Correction: Long-chain polyunsaturated fatty acids and extensively hydrolyzed casein-induced browning in a Ucp-1 reporter mouse model of obesity.

Correction for 'Long-chain polyunsaturated fatty acids and extensively hydrolyzed casein-induced browning in a Ucp-1 reporter mouse model of obesity' by Liufeng Mao et al., Food Funct., 2018, 9, 2362-2373, https://doi.org/10.1039/C7FO01835E.

Associations between breast milk intake volume, macronutrient intake and infant growth in a longitudinal birth cohort: the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF).

Growth patterns of breastfed infants show substantial inter-individual differences, partly influenced by breast milk (BM) nutritional composition. However, BM nutritional composition does not accurately indicate BM nutrient intakes. This study aimed to examine the associations between both BM intake volumes and macronutrient intakes with infant growth. Mother-infant dyads (n 94) were recruited into the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF) from a single maternity hospital at birth; all infants received exclusive breast-feeding (EBF) for at least 6 weeks. Infant weight, length and skinfolds thicknesses (adiposity) were repeatedly measured from birth to 12 months. Post-feed BM samples were collected at 6 weeks to measure TAG (fat), lactose (carbohydrate) (both by 1H-NMR) and protein concentrations (Dumas method). BM intake volume was estimated from seventy infants between 4 and 6 weeks using dose-to-the-mother deuterium oxide (2H2O) turnover. In the full cohort and among sixty infants who received EBF for 3+ months, higher BM intake at 6 weeks was associated with initial faster growth between 0 and 6 weeks (ß + se 3·58 + 0·47 for weight and 4·53 + 0·6 for adiposity gains, both P < 0·0001) but subsequent slower growth between 3 and 12 months (ß + se - 2·27 + 0·7 for weight and -2·65 + 0·69 for adiposity gains, both P < 0·005). BM carbohydrate and protein intakes at 4-6 weeks were positively associated with early (0-6 weeks) but tended to be negatively related with later (3-12 months) adiposity gains, while BM fat intake showed no association, suggesting that carbohydrate and protein intakes may have more functional relevance to later infant growth and adiposity.

The Progress of Intestinal Epithelial Models from Cell Lines to Gut-On-Chip.

Over the past years, several preclinical in vitro and ex vivo models have been developed that helped to understand some of the critical aspects of intestinal functions in health and disease such as inflammatory bowel disease (IBD). However, the translation to the human in vivo situation remains problematic. The main reason for this is that these approaches fail to fully reflect the multifactorial and complex in vivo environment (e.g., including microbiota, nutrition, and immune response) in the gut system. Although conventional models such as cell lines, Ussing chamber, and the everted sac are still used, increasingly more sophisticated intestinal models have been developed over the past years including organoids, InTESTine™ and microfluidic gut-on-chip. In this review, we gathered the most recent insights on the setup, advantages, limitations, and future perspectives of most frequently used in vitro and ex vivo models to study intestinal physiology and functions in health and disease.

Human Milk Short-Chain Fatty Acid Composition is Associated with Adiposity Outcomes in Infants.

BACKGROUND: Presumed benefits of human milk (HM) in avoiding rapid infancy weight gain and later obesity could relate to its nutrient composition. However, data on breast milk composition and its relation with growth are sparse. OBJECTIVE: We investigated whether short-chain fatty acids (SCFAs), known to be present in HM and linked to energy metabolism, are associated with infancy anthropometrics. METHODS: In a prospective birth cohort, HM hindmilk samples were collected from 619 lactating mothers at 4-8 wk postnatally [median (IQR) age: 33.9 (31.3-36.5) y, body mass index (BMI) (kg/m2): 22.8 (20.9-25.2)]. Their offspring, born at 40.1 (39.1-41.0) wk gestation with weight 3.56 (3.22-3.87) kg and 51% male, were assessed with measurement of weight, length, and skinfold thickness at ages 3, 12, and 24 mo, and transformed to age- and sex-adjusted z scores. HM SCFAs were measured by 1H-nuclear magnetic resonance spectroscopy (NMR) and GC-MS. Multivariable linear regression models were conducted to analyze the relations between NMR HM SCFAs and infancy growth parameters with adjustment for potential confounders. RESULTS: NMR peaks for HM butyrate, acetate, and formic acid, but not propionate, were detected. Butyrate peaks were 17.8% higher in HM from exclusively breastfeeding mothers than mixed-feeding mothers (P = 0.003). HM butyrate peak values were negatively associated with changes in infant weight (standardized B  = -0.10, P = 0.019) and BMI (B = -0.10, P = 0.018) between 3 and 12 mo, and negatively associated with BMI (B = -0.10, P = 0.018) and mean skinfold thickness (B = -0.10, P = 0.049) at age 12 mo. HM formic acid peak values showed a consistent negative association with infant BMI at all time points (B < = -0.10, P < = 0.014), whereas HM acetate was negatively associated with skinfold thickness at 3 mo (B = -0.10, P = 0.028) and 24 mo (B = -0.10, P = 0.036). CONCLUSIONS: These results suggest that HM SCFAs play a beneficial role in weight gain and adiposity during infancy. Further knowledge of HM SCFA function may inform future strategies to support healthy growth.

Soluble Mediators From Lactobacillus rhamnosus Gorbach-Goldin Support Intestinal Barrier Function in Rats After Massive Small-Bowel Resection.

BACKGROUND: Intestinal barrier plays an essential role in maintaining gastrointestinal health. This study aimed to explore the effects of a soluble mediator preparation derived from Lactobacillus rhamnosus Gorbach-Goldin (LGG) on intestinal barrier function in a rat model of short bowel syndrome (SBS). METHODS: Six-week-old male Sprague-Dawley rats underwent 80% small-bowel resection (SBR) and then were supplemented with water (SBS), 5 × 108 colony-forming unit viable LGG (SBS+LGG), or the LGG soluble mediators (SBS+LSM) in an equivalent dose to LGG by intragastric gavage daily from day 2 throughout day 14 after operation. Rats that underwent bowel transection and reanastomosis were used as the sham group. Body weight, ileum histology, intestinal permeability and bacterial translocation, inflammatory cytokines, and tight junction protein expressions of ileum were evaluated. RESULTS: Animals undergoing SBR showed higher intestinal permeability and decreased expression of tight junction proteins in the ileum than sham group. Both SBS+LGG and SBS+LSM groups had reduced bacterial translocation and intestinal permeability as compared with the SBS group, with lower levels of serum endotoxin and tumor necrotizing factor alpha in ileum tissues. Moreover, the SBS+LSM group showed better body weight gain, lower endotoxin and FD-40 levels, and higher expressions of claudin-1 and claudin-4 in ileum than the SBS+LGG group. CONCLUSION: Enteral supplementation of LSMs or viable LGG can ameliorate intestinal barrier disruption in a rat model of SBS. The LSM preparation not only mimicked biological effects of viable LGG but also was revealed to be more effective in reducing inflammation and supporting intestinal barrier function.

Long-chain polyunsaturated fatty acids and extensively hydrolyzed casein-induced browning in a Ucp-1 reporter mouse model of obesity.

Browning in adipose tissues, which can be affected by diet, may mitigate the detrimental effects of adiposity and improve longer-term metabolic health. Here, browning-inducing effects of long-chain polyunsaturated fatty acids, e.g., arachidonic acid (ARA)/docosahexaenoic acid (DHA) and extensively hydrolyzed casein (eHC) were investigated in uncoupling protein 1 (Ucp-1) reporter mice. To address the overall functionality, their potential role in supporting a healthy metabolic profile under obesogenic dietary challenges later in life was evaluated. At weaning Ucp1+/LUC reporter mice were fed a control low fat diet (LFD) with or without ARA + DHA, eHC or eHC + ARA + DHA for 8 weeks until week 12 after which interventions continued for another 12 weeks under a high-fat diet (HFD) challenge. Serology (metabolic responses and inflammation) and in vivo and ex vivo luciferase activity were determined; in the meantime browning-related proteins UCP-1 and the genes peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), PR domain containing 16 (PRDM16) and Ucp-1 were examined. ARA + DHA, eHC or their combination reduced body weight gain and adipose tissue weight compared to the HFD mice. The interventions induced Ucp-1 expression in adipose tissues prior to and during the HFD exposure. Ucp-1 induction was accompanied by higher PGC1a and PRDM16 expression. Glucose tolerance and insulin sensitivity were improved coinciding with lower serum cholesterol, triglycerides, free fatty acids, insulin, leptin, resistin, fibroblast growth factor 21, alanine aminotransferase, aspartate aminotransferase and higher adiponectin than the HFD group. HFD-associated increased systemic (IL-1ß and TNF-α) and adipose tissue inflammation (F4/80, IL-1ß, TNF-α, IL-6) was reduced. Studies in a Ucp-1 reporter mouse model revealed that early intervention with ARA/DHA and eHC improves metabolic flexibility and attenuates obesity during HFD challenge later in life. Increased browning is suggested as, at least, part of the underlying mechanism.

A casein hydrolysate based formulation attenuates obesity and associated non-alcoholic fatty liver disease and atherosclerosis in LDLr-/-.Leiden mice.

BACKGROUND: Obesity frequently associates with the development of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis. Chronic inflammation in white adipose tissue (WAT) seems to be an important driver of these manifestations. OBJECTIVE: This study investigated a combination of an extensively hydrolyzed casein (eHC), docosahexaenoic acid (DHA), arachidonic acid (ARA), and Lactobacillus Rhamnosus GG (LGG) (together referred to as nutritional ingredients, NI) on the development of obesity, metabolic risk factors, WAT inflammation, NAFLD and atherosclerosis in high-fat diet-fed LDLr-/-.Leiden mice, a model that mimics disease development in humans. METHODS: LDLr-/-.Leiden male mice (n = 15/group) received a high-fat diet (HFD, 45 Kcal%) for 21 weeks with or without the NI (23.7% eHC, 0.083% DHA, 0.166% ARA; all w/w and 1x109 CFU LGG gavage 3 times/week). HFD and HFD+NI diets were isocaloric. A low fat diet (LFD, 10 Kcal%) was used for reference. Body weight, food intake and metabolic risk factors were assessed over time. At week 21, tissues were analyzed for WAT inflammation (crown-like structures), NAFLD and atherosclerosis. Effects of the individual NI components were explored in a follow-up experiment (n = 7/group). RESULTS: When compared to HFD control, treatment with the NI strongly reduced body weight to levels of the LFD group, and significantly lowered (P<0.01) plasma insulin, cholesterol, triglycerides, leptin and serum amyloid A (P<0.01). NI also reduced WAT mass and inflammation. Strikingly, NI treatment significantly reduced macrovesicular steatosis, lobular inflammation and liver collagen (P<0.05), and attenuated atherosclerosis development (P<0.01). Of the individual components, the effects of eHC were most pronounced but could not explain the entire effects of the NI formulation. CONCLUSIONS: A combination of eHC, ARA, DHA and LGG attenuates obesity and associated cardiometabolic diseases (NAFLD, atherosclerosis) in LDLr-/-.Leiden mice. The observed reduction of inflammation in adipose tissue and in the liver provides a rationale for these comprehensive health effects.

Lactoferrin protects against intestinal inflammation and bacteria-induced barrier dysfunction in vitro.

The iron-binding glycoprotein lactoferrin (LF) is naturally present in human breast milk. Several studies suggest that LF contributes to infant health and development owing to a variety of protective effects, including antimicrobial and anti-inflammatory features. Therefore, we aimed to elucidate its protective properties on intestinal epithelial barrier dysfunction induced by infection or inflammation using the human epithelial cell culture models HT-29/B6 and T84. During barrier perturbation induced by the proinflammatory cytokine tumor necrosis factor α (TNF-α), bovine LF restored tight junction (TJ) morphometry and inhibited TNF-α-induced epithelial apoptosis. This resulted in an attenuation of the TNF-α-induced decrease in transepithelial resistance (TER) and increases in permeability of fluorescein and FITC-dextran (4 kDa) and was as effective as the apoptosis inhibitor Q-VD-Oph. The enteropathogenic bacterium Yersinia enterocolitica is a frequent cause of diarrhea in early childhood. This involves focal changes in TJ protein expression and localization. LF diminished the Y. enterocolitica-induced drop in TER in the present in vitro model, which was paralleled by an inhibition of the Yersinia-induced reduction of claudin-8 expression via c-Jun kinase signaling. In conclusion, LF exerts protective effects against inflammation- or infection-induced barrier dysfunction in human intestinal cell lines, supporting its relevance for healthy infant development.

The SCFA butyrate stimulates the epithelial production of retinoic acid via inhibition of epithelial HDAC.

In the intestinal mucosa, retinoic acid (RA) is a critical signaling molecule. RA is derived from dietary vitamin A (retinol) through conversion by aldehyde dehydrogenases (aldh). Reduced levels of short-chain fatty acids (SCFAs) are associated with pathological microbial dysbiosis, inflammatory disease, and allergy. We hypothesized that SCFAs contribute to mucosal homeostasis by enhancing RA production in intestinal epithelia. With the use of human and mouse epithelial cell lines and primary enteroids, we studied the effect of SCFAs on the production of RA. Functional RA conversion was analyzed by Adlefluor activity assays. Butyrate (0-20 mM), in contrast to other SCFAs, dose dependently induced aldh1a1 or aldh1a3 transcript expression and increased RA conversion in human and mouse epithelial cells. Epithelial cell line data were replicated in intestinal organoids. In these organoids, butyrate (2-5 mM) upregulated aldh1a3 expression (36-fold over control), whereas aldh1a1 was not significantly affected. Butyrate enhanced maturation markers (Mucin-2 and villin) but did not consistently affect stemness markers or other Wnt target genes (lgr5, olfm4, ascl2, cdkn1). In enteroids, the stimulation of RA production by SCFA was mimicked by inhibitors of histone deacetylase 3 (HDAC3) but not by HDAC1/2 inhibitors nor by agonists of butyrate receptors G-protein-coupled receptor (GPR)43 or GPR109A, indicating that butyrate stimulates RA production via HDAC3 inhibition. We conclude that the SCFA butyrate inhibits HDAC3 and thereby supports epithelial RA production.

Early intake of long-chain polyunsaturated fatty acids preserves brain structure and function in diet-induced obesity.

Worldwide, the incidence of obesity is increasing at an alarming rate, and the number of children with obesity is especially worrisome. These developments raise concerns about the physical, psychosocial and cognitive consequences of obesity. It was shown that early dietary intake of arachidonic acid (ARA) and docosahexaenoic acid (DHA) can reduce the detrimental effects of later obesogenic feeding on lipid metabolism and adipogenesis in an animal model of mild obesity. In the present study, the effects of early dietary ARA and DHA on cognition and brain structure were examined in mildly obesogenic ApoE*3Leiden mouse model. We used cognitive tests and neuroimaging during early and later life. During their early development after weaning (4-13weeks of age), mice were fed a chow diet or ARA and DHA diet for 8 weeks and then switched to a high-fat and high-carbohydrate (HFHC) diet for 12weeks (14-26weeks of age). An HFHC-diet led to increased energy storage in white adipose tissue, increased cholesterol levels, decreased triglycerides levels, increased cerebral blood flow and decreased functional connectivity between brain regions as well as cerebrovascular and gray matter integrity. ARA and DHA intake reduced the HFHC-diet-induced increase in body weight, attenuated plasma triglycerides levels and improved cerebrovasculature, gray matter integrity and functional connectivity in later life. In conclusion, an HFHC diet causes adverse structural brain and metabolic adaptations, most of which can be averted by dietary ARA and DHA intake early in life supporting metabolic flexibility and cerebral integrity later in life.

Breast milk nutrient content and infancy growth.

AIM: Benefits of human breast milk (HM) in avoiding rapid infancy weight gain and later obesity could relate to its nutrient content. We tested the hypothesis that differential HM total calorie content (TCC) or macronutrient contents may be associated with infancy growth. METHODS: HM hindmilk samples were collected at ages 4-8 weeks from 614 mothers participating in a representative birth cohort, with repeated infancy anthropometry. HM triglyceride (fat), lipid analytes and lactose (carbohydrate) were measured by (1) H-NMR, and protein content by the Dumas method. TCC and %macronutrients were determined. RESULTS: In 614 HM samples, fat content was as follows: [median(IQR)]: 2.6 (1.7-3.6) g/100 mL, carbohydrate: 8.6 (8.2-8.8) g/100 mL, protein: 1.2 (1.1-1.2) g/100 mL; TCC: 61.8 (53.7-71.3) kcal/100 mL. HM of mothers exclusively breast feeding vs. mixed feeding was more calorific with higher %fat, lower %carbohydrate and lower %protein. Higher HM TCC was associated with lower 12-months body mass index (BMI)/adiposity, and lower 3-12 months gains in weight/BMI. HM %fat was inversely related to 3-12 months gains in weight, BMI and adiposity, whereas %carbohydrate was positively related to these measures. HM %protein was positively related to 12-months BMI. CONCLUSION: HM analysis showed wide variation in %macronutrients. Although data on milk intakes were unavailable, our findings suggest functional relevance of HM milk composition to infant growth.

Towards microbial fermentation metabolites as markers for health benefits of prebiotics.

Available evidence on the bioactive, nutritional and putative detrimental properties of gut microbial metabolites has been evaluated to support a more integrated view of how prebiotics might affect host health throughout life. The present literature inventory targeted evidence for the physiological and nutritional effects of metabolites, for example, SCFA, the potential toxicity of other metabolites and attempted to determine normal concentration ranges. Furthermore, the biological relevance of more holistic approaches like faecal water toxicity assays and metabolomics and the limitations of faecal measurements were addressed. Existing literature indicates that protein fermentation metabolites (phenol, p-cresol, indole, ammonia), typically considered as potentially harmful, occur at concentration ranges in the colon such that no toxic effects are expected either locally or following systemic absorption. The endproducts of saccharolytic fermentation, SCFA, may have effects on colonic health, host physiology, immunity, lipid and protein metabolism and appetite control. However, measuring SCFA concentrations in faeces is insufficient to assess the dynamic processes of their nutrikinetics. Existing literature on the usefulness of faecal water toxicity measures as indicators of cancer risk seems limited. In conclusion, at present there is insufficient evidence to use changes in faecal bacterial metabolite concentrations as markers of prebiotic effectiveness. Integration of results from metabolomics and metagenomics holds promise for understanding the health implications of prebiotic microbiome modulation but adequate tools for data integration and interpretation are currently lacking. Similarly, studies measuring metabolite fluxes in different body compartments to provide a more accurate picture of their nutrikinetics are needed.

Effect of perinatally supplemented flavonoids on brain structure, circulation, cognition, and metabolism in C57BL/6J mice.

Evidence suggests that flavanol consumption can beneficially affect cognition in adults, but little is known about the effect of flavanol intake early in life. The present study aims to assess the effect of dietary flavanol intake during the gestational and postnatal period on brain structure, cerebral blood flow (CBF), cognition, and brain metabolism in C57BL/6J mice. Female wild-type C57BL/6J mice were randomly assigned to either a flavanol supplemented diet or a control diet at gestational day 0. Male offspring remained on the corresponding diets throughout life and performed cognitive and behavioral tests during puberty and adulthood assessing locomotion and exploration (Phenotyper and open field), sensorimotor integration (Rotarod and prepulse inhibition), and spatial learning and memory (Morris water maze, MWM). Magnetic resonance spectroscopy and imaging at 11.7T measured brain metabolism, CBF, and white and gray matter integrity in adult mice. Biochemical and immunohistochemical analyses evaluated inflammation, synaptic plasticity, neurogenesis, and vascular density. Cognitive and behavioral tests demonstrated increased locomotion in Phenotypers during puberty after flavanol supplementation (p = 0.041) but not in adulthood. Rotarod and prepulse inhibition demonstrated no differences in sensorimotor integration. Flavanols altered spatial learning in the MWM in adulthood (p = 0.039), while spatial memory remained unaffected. Additionally, flavanols increased diffusion coherence in the visual cortex (p = 0.014) and possibly the corpus callosum (p = 0.066) in adulthood. Mean diffusion remained unaffected, a finding that corresponds with our immunohistochemical data showing no effect on neurogenesis, synaptic plasticity, and vascular density. However, flavanols decreased CBF in the cortex (p = 0.001) and thalamus (p = 0.009) in adulthood. Brain metabolite levels and neuroinflammation remained unaffected by flavanols. These data suggest that dietary flavanols results in subtle alterations in brain structure, locomotor activity and spatial learning. Comparison of these data to published findings in aging or neurodegeneration suggests that benefits of dietary flavanols may increase with advancing age and in disease.

Nutritional ingredients modulate adipokine secretion and inflammation in human primary adipocytes.

Nutritional factors such as casein hydrolysates and long chain polyunsaturated fatty acids have been proposed to exert beneficial metabolic effects. We aimed to investigate how a casein hydrolysate (eCH) and long chain polyunsaturated fatty acids could affect human primary adipocyte function in vitro. Incubation conditions with the different nutritional factors were validated by assessing cell vitality with lactate dehydrogenase (LDH) release and neutral red incorporation. Intracellular triglyceride content was assessed with Oil Red O staining. The effect of eCH, a non-peptidic amino acid mixture (AA), and long-chain polyunsaturated fatty acids (LC-PUFAs) on adiponectin and leptin secretion was determined by enzyme-linked immunosorbent assay (ELISA). Intracellular adiponectin expression and nuclear factor-κB (NF-κB) activation were analyzed by Western blot, while monocyte chemoattractant protein-1 (MCP-1) release was explored by ELISA. The eCH concentration dependently increased adiponectin secretion in human primary adipocytes through its intrinsic peptide bioactivity, since the non-peptidic mixture, AA, could not mimic eCH's effects on adiponectin secretion. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and DHA combined with arachidonic acid (ARA) upregulated adiponectin secretion. However, only DHA and DHA/ARA exerted a potentanti-inflammatory effect reflected by prevention of tumor necrosis factor-α (TNF-α) induced NF-κB activation and MCP-1 secretion in human adipocytes. eCH and DHA alone or in combination with ARA, may hold the key for nutritional programming through their anti-inflammatory action to prevent diseases with low-grade chronic inflammation such as obesity or diabetes.

Impact of dietary n-3 polyunsaturated fatty acids on cognition, motor skills and hippocampal neurogenesis in developing C57BL/6J mice.

Maternal intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) is critical during perinatal development of the brain. Docosahexaenoic acid (DHA) is the most abundant n-3 PUFA in the brain and influences neuronal membrane function and neuroprotection. The present study aims to assess the effect of dietary n-3 PUFA availability during the gestational and postnatal period on cognition, brain metabolism and neurohistology in C57BL/6J mice. Female wild-type C57BL/6J mice at day 0 of gestation were randomly assigned to either an n-3 PUFA deficient diet (0.05% of total fatty acids) or an n-3 PUFA adequate diet (3.83% of total fatty acids) containing preformed DHA and its precursor α-linolenic acid. Male offspring remained on diet and performed cognitive tests during puberty and adulthood. In adulthood, animals underwent (31)P magnetic resonance spectroscopy to assess brain energy metabolites. Thereafter, biochemical and immunohistochemical analyses were performed assessing inflammation, neurogenesis and synaptic plasticity. Compared to the n-3 PUFA deficient group, pubertal n-3 PUFA adequate fed mice demonstrated increased motor coordination. Adult n-3 PUFA adequate fed mice exhibited increased exploratory behavior, sensorimotor integration and spatial memory, while neurogenesis in the hippocampus was decreased. Selected brain regions of n-3 PUFA adequate fed mice contained significantly lower levels of arachidonic acid and higher levels of DHA and dihomo-γ-linolenic acid. Our data suggest that dietary n-3 PUFA can modify neural maturation and enhance brain functioning in healthy C57BL/6J mice. This indicates that availability of n-3 PUFA in infant diet during early development may have a significant impact on brain development.

Enteral supplementation of bovine lactoferrin improves gut barrier function in rats after massive bowel resection.

Previous studies have shown that bovine lactoferrin (bLF) exerts antibacterial, immune-modulating and anti-inflammatory effects. The present study aimed to investigate the effect of enteral bLF supplementation on intestinal adaptation and barrier function in a rat model of short bowel syndrome (SBS). Male Sprague-Dawley rats aged 4 weeks were randomised into three groups (n 10 per group): Sham group (rats submitted to bowel transection and reanastomosis); SBS group (rats submitted to 80 % small-bowel resection); SBS-bLF group (rats submitted to 80 % small-bowel resection plus treatment with bLF (0·5 g/kg per d) by oral administration from day 2 to day 20). Despite similar food intake, both the SBS and SBS-bLF groups exhibited significantly lower body weight gain, but increased villus height and crypt depth and a higher intestinal epithelial cell proliferation index (P< 0·05) when compared with the Sham group. Compared with that in the SBS group, in the SBS-bLF group, bacterial translocation to regional organs was low and intestinal permeability was significantly reduced. The SBS-bLF group also had increased secretory IgA (sIgA) concentrations in ileal contents (29·9 (23·8-33·0) ng/ml), when compared with the other two groups having similar sIgA concentrations (17·5 (12·6-29·1) and 19·3 (11·5-27·0) ng/ml, respectively). The relative expression levels of two tight junction (TJ) proteins, occludin and claudin-4, in the SBS-bLF group were significantly higher than those in the SBS group (P< 0·05), but did not exhibit any significant differences when compared with those in the Sham group. In conclusion, enteral bLF supplementation up-regulates small-bowel sIgA concentrations and TJ protein expression and reduces intestinal permeability and could thus support intestinal barrier integrity and protect against bacterial infections in SBS.

Differential digestion of human milk proteins in a simulated stomach model.

A key element in understanding how human milk proteins support the health and development of the neonate is to understand how individual proteins are affected during digestion. In the present study, a dynamic gastric model was used to simulate infant gastric digestion of human milk, and a subsequent proteomic approach was applied to study the behavior of individual proteins. A total of 413 human milk proteins were quantified in this study. This approach demonstrated a high degree of variability in the susceptibility of human milk proteins to gastric digestion. Specifically this study reports that lipoproteins are among the class of slowly digested proteins during gastric processes. The levels of integral lysozyme C and partial lactadherin in milk whey increase over digestion. Mucins, ribonuclease 4, and macrophage mannose receptor 1 are also resistant to gastric digestion. The retention or enhancement in whey protein abundance can be ascribed to the digestive release of milk-fat-globule-membrane or immune-cell enclosed proteins that are not initially accessible in milk. Immunoglobulins are more resistant to digestion compared to total milk proteins, and within the immunoglobulin class IgA and IgM are more resistant to digestion compared to IgG. The gastric digestion of milk proteins becomes more apparent from this study.

Dietary polyunsaturated fatty acids and non-digestible oligosaccharides reduce dermatitis in mice.

BACKGROUND: Oral administration of specific food ingredients can modify mucosal and systemic inflammatory processes. Such food components are fatty acids or carbohydrates. Nevertheless, little is known about the impact of oral administration of polyunsaturated fatty acids (PUFA) and non-digestible oligosaccharides on allergen-induced dermatitis. METHOD: In this pilot study, skin inflammation was induced by serial epicutaneous OVA applications in OVA-sensitized mice. In parallel, mice were fed with solid food containing arachidonic acid/docosahexaenoic acid (AA/DHA), galactooligosaccharide/polydextrose (GOS/PDX) or their combination. Skin lesions were assessed by clinical skin score, but also skin barrier parameters, immunohistochemical analyses, and local cytokine expression profile. RESULTS: Both dietary AA/DHA and GOS/PDX significantly ameliorated the severity of allergen-induced dermatitis. The clinical improvement upon oral AA/DHA and GOS/PDX supplementation was associated with a reduction in transepidermal water loss and reduced KI-67 expression in the skin. Lesional CD8+ and mast cells were reduced in all treatment groups, but appeared to be most pronounced in combined AA/DHA/GOS/PDX-treated mice. Moreover, in GOS/PDX-treated mice, IFNγ and TGFß expression was increased in skin lesions. CONCLUSION: Dietary supplementation with DHA/AA and GOS/PDX ameliorates symptoms of allergen-induced dermatitis and may thus be beneficial in the dietary management of human atopic eczema.

Arachidonic acid/docosahexaenoic acid-supplemented diet in early life reduces body weight gain, plasma lipids, and adiposity in later life in ApoE*3Leiden mice.

SCOPE: This study addresses whether early life arachidonic acid (ARA)/docosahexaenoic acid (DHA) supplementation or eicosapentaenoic acid (EPA)/DHA (Omacor) supplementation affects body weight gain, lipid metabolism, and adipose tissue quantity and quality in later life in ApoE*3Leiden-transgenic mice, a humanized model for hyperlipidemia and mild obesity. METHODS AND RESULTS: Four-week-old male ApoE*3Leiden mice were fed chow diet with or without a mixture of ARA (0.129 wt%) and DHA (0.088 wt%) or Omacor (0.30 wt% EPA, 0.25 wt% DHA). At age 12 weeks, mice were fed high-fat/high-carbohydrate (HFHC) diet without above supplements until age 20 weeks. Control mice received chow diet throughout the study. Mice receiving ARA/DHA gained less body weight compared to control and this effect was sustained when fed HFHC. Omacor had no significant effect on body weight gain. Plasma cholesterol and triglycerides were significantly lowered by both supplementations. At 20 weeks, epididymal fat mass was less in ARA/DHA-supplemented mice, while Omacor had no significant effect on fat mass. Both ARA/DHA and Omacor reduced inguinal adipocyte cell size; only ARA/DHA significantly reduced epididymal macrophage infiltration. CONCLUSION: This study shows that early life ARA/DHA, but not Omacor supplementation improves body weight gain later in life. ARA/DHA and to a lesser extent Omacor both improved adipose tissue quality.

Transforming growth factor-ß, a whey protein component, strengthens the intestinal barrier by upregulating claudin-4 in HT-29/B6 cells.

TGFß (isoforms 1-3) has barrier-protective effects in the intestine. The mechanisms involved in regulating tight junction protein expression are poorly understood. The aim of this study was to elucidate TGFß-dependent protective effects with special attention to promoter regulation of tight junction proteins using the HT-29/B6 cell model. In addition, the effects of whey protein concentrate 1 (WPC1), a natural source of TGFß in human nutrition, were examined. For this purpose, the claudin-4 promoter was cloned and tested for its activity. It exhibited transactivation in response to TGFß1, which was intensified when Smad-4 was cotransfected, indicating a Smad-4-dependent regulatory component. Shortening and mutation of the promoter altered and attenuated this effect. WPC1 induced an increase in the claudin-4 protein level and resistance of HT-29/B6 cell monolayers. Anti-TGFß(1-3) antibodies blocked these whey protein effects, suggesting that a main part of this function was mediated through TGFß. This effect was observed on intact monolayers as well as when barrier function was impaired by preexposure to IFNγ. In conclusion, TGFß1 affects claudin-4 gene expression via Smad-4-dependent and -independent transcriptional regulation, resulting in barrier protection, a cytokine effect that is also found in whey protein concentrates used in enteral nutrition.