Human gut Bacteroidetes can utilize yeast mannan through a selfish mechanism

Yeasts, which have been a component of the human diet for at least 7,000 years, possess an elaborate cell wall α-mannan. The influence of yeast mannan on the ecology of the human microbiota is unknown. Here we show that yeast α-mannan is a viable food source for the Gram-negative bacterium Bacteroides thetaiotaomicron, a dominant member of the microbiota. Detailed biochemical analysis and targeted gene disruption studies support a model whereby limited cleavage of α-mannan on the surface generates large oligosaccharides that are subsequently depolymerized to mannose by the action of periplasmic enzymes. Co-culturing studies showed that metabolism of yeast mannan by B. thetaiotaomicron presents a ‘selfish’ model for the catabolism of this difficult to breakdown polysaccharide. Genomic comparison with B. thetaiotaomicron in conjunction with cell culture studies show that a cohort of highly successful members of the microbiota has evolved to consume sterically-restricted yeast glycans, an adaptation that may reflect the incorporation of eukaryotic microorganisms into the human diet

Hematological profile of beef cattle with divergent residual feed intake, following feed deprivation

O objetivo deste trabalho foi caracterizar os perfis hematológicos de novilhos e touros, de acordo com o consumo alimentar residual (CAR), após jejum de alimentos. Novilhos e touros Nelore, com 20 meses de idade, foram alimentados em confinamento por 70 e 56 dias, respectivamente. O CAR foi calculado como a diferença entre o consumo observado e o consumo esperado de alimentos. Novilhos e touros mais e menos eficientes, de acordo com o CAR, foram submetidos a jejum de alimentos por 24 horas. Amostras de sangue foram colhidas antes e após este período. As análises hematológicas incluíram contagem global e diferenciação de células brancas, contagem global e morfologia de células vermelhas, e concentração de glicose plasmática. A variação em CAR não influenciou a glicose plasmática ou o perfil de células sanguíneas. A concentração de glicose em touros diminuiu de 114 para 97 mg dL-1, mas manteve‑se inalterada em novilhos, e a razão neutrófilo:linfócito aumentou de 0,39 para 0,57 após o jejum. Não foram observadas diferenças no perfil hematológico de novilhos e touros mais e menos eficientes, de acordo com o CAR.The objective of this work was to  characterize the hematological profiles of steers  and bulls, according to residual feed intake (RFI), after feed deprivation. Twenty‑month‑old Nellore steers and bulls were fed feedlot diets for 70 and 56 days, respectively. RFI was calculated as the difference between actual feed intake and expected feed intake. More and less efficient steers and bulls, according to RFI, were subjected to 24 hours of food deprivation. Blood was sampled prior to and following the withdrawal period. Hematological analyses included total and differential white blood cell count, red blood cell count and morphology, and plasma glucose concentration. Variation in RFI did not influence plasma glucose concentration or blood cell profiles. Glucose concentrations in bulls decreased from 114 to 97 mg dL-1, but remained unchanged in steers, and the neutrophil:lymphocyte ratio increased from 0.39 to 0.57 following deprivation. Hematological profiles do not differ between more and less efficient steers and bulls, according to RFI

Hematological profile of beef cattle with divergent residual feed intake, following feed deprivation

The objective of this work was to characterize the hematological profiles of steers and bulls, according to residual feed intake (RFI), after feed deprivation. Twenty‑month‑old Nellore steers and bulls were fed feedlot diets for 70 and 56 days, respectively. RFI was calculated as the difference between actual feed intake and expected feed intake. More and less efficient steers and bulls, according to RFI, were subjected to 24 hours of food deprivation. Blood was sampled prior to and following the withdrawal period. Hematological analyses included total and differential white blood cell count, red blood cell count and morphology, and plasma glucose concentration. Variation in RFI did not influence plasma glucose concentration or blood cell profiles. Glucose concentrations in bulls decreased from 114 to 97 mg dL‑1, but remained unchanged in steers, and the neutrophil:lymphocyte ratio increased from 0.39 to 0.57 following deprivation. Hematological profiles do not differ between more and less efficient steers and bulls, according to RFI