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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the various aspects of digestion in the newborn have been studied for decades, we still lack quantitative information about the contribution of individual enzymes to the overall process. The information to date indicates that in spite of immaturity of many of the classical digestive mechanisms of the adult, the infant uses a number of compensatory systems to achieve adequate digestion of nutrients (Fig. 1). Thus, whereas in the infant gastric proteolysis is probably extremely limited, intestinal protein digestion is adequate. Although starch supplements are better tolerated in breast-fed infants, because of the compensation provided by human milk amylase, the infant is able to digest lactose and short-chain glucose polymers with endogenous brush border enzymes. Fat digestion is markedly aided by gastric lipase and, in breast-fed infants, the bile salt-dependent lipase of human milk. Thus, in the infant, gastric lipolysis is quantitatively much more significant than in adults. The absorption of human milk whey proteins (and probably also cow milk proteins) is probably associated more with the highly glycosylated form of these proteins than with immaturity of neonatal digestive enzymes.
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PMID:Digestion in the newborn. 878 Sep 1

In a comparative study of the lactational performance of 11 adolescent and 11 adult breast-feeding mothers from the US, adolescents were found to produce significantly less milk and lactate for a significantly shorter period of time than their adult counterparts. All subjects were assessed at 6-24 weeks postpartum. The adolescents produced 37% and 54% less milk at 6 and 24 weeks postpartum, respectively, than adult women. These differences in milk production were significant even when adjusted for differences in the frequency and duration of breast feeding episodes and use of supplementary feeds. The amount of dietary energy the infants of adolescents received from human milk alone was clearly inadequate, at every time point, to support normal growth rates. In both groups, the average frequency of nursing episodes during the first 12 weeks postpartum was 7 or more per 24 hours (consistent with current recommendations for adequate lactation); adolescents, however, spent significantly less time nursing and provided greater quantities of supplementary feeds. While all adult women breast-fed throughout the study period, 20% of adolescents had stopped breast feeding by 12 weeks, 50% weaned by 18 weeks, and 64% had discontinued breast feeding by 24 weeks. Unexpectedly, the energy, lactose, fat, total nitrogen, protein nitrogen, nonprotein nitrogen, sodium, potassium, calcium, and phosphorous concentrations showed little difference between the two age groups. The absence of data from the first 6 weeks of life makes it impossible to rule out a role for early formula supplementation in the decreased milk production of adolescents. It is believed,however, that adolescents may be biologically incapable of producing a full complement of milk because of their developmental immaturity.
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PMID:Lactational performance of adolescent mothers shows preliminary differences from that of adult women. 917 81

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.
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PMID:Nutrient requirements for preterm infant formulas. 1251 97

The gut of preterm neonates is colonised with a paucity of bacterial species originating more from the environment than from the mother. Furthermore, a delayed colonisation by bifidobacteria promotes colonisation by potentially pathogenic bacteria. This may contribute towards the development of neonatal necrotising enterocolitis (NEC). The physiopathology of NEC is still unclear but immaturity of the gut, enteral feeding and bacterial colonisation are all thought to be involved. None of the current preventive treatments are considered satisfactory. Modulating the autochthonous microflora by probiotics or prebiotics could be a more reliable approach to prevention. Using gnotobiotic quails as an experimental model of NEC we have shown that onset of intestinal lesions requires a combination of low endogenous lactase activity, lactose in diet, and colonisation by lactose-fermenting bacteria such as the clostridia. The protective role of bifidobacteria was demonstrated in this model through a decrease in clostridial populations and in butyric acid. Oligofructose dietary supplementation was shown to enhance this effect with an increase in the bifidobacterial level and consequently a greater decrease in clostridia. However, oligofructose was unable to promote a bifidobacterial acquisition when the microflora was initially deprived of this group. Nevertheless, oligofructose can act as an anti-infective agent and decrease the occurrence or severity of the lesions depending on the bacteria involved. According to these results and to the fact that oligosaccharides are a major component of breast milk, the addition of oligofructose in formula milks may be a nutritional approach to favouring colonisation by a beneficial flora.
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PMID:Oligofructose and experimental model of neonatal necrotising enterocolitis. 1208 21

The low birth weight infant's (LBW) nutrition needs special attention. Energy requirements are increased due to a high metabolic rate and a low thermogenesis. Increased protein requirements are, easy to be absorbed (from lacto-serum). Lipids, as important energetic source requires an appropriate content in essential fatty acids and medium chain triglycerides (TGM) which are easy absorbed in absence of lipase and deficit of bile salt secretion. The carbohydrates should be represented by lactose or equivalents like di-, oligo or polysaccharides. The addition of maltodextrin avoid an exaggerate supply and incomplete digestion of lactose. Sodium requirement are increased due to exaggerated loss consequence of renal immaturity. The rapid rate of growth impose the addition of Calcium, Phosphorus, Iron, Copper, and vitamins, especially Vitamin D, E and Folic acid. The appropriate nutrition of LBW must cover his special needs to maintain the homeostasis and rapid growth. Precise nutrient requirements are, however, difficult to establish.
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PMID:[Nutrition of low birth weight infants]. 1867 1

Infantile colic is a benign process in which an infant has paroxysms of inconsolable crying for more than three hours per day, more than three days per week, for longer than three weeks. It affects approximately 10% to 40% of infants worldwide and peaks at around six weeks of age, with symptoms resolving by three to six months of age. The incidence is equal between sexes, and there is no correlation with type of feeding (breast vs. bottle), gestational age, or socioeconomic status. The cause of infantile colic is not known; proposed causes include alterations in fecal microflora, intolerance to cow's milk protein or lactose, gastrointestinal immaturity or inflammation, increased serotonin secretion, poor feeding technique, and maternal smoking or nicotine replacement therapy. Colic is a diagnosis of exclusion after a detailed history and physical examination have ruled out concerning causes. Parental support and reassurance are key components of the management of colic. Simethicone and proton pump inhibitors are ineffective for the treatment of colic, and dicyclomine is contraindicated. Treatment options for breastfed infants include the probiotic Lactobacillus reuteri (strain DSM 17938) and reducing maternal dietary allergen intake. Switching to a hydrolyzed formula is an option for formula-fed infants. Evidence does not support chiropractic or osteopathic manipulation, infant massage, swaddling, acupuncture, or herbal supplements.
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PMID:Infantile Colic: Recognition and Treatment. 2644 41