Angela Rowan

Comparison of the ileal and faecal digestibility of dietary amino acids in adult humans and evaluation of the pig as a model animal for digestion studies in man.

The aim of the study was to determine if there is a difference between ileal and faecal assays for determining amino acid and N digestibilities in adult human subjects. Comparison of true ileal amino acid and N digestibilities was also made between adult human subjects and growing pigs to establish the usefulness of the pig as a model animal. Five subjects with established ileostomies and six subjects with intact large bowels consumed a constant diet consisting of meat, vegetables, fruit, bread and dairy products for 7 d with collection of ileostomy contents or faeces respectively over the last 4 d. The study was repeated using 25 kg body weight ileostomized and intact pigs. Apparent amino acid and N digestibility coefficients were determined. For human subjects the faecal digestibility values were significantly higher (P < 0.05) than the ileal values for Arg, Asp, Gly, Phe, Pro, Ser, Thr and Trp. The faecal digestibility of Met was significantly lower than the ileal value. Determination of DNA, diaminopimelic acid (DAPA) and the digestibilities of pectin, hemicellulose and cellulose in human subjects indicated that some microbial colonization had occurred at the terminal ileum after formation of an ileostomy; however, this was not as extensive as in the large intestine. True ileum amino acid and N digestibilities were calculated after correcting for the endogenous contribution of amino acids at the terminal ileum determined using a protein-free diet. There were no significant differences between adult human subjects and pigs for true ileal dietary amino acid digestibility except for Thr, Phe, Cys and Met. There were no significant differences between adult humans and pigs for the ileal digestibility of dry matter and the faecal digestibility of gross energy.

Association of complex lipids containing gangliosides with cognitive development of 6-month-old infants

BACKGROUND Human breastmilk contains gangliosides which may play an important role in infant neurodevelopment. AIM A pilot study was conducted to assess the impact of infant formula supplemented with gangliosides from complex milk lipid on cognitive functions of normal healthy infants. STUDY DESIGN The study was a double-blind, randomized, controlled, parallel group clinical trial in which infants received the treatment or control product from 2 to 8 weeks of age until 24 weeks of age. The control group (n=30) received standard infant formula and the treatment group (n=29) received the same formula supplemented with complex milk lipid to increase the ganglioside content to approximately 11 to 12 μg/ml. A reference group (n=32) consisted of normal healthy exclusively breast-fed infants. OUTCOME MEASURES Cognitive development using the Griffith Scales and serum gangliosides was measured before (2-8 weeks of age) and after intervention (24 weeks of age). RESULTS Ganglioside supplementation using complex milk lipids significantly increased ganglioside serum levels (control group vs treatment group, P=0.002) and resulted in increased scores for Hand and Eye coordination IQ (P<0.006), Performance IQ (P<0.001) and General IQ (P=0.041). Cognitive development scores and serum ganglioside levels for the treatment group did not differ from the reference group. CONCLUSIONS Supplementation of infant formula with complex milk lipid to enhance ganglioside content appears to have beneficial effects on cognitive development in healthy infants aged 0-6 months, which may be related to increased serum ganglioside levels.

The Role of Gangliosides in Neurodevelopment

Gangliosides are important components of neuronal cell membranes and it is widely accepted that they play a critical role in neuronal and brain development. They are functionally involved in neurotransmission and are thought to support the formation and stabilization of functional synapses and neural circuits required as the structural basis of memory and learning. Available evidence, as reviewed herein, suggests that dietary gangliosides may impact positively on cognitive functions, particularly in the early postnatal period when the brain is still growing. Further, new evidence suggests that the mechanism of action may be through an effect on the neuroplasticity of the brain, mediated through enhanced synaptic plasticity in the hippocampus and nigro-striatal dopaminergic pathway.

The flows of deoxyribonucleic acid and diaminopimelic acid and the digestibility of dietary fibre components at the terminal ileum, as indicators of microbial activity in the upper digestive tract of ileostomised pigs

The microbial markers deoxyribonucleic acid (DNA) and diaminopimelic acid (DAP) were used to compare the microbial biomass in the ileal digesta of ileostomised pigs with that in the faeces of intact pigs. Ileal and faecal (whole tract) digestibility of dietary fibre was also determined, to indicate the extent of microbial activity in the upper and lower digestive tracts. Six ileostomised pigs of 25 kg live weight and six intact pigs were given a human-type diet of bread, raw and cooked vegetable, cooked meat and dairy products for 12 days, total ileal digesta or faeces being collected over the final 4 days. The mean excretion of DNA in the ileal digesta (100.4 mg day−1) was significantly (P < 0.01) greater than that in the faeces (48.2 mg day−1), while the mean ileal and faecal excretions of DAP (56.7 mg day−1 and 62.8 mg day−1, respectively) were not significantly different. On the basis of the mean DAP concentrations, the estimated concentrations of bacterial dry matter in ileal or faecal dry matter were 208 mg g−1 and 694 mg g−1, respectively. The digestibility of the dietary fibre components was significantly (P < 0.001) greater when measured over the entire digestive tract than at the terminal ileum, though there was a considerable breakdown of pectin, hemicellulose and cellulose anterior to the end of the small intestine. It was concluded that there is a substantial and active microflora in the upper digestive tract of ileostomised pigs, and this may have implications for the determination of nutrient digestibility with surgically modified animals.

Maternal Serum and Breast Milk Vitamin D Levels: Findings from the Universiti Sains Malaysia Pregnancy Cohort Study

Background Vitamin D deficiency has become a global health issue in pregnant women. This study aimed to assess the adequacy of maternal vitamin D status by measuring maternal serum and breast milk 25-hydroxyvitamin D [25(OH)D] levels and to determine the association between maternal serum and milk 25(OH)D levels. Methods Data was obtained from the Universiti Sains Malaysia Pregnancy Cohort Study. This study was conducted from April 2010 to December 2012 in the state of Kelantan, Malaysia. Blood samples from pregnant women aged 19 to 40 years were drawn in the second and third trimesters of pregnancy, while breast milk samples at delivery, 2, 6 and 12 months postpartum were collected to analyze for 25(OH)D levels. A total of 102 pregnant women were included in the analysis. Results Vitamin D deficiency [25(OH)D <50 nmol/L] was detected in 60% and 37% of women in the second and third trimesters of pregnancy, respectively. There were 6% and 23% of women who reached normal level of vitamin D status in the second trimester and the third trimester, respectively. Multivitamin intakes during pregnancy were significantly associated with higher serum 25(OH)D levels in the second trimester (β = 9.16, p = 0.005) and the third trimester (β = 13.65, p = 0.003). 25(OH)D levels in breast milk during the first year of lactation ranged from 1.01 to 1.26 nmol/L. Higher maternal serum 25(OH)D level in the second trimester of pregnancy was associated with an elevated level of 25(OH)D in breast milk at delivery (β = 0.002, p = 0.026). Conclusions This study shows that high proportions of Malay pregnant women are at risk of vitamin D deficiency. Maternal vitamin D status in the second trimester of pregnancy was found to influence vitamin D level in breast milk at delivery.

Long-Term Supplementation with Beta Serum Concentrate (BSC), a Complex of Milk Lipids, during Post-Natal Brain Development Improves Memory in Rats

We have previously reported that the supplementation of ganglioside-enriched complex-milk-lipids improves cognitive function and that a phospholipid-enriched complex-milk-lipid prevents age-related cognitive decline in rats. This current study evaluated the effects of post-natal supplementation of ganglioside- and phospholipid-enriched complex-milk-lipids beta serum concentrate (BSC) on cognitive function in young rats. The diet of male rats was supplemented with either gels formulated BSC (n = 16) or blank gels (n = 16) from post-natal day 10 to day 70. Memory and anxiety-like behaviors were evaluated using the Morris water maze, dark–light boxes, and elevated plus maze tests. Neuroplasticity and white matter were measured using immunohistochemical staining. The overall performance in seven-day acquisition trials was similar between the groups. Compared with the control group, BSC supplementation reduced the latency to the platform during day one of the acquisition tests. Supplementation improved memory by showing reduced latency and improved path efficiency to the platform quadrant, and smaller initial heading error from the platform zone. Supplemented rats showed an increase in striatal dopamine terminals and hippocampal glutamate receptors. Thus BSC supplementation during post-natal brain development improved learning and memory, independent from anxiety. The moderately enhanced neuroplasticity in dopamine and glutamate may be biological changes underlying the improved cognitive function.

Ganglioside Composition in Beef, Chicken, Pork, and Fish Determined Using Liquid Chromatography-High-Resolution Mass Spectrometry.

Gangliosides (GA) are found in animal tissues and fluids, such as blood and milk. These sialo-glycosphingolipids have bioactivities in neural development, the gastrointestinal tract, and the immune system. In this study, a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was validated to characterize and quantitate the GA in beef, chicken, pork, and fish species (turbot, snapper, king salmon, and island mackerel). For the first time, we report the concentration of GM3, the dominant GA in these foods, as ranging from 0.35 to 1.1 mg/100 g and 0.70 to 5.86 mg/100 g of meat and fish, respectively. The minor GAs measured were GD3, GD1a, GD1b, and GT1b. Molecular species distribution revealed that the GA contained long- to very-long-chain acyl fatty acids attached to the ceramide moiety. Fish GA contained only N-acetylneuraminic acid (NeuAc) sialic acid, while beef, chicken, and pork contained GD1a/b species that incorporated both NeuAc and N-glycolylneuraminic acid (NeuGc) and hydroxylated fatty acids.

Correlation between dietary intake and serum ganglioside concentrations: a cross-sectional study among Malaysian toddlers

BackgroundGangliosides are a group of sialylglycosphingolipids, widely distributed in body tissues, mainly as components of plasma membranes. They play crucial roles in neurodevelopment, gut maturation, and immune system. Dietary gangliosides have been shown to bring about benefits including cognition and immune support for breastfed infants. There is dearth of studies on dietary gangliosides intake or plasma ganglioside levels for toddlers. Given toddlers are still growing rapidly, a good understanding of ganglioside intake during this early childhood period is important for future dietary recommendations. The aim of this study was to provide information on dietary ganglioside intake in Malaysian toddlers and correlations with serum ganglioside levels.MethodsToddlers who fulfilled the inclusion criteria were recruited from the Federal Territory of Putrajaya and neighboring urban suburbs. Background characteristics and food intake using food frequency questionnaire were collected for the entire sample (n = 153). As for ganglioside correlation determination, a 2 day weighed food record was conducted on a sub-group who provided blood (n = 74). Ganglioside levels in the food and blood were determined using modern high performance liquid chromatography mass spectrometry method.ResultsThe average dietary intake of total gangliosides for the Malaysian toddlers (aged 12–24.5 months) was 5.86 ± 0.56 mg/day. Growing up milks had a wide ganglioside concentration range (0.03 11.4 mg/100 g), and were the major contributor to dietary ganglioside intake (85%). The remaining dietary gangliosides were provided by other dairy products, meat, fish, bakery and biscuits.Serum levels varied from 5.05 μg/mL to 16.15 μg/mL. While no significant correlation was observed between dietary ganglioside intake from growing up milks and serum ganglioside levels in the toddlers, there was a significant but weak correlation between dietary ganglioside intake from dairy products (r = 0.241; p = 0.038) and meat (r = 0.294; p = 0.010) with serum ganglioside levelsConclusionsGangliosides are a component of the Malaysian toddlers’ diet (5.68 ± 0.56 mg/day), and were measured in their plasma at levels ranging from 5.05 to 16.15 μg/mL. Growing up milk contributed to 85% of the total dietary gangliosides intake, with remaining contributions from chicken meat and fish. More studies should be undertaken on the contributions of dietary gangliosides, including breast milk, in bringing about health benefits to young children.

Normative Interlimb Impedance Ratios: Implications for Early Diagnosis of Uni- and Bilateral, Upper and Lower Limb Lymphedema

BACKGROUND Bioimpedance spectroscopy detects unilateral lymphedema if the ratio of extracellular fluid (ECF) between arms or between legs is outside three standard deviations (SDs) of the normative mean. Detection of bilateral lymphedema, common after bilateral breast or gynecological cancer, is complicated by the unavailability of an unaffected contralateral limb. The objectives of this work were to (1) present normative values for interarm, interleg, and arm-to-leg impedance ratios of ECF and ECF normalized to intracellular fluid (ECF/ICF); (2) evaluate the influence of sex, age, and body mass index on ratios; and (3) describe the normal change in ratios within healthy individuals over time. METHODS Data from five studies were combined to generate a normative data set (n = 808) from which mean and SD were calculated for interarm, interleg, and arm-to-leg ratios of ECF and ECF/ICF. The influence of sex, age, and body mass index was evaluated using multiple linear regression, and normative change was calculated for participants with repeated measures by subtracting their lowest ratio from their highest ratio. RESULTS Mean (SD) interarm, interleg, dominant arm-to-leg, and nondominant arm-to-leg ratios were 0.987 (0.067), 1.005 (0.072), 1.129 (0.160), and 1.165 (0.174) for ECF ratios; and 0.957 (0.188), 1.024 (0.183), 1.194 (0.453), and 1.117 (0.367) for ECF/ICF ratios, respectively. Arm-to-leg ratios were significantly affected by sex, age, and body mass index. Mean normative change ranged from 7.2% to 14.7% for ECF ratios and from 14.7% to 67.1% for ECF/ICF ratios. CONCLUSION These findings provide the necessary platform for extending bioimpedance-based screening beyond unilateral lymphedema.

Dietary supplementation with bovine-derived milk fat globule membrane lipids promotes neuromuscular development in growing rats

BackgroundThe milk fat globule membrane (MFGM) is primarily composed of polar phospho- and sphingolipids, which have established biological effects on neuroplasticity. The present study aimed to investigate the effect of dietary MFGM supplementation on the neuromuscular system during post-natal development.MethodsGrowing rats received dietary supplementation with bovine-derived MFGM mixtures consisting of complex milk lipids (CML), beta serum concentrate (BSC) or a complex milk lipid concentrate (CMLc) (which lacks MFGM proteins) from post-natal day 10 to day 70.ResultsSupplementation with MFGM mixtures enriched in polar lipids (BSC and CMLc, but not CML) increased the plasma phosphatidylcholine (PC) concentration, with no effect on plasma phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylserine (PS) or sphingomyelin (SM). In contrast, muscle PC was reduced in rats receiving supplementation with both BSC and CMLc, whereas muscle PI, PE, PS and SM remained unchanged. Rats receiving BSC and CMLc (but not CML) displayed a slow-to-fast muscle fibre type profile shift (MyHCI → MyHCIIa) that was associated with elevated expression of genes involved in myogenic differentiation (myogenic regulatory factors) and relatively fast fibre type specialisation (Myh2 and Nfatc4). Expression of neuromuscular development genes, including nerve cell markers, components of the synaptogenic agrin–LRP4 pathway and acetylcholine receptor subunits, was also increased in muscle of rats supplemented with BSC and CMLc (but not CML).ConclusionsThese findings demonstrate that dietary supplementation with bovine-derived MFGM mixtures enriched in polar lipids can promote neuromuscular development during post-natal growth in rats, leading to shifts in adult muscle phenotype.