The effects of casein glycomacropeptide on general health status in children with PKU: A randomized crossover trial

Authors

Alex Pinto, Birmingham Women's and Children's NHS Foundation Trust
Anne Daly, Birmingham Women's and Children's NHS Foundation Trust
Camille Newby, University Hospitals Bristol and Weston NHS Foundation Trust
Abigail Robotham, University Hospitals Bristol and Weston NHS Foundation Trust
Simon Heales, University College London
Simon Eaton, University College London
Helen Aitkenhead, Great Ormond Street Hospital for Children NHS Foundation Trust
Kimberly Gilmour, Great Ormond Street Hospital for Children NHS Foundation Trust
Richard Jackson, University of Liverpool
Catherine Ashmore, Birmingham Women's and Children's NHS Foundation Trust
Sharon Evans, Birmingham Women's and Children's NHS Foundation Trust
Júlio Cesar Rocha, NOVA University Lisbon
Fatma Ilgaz, Hacettepe University
Mary Hickson, School of Health Professions
Anita MacDonald, Birmingham Women's and Children's NHS Foundation Trust

ORCID

• Mary Hickson: 0000-0001-7996-0095

Abstract

In PKU, it is suggested that casein glycomacropeptide based protein substitute (GMP) may have physiological advantage when satiety, oxidative stress, renal function and inflammation are considered. Its prebiotic properties may also help gastrointestinal (GI) tolerance. In children with PKU, a randomized/crossover trial comparing phenylalanine-free amino acids (AA) vs GMP as the single source of protein substitute for 12-weeks in each arm was conducted. There was a 4-week wash out period with AA in-between. At baseline and end of each intervention, blood and fecal samples were taken to monitor gut health, oxidative stress, renal function, inflammatory markers and plasma amino acids. Satiety and Pediatric Quality of Life (PedsQL) GI symptoms questionnaires were completed. Usual weekly blood spots for phenylalanine and tyrosine were done. Twelve patients (8 males; aged 4-9y) with PKU participated. GMP improved the following GI symptoms: stomach pain (p = 0.003), heartburn and reflux (p = 0.041) wind and bloating (p = 0.018). With GMP, there was also a trend for less constipation (p = 0.068), discomfort with eating (p = 0.065) and nausea and vomiting (p = 0.087). There were no changes on stool gut health markers (IgA, short chain fatty acids and fecal calprotectin). There were no statistically significant differences for renal, oxidative stress, inflammatory and gut health markers or measures of satiety except for adiponectin (p = 0.028) and total antioxidant capacity (p = 0.049), although the latter was possibly without clinical significance. Mean dried blood spot phenylalanine (Phe) was 114 μmol/L higher with GMP vs AA (p < 0.001). There was no difference in tyrosine levels. In conclusion, GI symptoms statistically significantly improved with GMP versus AA. The Phe content of GMP may present challenges when it is used as the only protein substitute in children with classical PKU with low Phe tolerance.

DOI

10.1016/j.ymgme.2024.108607

Publication Date

2024-12-01

Publication Title

Molecular Genetics and Metabolism

Volume

143

Issue

4

ISSN

1096-7192

Keywords

Amino acids, Gastrointestinal symptoms, Glycomacropeptide, Gut health, Inflammation, Oxidative stress, Phenylketonuria, Renal function, Satiety

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Pinto, A., Daly, A., Newby, C., Robotham, A., Heales, S., Eaton, S., Aitkenhead, H., Gilmour, K., Jackson, R., Ashmore, C., Evans, S., Rocha, J., Ilgaz, F., Hickson, M., & MacDonald, A. (2024) 'The effects of casein glycomacropeptide on general health status in children with PKU: A randomized crossover trial', Molecular Genetics and Metabolism, 143(4). Available at: 10.1016/j.ymgme.2024.108607" >https://doi.org/10.1016/j.ymgme.2024.108607