Breast-feeding is the ideal nutrition for a newborn’s integral necessities. It seems crucial therefore to know its composition in order to provide suitable infant formula when required. Of these, polyamines (with lactation and the microbiota being its intestinal source) are involved in the development of gut epithelium and immunity. Safety concerns limit human intervention studies. Therefore, we studied the amounts of polyamines supplied by breast milk (varying among mothers) or infant formula feeding, up to day 30 postpartum, in the faeces of newborns. Independent samples (68) of breast milk from fifty-nine healthy Caucasian woman (day 0, 1, 3, 5, 7, 15 and 30 postpartum) who had natural deliveries after week 38, same-day faeces of newborns when available (eighty-one from breast milk and fifty-five from infant formula fed) and six infant formulas were collected and the polyamine content was determined by HPLC. In breast milk, polyamines and isoamylamine (a primary amine), with inter-individual variations, increased over time (with a higher content of spermidine; no other amines were present). Overall, they were much higher than in infant formula. By the 2nd week after birth, polyamines, cadaverine and tyramine, but not isoamylamine, were higher in the faeces of those fed infant formula compared with those fed breast milk. Cadaverine and tyramine could be used to predict the feeding type used for newborns. The differences in the content may be related to distinct colonisation of amine-producing bacteria, which can be established by polyamines. Further studies are required to determine the clinical utility of these findings.

Infant microbiota is influenced by numerous factors, such as delivery mode, environment, prematurity and diet (breast milk or formula). In addition to its nutritional value, breast milk contains bioactive substances that drive microbial colonisation and support immune system development, which are usually not present in infant formulas. Among these substances, polyamines have been described to be essential for intestinal and immune functions in newborns. However, their effect on the establishment of microbiota remains unclear. Therefore, the aim of the present study was to ascertain whether an infant formula supplemented with polyamines has an impact on microbial colonisation by modifying it to resemble that in breast-fed neonatal BALB/c mice. In a 4 d intervention, a total of sixty pups (14 d old) were randomly assigned to the following groups: (1) breast-fed group; (2) non-enriched infant formula-fed group; (3) three different groups fed an infant formula enriched with increasing concentrations of polyamines (mixture of putrescine, spermidine and spermine), following the proportions found in human milk. Microbial composition in the contents of the oral cavity, stomach and small and large intestines was analysed by quantitative PCR targeted at fourteen bacterial genera and species. Significantly different (P< 0·05) microbial colonisation patterns were observed in the entire gastrointestinal tract of the breast-fed and formula-fed mice. In addition, our findings demonstrate that supplementation of polyamines regulates the amounts of total bacteria, Akkermansia muciniphila, Lactobacillus, Bifidobacterium, Bacteroides–Prevotella and Clostridium groups to levels found in the breast-fed group. Such an effect requires further investigation in human infants, as supplementation of an infant formula with polyamines might contribute to healthy gastrointestinal tract development.

Contaminants are a vast subject area of food safety and quality and can be present in our food chain from raw materials to finished products. Acrylamide, an α,β-unsaturated (conjugated) reactive molecule, can be detected as a contaminant in several foodstuffs including baby foods and infant formulas. It is anticipated that children will generally have intakes that are two to three times those of adults when expressed on a body-weight basis. Though exposure to acrylamide is inevitable, it is necessary to protect infant and children from high exposure. The present review focuses on the several adverse health effects of acrylamide including mutagenicity, genotoxicity, carcinogenicity, neurotoxicity and reproductive toxicity, and the possible outcomes of childhood exposure from baby foods and infant formulas.

The purpose of this review is to examine the need for and appropriate level of Fe fortification of infant formula, and to assess any adverse effects of Fe fortification. The appropriate level of Fe fortification of infant formula has been established through studies of Fe absorption or erythrocyte incorporation of Fe, and through clinical trials of formulas with varying levels of Fe that were aimed at preventing the development of Fe deficiency in participating infants. In addition, the effects of varying levels of Fe fortification on the absorption of other minerals and trace elements, and on the incidence of infection and immune function have been studied, as has the effect of adding bovine lactoferrin to formula. Studies of Fe absorption have shown that increasing the level of Fe fortification in formula does not significantly increase the amount absorbed, and that the addition of bovine lactoferrin is unlikely to further increase absorption of Fe. Quite different recommendations for the level of Fe fortification of formula are made in the USA and in Europe. The higher level (12 mg/l) commonly used in the USA is not well supported by the evidence from clinical trials that suggest that lower levels (4 mg/l or less) may be adequate to prevent the development of Fe deficiency. Higher levels of Fe fortification may also interfere with the absorption of other minerals such as Cu and Se. Concerns about potential adverse effects of Fe fortification on immune function and susceptibility to infections have been disproved as have concerns about associated gastrointestinal symptomatology. There are no clearly demonstrated advantages in using ‘follow-on’ formula with high Fe content (up to 13 mg/l) instead of the standard UK formulas with Fe fortification in the range 4–7 mg/l after the age of 6 months, although they may provide an important ‘safety net’ for the prevention of Fe deficiency in communities with weaning diets low in Fe.