Understanding prebiotics in infant and childhood nutrition

Prebiotics and probiotics are ingredients in the diet that strengthen beneficial microbes in the gut, especially bifidobacteria. This article discusses their effects on health and their use in infant formula and foods for children and adults. They may also have benefits for the elderly population, since bifidobacteria are known to decrease with old age.

Effects of bovine alpha-lactalbumin and casein glycomacropeptide-enriched infant formulae on faecal microbiota in healthy term infants

Objective: Certain milk factors may promote the growth of a host-friendly gastrointestinal microbiota, for example, one that is predominated by bifidobacteria, a perceived healthpromoting genus. This may explain why breast-fed infants experience fewer intestinal infections than their formula-fed counterparts who are believed to have a more diverse microbiota, which is similar to that of adults. The effects of formulas supplemented with 2 such ingredients from bovine milk, a-lactalbumin (alpha-lac) and casein glycomacropeptide (GMP), on gut flora were investigated in this study. Patients and Methods: Six-week-old (4-8 wk), healthy term infants were randomised to a standard infant formula or 1 of 2 test formulae enriched in alpha-Jac with higher or lower GMP until 6 months. Faecal bacteriology was determined by the culture-independent procedure fluorescence in situ hybridisation. Results: There was a large fluctuation of bacterial counts within groups with no statistically significant differences between groups. Although all groups showed a. predominance of bifidobacteria, breast-fed infants had a small temporary increase in counts. Other bacterial levels varied in formula-fed groups, which overall showed an adult-like faecal microflora. Conclusions: It can be speculated that a prebiotic effect for alpha-lac and GMP is achieved only with low starting populations of beneficial microbiota (eg, infants not initially breast-fed.

rRNA probes used to quantify the effects of glycomacropeptide and alpha-lactalbumin supplementation on the predominant groups of intestinal bacteria of infant rhesus monkeys challenged with enteropathogenic Escherichia coli

Objectives: Certain milk factors may help to promote the growth of a host-friendly colonic microflora (e.g. bifidobacteria, lactobacilli) and explain why breast-fed infants experience fewer and milder intestinal infections than those who are formula-fed. The effects of supplementation of formula with two such milk factors was investigated in this study. Materials and Methods: Infant rhesus macaques were breastfed, fed control formula, or formula supplemented with glycomacropeptide (GMP) or alpha-lactalburnin (alpha-LA) from birth to 5 months of age. Blood was drawn monthly and rectal swabs were collected weekly. At 4.5 months of age, 10(8) colonyforming units of enteropathogenic E.coli O127, strain 2349/68 (EPEC) was given orally and the response to infection assessed. The bacteriology of rectal swabs pre- and post-infection was determined by culture independent fluorescence in situ hybridization. Results: Post-challenge, breast-fed infants and infants fed alpha-LA-supplemented formula had no diarrhea, whilst those infants fed GMP-supplemented formula had intermittent diarrhea. In infants fed control formula the diarrhea was acute. Conclusions: Supplementation of infant formula with appropriate milk proteins may be useful for improving the infant's ability to resist acute infection caused by E.coli.

Post-partum depression and infant growth in a South African peri-urban settlement

Aim: To examine the association between maternal post-natal depression and infant growth. Background: Infant growth has recently been shown, in two studies from South Asia, to be adversely affected by maternal depression in the early post-partum period. It is uncertain whether a similar association obtains in developing countries outside Asia. Method: A sample of 147 mother–infant dyads was recruited from a peri-urban settlement outside Cape Town and seen at 2 and 18 months post partum. Results: No clear effect of post-partum depression on infant growth was found. Although maternal depression at 2 months was found to be associated with lower infant weight at 18 months, when birthweight was considered this effect disappeared. Conclusions: Possible explanations for the non-replication of the South Asian findings are considered.

The mother-infant relationship and infant attachment in a south African peri-urban settlement

A sample of 147 mother-infant dyads was recruited from a peri-urban settlement outside Cape Town and seen at 2- and 18-months postpartum. At 18 months, 61.9% of the infants were rated as securely attached (B); 4.1% as avoidant (A); 8.2% as resistant (C); and 25.8% disorganized (D). Postpartum depression at 2 months, and indices of poor parenting at both 2 and 18 months, were associated with insecure infant attachment. The critical 2-month predictor variables for insecure infant attachment were maternal intrusiveness and maternal remoteness, and early maternal depression. When concurrent maternal sensitivity was considered, the quality of the early mother-infant relationship remained important, but maternal depression was no longer predictive. Cross-cultural differences and consistencies in the development of attachment are discussed.

The effect of postnatal depression on mother-infant interaction, infant response to the still-face perturbation, and performance on an instrumental learning task

A representative community sample of primiparous depressed women and a nondepressed control group were assessed while in interaction with their infants at 2 months postpartum. At 3 months, infants were assessed on the Still-face perturbation of face to face interaction, and a subsample completed an Instrumental Learning paradigm. Compared to nondepressed women, depressed mothers' interactions were both less contingent and less affectively attuned to infant behavior. Postnatal depression did not adversely affect the infant's performance in either the Still-face perturbation or the Instrumental Learning assessment. Maternal responsiveness in interactions at 2 months predicted the infant's performance in the Instrumental Learning assessment but not in the Still-face perturbation. The implications of these findings for theories of infant cognitive and emotional development are discussed.

The effect of cleft lip and palate, and the timing of lip repair on mother-infant interactions and infant development

Background: Children with cleft lip and palate are at risk for psychological problems. Difficulties in mother-child interactions may be relevant, and could be affected by the timing of lip repair. Method: We assessed cognitive development, behaviour problems, and attachment in 94 infants with cleft lip (with and without cleft palate) and 96 non-affected control infants at 18 months; mother-infant interactions were assessed at two, six and 12 months. Index infants received either 'early', neonatal, lip repair, or 'late' repair (3-4 months). Results: Index infants did not differ from controls on measures of behaviour problems or attachment, regardless of timing of lip repair; however, infants having late lip repair performed worse on the Bayley Scales of Mental Development; the cognitive development of early repair infants was not impaired. Difficulties in early mother-infant interactions mediated the effects of late lip repair on infant cognitive outcome. Conclusions: Early interaction difficulties between mothers and infants having late repair of cleft lip are associated with poor cognitive functioning at 18 months. Interventions to facilitate mother-infant interactions prior to surgical lip repair should be explored.

The effects of maternal social phobia on mother-infant interactions and infant social responsiveness

Background: Social phobia aggregates in families. The genetic contribution to intergenerational transmission is modest, and parenting is considered important. Research on the effects of social phobia on parenting has been subject to problems of small sample size, heterogeneity of samples and lack of specificity of observational frameworks. We addressed these problems in the current study.Methods: We assessed mothers with social phobia (N = 84) and control mothers (N = 89) at 10 weeks in face-to-face interactions with their infants, and during a social challenge, namely, engaging with a stranger. We also assessed mothers with generalised anxiety disorder (GAD) (N = 50). We examined the contribution to infant social responsiveness of early infant characteristics (neonatal irritability), as well as maternal behaviour. Results: Mothers with social phobia were no less sensitive to their infants during face-to-face interactions than control mothers, but when interacting with the stranger they appeared more anxious, engaged less with the stranger themselves, and were less encouraging of the infant's interaction with the stranger; infants of index mothers also showed reduced social responsiveness to the stranger. These differences did not apply to mothers with GAD and their infants. Regression analyses showed that the reduction in social responsiveness in infants of mothers with social phobia was predicted by neonatal irritability and the degree to which the mother encouraged the infant to interact with the stranger.Conclusions: Mothers with social phobia show specific parenting difficulties, and their infants show early signs of reduced social responsiveness that are related to both individual infant differences and a lack of maternal encouragement to engage in social interactions.

Distinguishing novelty and familiarity effects in infant preference procedures

This paper considers possible problems researchers might face when interpreting the results of studies that employ variants of the preference procedure. Infants show a tendency to shift their preference from familiar to novel stimuli with increasing exposure to the familiar stimulus, a behaviour that is exploited by the habituation paradigm. This change in attentional preference with exposure leads us to suggest that researchers interested in infants' pre-experimental or spontaneous preferences should beware of the potentially confounding effects of exposing infants to familiarization trials prior to employing the preference procedure. The notion that infant attentional preference is dynamic also calls into question the use of the direction of post-familiarization preference per se when interpreting the knowledge or strategies available to infants. We look into the results of a cross-modal word learning study to show how the interpretation of results may be difficult when infants exhibit a significant preference in an unexpected direction. As a possible solution to this problem we propose that significant preferences in both directions should be sought at multiple intervals over time. Copyright (C) 2004 John Wiley Sons, Ltd.

Freeze-frame: a new infant inhibition task and its relation to frontal cortex tasks during infancy and early childhood

The current study investigated a new, easily administered, visual inhibition task for infants termed the Freeze-Frame task. In the new task, 9-month-olds were encouraged to inhibit looks to peripheral distractors. This was done by briefly freezing a central animated stimulus when infants looked to the distractors. Half of the trials presented an engaging central stimulus, and the other half presented a repetitive central stimulus. Three measures of inhibitory function were derived from the task and compared with performance on a set of frontal cortex tasks administered at 9 and 24 months of age. As expected, infants' ability to learn to selectively inhibit looks to the distractors at 9 months predicted performance at 24 months. However, performance differences in the two Freeze-Frame trial types early in the experiment also turned out to be an important predictor. The results are discussed in terms of the validity of the Freeze-Frame task as an early measure of different components of inhibitory function. (C) 2007 Elsevier Inc. All rights reserved.

Measurement of mother-infant interactions and the home environment in a European setting: preliminary results from a cross-cultural study

Background Infant development is adversely affected in the context of postnatal depression. This relationship may be mediated by both the nature of early mother-infant interactions and the quality of the home environment. Aim To establish the usefulness of the Global Ratings Scales of Mother-Infant Interaction and the Infant-Toddler version of the Home Observation for the Measurement of the Environment (IT-HOME), and to test expected associations of the measures with characteristics of the social context and with major or minor depression. Method Both assessments were administered postnatally in four European centres; 144 mothers were assessed with the Global Ratings Scales and 114 with the IT-HOME. Affective disorder was assessed by means of the Structured Clinical Interview for DSM-IV Disorders. Results Analyses of mother-infant interaction indicated no main effect for depression but maternal sensitivity to infant behaviour was associated with better infant communication, especially for women who were not depressed. Poor overall emotional support also reduced sensitivity scores. Poor support was also related to poorer IT-HOME scores, but there was no effect of depression. Conclusions The Global Ratings Scales were effectively applied but there was less evidence of the usefulness of the IT-HOME. Declaration of interest None.

Transmission of social anxiety from mother to infant: an experimental study using a social referencing paradigm

In this experiment we investigated the impact of indirect expressions of maternal social anxiety on infant interactions with a stranger. A social referencing paradigm was used in which infants first observed their mothers interacting with a stranger and then interacted with the stranger themselves. Mothers made no direct communicative gestures to the infant concerning the stranger throughout the procedure. There were two experimental conditions experienced by all mother-infant pairs (N = 24; 12 boys)-non-anxious and socially anxious-and there were two male strangers. Infants were between 12 and 14 months (M = 12.8, SD =.76). Order of condition and stranger presentation were counterbalanced. Before testing, mothers, none of whom were significantly socially anxious, were trained to behave in a non-anxious and a socially anxious manner on the basis of clinical and empirical descriptions of social phobia. The results showed that, compared to their responses following their mothers interacting normally with a stranger, following a socially anxious mother-stranger interaction, infants were significantly more fearful and avoidant with the stranger. Infant-stranger avoidance was further modified by infant temperament; high fear infants were more avoidant in the socially anxious condition than low-fear infants. We discuss these findings in light of the possible mechanisms underpinning infant affective and behavioral responsiveness. (c) 2005 Elsevier Ltd. All rights reserved

Maternal psychosocial adversity and the longitudinal development of infant sleep

Research has identified associations between indicators of social disadvantage and the presence of child sleep problems. We examined the longitudinal development of infant sleep in families experiencing high (n = 58) or low (n = 64) levels of psychosocial adversity, and the contributions of neonatal self-regulatory capacities and maternal settling strategies to this development. Assessments of infant sleep at 4-, 7-, and 12-weeks postpartum indicated no differences in sleeping difficulties between high- and low-adversity groups. However, more infant sleep difficulties were reported in the high- versus low-adversity groups at 12- and 18-month follow-ups. Neonatal self-regulatory capacities were not related to the presence or absence of adversity, or to subsequent infant sleep quality. However, there were group differences in maternal settling strategies that did predict subsequent infant sleep difficulties. The pattern of sleep disturbance observed in association with maternal psychosocial adversity at 18-months was consistent with risk for broader impairments in child functioning.

Improving quality of mother-infant relationship and infant attachment in socioeconomically deprived community in South Africa: randomised controlled trial

Objective To assess the efficacy of an intervention designed to improve the mother-infant relationship and security of infant attachment in a South African peri-urban settlement with marked adverse socioeconomic circumstances. Design Randomised controlled trial. Setting Khayelitsha, a peri-urban settlement in South Africa. Participants 449 pregnant women. Interventions The intervention was delivered from late pregnancy and for six months postpartum. Women were visited in their homes by previously untrained lay community workers who provided support and guidance in parenting. The purpose of the intervention was to promote sensitive and responsive parenting and secure infant attachment to the mother. Women in the control group received no therapeutic input from the research team. Main outcome measures Primary outcomes: quality of mother-infant interactions at six and 12 months postpartum; infant attachment security at 18 months. Secondary outcome: maternal depression at six and 12 months. Results The intervention was associated with significant benefit to the mother-infant relationship. At both six and 12 months, compared with control mothers, mothers in the intervention group were significantly more sensitive (6 months: mean difference=0.77 (SD 0.37), t=2.10, P<0.05, d=0.24; 12 months: mean difference=0.42 (0.18), t=-2.04, P<0.05, d=0.26) and less intrusive (6 months: mean difference=0.68 (0.36), t=2.28, P<0.05, d=0.26; 12 months: mean difference=-1.76 (0.86), t=2.28, P<0.05, d=0.24) in their interactions with their infants. The intervention was also associated with a higher rate of secure infant attachments at 18 months (116/156 (74%) v 102/162 (63%); Wald=4.74, odds ratio=1.70, P<0.05). Although the prevalence of maternal depressive disorder was not significantly reduced, the intervention had a benefit in terms of maternal depressed mood at six months (z=2.05, P=0.04) on the Edinburgh postnatal depression scale). Conclusions The intervention, delivered by local lay women, had a significant positive impact on the quality of the mother-infant relationship and on security of infant attachment, factors known to predict favourable child development. If these effects persist, and if they are replicated, this intervention holds considerable promise for use in the developing world. Trial registration Current Controlled Trials ISRCTN25664149.