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Background: β-lactoglobulin (BLG) stimulates muscle protein synthesis and β-hydroxybutyrate (BHB) inhibits muscle breakdown. Whether combining the 2 can additively attenuate disease-induced muscle loss is unknown., Objective: Based on previous observations of anticatabolic effects of protein and ketone bodies during inflammation, and using a novel model combining ongoing systemic inflammation, fasting, and immobilization, we tested whether the anticatabolic muscle response to oral amino acids is altered compared with control conditions, as well as whether coadministration of oral BHB and BLG further improves the muscle anabolic response. Muscle net balance (NBphe) was the primary outcome and intramyocellular signals were assessed., Methods: In a randomized crossover design, 8 young men underwent either preconditioning with LPS (prestudy day: 1 ng/kg, study day: 0.5 ng/kg) combined with a 36-h fast and bed rest to mimic catabolic inflammatory disease (CAT) or an overnight fast (control [CTR]) prior to isocaloric nutritional interventions on 3 occasions separated by ∼6 wk (range 42 to 83 d)., Results: NBphe increased similarly upon all conditions (interaction P = 0.65). From comparable baseline rates, both Rdphe [muscle synthesis, median ratio (95% CI): 0.44 (0.23, 0.86) P = 0.017] and Raphe [muscle breakdown, median ratio (95% CI): 0.46 (0.27, 0.78) P = 0.005] decreased following BHB + BLG compared with BLG. BLG increased Rdphe more under CAT conditions compared with CTR (interaction P = 0.02). CAT increased inflammation, energy expenditure, and lipid oxidation and decreased Rdphe and anabolic signaling [mammalian target of rapamycin (mTOR) and eukaryotic translation initiation factor 4E-binding protein 1 (4EPB1) phosphorylation]., Conclusion: In contrast to our initial hypothesis, NBphe increased similarly following BLG during CAT and CTR conditions; CAT however, specifically stimulated the BLG-mediated increase in protein synthesis, whereas BHB coadministration did not affect NBphe, but distinctly dampened the BLG-induced increase in muscle amino acid fluxes thereby liberating circulating amino acids for anabolic actions elsewhere., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Background: Muscle loss during acute infectious disease is mainly triggered by inflammation, immobilization, and malnutrition., Objective: The objective was to compare muscle protein kinetics and metabolism following ingestion of the dairy protein supplements β-lactoglobulin (BLG), casein (CAS), and whey (WHE) during controlled catabolic conditions., Methods: We used a randomized crossover design (registered at clinicaltrials.gov as NCT03319550) to investigate 9 healthy male participants [age: 20-40 y; BMI (in kg/m2) 20-30] who were randomly assigned servings of BLG, CAS, or WHE (0.6 g protein/kg, one-third as bolus and two-thirds as sip every 20 min) on 3 separate occasions separated by ∼6-8 wk. The participants received an infusion of lipopolysaccharide (1 ng/kg) combined with 36 h of fasting and bed rest before each study day, mimicking a clinical catabolic condition. The forearm model and isotopic tracer techniques were used to quantify muscle protein kinetics. Muscle biopsy specimens were obtained and intramyocellular signaling investigated using Western blot., Results: BLG, CAS, and WHE improved the net balance of phenylalanine (NBphe) from baseline with ∼75% (P < 0.001) with no difference between interventions (primary outcome, P < 0.05). No difference in rates of appearance and disappearance of phenylalanine or in intramyocellular signaling activation was found between interventions (secondary outcomes). The incremental AUC for serum insulin was 62% higher following BLG compared with CAS (P < 0.001) and 30% higher compared with WHE (P = 0.002), as well as 25% higher in WHE compared with CAS (P = 0.006). Following BLG consumption, plasma concentrations of glucose-dependent insulinotropic peptide (GIP) increased 70% compared with CAS (P = 0.001) and increased 34% compared with WHE (P = 0.06). No significant difference was found between WHE and CAS (P = 0.12)., Conclusion: BLG, WHE, and CAS have similar effects on muscle in young male participants during catabolic conditions. BLG showed specific, possibly GIP-dependent, insulinotropic properties, which may have future clinical implications., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

The low stability of β-lactoglobulin (βlg) under gastric conditions decreases the protein amount reaching the small intestine. Thus, it is crucial to develop a vehicle that can protect βlg from the stomach harsh acidity and enable its sustained and prolonged release in the small intestine. Herein, a fresh hydrogel composed of salecan-g-poly(N,N-dimethylaminoethyl acrylate) (PDMAEA) and nutgall tannic acid (TA) was fabricated by microwave-assisted polymerization. The incorporation of salecan into hydrogels markedly affected the hydrogels' thermal stability, microstructure, and mechanical strength. Particularly, the multiple phenolic groups of TA can form complexes with βlg, and this enables the highly effective loading of proteins. As expected, βlg not only achieved effective entrapment into the hydrogels but also achieved a tunable and pH-controlled release. Such a release profile will enable βlg protection in the stomach and its targeted release in the small intestine. Increasing the salecan content dramatically enhanced the βlg release in simulated intestinal fluid (SIF). Furthermore, the βlg release was driven by Fickian diffusion in simulated gastric fluid (SGF), but the mechanism changed to non-Fickian diffusion in SIF. The release mechanism excellently matched Ritger-Peppas model. Overall, these results indicate that TA/salecan-g-PDMAEA hydrogels hold great potential for protein delivery in the gastrointestinal tract., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Probiotic supplementation and oral tolerance induction can reduce certain types of food allergy. The objectives of this study were to investigate the allergy-reducing effects of probiotics (VSL#3) and/or oral tolerance induction via low doses of an allergen supplementation in β-lactoglobulin (BLG)-sensitized mice. Three-week-old, male BALB/c mice were divided into 6 groups (n = 8/group): sham-sensitized negative control (CTL-), BLG-sensitized positive control (CTL+), oral tolerance-induced and BLG-sensitized group (OT), probiotic-supplemented OT group (OTP), probiotic-supplemented CTL- (PRO), and probiotic-supplemented and BLG-sensitized (PROC) groups. Mice were i.p. sensitized with BLG and alum and then orally challenged with BLG. Immunological responses were assessed by monitoring hypersensitivity scores and measuring levels of BLG-specific serum Igs, total serum IgE and fecal IgA, and cytokines from serum and spleen lysates. Hypersensitivity scores were significantly lower in the PROC (2.00 ± 0.53), OT (0.75 ± 0.46), and OTP mice (1.00 ± 0.53) than in the CTL+ mice (2.63 ± 0.52) as were BLG-specific serum IgE concentrations (34.3 ± 10, 0.442 ± 0.36, 3.54 ± 3.5, and 78.5 ± 8.7 μg/L for PROC, OT, OTP, and CTL+, respectively). Our results suggest that supplementation of VSL#3 suppressed the allergic reaction mainly through increased intestinal secretary IgA (sIgA) in PROC mice, and oral tolerance offered allergen-specific protective effects to BLG-induced allergy, probably through CD4+CD25+ regulatory T cell-mediated active suppression. In OTP mice, probiotics did not induce a further reduction of hypersensitivity score compared with OT mice but may provide additional protection to unforeseen nonspecific challenges through increased intestinal sIgA.

The fertilization capacity of goat sperm stored in milk extenders is approximately 12-24h. Long-term storage of goat sperm (up to 3 days) is desirable as it would confer greater flexibility to breeding farms. The aim of this study was to evaluate in vitro motility parameters of buck spermatozoa for up to 7 days of storage using skim milk or chemically defined extender supplemented with native phosphocaseinate (NPPC). Four experiments were conducted to determine optimum temperature (4 or 15 degrees C) and storage conditions (aerobic versus anaerobic), the effect of seminal plasma on sperm survival, the optimal concentration of NPPC and the effect of beta lactoglobulin (BL). Both skim milk and NPPC were found to be more efficient for preserving goat sperm at 4 degrees C than at 15 degrees C (P<0.01). Furthermore, when sperm was stored at 4 degrees C, no detrimental effects of seminal plasma were observed. Our results showed that motility parameters can be maintained with success until Day 4. However, NPPC-based extenders extend the in vitro survival to 7 days of storage. The optimal concentration of NPPC for the preservation of sperm cells for 4 days of storage was 81g/l and for 7 days of storage was 81 and 54g/l. No effect of the supplementation of the NPPC extender with BL was found.

The evolution and luminal effects of different quantities of casein and beta-lactoglobulin were investigated in the upper jejunum of 35 volunteers who ingested 400 mL water with either beta-lactoglobulin or casein in either low or high doses (72.6 mmol N, Lbetalg; 71.7 mmol N, LCas; 368.2 mmol N, Hbetalg; 386.8 mmol N, HCas). The flow rate of the liquid effluents as well as the nitrogen movements were measured and the exogenous ([15N]) and endogenous nitrogen fractions analyzed in the upper jejunum after milk protein ingestion. The basal jejunal liquid flow rate (mL/min) was 3.88+/-1.84 and peaked in the 0-20 min period for water (9.92+/-3.72) and Lbetalg (7.27+/-3.08) and during the 20-40 min period for LCas (5.69+/-2.49), HCas (6.32+/-1.85), and Hbetalg (6.11+/-2.31). One hour after water, LCas, Lbetalg, Hbetalg, and HCas ingestion, 100%, 95%, 85%, 71%, but only 38% of the liquid phase of the meal were passed through the jejunum, respectively. The flow rate of the endogenous nitrogen was 12.93+/-5.22 mmol N/h before meal ingestion; remained unchanged after water, LCas or Hbetalg ingestion; but increased significantly (P<0.05) after Lbetalg and HCas ingestion. The net disappearance of exogenous nitrogen in the upper jejunum 240 min after HCas, Lbetalg, LCas and Hbetalg ingestion was 82.6+/-9.5%, 61.6+/-9.6%, 58.4+/-14.7%, and 44.7%+/-24.4%, respectively. The exogenous fraction of protein nitrogen recovered in the upper intestinal lumen represented 43.3% of the ingested Hbetalg nitrogen, but only 4.9% of the ingested HCas nitrogen. In conclusion, casein and beta-lactoglobulin present differences in both the intestinal kinetics of amino acid delivery and in the nature of the products in the intestinal lumen. These differences have to be taken into account from both nutritional and physiologic points of view for the utilization of these proteins in humans.

Rabbit granulocyte lactoferrin, when infused into hamsters or rabbits, induces transient neutropenia, and in hamsters the lactoferrin promotes adherence of the granulocytes to the endothelial cell wall as monitored visually. In contrast, neither rabbit granule lysozyme nor human transferrin induces neutropenia in the rabbit nor does transferrin or bovine serum albumin affect the adherent properties in vivo of the phagocytic cells of the hamster. Thus lactoferrin enhances granulocyte adherence both in vivo and in vitro. It would appear that the promotion of margination of leukocytes by lactoferrin in vivo may contribute to the phenomenon of neutropenia during activation of granulocytes by chemotactic factors.

Purified human lactoferrin was assessed for its influence in vivo in untreated mice and in mice undergoing rebound myelopoiesis after sublethal dosages of Cytoxan. Fully iron-saturated lactoferrin suppressed the numbers of granulocytes and monocytes per femur, the numbers of granulocyte-macrophage progenitor cells (CFU-GM) per femur and spleen, and decreased the cycle status of femoral and splenic CFU-GM. These effects were detected after administration of lactoferrin i.v. or i.p. into untreated and Cytoxan-treated mice. The suppressive effects on cellularity and numbers of CFU-GM per femur were apparent to a greater degree in mice treated with Cytoxan, and the i.v. route appeared preferable to the i.p. route. Heat-treated lactoferrin, inactive in vitro, was inactive in vivo, but iron-depleted (apo-) lactoferrin, inactive in vitro, was active in vivo, suggesting that the apo-lactoferrin acquired the iron in vivo that was necessary to change it into an active form. Titration of the effects of lactoferrin in Cytoxan-treated mice demonstrated a plateau curve of suppression of nucleated cells and CFU-GM per femur with dosages ranging from 100 micrograms to 10(-4) micrograms lactoferrin per mouse, with loss of activity at 10(-5) micrograms. The suppressive effect of lactoferrin on cycle status of CFU-GM required concentrations of 10 micrograms or higher. The effects of lactoferrin were reversible with time, with the suppressive influence on cycling status being lost before that on numbers of CFU-GM per femur. Purified human transferrin was also assessed for its influence in mice undergoing rebound myelopoiesis. Transferrin decreased the nucleated cellularity and the number of CFU-GM per femur and per spleen, but had little or no influence on the cycling status of CFU-GM and differed in its temporal effect on myelopoiesis from that of lactoferrin. These results suggest that lactoferrin and transferrin suppress the number of progenitor cells moving into the CFU-GM compartment and lactoferrin suppresses the cycling status of cells within the CFU-GM compartment. These effects are probably mediated by an action on the production of factors necessary for movement of cells into, and cell cycling within, the CFU-GM compartment.