Project description:Bifidobacteria are among the earliest colonizers of the human gut, conferring multiple health benefits. While multiple Bifidobacterium strains are used as probiotics, accumulating evidence suggests that the individual responses to probiotic supplementation may vary, likely due to a variety of factors, including strain type(s), gut community composition, dietary habits of the consumer, and other health/lifestyle conditions. Given the saccharolytic nature of bifidobacteria, the carbohydrate composition of the diet is one of the primary factors dictating the colonization efficiency of Bifidobacterium strains. Therefore, a comprehensive understanding of bifidobacterial glycan metabolism at the strain level is necessary to rationally design probiotic or synbiotic formulations that combine bacterial strains with glycans that match their nutrient preferences. In this study, we systematically reconstructed 66 pathways involved in the utilization of mono-, di-, oligo-, and polysaccharides by analyzing the representation of 565 curated functional roles (catabolic enzymes, transporters, transcriptional regulators) in 2973 non-redundant cultured Bifidobacterium isolates and metagenome-assembled genomes (MAGs). Our analysis uncovered substantial heterogeneity in the predicted glycan utilization capabilities at the species and strain level and revealed the presence of a yet undescribed phenotypically distinct clade within the Bifidobacterium longum species. We also identified Bangladeshi isolates harboring unique gene clusters tentatively implicated in the breakdown of xyloglucan and human milk oligosaccharides. Predicted carbohydrate utilization phenotypes were experimentally characterized and validated. Our large-scale genomic analysis expands the knowledge of carbohydrate metabolism in bifidobacteria and provides a foundation for rationally designing single- or multi-strain probiotic formulations of a given bifidobacterial species as well as synbiotic combinations of bifidobacterial strains matched with their preferred carbohydrate substrates.
Project description:Each year in the United States, more than 530,000 babies are born prior to full 37 weeks of gestation. One of the major problems associated with prematurity is the development of a condition known as necrotizing enterocolitis (NEC). In 50% of infants with NEC a large amount of damaged and dead intestine must be surgically removed, often resulting in death or lifelong health problems. A growing body of experimental and clinical evidence supports a conclusion that deficient quantities of epidermal growth factor (EGF) leads to the development of NEC. The EGF peptide appears to be fundamental for normal intestinal development and repair. Soy-milk containing engineered EGF may be a suitable therapy if given to premature infants to prevent NEC. Human mature EGF is 6 kDa protein with three intramolecular disulfide bonds. To produce EGF a synthetic codon-optimized gene was transferred to soybean by biolistic transformation. The resulting transgenic lines were regenerated into somatic embryos that were screened by PCR and the production of EGF assayed by ELISA. Crude extracts of somatic embryos producing EGF were assessed for bioactivity by induction of phosphorylation of the EGF receptor in HeLa cells that showed soy-produced EGF exhibited the same activity as authentic EGF. T0 transgenic EGF seeds have showed positive ELISA for EGF demonstrating the feasibility to produce a therapeutic soy-milk to mitigate the development of NEC by premature infants. The next stage of this project will test the efficacy of Soy/EGF in an animal model for short bowel syndrome.
2016-06-22 | PXD003326 | Pride
Project description:Developmental Ecology of the Human Microbiome - Restoration Study of babies.
Project description:Bifidobacterium longum subsp. infantis (B. infantis) colonizes the infant gut microbiome with a 43-kb gene cluster that enables human milk oligosaccharide (HMO) utilization. Although there is relative genomic homogeneity in this regard, previous observations suggest that B. infantis strains may differ in their utilization phenotype. To test this hypothesis, a panel of B. infantis strains were evaluated for their ability to utilize pooled HMOs to yield differential phenotypes including biomass accumulation, HMO consumption glycoprofile, end-product secretion, and global transcriptomes. Two strains (ATCC 15697 and UMA301) efficiently consumed several HMO isomers/anomers that exhibit degrees of polymerization (DP) ³ 4. These same strains partially consumed the smaller DP HMOs including fucosyllactose and lactodifucotetraose isomers/anomers. In contrast, UMA299 efficiently utilized fucosylated small molecular weight HMOs (DP<4), and accumulated greater biomass on purified 2´FL with significantly higher 1,2-propanediol production. This study identifies several strain-dependent features in HMO utilization phenotypes that are consistent with metabolic variation within a bifidobacterial-dominated infant-gut microbiome.
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:This study applied peptidomics to investigate the peptides released in gastric digestion of mother’s milk proteins and supplemental bovine milk proteins in premature infants.
Project description:The factors that govern the retention and abundance of specific microbial lineages within a developing intestinal microbiota remain poorly defined. Human milk oligosaccharides consumed by nursing infnats pass undigested to the distal gut where they may be consumed by microbes. We investigated the transcriptional response of Bacterides fragilis, a prominent gut resident, to the presence of HMOs. In vitro transcriptional profiles of Bacteroides fragilis obtained from biological duplicate cultures taken at middle log phase in minimal media glucose (MM-Glu) and in minimal media with human milk oligosaccharides (MM-HMO).
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.
Project description:We describe the molecular cross talk established under in vivo conditions between a set of human gut bifidobacterial commensals. Eleven groups of five conventional female 8-wk-old BALB/c mice taking a standard polysaccharide-rich Chow diet were administered a single daily dose of 109 CFU of either B. bifidum PRL2010, B. breve 12L , B. adolescentis 22L , B. longum subsp. infantis ATCC15697, or bifidobacterial couples, i.e., PRL2010-12L, PRL2010-22L, PRL2010-ATCC15696, 12L-22L, 12L-ATCC15697, 22L-ATCC15697, or a combination of all bifidobacterial strains. The transcriptome of bifidobacterial strains under in vivo conditions was analyzed. The transcripts expressed in B. bifidum PRL2010, B. breve 12L, B. adolescentis 22L and B. longum subsp. infantis ATCC15697 were profiled using a custom-made PRL2010-12L-22L-ATCC15697 (multibifido)-array representing 100%, 99%, 96%, 99% of the identified genes of these organisms, respectively.The observed functional changes in the trascriptomes of bifidobacteria might be caused by the possible shifts of the mice cecum microbiota upon colonization with bifidobacteria. Thus, we assessed if the presence of B. bifidum PRL2010, B. breve 12L, B. adolescentis 22L and B. longum subsp. infantis ATCC15697 on mono-, bi- or multi-association in the cecum of mice affects the overall composition of the microbiota of this environment.