. ROS are responsible for intestinal epithelium oxidative damage and the increased intestinal permeability found in IBD patients, and their reduction could represent a potential therapeutic strategy to limit IBD progression and alleviate its symptoms. Recent evidence has highlighted that dietary polyphenols, the natural antioxidants, can maintain redox equilibrium in the GT, preventing gut dysbiosis, intestinal epithelium damage, and radical inflammatory responses. Here, we suggest that the relatively new foodomics approaches, together with new technologies for promoting the antioxidative properties of dietary polyphenols, including novel delivery systems, chemical modifications, and combination strategies, may provide critical insights to determine the clinical value of polyphenols for IBD therapy and a comprehensive perspective for implementing natural antioxidants as potential IBD candidate treatment.

Crosstalk between Breast Milk N-Acetylneuraminic Acid and Infant Growth in a Gut Microbiota-Dependent Manner

The healthy growth of infants during early life is associated with lifelong consequences. Breastfeeding has positive impacts on reducing obesity risk, which is likely due to the varied components of breast milk, such as N-acetylneuraminic acid (Neu5Ac). However, the effect of breast milk Neu5Ac on infant growth has not been well studied. In this study, targeted metabolomic and metagenomic analyses were performed to illustrate the association between breast milk Neu5Ac and infant growth. Results demonstrated that Neu5Ac was significantly abundant in breast milk from infants with low obesity risk in two independent Chinese cohorts. Neu5Ac from breast milk altered infant gut microbiota and bile acid metabolism, resulting in a distinct fecal bile acid profile in the high-Neu5Ac group, which was characterized by reduced levels of primary bile acids and elevated levels of secondary bile acids. Taurodeoxycholic acid 3-sulfate and taurochenodeoxycholic acid 3-sulfate were correlated with high breast milk Neu5Ac and low obesity risk in infants, and their associations with healthy growth were reproduced in mice colonized with infant-derived microbiota. Parabacteroides might be linked to bile acid metabolism and act as a mediator between Neu5Ac and infant growth. These results showed the gut microbiota-dependent crosstalk between breast milk Neu5Ac and infant growth.

Oxidative Stress, Inflammation, Gut Dysbiosis: What Can Polyphenols Do in Inflammatory Bowel Disease?

Inflammatory bowel disease (IBD) is a long-term, progressive, and recurrent intestinal inflammatory disorder. The pathogenic mechanisms of IBD are multifaceted and associated with oxidative stress, unbalanced gut microbiota, and aberrant immune response. Indeed, oxidative stress can affect the progression and development of IBD by regulating the homeostasis of the gut microbiota and immune response. Therefore, redox-targeted therapy is a promising treatment option for IBD. Recent evidence has verified that Chinese herbal medicine (CHM)-derived polyphenols, natural antioxidants, are able to maintain redox equilibrium in the intestinal tract to prevent abnormal gut microbiota and radical inflammatory responses. Here, we provide a comprehensive perspective for implementing natural antioxidants as potential IBD candidate medications. In addition, we demonstrate novel technologies and stratagems for promoting the antioxidative properties of CHM-derived polyphenols, including novel delivery systems, chemical modifications, and combination strategies.