Milk-Oligosaccharides-Growth-Factors-Bifidobacteria-u

HMOs contain two major structures of core tetrasaccharide lacto-N-tetraose metabolic pathway for lacto-N-tetraose in Bifidobacterium bifidum. Here, we clarified the degradation pathway for lacto-N-neotetraose in the same bifidobacteria. We cloned one β-galactosidase (BbgIII) and two β-N-acetylhexosaminidases (BbhI and BbhII), all of which are extracellular membrane-bound enzymes. The recombinant BbgIII hydrolyzed lacto-N-neotetraose into Gal and lacto-N-triose II, and furthermore the recombinant BbhI, but not BbhII, catalyzed the hydrolysis of lacto-N-triose II to GlcNAc and lactose. Since BbgIII and BbhI were highly specific for lacto-N-neotetraose and lacto-N-triose II, respectively, they may play essential roles in degrading the Maternal Human Milk Oligosaccharide Profile Modulates the Impact of an Intervention with Iron and Galacto-Oligosaccharides in Kenyan Infants.Paganini D(1), Uyoga MA(2)(3), Kortman GAM(4), Boekhorst J(5), Schneeberger University of Agriculture and Technology,00 Nairobi, Kenya.

University of Agriculture and Technology,00 Nairobi, Kenya. There is little data on human milk oligosaccharide (HMO) composition in Sub-Saharan Africa. Iron fortificants adversely affect the infant gut microbiota, while co-provision of prebiotic galacto-oligosaccharides (GOS) mitigates most of the adverse effects. Whether variations in maternal HMO profile can influence the infant response to iron andor GOS fortificants is unknown. The aim of this study was to determine HMO profiles and the secretornon-secretor phenotype of lactating Kenyan mothers and investigate their effects on the maternal and infant gut microbiota, and on the infant response to a fortification intervention with 5 mg iron (2 mg as sodium iron ethylenediaminetetraacetate and 2 mg as ferrous fumarate) and 7 g GOS. We studied mother-infant pairs (n = ) participating in a 4-month intervention trial in which the infants (aged 6-9 months) received daily a micronutrient powder without iron, with iron or with iron and GOS. We assessed (1) maternal secretor status and HMO composition; (2) effects of secretor status on the maternal and infant gut microbiota in a cross-sectional analysis at baseline of the intervention trial; and (3) interactions between secretor status and intervention groups during the intervention trial on the infant gut microbiota, gut inflammation, iron status, growth and infectious morbidity.

2'-fucosyllactose was 72% and HMOs differed between secretors and non-secretors and over time of lactation. Secretor status did not predict the baseline composition of the maternal and infant gut microbiota. There was a secretor-status-by-intervention-group interaction on Bifidobacterium (p =21), Z-scores for length-for-age (p =22) and weight-for-age (p =18), and soluble transferrin receptor (p =41). In the no iron group, longitudinal prevalence of diarrhea was higher among infants of non-secretors (23%) than of secretors (%) (p =01). In conclusion, HMO profile may modulate the infant gut microbiota response to fortificant iron; compared to infants of secretor mothers, infants of non-secretor mothers may be more vulnerable to the adverse effect of iron but also benefit more from the co-provision of GOS.Conflict of interest statement The authors declare no conflict of interest.Loop engineering of an α-1,34-l-fucosidase for improved synthesis of human milk Engineering, Technical University of Denmark, Building 229, DK-20 Kgs.

Lyngby, Engineering, Technical University of Denmark, Building 229, DK-20 Kgs. Order now , The α-1,34-l-fucosidases (EC 311; GH29) BbAfcB from Bifidobacterium bifidum and CpAfc2 from Clostridium perfringens can catalyse formation of the human milk oligosaccharide (HMO) lacto-N-fucopentaose II (LNFP II) through regioselective transfucosylation of lacto-N-tetraose (LNT) with 3-fucosyllactose between the two enzymes with the aim of engineering BbAfcB into a more efficient transfucosidase and approaches an understanding of structure-function relations of hydrolytic activity vs. transfucosylation activity in GH29. Replacement of a 23 amino acids long α-helical loop close to the active site of BbAfcB with the corresponding 17-aminoacid α-helical loop of CpAfc2 resulted in almost complete abolishment of the hydrolytic activity on 3FL ( times lower hydrolytic activity than WT BbAfcB), while the transfucosylation activity was lowered only one order of magnitude. In turn, the loop engineering resulted in an α-1,34-l-fucosidase with transfucosylation activity reaching molar yields of LNFP II of 39 ± 2% on 3FL and negligible product hydrolysis. This was almost 3 times higher than the yield obtained with WT BbAfcB (14 ±%) and comparable to that obtained with CpAfc2 ( ± 8%).