Babies, Bugs, and Barriers: Dietary Modulation of Intestinal Barrier Function in Early Life.

The intestinal barrier is essential in early life to prevent infection, inflammation, and food allergies. It consists of microbiota, a mucus layer, an epithelial layer, and the immune system. Microbial metabolites, the mucus, antimicrobial peptides, and secretory immunoglobulin A (sIgA) protect the intestinal mucosa against infection. The complex interplay between these functionalities of the intestinal barrier is crucial in early life by supporting homeostasis, development of the intestinal immune system, and long-term gut health. Exclusive breastfeeding is highly recommended during the first 6 months. When breastfeeding is not possible, milk-based infant formulas are a safe alternative. Breast milk contains many bioactive components that help to establish the intestinal microbiota and influence the development of the intestinal epithelium and the immune system. Importantly, breastfeeding lowers the risk for intestinal and respiratory tract infections. Here we review all aspects of intestinal barrier function and the nutritional components that impact its functionality in early life, such asmicronutrients, bioactive milk proteins, milk lipids, and human milk oligosaccharides. These components are present in breast milk and can be added to milk-based infant formulas to support gut health and immunity.

Early Effect of Supplemented Infant Formulae on Intestinal Biomarkers and Microbiota: A Randomized Clinical Trial.

BACKGROUND: Post-natal gut maturation in infants interrelates maturation of the morphology, digestive, and immunological functions and gut microbiota development. Here, we explored both microbiota development and markers of gut barrier and maturation in healthy term infants during their early life to assess the interconnection of gut functions during different infant formulae regimes. METHODS: A total of 203 infants were enrolled in this randomized double-blind controlled trial including a breastfed reference group. Infants were fed starter formulae for the first four weeks of life, supplemented with different combination of nutrients (lactoferrin, probiotics (Bifidobacterium animal subsp. Lactis) and prebiotics (Bovine Milk-derived Oligosaccharides-BMOS)) and subsequently fed the control formula up to eight weeks of life. Stool microbiota profiles and biomarkers of early gut maturation, calprotectin (primary outcome), elastase, α-1 antitrypsin (AAT) and neopterin were measured in feces at one, two, four, and eight weeks. RESULTS: Infants fed formula containing BMOS had lower mean calprotectin levels over the first two to four weeks compared to the other formula groups. Elastase and AAT levels were closer to levels observed in breastfed infants. No differences were observed for neopterin. Global differences between the bacterial communities of all groups were assessed by constrained multivariate analysis with hypothesis testing. The canonical correspondence analysis (CCA) at genus level showed overlap between microbiota profiles at one and four weeks of age in the BMOS supplemented formula group with the breastfed reference, dominated by bifidobacteria. Microbiota profiles of all groups at four weeks were significantly associated with the calprotectin levels at 4 (CCA, p = 0.018) and eight weeks of age (CCA, p = 0.026). CONCLUSION: A meaningful correlation was observed between changes in microbiota composition and gut maturation marker calprotectin. The supplementation with BMOS seems to favor gut maturation closer to that of breastfed infants.

Oral Tolerance Induction to Newly Introduced Allergen is Favored by a Transforming Growth Factor-ß-Enriched Formula.

Food allergies have become a major healthcare concern, hence preventive efforts to ensure oral tolerance induction to newly introduced antigens are particularly relevant. Given that transforming growth factor-ß (TGF-ß) plays a key role in immune tolerance, we tested whether an infant formula enriched with TGF-ß would improve oral tolerance induction. A partially hydrolyzed whey protein-based formula was enriched with cow's-milk-derived TGF-ß (TGF-ß-enriched formula) by adding a specific whey protein isolate (WPI). The manufacturing process was optimized to achieve a concentration of TGF-ß within the range of human breast milk concentrations. Protection from allergic sensitization and immune response was assessed in a mouse model. Adult mice received the TGF-ß-enriched formula, a control non-enriched formula, or water ad libitum for 13 days before sensitization and suboptimal tolerization to ovalbumin (OVA). When compared to non-tolerized mice, suboptimally-tolerized mice supplemented with the TGF-ß-enriched formula showed significantly lower levels of total immunoglobulin-E (IgE) and OVA-specific (IgG1). Mouse mast-cell protease-1 (mMCP-1) and cytokine levels were also significantly decreased in suboptimally-tolerized mice fed the TGF-ß-enriched formula. In conclusion, oral supplementation with cow's-milk-derived TGF-ß decreased allergic responses to newly introduced allergens and thus reduced the risk of developing food allergy.

Growth, stool consistency and bone mineral content in healthy term infants fed sn-2-palmitate-enriched starter infant formula: A randomized, double-blind, multicentre clinical trial.

BACKGROUND: Palmitate in breast milk is predominantly located in the triacylglycerol sn-2 position, while infant formulae contain palmitate predominantly in the sn-1 and sn-3 positions. During digestion, palmitate in the sn-1 and sn-3 positions is hydrolyzed to free palmitic acid that can subsequently complex with calcium to form insoluble soaps; this may partially explain why formula-fed infants have harder stools than breast-fed infants. METHODS: This large (n = 488) randomized, double-blind, multicentre trial investigated whether increasing the sn-2 palmitate content of infant formula improves stool consistency and bone mineral content (measured by dual-energy x-ray absorptiometry), without affecting growth or health. From ∼1 week to 4 months of age, infants were exclusively fed one of three formulae: i) control formula (CF; 16% of total palmitate at sn-2; n = 162), (ii) experimental formula 1 (EF1; 43% of total palmitate at sn-2; n = 166) or (iii) experimental formula 2 (EF2; 51% of total palmitate at sn-2; n = 160). RESULTS: Intention-to-treat analysis showed softer stools in both EF groups (vs. CF) at ages 2 weeks and 1 and 2 months (p ≤ 0.01), but not 3 and 4 months. At 4 months, all groups had similar growth outcomes while bone mineral content was significantly higher in EF1 (p = 0.0012) and EF2 (p = 0.0002) compared with CF. Comparison of reported adverse events up to 12 months revealed no differences among groups. All 3 infant formulae exhibited equally good digestive tolerance. CONCLUSIONS: Formulae enriched in sn-2 palmitate fed in early infancy are safe, improve stool consistency (from 2 weeks to 2 months) and increase bone mineral content (at 4 months).

Partially Hydrolyzed Whey Infant Formula: Literature Review on Effects on Growth and the Risk of Developing Atopic Dermatitis in Infants from the General Population.

Limited evidence is available regarding the effect of partially hydrolyzed whey-based formula (pHF-W) on growth and atopic dermatitis (AD) risk reduction in infants within the general infant population, and without a familial history of allergy as an inclusion or exclusion criterion. We reviewed the current evidence available from studies using pHF-W in the general population and summarized the data on safety (growth) and efficacy outcomes (reduction of AD), comparing the studies side by side. A total of 8 clinical trials were identified from the literature search, 7 of which used the same pHF-W. Six out of 8 studies indicated a reduction of atopic manifestations using a specific pHF-W versus cow's milk formula (CMF) in the first years of life. Data were summarized and compared side by side for growth (3 studies) and efficacy (5 studies). In these diverse general populations, the results on growth and AD were consistent with the previous findings reported on infants with a family history of allergy, but numerous limitations to these studies were identified. This literature review confirms that pHF-W supports normal growth in infants, and suggests that the risk of AD may be reduced in not-fully breastfed infants from the general population when supplemented with a specific pHF-W when compared to CMF during the first 4-6 months of life. Further studies are warranted to confirm these results.

Starter formula enriched in prebiotics and probiotics ensures normal growth of infants and promotes gut health: a randomized clinical trial.

This corrects the article DOI: 10.1038/pr.2016.270.

Starter formula enriched in prebiotics and probiotics ensures normal growth of infants and promotes gut health: a randomized clinical trial.

BACKGROUND: Prebiotics and probiotics exert beneficial effects by modulating gut microbiota and immune system. This study evaluates efficacy and safety of an infant formula containing bovine milk-derived oligosaccharides and Bifidobacterium animalis ssp lactis (B. lactis) (CNCM I-3446) on incidence of diarrhea and febrile infections during the first year of life (primary outcome). METHODS: Full-term infants receiving Test or Control (without bovine milk-derived oligosaccharide and B. lactis) formulae were enrolled in a multicenter, randomized, controlled, and double-blind trial with a reference breastfeeding group. . RESULTS: 413 infants were assigned between Test (n = 206) and Control (n = 207) formula. There was no significant difference for diarrhea and febrile infections incidence between groups at 6 (odds ratio (95% confidence interval) = 0.56 (0.26-1.15), P = 0.096) and 12 mo (odds ratio = 0.66 (0.38-1.14), P = 0.119). Test formula was well tolerated, anthropometrics parameters were not significantly different between groups and aligned with WHO growth standards up to 12 mo. Data from test group showed that gut microbiota pattern, fecal IgA and stool pH were brought to be closer to those of breastfed infants. CONCLUSION: An infant formula enriched with bovine milk-derived oligosaccharide and B. lactis supports normal infant growth, is well tolerated and improves intestinal health markers. No differences in diarrhea and febrile infection incidence were found in the population studied.

Early Benefits of a Starter Formula Enriched in Prebiotics and Probiotics on the Gut Microbiota of Healthy Infants Born to HIV+ Mothers: A Randomized Double-Blind Controlled Trial.

The gut microbiota of infants is shaped by both the mode of delivery and the type of feeding. The gut of vaginally and cesarean-delivered infants is colonized at different rates and with different bacterial species, leading to differences in the gut microbial composition, which may persist up to 6 months. In a multicenter, randomized, controlled, double-blind trial conducted in South Africa, we tested the effect of a formula supplemented with a prebiotic (a mixture of bovine milk-derived oligosaccharides [BMOS] generated from whey permeate and containing galactooligosaccharides and milk oligosaccharides such as 3'- and 6'-sialyllactose) and the probiotic Bifidobacterium animalis subsp. lactis (B. lactis) strain CNCM I-3446 on the bifidobacteria levels in the gut of infants born vaginally or via cesarean section in early life. Additionally, the safety of the new formulation was evaluated. A total of 430 healthy, full-term infants born to HIV-positive mothers who had elected to feed their child beginning from birth (≤3 days old) exclusively with formula were randomized into this multicenter trial of four parallel groups. A total of 421 infants who had any study formula intake were included in the full analysis set (FAS). The first two groups consisted of cesarean-delivered infants assigned to the Test formula (n = 92) (a starter infant formula [IF] containing BMOS at a total oligosaccharide concentration of 5.8 ± 1.0 g/100 g of powder formula [8 g/L in the reconstituted formula] + B. lactis [1 × 107 colony-forming units {cfu}/g]) or a Control IF (n = 101); the second two groups consisted of vaginally delivered infants randomized to the same Test (n = 115) or Control (n = 113) formulas from the time of enrollment to 6 months. The primary efficacy outcome was fecal bifidobacteria count at 10 days, and the primary safety outcome was daily weight gain (g/d) between 10 days and 4 months. At 10 days, fecal bifidobacteria counts were significantly higher in the Test formula than in the Control formula group among infants with cesarean birth (median [range] log: 9.41 [6.30-10.94] cfu/g versus 6.30 [6.30-10.51] cfu/g; P = 0.002) but not among those with vaginal birth (median [range] log: 10.06 [5.93-10.77] cfu/g versus 9.85 [6.15-10.79] cfu/g; P = 0.126). The lower bound of the two-sided 95% confidence interval of the difference in the mean daily weight gain between the Test and Control formula groups was more than -3 g/d in both the vaginally and cesarean-delivered infants, indicating that growth in the Test formula-fed infants was not inferior to that of Control formula-fed infants. At 10 days and 4 weeks, the fecal pH of infants fed the Test formula was significantly lower than in those fed the Control formula, irrespective of mode of delivery: for vaginal delivery: 4.93 versus 5.59; P < 0.001 (10 days) and 5.01 versus 5.71; P < 0.001 (4 weeks); for cesarean delivery: 5.14 versus 5.65, P = 0.009 (10 days) and 5.06 versus 5.75, P < 0.001 (4 weeks). At 3 months, this acidification effect only persisted among cesarean-born infants. IF supplemented with the prebiotic BMOS and probiotic B. lactis induced a strong bifidogenic effect in both delivering modes, but more explicitly correcting the low bifidobacteria level found in cesarean-born infants from birth. The supplemented IF lowered the fecal pH and improved the fecal microbiota in both normal and cesarean-delivered infants. The use of bifidobacteria as a probiotic even in infants who are immunologically at risk is safe and well tolerated.

Induction of Staphylococcus aureus-specific IgA and agglutination potency in milk of cows by mucosal immunization.

Lactating cows were immunized with inactivated Staphylococcus aureus strains and concentrated culture supernatants. Application of a repeated mucosal immunization scheme resulted in significant levels of S. aureus-specific IgA in milk of dairy cows. Average IgA titers against whole cell S. aureus increased during the first 10 weeks of immunization after which a plateau level was reached and maintained during lactation. Immune whey agglutinated both bovine and human S. aureus strains including methicillin-resistant S. aureus (MRSA) strains and recognized extracted S. aureus proteins on Western blot. ELISAs to quantify milk IgA reactive with a number of S. aureus virulence proteins (e.g. enterotoxins, microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) and immune modulating proteins) and cell wall components, demonstrated the polyclonality of the IgA. Correlations observed between agglutination and specific IgA titers for whey and for purified IgA suggested functionality of the induced antibodies. Milk from immunized cows may provide a way of producing potentially therapeutic polyclonal antibodies against S. aureus colonization and infection.

Serum- and animal tissue-free medium for transport and growth of Helicobacter pylori.

The important human gastric pathogen Helicobacter pylori is the subject of many studies, and as a consequence it is frequently being transported between national and international laboratories. Unfortunately, common bacterial growth and transport media contain serum- and animal tissue-derived materials, which carry the risk of spreading infectious diseases. We have therefore developed a growth and transport medium for H. pylori, designated 'Serum- and Animal Tissue-Free Medium' (SATFM), which does not contain serum- or animal tissue-derived components. SATFM supported growth of H. pylori isolates to similar levels as obtained with serum-supplemented Brucella medium, and SATFM with 0.5% agar supported transport and storage of H. pylori strains, as 4/4 reference strains and 11/11 clinical isolates survived for at least 3 days at room temperature in SATFM, with some strains (2/15) even surviving for up to 7 days. In conclusion, SATFM can be used both as transport and growth medium for H. pylori. The formulation of SATFM may allow its use in international transport of H. pylori, and may also allow certified use in immunization studies requiring growth of H. pylori and other bacterial pathogens.

Bovine antibody-enriched whey to aid in the prevention of a relapse of Clostridium difficile-associated diarrhoea: preclinical and preliminary clinical data.

In a pilot study, the feasibility of immune whey protein concentrate (40%; immune WPC-40) to aid the prevention of relapse of Clostridium difficile diarrhoea was evaluated. Immune WPC-40 was made from milk after immunization of Holstein-Frisian cows with C. difficile-inactivated toxins and killed whole-cell C. difficile. Immune WPC-40 contained a high concentration of specific sIgA antibodies, and was effective in neutralizing the cytotoxic effect of C. difficile toxins in cell assays in vitro. Immune WPC-40 conferred protection from otherwise lethal C. difficile-associated caecitis in hamsters. To obtain preliminary data in humans, 16 patients (10 male; median 57 years) with toxin- and culture-confirmed C. difficile diarrhoea were enrolled in an uncontrolled cohort study. Nine had a history of relapsing C. difficile diarrhoea. After completion of standard antibiotic treatment, the patients received immune WPC-40 TID for 2 weeks; it was well tolerated and no treatment-related adverse effects were observed. In all but one case, C. difficile toxins had disappeared from the faeces upon completion of treatment. During a follow-up period of median 333 days (range 35 days to 1 year), none of the patients had suffered another episode of C. difficile diarrhoea. These preliminary data suggest that immune whey protein concentrate-40 may be of help in the prevention of relapse of C. difficile diarrhoea.