Milk fat globule membrane coating of large lipid droplets in the diet of young mice prevents body fat accumulation in adulthood.

Epidemiological studies have demonstrated protective effects of breast-feeding on childhood obesity. Differences between human milk and infant milk formula (IMF) in dietary lipid structure may contribute to this effect. In our mouse model, feeding a diet containing large lipid droplets coated with phospholipids (PL) (Nuturis®; PL of milk fat globule membrane (MFGM) fraction origin) in early life protected against excessive body fat accumulation following a diet challenge in adult life. We now set out to determine the relevance of increased droplet size and/or MFGM lipid droplet coating to the observed anti-obesogenic effects in adult life. From day 16 to 42, male mouse pups were exposed to diets with small (S) or large (L) lipid droplets (0·3 v. 2·9 µm average mode diameter, respectively), either without MFGM or with MFGM coating around the lipid droplet, resulting in four groups: S (control diet), L, Scoating and Lcoating (Nuturis® IMF diet). Mice were subsequently challenged with a Western-style diet until dissection at postnatal day 98. A non-challenged group served as reference (REF). We repeatedly determined body composition between postnatal day 42 and 98. At day 98 plasma and gene expression measurements were performed. Only the Nuturis® IMF diet (Lcoating) in early life containing MFGM-coated large lipid droplets reduced body fat mass to a level comparable with the REF group. These data support the notion that the structural aspects of lipids in human milk, for example, both lipid droplet size as well as the MFGM coating, may contribute to its reported protective effect against obesity in later life.

Effect of dietary lipid structure in early postnatal life on mouse adipose tissue development and function in adulthood.

Obese individuals have more (hyperplastic) and larger (hypertrophic) adipocytes in their white adipose tissue (WAT) than normal-weight individuals. The difference in cell number emerges early in childhood, suggesting that this is a critical period for being susceptible to obesity. Breast-feeding has been shown to be protective against obesity, and we have previously shown in mice that the physical structure of lipids in human milk may contribute to this protective effect. In the present study, we investigated how differences in the physical structure of lipids in the early diet may modulate adipose tissue development. Male mice were fed a diet containing control infant milk formula (Control IMF; Danone Research) or Nuturis® (Concept IMF with large phospholipid-coated lipid droplets; Danone Research) from postnatal day (PN)16 to 42. Subsequently, mice were challenged with a moderate Western-style diet (WSD) until PN98, and body composition was monitored by dual-energy X-ray absorptiometry. Epididymal WAT was analysed for adipocyte size, number and gene expression of metabolic transcription factors. Early Concept IMF exposure reduced fat accumulation during the WSD challenge by 30 % compared with the Control IMF. It reduced adipocyte size without affecting adipocyte number in adult mice. The Concept IMF decreased the expression of PPARγ, CCAAT/enhancer-binding protein and retinoid X receptor α in WAT in adulthood, key regulators of metabolic activity. In conclusion, Concept IMF exposure in early life reduced susceptibility to obesity in adult life, by preventing adipocyte hypertrophia upon adult dietary challenge without affecting adipogenesis. These data emphasise the importance of the physical properties of dietary lipids in early life in obesity risk later in life.

Size and phospholipid coating of lipid droplets in the diet of young mice modify body fat accumulation in adulthood.

BACKGROUND: In addition to contemporary lifestyle factors that contribute to the increased obesity prevalence worldwide, early nutrition is associated with sustained effects on later life obesity. We hypothesized that physical properties of dietary lipids contribute to this nutritional programming. We developed a concept infant formula (IMF) with large, phospholipid-coated lipid droplets (Nuturis; Danone Research, Paris, France) and investigated its programming effect on metabolic phenotype later in life. METHODS: Male C57Bl/6j mice were fed a control formula (Control IMF) or Nuturis (Concept IMF) diet between postnatal day (PN)16 and PN42. All mice were subsequently fed a Western-style diet (WSD) until PN126. Body composition was monitored repeatedly by dual-energy X-ray absorptiometry between PN42 and PN126. RESULTS: Concept IMF slightly increased lean body mass as compared with Control IMF at PN42 but did not affect fat mass. Upon 84 d of WSD feeding, the Concept IMF group showed reduced fat accumulation as compared with Control IMF. In addition, fasting plasma leptin, resistin, glucose, and lipids were significantly lower in the Concept IMF group. CONCLUSION: Large phospholipid-coated lipid droplets in young mice reduced fat accumulation and improved metabolic profile in adulthood. These data emphasize that physical properties of early dietary lipids contribute to metabolic programming.

Bacterial translocation is reduced by a specific nutritional combination in mice with chemotherapy-induced neutropenia.

Immune function is compromised in many cancer patients, leading to an increased risk of (infectious) complications. Chemotherapy-induced neutropenia is a common cause of treatment-induced immune suppression. In the present study, the effect of a specific nutritional combination (SNC) on bacterial translocation was studied in a model of chemotherapy-induced neutropenia in C3H/HeN mice colonized with Pseudomonas aeruginosa PAO-1. Dietary intervention started after stable colonization with P. aeruginosa to compare the SNC containing high protein, l-leucine, fish oil, and specific oligosaccharides to an isoenergetic control diet. After 3 wk, the mice were treated with cyclophosphamide to induce neutropenia. This rendered the mice susceptible to Pseudomonas translocation, which was quantified 5 d later. Intervention with the SNC resulted in a reduced incidence and intensity of bacterial translocation to the liver (P < 0.05) and a similar trend in the lungs (P ≤ 0.057). In addition, the SNC reduced the fecal pH (P < 0.05) and decreased P. aeruginosa counts in fecal samples (P < 0.05). Moreover, plasma concentrations of proinflammatory cytokines were correlated with the reduced bacterial translocation to the liver (ρ > 0.78; P < 0.001). In conclusion, dietary intervention with the SNC significantly reduced the incidence and severity of P. aeruginosa translocation in a mouse model of chemotherapy-induced immune suppression. Several mechanisms might have played a role, including the modulation of the intestinal microbiota, an improved gut barrier function, immune function, and a reduced inflammatory state. These results suggest an opportunity to develop new applications in cancer patients, with the aim to reduce infectious and other complications.

N-3 long-chain polyunsaturated fatty acids prevent excessive fat deposition in adulthood in a mouse model of postnatal nutritional programming.

This study investigates whether improved quality of nutrients during early postnatal life has effects on adult metabolic profile and body composition in a murine model of nutritional programming. Male offspring of C57Bl/6j dams received a diet containing 21% energy (En%) as fat of either 100% vegetable oils [control (CTRL)] or 80% vegetable oils/20% tuna fish oil [rich in n-3 long-chain polyunsaturated fatty acids (n-3 LCP)] from postnatal day (PN) 2 to 42. Subsequently, mice of both experimental groups were switched to a western style diet (WSD; 21 En% fat, high saturated fatty acid [FA] content, and cholesterol) until dissection at PN98. Body composition was analyzed by dual x-ray absorptiometry during the WSD challenge. Results showed that a n-3 LCP-rich diet during postnatal life not only reduced fat accumulation by ∼30% during the WSD challenge from PN42 to 98 (p < 0.001) but also led to a healthier plasma lipid profile, healthier plasma glucose homeostasis, and less hypertrophic adipocytes compared with CTRL. This study shows that postnatal nutrition has programming effects on adult body composition and metabolic homeostasis. In addition, it emphasizes that moderate alterations in fat quality during early postnatal life considerably affect adult metabolic health.

An Increased Dietary Supply of Medium-Chain Fatty Acids during Early Weaning in Rodents Prevents Excessive Fat Accumulation in Adulthood.

Medium-chain fatty acids (MCFA) are a directly and readily absorbed source of energy. Exposure early-in-life to increased MCFA levels might affect development and impact (lipid) metabolism later in life. We tested whether an increased MCFA intake early-in-life positively affects adult body composition and metabolic status when challenged by a western-style diet (WSD). Male offspring of C57Bl/6j mice and Wistar rats were fed a control diet (CTRL; 10 w% fat, 14% MCFA) or a medium-chain triglycerides (MCT) diet with 20% MCFA until postnatal (PN) day 42, whereupon animals were fed a WSD (10 w% fat) until PN day 98. Body composition was monitored by Dual Energy X-ray Absorptiometry (DEXA). In rats, glucose homeostasis was assessed by glucose tolerance test (GTT) and insulin tolerance test (ITT); in mice, the HOmeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated. At autopsy on PN day 98, plasma lipid profiles, glucose, insulin, and adipokines were measured; organs and fat pads were collected and the adipocyte size distribution was analysed. Milk analysis in mice showed that the maternal MCT diet was not translated into milk, and pups were thus only exposed to high MCT levels from early weaning onward: PN day 16 until 42. Mice exposed to MCT showed 28% less fat accumulation vs. CTRL during WSD. The average adipocyte cell size, fasting plasma triglycerides (TG), and leptin levels were reduced in MCT mice. In rats, no effects were found on the adult body composition, but the adipocyte cell size distribution shifted towards smaller adipocytes. Particularly mice showed positive effects on glucose homeostasis and insulin sensitivity. Increased MCFA intake early-in-life protected against the detrimental effects of an obesogenic diet in adulthood.

Intra- and inter-laboratory validation of an innovative huFcεRIα-RBL-2H3 degranulation assay for in vitro allergenicity assessment of whey hydrolysates.

Cow's milk-derived whey hydrolysates are milk substitutes for cow's milk allergic infants. Safety assessment of these hydrolysates is crucial. Currently, huFcεRIα-RBL-2H3 cells, sensitized with serum IgE from cow's milk allergic patients, are used to assess in vitro residual allergenicity. However, limited availability and high inter-lot variation of sera impede the standardization of safety testing. Recently, we generated an oligoclonal pool of chimeric human (chu)IgE antibodies against bovine ß-lactoglobulin (BLG) as an alternative for human serum. These antibodies demonstrated increased sensitivity, specificity and reproducibility. An inter-laboratory ring trial using our new degranulation assay with different whey-based hydrolysates was performed at four independent laboratories to investigate the robustness and reproducibility. RBL-2H3 cells expressing huFcεRIα were sensitized with our oligoclonal pool of anti-BLG chuIgE antibodies. The cells were subsequently incubated with an amino-acid based formula (AAF), two extensively hydrolyzed formulas (eHF) and three partially hydrolyzed formulas (pHF) to assess the degranulation upon challenge. Results demonstrated a very strong inter-laboratory correlation and the intra- and inter-laboratory variations were acceptable. The AAF and both eHFs showed no degranulation, whereas all pHFs demonstrated degranulation. The study showed that this degranulation assay is robust and reproducible within and between laboratories. This new in vitro degranulation assay seems predictive for allergenicity outcome and might therefore be considered as a relevant substitute for animal models.

Reduced linoleic acid intake in early postnatal life improves metabolic outcomes in adult rodents following a Western-style diet challenge.

The global increase in dietary n-6 polyunsaturated fatty acid (PUFA) intake has been suggested to contribute to the rise in obesity incidence. We hypothesized that reduced n-6 PUFA intake during early postnatal life improves adult body composition and metabolic phenotype upon a Western diet challenge. Male offspring of C57Bl/6j mice and Wistar rats were subjected to a control diet (CTRL; 3.16 En% linoleic acid [LA]) or a low n-6 PUFA diet (low LA; 1.36 En% LA) from postnatal days (PNs) 2 to 42. Subsequently, all animals were switched to a Western-style diet (2.54 En% LA) until PN98. We monitored body composition by dual-energy x-ray absorptiometry and glucose homeostasis by an intravenous glucose and insulin tolerance test in rats and by the homeostasis model assessment of insulin resistance (HOMA-IR) in mice. At PN98, plasma lipids, glucose, insulin, and adipokines were measured and adipocyte number and size were analyzed. In mice, the postnatal low-LA diet decreased fat accumulation during the adult Western-style diet challenge (-27% compared with CTRL, P < .001). Simultaneously, it reduced fasting triglyceride levels and lowered fasting resistin and leptin levels. In rats, the low-LA diet did not affect adult body composition, but decreased the number of retroperitoneal adipocytes and increased the number of large adipocytes. In conclusion, lowering dietary n-6 PUFA intake in early life protected against detrimental effects of an obesogenic diet in adulthood on metabolic homeostasis and fat mass accumulation.

Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity.

Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN) Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control). A 50%-75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed.

Rapid and selective manipulation of milk fatty acid composition in mice through the maternal diet during lactation.

Dietary fatty acid (FA) composition in early postnatal life can modulate growth and development and later metabolic health. Investigating programming effects of early dietary FA manipulations in rodents may be stressful and complicated due to the need of artificial feeding techniques. It is largely unknown to what extent breast milk (BM) FA composition can be directly manipulated by the diet. We exposed dams to different dietary FA compositions from postnatal day (PN) 2 until PN28. Dams with litters were randomly assigned to control (CTRL), high-medium-chain FA (MCFA), low-linoleic acid (LowLA), high-n-3 long-chain PUFA (n-3LCP) or high-n-3LCP and MCFA (n-3LCP/MCFA) diets, and diets were continued after weaning until PN28. FA compositions were determined in feeds, milk and in erythrocytes. BM MCFA content was independent from dietary MCFA intake. In contrast, the LowLA diet reduced BM LA content by about 50 % compared with the CTRL diet at PN7. BM of dams fed the n-3LCP or n-3LCP/MCFA diet contained about 6-fold more n-3 LCP than BM of the dams fed the CTRL diet at PN7. These changes in milk FA composition established after 5 d of dietary exposure did not further change over the lactation period. At PN28, the erythrocyte FA composition of the male pups correlated with analysed milk FA profiles. In conclusion, manipulation of the diet of lactating mice can strongly and rapidly affect BM FA composition, in particular of n-6 LA and n-3 LCP. Our present findings will facilitate mechanistic studies on the programming of adult metabolic health by dietary FA in the early postnatal period via direct and selective manipulation of the maternal diet.

In vivo pertussis toxin treatment reduces contraction of rat resistance arteries but not that of mouse trachea.

In order to develop an in vitro method for detecting residual pertussis toxin activity in acellular pertussis vaccines, the effects of in vivo pertussis toxin treatment on contraction and relaxation properties of isolated mouse trachea and of isolated rat small mesenteric resistance arteries were studied. In vivo pertussis toxin treatment (24 or 72 microg/kg, intraperitoneally (i.p.)) did not affect contraction and relaxation properties of isolated BALB/c or NIH mouse trachea. In vivo pertussis toxin treatment (30 microg/kg, intravenously) significantly reduced noradrenaline- or KCl-induced maximal contraction and reduced sensitivity to noradrenaline in isolated male Wistar rat small mesenteric resistance arteries. However, in vivo pertussis toxin treatment did not affect relaxation properties of isolated rat small mesenteric resistance arteries. These results support the hypothesis that vasoconstriction-regulating mechanisms and not airway constriction mechanisms are involved in pertussis toxin-induced histamine sensitisation. The vasoconstriction-regulating mechanisms may provide a lead for further development of an in vitro method for measuring biologically active pertussis toxin in acellular pertussis vaccines based on mechanisms involved in the histamine sensitisation test.

Impaired immune function: an early marker for cancer cachexia.

Cachexia and chronic inflammation are major challenges for cancer patients, leading to serious consequences. Accordingly, it is of high clinical relevance to identify early risk factors for optimal treatment, as these are currently not available. The present study demonstrates a strong decline in contact hypersensitivity, a parameter for cell-mediated immunity, in tumor-bearing cachectic mice. Interestingly, a significant reduction was already observed during the pre-cachectic state, reflecting an impaired immune function prior to weight loss. Extrapolating to the human setting, reduced immune competence of cancer patients could serve as an early marker for cancer cachexia, enabling an early supportive care strategy.

Mass-dependent decline of skeletal muscle function in cancer cachexia.

CD2F1 mice were inoculated with C26 adenocarcinoma cells, followed by assessment of ex vivo muscular function. Muscles from tumor-bearing mice had a significantly lower force output during a single maximal contraction and during repeated contractions than control muscles. The relative force output, however, did not differ when corrected for muscle mass. Thus, cachexia significantly reduces absolute skeletal muscle function, but muscle "quality" appears unaltered.