Project description:Microbiota assembly in the infant gut is influenced by time and duration of dietary exposure to breast-milk, infant formula and solid foods. In this randomized controlled intervention study, longitudinal sampling of infant stools (n=998) showed similar development of fecal bacterial communities between formula- and breast-fed infants during the first year of life (N=210). Infant formula supplemented with galacto-oligosaccharides (GOS) was most efficient to sustain high levels of bifidobacteria compared to formula containing B. longum and B. breve or placebo. Metabolite (untargeted) and bacterial profiling (16S rRNA/shallow metagenomics sequencing) revealed 24-hour oscillations and integrated data analysis identified circadian networks. Rhythmicity in bacterial diversity, specific taxa and functional pathways increased with age and was most pronounced following breast-feeding and GOS-supplementation. Circadian rhythms in dominant taxa were discovered ex-vivo in a chemostat model. Hence microbiota rhythmicity develops early in life, likely due to bacterial intrinsic clock mechanism and is affected by diet.
Project description:A metaproteomics analysis was conducted on the infant fecal microbiome to characterize global protein expression in 8 samples obtained from infants with a range of early-life experiences. Samples included breast-, formula- or mixed-fed, mode of delivery, and antibiotic treatment and one set of monozygotic twins. Although label-free mass spectrometry-based proteomics is routinely used for the identification and quantification of thousands of proteins in complex samples, the metaproteomic analysis of the gut microbiome presents particular technical challenges. Among them: the extreme complexity and dynamic range of member taxa/species, the need for matched, well-annotated metagenomics databases, and the high inter-protein sequence redundancy/similarity between related members. In this study, a metaproteomic approach was developed for assessment of the biological phenotype and functioning, as a complement to 16S rRNA sequencing analysis to identify constituent taxa. A sample preparation method was developed for recovery and lysis of bacterial cells, followed by trypsin digestion, and pre-fractionation using Strong Cation Exchange chromatography. Samples were then subjected to high performance LC-MS/MS. Data was searched against the Human Microbiome Project database, and a homology-based meta-clustering strategy was used to combine peptides from multiple species into representative proteins. Bacterial taxonomies were also identified, based on species-specific protein sequences, and protein metaclusters were assigned to pathways and functional groups. The results obtained demonstrate the applicability of this approach for performing qualitative comparisons of human fecal microbiome composition, physiology and metabolism, and also provided a more detailed assessment of microbial composition in comparison to 16S rRNA.
Project description:The current study directly compared the effects of soy formula feeding with those of estradiol or pure genistein in the neonatal piglet, an animal model which most closely resembles the human infant physiologically and in isoflavone metabolism
Project description:91 preterm infant gut metaproteomes measured in technical duplicate using an eleven salt pulse 2D-LC-MS/MS method. Samples represent 17 preterm infants over the first several weeks of life, of which 6 preterm infants eventually developed necrotizing enterocolitis.
Project description:Microbiota assembly in the infant gut is influenced by time and duration of dietary exposure to breast-milk, infant formula and solid foods. In this randomized controlled intervention study, longitudinal sampling of infant stools (n=998) showed similar development of fecal bacterial communities between formula- and breast-fed infants during the first year of life (N=210). Infant formula supplemented with galacto-oligosaccharides (GOS) was most efficient to sustain high levels of bifidobacteria compared to formula containing B. longum and B. breve or placebo. Metabolite (untargeted) and bacterial profiling (16S rRNA/shallow metagenomics sequencing) revealed 24-hour oscillations and integrated data analysis identified circadian networks. Rhythmicity in bacterial diversity, specific taxa and functional pathways increased with age and was most pronounced following breast-feeding and GOS-supplementation. Circadian rhythms in dominant taxa were discovered ex-vivo in a chemostat model. Hence microbiota rhythmicity develops early in life, likely due to bacterial intrinsic clock mechanism and is affected by diet.
Project description:The majority of babies in the US are formula-fed instead of breast fed. There are major differences in the composition of formulas and breast milk and yet little is known about metabolic differences in babies as the result of feeding these very different diets and how that might affect development or disease risk in later life. One concern is that soy-based formulas might have adverse health effects in babies as a result of the presence of low levels of estrogenic phytochemicals genistein and daidzein which are normally present in soy beans. In the current study, we used a piglet model to look at this question. Piglets were either fed breast milk from the sow or were fed two different infant formulas (cow's milk-based or soy-based) from age 2 days to 21 days when pigs are normally weaned onto solid food. Blood glucose and lipids were measured. Formula-fed pigs were found to have lower cholesterol than breast fed piglets and in addition had larger stores of iron in their liver.Microarray analysis was carried out to see if changes in liver gene expression could explain these effects of formula feeding. It was found that overall gene expression profiles were influenced by formula feeding compared to breast fed neonates. Gender-independent and unique effects of formula influenced cholesterol and iron metabolism. Further, soy formula feeding in comparison to milk-based formula failed to reveal any estrogenic actions on hepatic gene expression in either male or female pigs. Piglets (female, male) were either fed breast milk from the sow or were fed two different infant formulas (cow's milk-based or soy-based) from age 2 days to 21 days when pigs are normally weaned onto solid food.
Project description:We show that infant trauma, as modeled by infant paired odor-shock conditioning, results in later life depressive-like behavior that can be modulated by learned infant cues (i.e., odor previously paired with shock). We have previously shown that this infant attachment odor learning paradigm results in the creation of a new artificial maternal odor that is able to control pup behavior and retain its value throughout development. Here, we assess the mechanism by which this artificial maternal odor is able to rescue depressive-like behavior and show that this anti-depressant like effect results in glucocorticoid and serotonin (5-HT) related changes in amygdala gene expression and is dependent on amygdala 5-HT. Furthermore, increasing amygdala 5-HT and blocking corticosterone (CORT) in the absence of odor mimics the adult rescue effects elicited by the artificial maternal odor, suggesting a mechanism by which odor presentation exerts its repair effects. There are three experimental groups: 1: pups with no infant shock and the adult forced swim test (FST)with no odor; 2. pups with infant odor-shock pairing and the adult forced swim test (FST) with no odor; 3. pups with infant odor-shock pairing and adult forced swim test with infant odor.
Project description:Diet-microbe interactions play a crucial role in infant development and modulation of the early-life microbiota. The genus Bifidobacterium dominates the breast-fed infant gut, with strains of B. longum subsp. longum (B. longum) and B. longum subsp. infantis (B. infantis) particularly prevalent within the early-life microbiota. Although, transition from milk to a more diversified diet later in infancy initiates a shift to a more complex microbiome, with concurrent reductions in Bifidobacterium abundance, specific strains of B. longum may persist in individual hosts for prolonged periods of time. Here, we sought to investigate the adaptation of B. longum to the changing infant diet during the early-life developmental window. Genomic characterisation of 75 strains isolated from nine either exclusively breast- or formula-fed infants in the first 18 months of their lives revealed subspecies- and strain-specific intra-individual genomic diversity with respect to glycosyl hydrolase families and enzymes, which corresponded to different dietary stages. Complementary phenotypic growth studies indicated strain-specific differences in human milk oligosaccharide and plant carbohydrate utilisation profiles between and within individual infants, while proteomic profiling identified proteins involved in metabolism of selected carbohydrates. Our results indicate a strong link between infant diet and B. longum subspecies/strain genomic and carbohydrate utilisation diversity, which aligns with a changing nutritional environment i.e. moving from breast milk to a solid food diet. These data provide additional insights into possible mechanisms responsible for the competitive advantage of this bifidobacterial species and their long-term persistence in a single host and may contribute to rational development of new dietary therapies for this important development window.