True Digestibility of Tryptophan in Plant and Animal Protein.

Background: Protein quality, evaluated using Digestible Indispensable Amino Acid Score (DIAAS), requires ileal digestibility values of individual indispensable amino acids (IAAs) in each protein. However, true tryptophan (Trp) digestibility has rarely been quantified in humans.

Objective: To measure the true Trp digestibility and DIAAS of H-intrinsically labeled plant and animal protein sources in humans, using the dual isotope tracer technique.

Effect of calcium supplementation on reversing metformin-based inhibition of vitamin B bioavailability in healthy adults using a [C] cyanocobalamin tracer - A pilot study.

Background & Aims: Metformin is a widely prescribed first line drug for the treatment of type 2 diabetes mellitus (DM). Studies have shown that the use of metformin is often associated with a decrease in vitamin B (B) levels in patients with DM. Few studies have shown that this effect could be mitigated with calcium supplementation.

Untargeted Maternal Plasma Metabolomics in Hirschsprung Disease: A Pilot Study.

Background And Aims: Hirschsprung disease (HSCR) is a congenital disorder of unknown etiology affecting the enteric nervous system (ENS). Since the early gestational development of the ENS is dependent on the prenatal maternal metabolic environment, the objective of this pilot study was to explore the role of specific maternal plasma metabolites in the etiology of HSCR.

Methods: In this cross-sectional study, postnatal (as a surrogate for prenatal) plasma samples were obtained from mothers of children diagnosed with HSCR ( = 7) and age-matched mothers of normal children ( = 6).

Bioavailability and daily requirement of vitamin B in adult humans: an observational study of its colonic absorption and daily excretion as measured by [C]-cyanocobalamin kinetics.

Background: Clinical and biochemical vitamin B (B) deficiency is lower than anticipated in vegetarians. Extraileal absorption, such as from the colon, as well as reduced daily excretion, may be adaptive mechanisms to maintain B homeostasis with marginal intakes.

Objective: To measure the absorption of B from the small and large intestine, and its daily rate of excretion from the body, using a [C]-cyanocobalamin tracer.

Variability of human fasted venous plasma metabolomic profiles with tourniquet induced hemostasis.

Venous plasma metabolomics is a potent and highly sensitive tool for identifying and measuring metabolites of interest in human health and disease. Accurate and reproducible insights from such metabolomic studies require extreme care in removing preanalytical confounders; one of these is the duration of tourniquet application when drawing the venous blood sample. Using an untargeted plasma metabolomics approach, we evaluated the effect of varying durations of tourniquet application on the variability in plasma metabolite concentrations in five healthy female subjects.

Measuring vitamin B-12 bioavailability with [13C]-cyanocobalamin in humans.

Background: Vitamin B-12 deficiency is widespread in many parts of the world, affecting all age groups and increasing with age. It is primarily due to a low intake of animal source foods or malabsorption. The measurement of bioavailability of vitamin B-12 is etiologically important in deficiency but is limited due to the use of radioactive isotopes like [57Co]- or [14C]-cyanocobalamin.

Acyl ethanolamides in Diabetes and Diabetic Nephropathy: Novel targets from untargeted plasma metabolomic profiles of South Asian Indian men.

The pathophysiology of diabetic nephropathy (DN) in type 2 diabetes (T2D) patients is minimally understood. We compared untargeted high-resolution accurate mass (HRAM) orbitrap-based plasma metabolomic profiles of 31 T2D-DN (with estimated glomerular filtration rate ≤80 mL/min/1.73 m), 29 T2D and 30 normal glucose tolerance (NGT) Indian men.