Human milk oligosaccharides (HMOs) are multifunctional carbohydrates naturally present in human milk that act as prebiotics, prevent pathogen binding and infections, modulate the immune system and may support brain development in infants. HMOs composition is very individualized and differences in HMOs concentrations may affect the infant’s health. HMOs variability can be partially explained by the activity of Secretor (Se) and Lewis (Le) genes in the mother, but non-genetic maternal factors may also be involved. In this cross-sectional, observational study, 78 single human milk samples ranging from 17 to 76 days postpartum (median: 32 days, IQR: 25–46 days) were collected from breastfeeding Brazilian women, analyzed for 16 representative HMOs by liquid chromatography coupled to mass spectrometry and associations between maternal and infant factors with HMOs concentrations were investigated. HMOs concentrations presented a high variability even in women with the same SeLe phenotype and associations with maternal allergic disease, time postpartum and with infant’s weight, weight gain and sex. Overall, we present unprecedented data on HMOs concentrations from breastfeeding Brazilian women and novel associations of maternal allergic disease and infant’s sex with HMOs concentrations. Differences in HMOs composition attributed to maternal SeLe phenotype do not impact infant growth, but higher concentrations of specific HMOs may protect against excessive weight gain.

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Background Exclusive breastfeeding promotes beneficial modifications on the microbiota of cesarean born infants, but little is known about the role of specific breast milk components in this modulation. Women with an active FUT2 gene (called secretors) secrete α1–2 fucosylated human milk oligosaccharides (HMOs), which promote Bifidobacterium in the infant’s gut and may modulate the microbiota of cesarean born infants. Objective To compare the microbiota composition of cesarean and vaginally born infants breastfed by secretor mothers. Methods Maternal secretor status was determined by the occurrence of 4 different α1–2 fucosylated HMOs in breast milk by LC-MS. The fecal microbiota composition from cesarean and vaginally born infants was analyzed by 16S rRNA gene sequencing and qPCR, stratified by the maternal secretor status, and compared. Results Alpha and beta diversity were not significantly different in cesarean born, secretor-fed infants (CSe+) compared to vaginally born, secretor-fed infants (VSe+). There were no significant differences in the fecal relative abundance of Bifidobacterium between CSe+ and VSe+ infants, but the prevalence of the species B. longum was lower in CSe+. The fecal relative abundance of Bacteroides was also lower, while Akkermansia and Kluyvera were higher in CSe+ infants. Conclusion Cesarean and vaginally born infants fed with breast milk containing the α1–2 fucosylated HMOs fraction present similar amounts of Bifidobacterium in the feces, but differences are observed in other members of the microbiota.

An analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was validated and applied for the analysis of aflatoxin M (AFM), ochratoxin A (OTA) and deoxynivalenol (DON) in infant formula and milk-based products for young children commercialized in Brazil. A total of 38 samples were evaluated, including 12 infant formula, 14 follow-on formula and 12 samples of milk-based products. AFM was detected in 12 (32%) samples, and seven (18%) samples contained AFM levels above the method limit of quantification in a concentration range between 0.013 and 0.067 ng mL (0.026 ± 0.019). Two samples of milk-based products exceeded the maximum level (ML) fixed by the European Union for AFM in baby foods, however, all samples were in agreement with the levels established by the Brazilian regulation. OTA and DON were not detected in any of the analyzed samples.

There is a lack of studies investigating the clinical benefits of prebiotic-supplemented infant formula. In this study, healthy infants that started, on medical recommendation, artificial feeding with one of 2 infant formulas containing 4 g/L of GOS/FOS (9:1) (IF4 group; n = 60) or 8 g/L of GOS/FOS (9:1) (IF8 group; n = 60) were followed for 30 days to the evaluation of growth and gastrointestinal symptoms. Exclusively breastfed infants (EBF; n = 60) were followed up as a reference. Both infant formulas supported adequate weight gain, however, IF4 formula promotes growth more similar to breastfed infants. There was no additional benefit of a dose higher than 4 g/L of GOS/FOS on gastrointestinal symptoms.