Inulin-Type Fructan Supplementation of 3- to 6-Year-Old Children Is Associated with Higher Fecal Bifidobacterium Concentrations and Fewer Febrile Episodes Requiring Medical Attention.

Background: Inulin-type fructans used in formula have been shown to promote microbiota composition and stool consistency closer to those of breastfed infants and to have beneficial effects on fever occurrence, diarrhea, and incidence of infections requiring antibiotic treatment in infants. Objectives: The primary study aim was to explore whether prophylactic supplementation with prebiotic fructans is able to influence the frequency of infectious diseases in kindergarten children during a winter period. A secondary objective was to ascertain the effect on the intestinal microbiota. Methods: 142 boys and 128 girls aged 3-6 y were randomly allocated to consume 6 g/d fructans or maltodextrin for 24 wk. At baseline, stool samples were collected for microbiota analysis and anthropometric measurements were made. During the intervention period diagnoses were recorded by physicians, whereas disease symptoms, kindergarten absenteeism, dietary habits, and stool consistency were recorded by parents. Baseline measurements were repeated at wk 24. Results: In total 219 children finished the study. Both the relative abundance of Bifidobacterium (P < 0.001) and that of Lactobacillus (P = 0.014) were 19.9% and 7.8% higher, respectively, post data normalization, in stool samples of children receiving fructans as compared with those of controls at wk 24. This was accompanied by significantly softer stools within the normal range in the prebiotic group from wk 12 onwards. The incidence of febrile episodes requiring medical attention [0.65 ± 1.09 compared with 0.9 ± 1.11 infections/(24 wk × child), P = 0.04] and that of sinusitis (0.01 ± 0.1 compared with 0.06 ± 0.25, P = 0.03) were significantly lower in the prebiotic group. The number of infectious episodes and their duration reported by parents did not differ significantly between the 2 intervention groups. Conclusions: Prebiotic supplementation modified the composition of the intestinal microbiota and resulted in softer stools in kindergarten-aged children. The reduction in febrile episodes requiring medical attention supports the concept of further studies on prebiotics in young children. This trial was registered at clinicaltrials.gov as NCT03241355.

Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs.

We examined whether changes in the gut microbiota induced by clinically relevant interventions would impact the bioavailability of dietary amino acids in neonates. We tested the hypothesis that modulation of the gut microbiota in neonatal pigs receiving no treatment (control), intravenously administered antibiotics, or probiotics affects whole body nitrogen and amino acid turnover. We quantified whole body urea kinetics, threonine fluxes, and threonine disposal into protein, oxidation, and tissue protein synthesis with stable isotope techniques. Compared with controls, antibiotics reduced the number and diversity of bacterial species in the distal small intestine (SI) and colon. Antibiotics decreased plasma urea concentrations via decreased urea synthesis. Antibiotics elevated threonine plasma concentrations and turnover, as well as whole body protein synthesis and proteolysis. Antibiotics decreased protein synthesis rate in the proximal SI and liver but did not affect the distal SI, colon, or muscle. Probiotics induced a bifidogenic microbiota and decreased plasma urea concentrations but did not affect whole body threonine or protein metabolism. Probiotics decreased protein synthesis in the proximal SI but not in other tissues. In conclusion, modulation of the gut microbiota by antibiotics and probiotics reduced hepatic ureagenesis and intestinal protein synthesis, but neither altered whole body net threonine balance. These findings suggest that changes in amino acid and nitrogen metabolism resulting from antibiotic- or probiotic-induced shifts in the microbiota are localized to the gut and liver and have limited impact on whole body growth and anabolism in neonatal piglets.

Breast milk fatty acid profile in relation to infant growth and body composition: results from the INFAT study.

BACKGROUND: There is some evidence that the n-6/n-3 long-chain polyunsaturated fatty acids (LCPUFAs) ratio in early nutrition, and thus in breast milk, could influence infant body composition. METHODS: In an open-label randomized controlled trial (RCT), 208 healthy pregnant women were allocated to a dietary intervention (supplementation with 1,200 mg n-3 LCPUFAs per day and instructions to reduce arachidonic acid (AA) intake) from the 15th wk of gestation until 4 mo of lactation or to follow their habitual diet. Breast milk LCPUFAs at 6 wk and 4 mo postpartum were related to infant body composition assessed by skinfold thickness (SFT) measurements and ultrasonography during the first year of life. RESULTS: Dietary intervention significantly reduced breast milk n-6/n-3 LCPUFAs ratio. In the whole sample, early breast milk docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and n-3 LCPUFAs at 6 wk postpartum were positively related to the sum of four SFT measurements at age 1. Breast milk AA and n-6 LCPUFAs at 6 wk postpartum were negatively associated with weight, BMI, and lean body mass (LBM) up to 4 mo postpartum. CONCLUSION: Breast milk n-3 LCPUFAs appear to stimulate fat mass growth over the first year of life, whereas AA seems to be involved in the regulation of overall growth, especially in the early postpartum period.

Antibiotic use in infants in the first year of life in five European countries.

AIM: To assess in infants the number of illness episodes treated with antibiotics and prescription rates in five European countries. METHODS: This study was embedded in a multicenter nutritional intervention study and was conducted in five European countries. Infants were followed until 1 year of age. Illness episodes and prescriptions of systemic antibiotics were recorded by the parents. RESULTS: Illness episodes were caused by upper respiratory tract infections (URTIs) in 55-64% and by otitis media (OM) in 2-6.8%. URTIs were statistically significant and more frequently treated with antibiotics in Italy (18.8%), and less frequently in Switzerland (1.4%). OM was statistically significant and less frequently treated with antibiotics in the Netherlands (55%) when compared to Italy (82%). The antibiotic prescription rate varied between countries, ranging from 0.2 to 1.3 prescriptions per infant per year. CONCLUSIONS: As the frequency of illness episodes did not differ between countries, other factors, such as physician's attitude, parental pressure or other socio-economic determinants, most likely play a role in antibiotic prescribing habits in the first year of life.

Colitis development during the suckling-weaning transition in mucin Muc2-deficient mice.

The mucin Muc2 is the structural component of the colonic mucus layer. Adult Muc2 knockout (Muc2(-/-)) mice suffer from severe colitis. We hypothesized that Muc2 deficiency induces inflammation before weaning of mother's milk [postnatal day (P) 14] with aggravation of colitis after weaning (P28). Muc2(-/-) and wild-type mice were killed at embryonic day 18.5 and P1.5, P7.5, P14, P21, and P28. Colonic morphology, influx of T cells, and goblet cell-specific protein expression was investigated by (immuno)histochemistry. Cytokine and Toll-like receptor (TLR) profiles in the colon were analyzed by quantitative RT-PCR. Muc2(-/-) mice showed an increased and persistent influx of Cd3ε-positive T cells in the colonic mucosa as of P1.5. This was accompanied by mucosal damage at P28 in the distal colon but not in the proximal colon. At P14, the proinflammatory immune response [i.e., increased interleukin (IL)-12 p35, IL-12 p40, and tumor necrosis factor-α, expression] in the distal colon of Muc2(-/-) mice presented with an immune suppressive response [i.e., increased Foxp3, transforming growth factor (TGF)-ß1, IL-10, and Ebi3 expression]. In contrast, at P28, a proinflammatory response remained in the distal colon, whereas the immune suppressive response (i.e., Foxp3 and TGF-ß1 expression) declined. The proximal colon of Muc2(-/-) mice did not show morphological damage and was dominated by an immune suppressive response at P14 and P28. Interestingly, changes in expression of TLRs and TLR-related molecules were observed in the distal colon at P14 and P28 and in the proximal colon only at P28. Colitis in Muc2(-/-) mice is limited before weaning by immune suppressive responses and exacerbates in the distal colon after weaning because of the decline in the immune suppressive response.

A specific prebiotic mixture added to starting infant formula has long-lasting bifidogenic effects.

There is some evidence that early colonization of the intestine affects the composition of the intestinal microbiota after weaning. In the present study, the effect of prebiotics administered from the first day of life on fecal counts of bifidobacteria and lactobacilli were studied during and after the administration of the prebiotics. In this double-blind, randomized, placebo-controlled, explorative study, 20 newborns of hepatitis C virus-infected mothers who decided not to breast feed due to their concerns regarding their plasma viral load were randomly assigned to either a formula with 8 g/L of a specific prebiotic mixture (short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides, ratio 9:1) or a formula containing the same amount of maltodextrin (placebo). Clinical examination including anthropometric measurements, microbiological analysis of fecal samples, and blood leukocyte population analysis were performed at birth and 3, 6, and 12 mo age. At the age of 12 mo, hepatitis B vaccine-specific IgG serum titers (Hepatitis B virus surface antibodies) were also measured. Prebiotic supplementation resulted in more fecal bifidobacteria (P < 0.0001) and lactobacilli (P = 0.0044) compared with the placebo group. These differences between the groups were maintained during the second half of the first year without any prebiotic supplementation. There was no influence of the different diets on anthropometric data or the measured immunological variables. The data from this small explorative study indicate that early colonization of the intestine might have long-lasting effects on the composition of the intestinal microbiota.

Intestinal threonine utilization for protein and mucin synthesis is decreased in formula-fed preterm pigs.

Threonine is an essential amino acid necessary for synthesis of intestinal (glyco)proteins such as mucin MUC2 to maintain adequate gut barrier function. In premature infants, reduced barrier function may contribute to the development of necrotizing enterocolitis (NEC). Human milk protects against NEC compared with infant formula. Therefore, we hypothesized that formula feeding decreases the MUC2 synthesis rate concomitant with a decrease in intestinal first-pass threonine utilization, predisposing the preterm neonate to NEC. Preterm pigs were delivered by caesarian section and received enteral feeding with formula (FORM; n = 13) or bovine colostrum (COL; n = 6) for 2 d following 48 h of total parenteral nutrition. Pigs received a dual stable isotope tracer infusion of threonine to determine intestinal threonine kinetics. NEC developed in 38% of the FORM pigs, whereas none of the COL pigs were affected (P = 0.13). Intestinal fractional first-pass threonine utilization was lower in FORM pigs (49 ± 2%) than in COL pigs (60 ± 4%) (P = 0.02). In FORM pigs compared with COL pigs, protein synthesis (369 ± 31 mg·kg(-1)·d(-1) vs. 615 ± 54 mg·kg(-1)·d(-1); P = 0.003) and MUC2 synthesis (121 ± 17%/d vs. 184 ± 15%/d; P = 0.02) were lower in the distal small intestine (SI). Our results suggest that formula feeding compared with colostrum feeding in preterm piglets reduces mucosal growth with a concomitant decrease in first-pass splanchnic threonine utilization, protein synthesis, and MUC2 synthesis in the distal SI. Hence, decreased intestinal threonine metabolism and subsequently impaired gut barrier function may predispose the formula-fed infant to developing NEC.

The Groningen LCPUFA study: No effect of short-term postnatal long-chain polyunsaturated fatty acids in healthy term infants on cardiovascular and anthropometric development at 9 years.

Conflicting evidence exists on the effect of long-chain polyunsaturated fatty acid (LCPUFA) formula supplementation on cardiovascular health in term infants. It is known that LCPUFA supplementation does not affect infant growth, but long term outcome data are not available. The current study investigates whether 2 mo LCPUFA formula supplementation affects cardiovascular and anthropometric development at 9 y. A prospective, double-blind, randomized trial was performed in healthy term infants: a standard formula control group (CF, n = 169) and a LCPUFA-supplemented group [LF, n = 145; 0.45% (by wt) AA and 0.30% (by wt) docosahexaenoic acid (DHA)]. A breastfed group (BF; n = 159) served as reference. At the age of 9 y, systolic and diastolic blood pressure, heart rate, head circumference, weight, and height were measured. Univariate and multivariate analyses were performed; 63 to 79% of children were assessed. None of the cardiovascular or anthropometric measurements differed between the formula groups. Breastfed children had a marginally lower heart rate than formula-fed children, in particular compared with children fed control formula. Blood pressure and parameters of growth including BMI of breast and formula-fed children did not differ. In conclusion, the study suggests that short-term LCPUFA supplementation does not influence cardiovascular and anthropometric development at 9 y.

Non-digestible oligosaccharides reduce immunoglobulin free light-chain concentrations in infants at risk for allergy.

Prebiotic oligosaccharides influence the intestinal microbiota and can positively modulate the infant's immune system. It was demonstrated that a special prebiotic mixture (Immunofortis(®)) of short-chain galacto-oligosaccharides (scGOS) and long-chain fructo-oligosaccharides (lcFOS) can reduce the cumulative incidence of atopic dermatitis (AD) in infants at risk for allergy as determined using the AD symptom score (SCORAD). Additionally, it was shown very recently that immunoglobulin free light-chain (Ig-fLC) might be involved in the pathophysiology of allergic disease. Increased Ig-fLC concentrations were found in patients suffering from AD, cow's milk allergy, allergic rhinitis, or asthma. In this study, the effect of supplementation of scGOS/lcFOS on the Ig-fLC plasma concentrations in infants at risk for allergy was assessed. The plasma kappa and lambda Ig-fLC concentrations were measured in a double-blind, placebo-controlled, randomized trial, in which infants at risk for developing allergic disease received a hypoallergenic whey formula containing 8 g/l of the scGOS/lcFOS mixture (n = 34) or maltodextrin as a placebo (n=40) for 6 months. After intervention, plasma samples were collected, and total plasma concentrations of lambda and kappa Ig-fLC were analyzed using ELISA. Total kappa and lambda Ig-fLC plasma concentrations were higher in infants suffering from AD when compared to infants without any sign of AD. In infants receiving the prebiotic mixture, the Ig-fLC levels were significantly lower compared to the placebo-fed infants (p<0.001). Interestingly, lambda Ig-fLC concentrations were positively correlated with total IgE (p<0.05). These data demonstrate for the first time that the specific scGOS/lcFOS mixture lowered kappa and lambda Ig-fLC plasma concentrations in infants at high risk for allergies when compared to infants receiving placebo formula. Because Ig-fLC concentrations were increased in infants suffering from AD, this may have contributed, at least in part, to the reduced incidence in AD as described previously. This suggests a possible role for Ig-fLC in the pathophysiology of AD in infants at risk for allergy development.

Do prebiotics reduce the number of fever episodes in healthy children in their first year of life: a randomised controlled trial.

The objective of the present study was to assess the effect of adding specific prebiotics to standard formula feeding on the number of fever episodes in the first year of life. In the present randomised, double-blind, placebo-controlled trial in seven centres in five West European countries, 830 healthy term infants, without a first-degree family history of allergic disease, of mothers who indicated to give only formula feeding were randomised either to receive a standard non-hydrolysed cows' milk-based formula to which a mixture of specific oligosaccharides was added (prebiotics group (PG)), or to receive a similar formula without oligosaccharides (control group (CG)). A separate reference group consisted of 300 breast-fed infants. The primary outcome was the number of fever episodes prospectively documented by the parents. There was no difference in the number of fever episodes between the PG (median value 1·19; 25th-75th percentile 0·09-2·34) and CG (1·16; 25th-75th percentile 0·06-2·38). The median number of fever episodes in the separate breast-feeding reference group was 1·24 (25th-75th percentile 0·51-3·45). There was no effect of adding specific prebiotics to standard formula feeding in reducing the number of fever episodes in the present study.

Reduced occurrence of early atopic dermatitis because of immunoactive prebiotics among low-atopy-risk infants.

BACKGROUND: Most infants developing atopic dermatitis have a low risk for atopy. Primary prevention of atopic dermatitis is difficult. OBJECTIVE: To assess the effect of supplementation of an infant and follow-on formula with prebiotic and immunoactive oligosaccharides on the occurrence of atopic dermatitis in the first year of life. METHODS: Healthy term infants from 5 European countries with low atopy risk were recruited before the age of 8 weeks, either having started with formula feeding or being on full breast-feeding (breast-feeding group). Formula-fed infants were randomized to feeding with a regular formula containing a specific mixture of neutral oligosaccharides and pectin-derived acidic oligosaccharides (prebiotic formula group) or regular formula without oligosaccharides (control formula group). RESULTS: A total of 414 infants were randomized to the prebiotic group and 416 infants to the control group. A total of 300 infants were followed in the breast-feeding group. Up to the first birthday, atopic dermatitis occurred in significantly fewer infants from the prebiotic group (5.7%) than from the control group (9.7%; P = .04). The cumulative incidence of atopic dermatitis in the prebiotic group was in the low range of the breast-feeding group (7.3%). In a Cox regression model, the rate of atopic dermatitis was significantly lower by 44% in the prebiotic group versus the control group (P = .04). The number needed to prevent 1 case of atopic dermatitis by supplementation of prebiotics was 25 infants. CONCLUSION: Formula supplementation with a specific mixture of oligosaccharides was effective as primary prevention of atopic dermatitis in low atopy risk infants.

Contribution of IgE and immunoglobulin free light chain in the allergic reaction to cow's milk proteins.

BACKGROUND: Cow's milk allergy (CMA) affects 2.5% of young infants. In previous murine studies it was observed that allergic sensitization to the major cow's milk allergens casein and whey led, respectively, to IgE-independent and IgE-dependent clinical responses. OBJECTIVES: In this study the involvement of immunoglobulin free light chains (Ig-fLCs) in the hypersensitivity response to cow's milk proteins was explored in mice, and Ig-fLC serum levels were determined in children affected by CMA or atopic dermatitis (AD). METHODS: Mice were orally sham, casein, or whey sensitized. Acute allergen-specific skin responses were determined, and serum immunoglobulin and Ig-fLC concentrations were measured. Ig-fLC dependency was validated by using the Ig-fLC blocker F991 in actively and passively sensitized mice. Ig-fLC serum concentrations were measured in a cohort of infants with CMA and infants with AD. RESULTS: After sensitization, no specific IgE was detectable in sera of casein-sensitized mice, whereas specific IgE levels were enhanced in whey-sensitized mice. Instead, Ig-fLC levels were increased in sera from casein-sensitized mice. Furthermore, blocking Ig-fLCs strongly diminished the allergic skin responses not only in casein-sensitized mice but also in mice transferred with splenocyte supernatants of casein-sensitized mice. In both patients with CMA and patients with AD, serum Ig-fLC concentrations were significantly enhanced. CONCLUSIONS: This study indicates that sensitization with cow's milk proteins can lead to both IgE-dependent and Ig-fLC-dependent allergic hypersensitivity responses. Also, in children affected with CMA or AD, serum Ig-fLC concentrations were increased, implying the relevance of Ig-fLC measurements in the diagnoses of human allergic disease.

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.

Prebiotic oligosaccharides: in vitro evidence for gastrointestinal epithelial transfer and immunomodulatory properties.

Prebiotic oligosaccharides are present in breast milk and evidence is pointing toward immunomodulatory properties of the acidic fraction. Recently, prebiotic supplements of infant formula [short-chain galacto (scGOS)-, long-chain fructo (lcFOS)-oligosaccharides] showed preventive effects on atopic disease development. We aimed to define the direct immunologic effects of these oligosaccharides and of human (aHMOS) and cows' milk (aCMOS) acidic oligosaccharides and to investigate the systemic uptake of prebiotic supplements of infant formula and a specific pectin-derived acidic oligosaccharide hydrolysate (pAOS) in vitro. After assurance of LPS-free conditions (limulus assay, toll like receptor-2, -4 transfected human embryonic kidney-cells), in vitro-transfer through a CaCo-2 cell monolayer was measured using high-pH anion exchange chromatography with pulsed amperometric detection. Direct effects on proliferation, cytokine-induction of cord blood mononuclear cells and modulation of allergen-specific CD4+ T-cell cytokine profiles from allergic and non-allergic individuals were investigated. Transfer of scGOS/lcFOS and pAOS in-vitro was detected with a rate of transfer of 4-14%, depending on the molecular size and structure. AHMOS induced IFN-γ and IL-10 but not the Th-2 cytokine IL-13 at physiologic concentrations (10-100 µg/ml) in cord blood, whereas aCMOS did not induce any of these cytokines. AHMOS significantly suppressed Th-2 type cytokine-production by Ara h1-specific CD4+ T cells (CFSE(low) CD3(+) CD4(+) cells) from peanut allergic patients. In conclusion, human milk-derived acidic oligosaccharides may modulate postnatal allergen-specific immune responses by the suppression of Th-2-type responses in atopy-prone individuals. Moreover, there is in vitro evidence for epithelial transport of prebiotic oligosaccharides.

Variation of human milk oligosaccharides in relation to milk groups and lactational periods.

Human milk oligosaccharides, representing the third largest fraction of human milk, have been assigned important protective functions for newborns acting as bifidogenic substrates or as inhibitory agents towards pathogens. Using high-pH anion-exchange chromatography and an enzyme test kit, twenty oligosaccharides and lactose were determined in milk samples of German women from days 3 to 90 postpartum. Twenty-two secretor mothers with Lewis blood group Le(a - b+) synthesised all twenty oligosaccharides, and could be assigned to milk group 1. Five non-secretor mothers (Le(a+b - )) produced all oligosaccharides with the exception of α1,2-fucosylated compounds (milk group 2), whereas three secretor mothers with blood type Le(a - b - ) lacked α1,4-fucosyloligosaccharides, corresponding to milk group 3. Secretor women of milk groups 1 and 3 synthesised significantly higher amounts of total neutral oligosaccharides and of several total core structures (e.g. lacto-N-tetraose) than non-secretor women. Generally, these oligosaccharides significantly decrease during the first 3 months postpartum. By comparing fucosyloligosaccharides within and among the three milk groups, insight into their biosynthesis could be gained. Six acidic oligosaccharides without fucose residues were detected in milk samples of all mothers. Regression analysis confirmed that total acidic oligosaccharides declined threefold during the study period. Milk samples corresponding to the three milk groups exhibited significant qualitative and quantitative differences during the first 3 months of lactation. It can be assumed that particularly milk of non-secretor women (milk group 2) exerts a modified biological protection in the babies in comparison with milks of secretors (groups 1 and 3).

Fatty acid profile comparisons in human milk sampled from the same mothers at the sixth week and the sixth month of lactation.

OBJECTIVES: To compare fatty acid composition of human milk at 2 different stages of lactation and investigate the relation between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFAs) in human milk at the sixth month of lactation. SUBJECTS AND METHODS: We investigated human milk samples obtained at the sixth week and sixth month of lactation from 462 mothers who participated in a large birth cohort study. Fatty acid composition of human milk lipids was determined by high-resolution capillary gas-liquid chromatography. RESULTS: Fat contents of human milk increased significantly between the sixth week and sixth month of lactation (1.63 [2.06] and 3.19 [3.14], g/100 mL; median [interquartile range], P < 0.001). Percentage contributions to human milk fatty acid composition of nearly all polyunsaturated fatty acids also increased significantly (linoleic acid: 10.09 [4.41] and 11.01 [4.53], arachidonic acid: 0.46 [0.32] and 0.48 [0.23], alpha-linolenic acid: 0.69 [0.42] and 0.75 [0.41], and docosahexaenoic acid: 0.17 [0.23] and 0.23 [0.15], % wt/wt, P < 0.001). Values of the 18-carbon trans octadecenoic acid (C18:1n-7/9t) significantly inversely correlated to linoleic acid (r = -0.24, P < 0.001), alpha-linolenic acid (r = -0.19, P < 0.001), and arachidonic acid (r = -0.43, P < 0.001). In contrast, we found no correlation between the 16-carbon trans hexadecenoic acid (C16:1n-7t) and the same LCPUFAs. CONCLUSIONS: Data obtained in the present study indicate increasing fat contents with stable or increasing percentage contribution of LCPUFAs in human milk samples between the sixth week and at the sixth month of lactation, and the availability of 18-carbon trans isomeric fatty acids is inversely associated to the availability of several LCPUFAs in human milk at the sixth month of lactation.

The regulation of intestinal mucin MUC2 expression by short-chain fatty acids: implications for epithelial protection.

SCFAs (short-chain fatty acids), fermentation products of bacteria, influence epithelial-specific gene expression. We hypothesize that SCFAs affect goblet-cell-specific mucin MUC2 expression and thereby alter epithelial protection. In the present study, our aim was to investigate the mechanisms that regulate butyrate-mediated effects on MUC2 synthesis. Human goblet cell-like LS174T cells were treated with SCFAs, after which MUC2 mRNA levels and stability, and MUC2 protein expression were analysed. SCFA-responsive regions and cis-elements within the MUC2 promoter were identified by transfection and gel-shift assays. The effects of butyrate on histone H3/H4 status at the MUC2 promoter were established by chromatin immunoprecipitation. Butyrate (at 1 mM), as well as propionate, induced an increase in MUC2 mRNA levels. MUC2 mRNA levels returned to basal levels after incubation with 5-15 mM butyrate. Interestingly, this decrease was not due to loss of RNA stability. In contrast, at concentrations of 5-15 mM propionate, MUC2 mRNA levels remained increased. Promoter-regulation studies revealed an active butyrate-responsive region at -947/-371 within the MUC2 promoter. In this region we identified an active AP1 (c-Fos/c-Jun) cis-element at -818/-808 that mediates butyrate-induced activation of the promoter. Finally, MUC2 regulation by butyrate at 10-15 mM was associated with increased acetylation of histone H3 and H4 and methylation of H3 at the MUC2 promoter. In conclusion, 1 mM butyrate and 1-15 mM propionate increase MUC2 expression. The effects of butyrate on MUC2 mRNA are mediated via AP-1 and acetylation/methylation of histones at the MUC2 promoter.

Prebiotics improve gastric motility and gastric electrical activity in preterm newborns.

The aim of this double-blind, randomized, placebo-controlled study was to evaluate the effect of a prebiotic mixture on gastric motility in preterm newborns. After a feeding period of 15 days, gastric electrical activity was measured by electrogastrography, and the gastric emptying time was studied by ultrasound technique. No difference was seen in the daily increase of body weight, and no adverse events have been reported. The percentage of time in which propagation was detected in the electrogastrography signal was twice in newborns receiving formula with prebiotics with respect to placebo, and the gastric half-emptying time was 30% faster in the prebiotic group than the placebo group. Prebiotic oligosaccharides can modulate the electrical activity and the gastric emptying and may improve the intestinal tolerance of enteral feeding in preterm infants.

Structural and functional aspects of prebiotics used in infant nutrition.

Breast-feeding is associated with several benefits. Among them, the balanced postnatal development of the immune system is 1 of the key functions of breast-feeding. Although this effect is of multifactorial origin, it is widely accepted that the entire intestinal microbiota of breast-fed infants represents an important stimulating factor of the postnatal development of the immune system. The effect of breast-feeding on the intestinal microbiota can not be attributed to a single compound, but there is accumulating evidence that human milk oligosaccharides play a crucial role. Because there is a broad consensus that the intestinal microbiota plays an important physiological role for the host, many attempts have been made to influence the intestinal flora by dietary interventions. This article summarizes results of intervention studies in which nonmilk oligosaccharides have been used to mimic the prebiotic effect of breast-feeding. A second focus has been related to the question of whether the prebiotic activity has beneficial effects on the postnatal development of the immune system. The data clearly demonstrate that prebiotics of nonmilk origin can mimic the prebiotic effect of breast-feeding, and this has positive consequences for the postnatal development of the immune system.