Faecal excretion in infants

Data on normal defaecation patterns in relation to diet during the first months of infancy are very limited. We therefore investigated in a prospective study faecal weight and gastro-intestinal passage time of breast fed (n = 12) and formula fed (n = 14) male infants. These were studied in 72 h collecting periods at the age of 17, 35, 57, 87 and 113 (+/- 4) days. Breast fed infants had a significantly lower daily dry faecal weight than formula fed infants in all periods investigated (median at the age of 113 days: 0.28 (0.17-0.75) g/kg and 0.81 (0.22-1.2) g/kg, respectively). Breast fed infants showed a large variation of gastro-intestinal passage time (6.79 h [range: 1.79-13.38 h] at the age of 17 days, 21.84 h [range: 5.41-75 h] at the age of 113 days). Comparable values of formula red infants were 13.75 h (range: 7.13-35.25 h) and 17.42 h (range: 5.38-36.5 h). Despite the efforts of approximation of infant formula to breast milk, differences of defaecation patterns in relation to diet are still relevant at this age and have to be considered in clinical practice.

[Sodium and potassium metabolism in infancy]

BACKGROUND

Recommendations for the concentration of most nutrients in infant formulas are based on their concentration in human milk. Industry succeeded in adapting sodium and potassium content in infant formulas to concentration found in human milk. Whether this adaptation affects on infants' mineral balances was studied in breast-fed and artificially-fed infants.

METHODS

Sodium and potassium balances were performed in 16 term male infants from their 3rd until their 17th week of life. The balances were performed at home and comprised up to five periods in intervals of three to four weeks. Each balance period consisted of subsequent three 24 h collections of milk, stool and urine samples. Ten infants were breast-fed, six received an adapted infant formula supplemented with copper, zinc and iron.

RESULTS

The breast-fed infants got a mean intake of 1 mmol Na/kg b w x day and a mean intake of 1.8 mmol K/kg b w x day. Man retention was 0.4 mmol Na and 0.7 mmol K/kg b w x day. The formula-fed infants received 1.9 mmol Na/kg b w x day and 2.1 mmol K/kg b w x day. Na- and K-retention in this group was 0.5 and 0.6 mmol/kg b w x day respectively. Although sodium intake in the formula-fed infants was nearly twice as much as in the breast-fed infants the difference in sodium retention was only small (0.4 vs 0.5 mmol/kg b w x day). The formula-fed infants got more potassium than the breast-fed infants, but potassium retention was the same in both groups.

CONCLUSIONS

With the adapted infant formula of this study the artificially fed infant was as well supplied with sodium and potassium as the breast-fed infant. A further reduction of the sodium concentration seems not to be useful.

Iron availability from an infant formula supplemented with bovine lactoferrin

Iron balance studies were performed in 16 term infants from their 3rd until their 17th week of life. The balance studies were performed at home and comprised five periods with an interval of 3 to 4 weeks, each consisting of three 24-hour collections of milk and stool samples. Seven infants were fed an adapted infant formula supplemented with bovine lactoferrin (100 mg/100 ml) and nine received the same formula without lactoferrin. The lactoferrin supplemented group received 169 micrograms iron/kg b.w. x day and retained 63 micrograms/kg b.w. x day. The mean iron intake of infants fed with the adapted formula without supplementation of lactoferrin was 118 micrograms/kg b.w. x day. The retention of iron was 43 micrograms/kg b.w. x day. Mean percentage retention of iron in the supplemented group was 36%, in the non-supplemented group 28%.

[Arterial thrombosis in a premature infant]

A preterm infant of 30 weeks gestation developed thrombosis of the left arteria femoralis on his fourth day of life. Continuous intravenous heparinization with 350 to 750 U/kg bw/d was performed during the course of several weeks. Although arterial thrombosis in term and preterm infants is not a rare event, there are no generally accepted guidelines for treatment. In this article alternatives of treatment--namely surgical management, thrombolytic therapy, heparinization and supportive therapy are discussed.

Selenium balances in young infants fed on breast milk and adapted cow's milk formula

Selenium intake, renal and fecal excretion, and retention were determined in 11 breast-fed term infants and in 9 term infants fed with an adapted cow's milk formula. In most cases three-day-balances were determined five times at the age of 2, 5, 8, 12, and 16 weeks. Analytical determination of selenium was by atomic absorption spectroscopy with a selenium hybrid system after wet ashing of samples. The mean breast milk concentrations of selenium show a significant decrease in the course of lactation from 31.0 micrograms/L in the first collecting period to 17.6 micrograms/L in the last one. The two formula milks contained 11.8 and 7.7 micrograms/L. Intake in the breast milk group was higher than in the formula group, whereas absolute renal and fecal excretion were essentially the same. This leads to a higher selenium retention in the breast-fed infants than in the formula-fed infants, where most of the balances are negative.

Longitudinal manganese and copper balances in young infants and preterm infants fed on breast-milk and adapted cow's milk formulas

1. Mn and Cu intake and retention in twenty full-term infants and six preterm infants were studied on the basis of 72 h balances. The age of the infants was 2-16 weeks and the gestational age of the preterm infants (triplets) 34 and 36 weeks. Three nutrition schemes were pursued: breast-fed, formula-fed with unsupplemented adapted formula and formula-fed with trace element supplementation. 2. The mean Mn concentration of all breast-milk samples (n 2339) was 6.2 micrograms/l. The two formulas had similar Mn concentrations (77 and 99 micrograms/l) but had different Fe, Cu (121 and 619 micrograms/l), Zn and I contents. The mean Cu concentration in mother's milk was 833 micrograms/l. 3. The following mean daily Mn intakes and retentions (micrograms/kg) respectively were measured: breast-fed full-term 1.06 (SD 0.43) and 0.43 (SD 0.65), formula-fed full-term 14.2 (SD 3.1) and 2.8 (SD 4.8), formula-fed preterm 15.0 (SD 2.2) and 0.06 (SD 5.87). The results for Cu were 114.5 (SD 22.3) and 88.0 (SD 46.5) micrograms/kg in breast-fed, 19.8 (SD 4.2) and 4.6 (-11.5-9.6) in the unsupplemented formula-fed and 106.4 (SD 18.9) and 55.5 (SD 20.3) in the supplemented formula full-term infant group. No significant influence of the trace element contents of the formulas on the relative retention of Mn or Cu was found. 4. Young preterm infants, and to some degree young full-term infants, often had negative Mn balances caused by a high faecal excretion. The formulas with a Mn concentration below 100 micrograms/l gave a sufficient supply of Mn. Preterm infants fed on the unsupplemented formula had a marginal Cu supply and their first balances were negative (-3.8 (SD 1.8) micrograms/kg). 5. In accordance with the estimated safe and adequate daily dietary intakes (recommended dietary allowances), formula-fed infants receive much more Mn than breast-fed infants and their absolute retention is higher. 6. Cu from breast-milk had a significantly better biological availability than that from cow's milk formula. If retentions similar to those in breast-fed infants are intended, we conclude, therefore, that cow's milk formula should be fortified with Cu up to a level of at least 600 micrograms/l.

Iron balances in infant nutrition

Iron balance studies were performed in 17 full term male infants from their 3rd until their 17th week of life. The balance studies were made in the infant's home and comprised 5 periods with an interval of 3-4 weeks, each consisting of three 24-hour collections. Ten infants were breast-fed, 3 received an adapted infant formula (P1, iron content 1.1 mg/l) and 4 were given the same formula enriched with iron, copper and zinc (P2, iron content 10.35 mg/l). From the 3rd to the 17th week of life the breast-fed infants got a mean iron intake of 0.2 mg/kg body weight X 3 days and they retained 0.09 mg/kg b.w. X 3 days. The P1 group received 0.48 and 0.47 mg/kg b.w. X 3 days and retained -0.01 and -0.5 mg iron/kg b.w. X 3 days, while the P2 group had an intake from 5.04 to 6.38 mg b.w. X 3 days and retained between 1.13 and 3.66 mg iron/kg b.w. X 3 days. Comparing the 3 groups it can be concluded that the P1 group retained definitely less iron than the breast-fed group, whereas the P2 group retained 12 to 40 times more iron than the breast-fed babies.