High protein diet mimics hypertyrosinemia in newborn infants

Bovine Colostrum for Preterm Infants in the First Days of Life: A Randomized Controlled Pilot Trial

OBJECTIVES

Mother's own milk (MM) is the best nutrition for newborn preterm infants, but is often limited in supply just after birth. Pasteurized human donor milk (DM), and especially preterm infant formula (IF) are less optimal diets than MM. We hypothesized that it is feasible to use bovine colostrum (BC), the first milk from cows, as a supplement to MM, during the first weeks after preterm birth.

METHODS

In an open-label, randomized, controlled pilot safety trial, supplementation of MM with BC was compared with DM supplementation (Danish unit) or IF supplementation (Chinese unit). If MM was limited or lacking, BC, DM or IF were given according to local feeding guidelines during the first 14 days of life.

RESULTS

Forty infants were included and randomized in Denmark and in China, with gestational ages 29.9 ± 0.4 and 31.1 ± 0.2 weeks, respectively. Infants supplemented with BC received more enteral protein (P < 0.05) and tended to reach full enteral feeding earlier (China only). Eight infants fed BC showed a temporary elevation in plasma tyrosine on day 7, versus 2 infants in the DM/IF groups. There were no differences between diet groups in feeding intolerance or clinical adverse events.

CONCLUSIONS

Our results indicate that it is feasible to use BC as a supplement to MM during the first weeks of life to increase enteral protein intake in preterm infants. Plasma tyrosine levels may be a good marker for excessive protein intake. A larger randomized trial is required to test the safety and possible short- and long-term clinical benefits of BC supplementation during the first weeks of life for preterm infants.

High-protein goat’s milk diet identified through newborn screening: clinical warning of a potentially dangerous dietetic practice

Objective

Breast-feeding is an unequalled way of providing optimal food for infants’ healthy growth and development and the WHO recommends that infants should be exclusively breast-fed for the first 6 months of life. For mothers who are unable to breast-feed or who decide not to, infant formulas are the safest alternative. Despite recommendations, it is possible that parents make potentially harmful nutritional choices for their children because of cultural beliefs or misinformation on infant nutrition. We describe a possible health risk of not breast-feeding, highlighting a potentially dangerous dietetic practice.

Design/Setting/Subjects

We report the case of a newborn who was fed with undiluted goat’s milk because her mother could not breast-feed and was not aware of infant formulas.

Results

The dietary mistake was detected because of a positive expanded newborn screening result, characterized by severe hypertyrosinaemia with high methionine and phenylalanine levels, a pattern suggestive of severe liver impairment. The pattern of plasma amino acids was related to a goat’s milk diet, because of its very different composition compared with human milk and infant formula.

Conclusions

Our experience demonstrates that, when breast-feeding is not possible or is not exclusive, infants may be at risk of dangerous nutritional practices, including diets with very high protein content, such as a goat’s milk diet. Families of not breast-fed infants may need appropriate advice on safe alternatives for infant nutrition to avoid the risks of inappropriate diets.

LC-MS/MS progress in newborn screening

Newborn screening programs detect treatable disorders in infants before they become symptomatic. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has greatly increased the screening possibilities by monitoring levels of amino acids and acylcarnitines. After the initial screening step, LC-MS/MS can also be used in screening positive samples as a second tier test to differentiate between true and false positive samples. As the list of disorders screened for by LC-tandem MS increases, questions arise about screening for untreatable disorders, such as some lysosomal storage diseases (LSDs). For LSDs screening methods are being developed and tested more quickly than treatments are becoming available. This goes against one of the main tenets of newborn screening which requires that a treatment be available. LC-MS/MS can detect several disorders with a single injection, which is important in high throughput laboratories. Measuring different amino acids and acylcarnitines can be used to detect up to 45 different inherited disorders depending on how diseases are counted. The LSD assays are designed in a similar way to detect multiple disorders with common sample preparation and a single injection. The clinical implications of applying this technology to NBS on a large scale in many jurisdictions across the world are discussed.

Single-Gene Autosomal Recessive Disorders and Prader-Willi Syndrome: An Update for Food and Nutrition Professionals

This review is an update for food and nutrition professionals about single-gene autosomal recessive disorders and Prader-Willi syndrome. These disorders highlight the application of new genetic tools for screening newborns for conditions managed by medical nutrition therapy. Early detection and dietary treatment have been crucial since the 1960s for patients diagnosed with phenylketonuria. The same concept of reducing the dietary substrate that accumulates in disease is applied today for some conditions difficult to diagnose a decade ago. More than 6,000 human single-gene disorders have been identified to date, including more than 100 protein-based metabolic disorders. Tandem mass spectrometry has facilitated newborn screening for more disorders at low cost and high speed. Presently, screening newborns for 29 disorders is recommended in the United States and many states are doubling or tripling the number of tests offered in their screening programs. Complex dietary therapies have evolved for rare disorders, such as fatty acid oxidation, urea cycle, organic acid metabolism, glycogen storage, and energy production. Diagnosis-specific therapy may challenge routine dietary recommendations, such as encouraging fatty and sugary foods or avoiding fruits and milk, and treatment options have spawned a market in special formulas and substitute foods; recommended references and Web sites are provided to assist food and nutrition professionals in navigating this territory. Single-gene autosomal recessive disorders have increased the need for, and created opportunities for, food and nutrition professionals, especially those who enjoy biochemistry.