Intestinal colonisation patterns in breastfed and formula-fed infants during the first 12 weeks of life reveal sequential microbiota signatures.

The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic and intrinsic factors. We characterized the faecal microbiota of 4 breastfed infants and 4 formula-fed infants at 17 consecutive time points during the first 12 weeks of life. Microbiota composition was analysed by a combination of 16S rRNA gene sequencing and quantitative PCR (qPCR). In this dataset, individuality was a major driver of microbiota composition (P = 0.002) and was more pronounced in breastfed infants. A developmental signature could be distinguished, characterized by sequential colonisation of i) intrauterine/vaginal birth associated taxa, ii) skin derived taxa and other typical early colonisers such as Streptococcus and Enterobacteriaceae, iii) domination of Bifidobacteriaceae, and iv) the appearance of adultlike taxa, particularly species associated with Blautia, Eggerthella, and the potential pathobiont Clostridium difficile. Low abundance of potential pathogens was detected by 16S profiling and confirmed by qPCR. Incidence and dominance of skin and breast milk associated microbes were increased in the gut microbiome of breastfed infants compared to formula-fed infants. The approaches in this study indicate that microbiota development of breastfed and formula-fed infants proceeds according to similar developmental stages with microbiota signatures that include stage-specific species.

Effect of an α-lactalbumin-enriched infant formula supplemented with oligofructose on fecal microbiota, stool characteristics, and hydration status: a randomized, double-blind, controlled trial.

AIMS: To evaluate the impact of oligofructose (OF)-supplemented infant formula on fecal microbiota, stool characteristics, and hydration. METHODS: Ninety-five formula-fed infants were randomized to α-lactalbumin-enriched control formula (CF) or identical formula with 3.0 g/L OF (EF) for 8 weeks; 50 infants fed human milk (HM) were included. RESULTS: Eighty-four infants completed the study, 70 met per-protocol criteria. Over 8 weeks, bifidobacteria increased more in EF than CF group (0.70 vs. 0.16 log10 bacterial counts/g dry feces, P = .008); EF was not significantly different from HM group (P = .32). EF group stool consistency was intermediate between CF and HM groups; at week 8, EF group had softer stools than CF (5-point scale: 1 = hard, 5 = watery; consistency score 3.46 vs. 2.82, P = .015) without significant differences in stool frequency. Physician-assessed hydration status was normal for all infants. CONCLUSIONS: Infant formula with 3.0 g/L OF promoted bifidobacteria growth and softer stools without adversely affecting stool frequency or hydration.

Maternal-to-infant transmission of probiotics: concept validation in mice, rats, and pigs.

BACKGROUND: Postnatal introduction of probiotics results in a low incidence of colonization, whereas maternal fecal and vaginal bacteria colonize the gastrointestinal tract (GIT) of vaginally delivered infants. OBJECTIVE: We tested if probiotic bacteria, fed to three pregnant animal models, would colonize the GIT of offspring delivered vaginally. METHODS: Probiotic strains of Lactobacillus acidophilus and Bifidobacterium lactis were fed to pregnant mice, rats, and sows for at least 7 days prior to vaginal delivery. Cultural approaches and genotyping were used to determine if the probiotic bacteria colonized the GIT after birth. RESULTS: The probiotic bacteria were detected in the feces and vagina of maternal mice, rats, and sows after, but not before, administration. L. acidophilus was detected at postnatal day 14 in 22, 33, and 75% of the mice, rats, and pigs, respectively, and after weaning in 35% of the mice and 1 of 5 pigs. B. lactis was present at postnatal day 14 in 30 and 80% of the mice and pigs. Bacterial assemblages in the GIT of the colonized young differed from those in which the probiotics were not detected. CONCLUSIONS: Probiotic bacteria administered to mothers during late gestation are transferred to infants born vaginally and influence the assemblages of GIT bacteria. However, colonization of the neonatal GIT and persistence past weaning does not occur in all offspring and varies among probiotics and animal models.