Adaptive metabolic response to injury includes the utilization of alternative energy substrates -such as ketone bodies (KB) -to protect the brain against further damage. Here, we examined cerebral ketone metabolism in patients with traumatic brain injury (TBI; n ¼ 34 subjects) monitored with cerebral microdialysis to measure total brain interstitial tissue KB levels (acetoacetate and b-hydroxybutyrate). Nutrition -from fasting vs. stable nutrition state -was associated with a significant decrease of brain KB (34.7 [10th-90th percentiles 10.7-189] mmol/L vs. 13.1 [6.5-64.3] mmol/L, p < 0.001) and blood KB (668 [168.4-3824.9] vs. 129.4 [82.6-1033.8] mmol/L, p < 0.01). Blood KB correlated with brain KB (Spearman's rho 0.56, p ¼ 0.0013). Continuous feeding with medium-chain triglycerides-enriched enteral nutrition did not increase blood KB, and provided a modest increase in blood and brain free medium chain fatty acids. Higher brain KB at the acute TBI phase correlated with age and brain lactate, pyruvate and glutamate, but not brain glucose. These novel findings suggest that nutritional ketosis was the main determinant of cerebral KB metabolism following TBI. Age and cerebral metabolic distress contributed to brain KB supporting the hypothesis that ketones might act as alternative energy substrates to glucose. Further studies testing KB supplementation after TBI are warranted.

There is growing interest in the metabolism of ketones owing to their reported benefits in neurological and more recently in cardiovascular and renal diseases. As an alternative to a very high fat ketogenic diet, ketones precursors for oral intake are being developed to achieve ketosis without the need for dietary carbohydrate restriction. Here we report that an oral D-beta-hydroxybutyrate (D-BHB) supplement is rapidly absorbed and metabolized in humans and increases blood ketones to millimolar levels. At the same dose, D-BHB is significantly more ketogenic and provides fewer calories than a racemic mixture of BHB or medium chain triglyceride. In a whole body ketone positron emission tomography pilot study, we observed that after D-BHB consumption, the ketone tracer 11 C-acetoacetate is rapidly metabolized, mostly by the heart and the kidneys. Beyond brain energy rescue, this opens additional opportunities for therapeutic exploration of D-BHB supplements as a "super fuel" in cardiac and chronic kidney diseases.

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There is growing evidence supporting the benefit of human milk oligosaccharides (HMOs) on reducing risk of illnesses and improving immune function in newborn infants, but evidence in pre-term infants is lacking. This randomized, double-blind, placebo-controlled trial (NCT03607942) of pre-term infants evaluated the effects of HMO supplementation on feeding tolerance, growth, and safety in 7 neonatal units in France. Pre-term infants (27–33 weeks' gestation, birth weight &lt;1,700 g) were randomized early after birth to receive HMO supplement (n = 43) [2′-fucosyllactose (2′FL) and lacto-N-neotetraose (LNnT) in a 10:1 ratio (0.374 g/kg body weight/day)] or an isocaloric placebo (n = 43) consisting of only glucose (0.140 g/kg/day) until discharge from the neonatal unit. Anthropometric z-scores were calculated using Fenton growth standards. Primary outcome was feeding tolerance, measured by non-inferiority (NI) in days to reach full enteral feeding (FEF) from birth in HMO vs. placebo group (NI margin = 4+ days). Mean number of days on intervention prior to FEF was 8.9 and 10.3 days in HMO and placebo, respectively. Non-inferiority in time to reach FEF in HMO (vs. placebo) was achieved [LS mean difference (95% CI) = −2.16 (−5.33, 1.00); upper bound of 95% CI &lt; NI margin] in full analysis set and similar for per protocol. Adjusted mean time to reach FEF from birth was 2 days shorter in HMO (12.2) vs. placebo (14.3), although not statistically significant (p = 0.177). There was no difference in weight-for-age z-scores between groups throughout the FEF period until discharge. Length-for-age z-scores were higher in HMO at FEF day 14 [0.29 (0.02, 0.56), p = 0.037] and 21 [0.31 (0.02, 0.61), p = 0.037]. Head circumference-for-age z-score was higher in HMO vs. placebo at discharge [0.42 (0.12, 0.71), p = 0.007]. Occurrence of adverse events (AEs) was similar in both groups and relatively common in this population, whereas 2.3 and 14.3%, respectively, experienced investigator-confirmed, related AEs. HMO supplementation is safe and well-tolerated in pre-term infants. After 9 days of supplementation, the HMO group reached FEF 2 days earlier vs. placebo, although the difference was not statistically significant. In addition, HMO supplementation supports early postnatal growth, which may have a positive impact on long-term growth and developmental outcomes.

Background and ObjectivesObservational studies suggest differences between breast-fed and formula-fed infants in developmental myelination, a key brain process for learning. The study aims to investigate the efficacy of a blend of docosahexaenoic acid (DHA), arachidonic acid (ARA), iron, vitamin B12, folic acid, and sphingomyelin (SM) from a uniquely processed whey protein concentrate enriched in alpha-lactalbumin and phospholipids compared with a control formulation on myelination, cognitive, and behavioral development in the first 6 months of life.MethodsThese are 6-month results from an ongoing two-center, randomized controlled trial with a 12-month intervention period (completed for all participants). In this study, full term, neurotypical infants of both sexes (N = 81) were randomized into investigational (N = 42) or control groups (N = 39). In addition, non-randomized breast-fed children (N = 108) serve as a natural reference group. Main outcomes are myelination (MRI), cognitive (Bayley Scales of Infant and Toddler Development, 3rd edition [Bayley-III]), social-emotional development (Ages and Stages Questionnaires: Social-Emotional, 2nd edition [ASQ:SE-2]), sleep (Brief Infant Sleep Questionnaire [BISQ]), and safety (growth and adverse events [AEs]).ResultsThe full analyses set comprises N = 66 infants. Significant differences in myelin structure, volume, and rate of myelination were observed in favor of the investigational myelin blend at 3 and 6 months of life. Effects were demonstrated for whole brain myelin and for cerebellar, parietal, occipital, and temporal regions, known to be functionally involved in sensory, motor, and language skills. No statistically significant differences were found for early behavior and cognition scores.ConclusionsThis is the first study demonstrating the efficacy of a myelin nutrient blend in well-nourished, term infants on developmental myelination, which may be foundational for later cognitive and learning outcomes.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT03111927.

Human milk oligosaccharides play a key role in the maturation of the infant gut microbiome and immune system and are hypothesized to affect growth. This study examined the temporal changes of 24 HMOs and their associations to infant growth and appetitive traits in an exploratory, prospective, observational, study of 41 Filipino mother-infant dyads. Exclusively breastfed, healthy, term infants were enrolled at 21–26 days of age (≈ 0.75 mo) and followed for 6 months. Infant growth measures and appetitive traits were collected at visit 1 (V1) (≈ 0.75 mo), V2 (≈ 1.5 mo), V3 (2.5 mo), V4 (2.75 mo), V5 (4 mo), and V6 (6 mo), while HMOs were measured at V1, V2, V3 and V5. Overall exposure to each HMO was summarized as area under the curve from baseline to 4 months of age and examined in association with each measure of growth at 6 months using linear regression adjusted for maternal age at birth, infant sex, birth weight, and mode of delivery. We saw modest associations between several HMOs and infant growth parameters. Our results suggest that specific HMOs, partly as proxy for milk groups (defined by Secretor and Lewis status), may be associated with head circumference and length, increasing their relevance especially in populations at the lower end of the WHO growth curve. We did not identify the same HMOs associated with infant appetitive traits, indicating that at least in our cohort, changes in appetite were not driving the observed associations between HMOs and growth.Clinical trial registration: NCT03387124.

Background A defining feature of prolonged critical illness is muscle wasting, leading to impaired recovery. Supplementation with a tailored blend of amino acids may bolster the innate gut defence, promote intestinal mucosa repair and limit muscle loss. Methods This was a monocentric, randomized, double-blind, placebo-controlled study that included patients with sepsis or acute respiratory distress syndrome. Patients received a specific combination of five amino acids or placebo mixed with enteral feeding for 21 days. Markers of renal function, gut barrier structure and functionality were collected at baseline and 1, 2, 3 and 8 weeks after randomization. Muscle structure and function were assessed through MRI measurements of the anterior quadriceps volume and by twitch airway pressure. Data were compared between groups relative to the baseline. Results Thirty-five critically ill patients were randomized. The amino acid blend did not impair urine output, blood creatinine levels or creatinine clearance. Plasma citrulline levels increased significantly along the treatment period in the amino acid group (difference in means [95% CI] 5.86 [1.72; 10.00] nmol/mL P = 0.007). Alanine aminotransferase and alkaline phosphatase concentrations were lower in the amino acid group than in the placebo group at one week (ratio of means 0.5 [0.29; 0.86] (P = 0.015) and 0.73 [0.57; 0.94] (P = 0.015), respectively). Twitch airway pressure and volume of the anterior quadriceps were greater in the amino acid group than in the placebo group 3 weeks after randomization (difference in means 10.6 [0.99; 20.20] cmH20 (P = 0.035) and 3.12 [0.5; 5.73] cm3/kg (P = 0.022), respectively). Conclusions Amino acid supplementation increased plasma citrulline levels, reduced alanine aminotransferase and alkaline phosphatase levels, and improved twitch airway pressure and anterior quadriceps volume. Trial registration ClinicalTrials.gov, NCT02968836. Registered November 21, 2016.

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