Evaluation of Milk and Lactose Sensitivity in Lactase Non-Persistence Genotypes †
by
and
Aahana Shrestha
1,2, 
Jakob André Martinsson
3,
Helga Josefin Karlström
3,
Nils Jimmy Nilsson
3,
Mathew Philip Greig Barnett
2,4,5, 
Jo Kate Perry
1, 
Amber Marie Milan
1 and
David Cameron-Smith
1,2,6,* 
1
Liggins Institute, The University of Auckland, Auckland 1023, New Zealand
2
The Riddet Institute, Palmerston North 4442, New Zealand
3
Faculty of Medicine and Health Science, Linköping University, Linköping 581 83, Sweden
4
Food Nutrition & Health Team,AgResearch Limited, Palmerston North 4442, New Zealand
5
The High-Value Nutrition National Science Challenge, Auckland 1023, New Zealand
6
Food & Bio-Based Products Group, AgResearch Limited, Palmerston North 4442, New Zealand
*
Author to whom correspondence should be addressed.
†
Presented at the 2018 Nutrition Society of New Zealand Annual Conference, Auckland, New Zealand,
28–30 November 2018.
Proceedings 2019, 8(1), 21; https://doi.org/10.3390/proceedings2019008021
Published: 7 March 2019
(This article belongs to the Proceedings of 2018 Annual Meeting of the Nutrition Society of New Zealand)
Background: Lactase non-persistence, a condition affecting 75% of the world’s population, is characterized by inactivity of the lactase enzyme, resulting in lactose intolerance. The single nucleotide polymorphisms (SNPs) C/T13910 and G/A22018 are associated with lactase persistence. However, whether these genotypes relate to symptoms and biomarkers of lactose malabsorption, especially in response to milk, is not well defined. Furthermore, we hypothesized that differences in the β-casein content of milk (conventional milk, containing A1 β-casein, and a2 Milk™, A1 β-casein free) may influence the digestive impact of lactase non-persistence. Thus, this study aimed to explore differences in lactose intolerance of different genotypes in response to lactose, and to milks with differing casein composition.
Methods: 40 healthy young women were challenged with 50 g lactose and then assigned to ingest 750 mL of conventional milk and a2 Milk™ in a randomized order on different occasions one week apart. Breath hydrogen and digestive symptoms (e.g., cramps, bloating, fecal urgency) were recorded before, and at frequent intervals for 3 h after, ingestion of lactose and the two milks. Subjects were genotyped for lactase gene polymorphisms (C/T13910 and G/A22018) by restriction fragment length polymorphism.
Results: CC13910/GG22018 genotypes showed a greater increase in breath hydrogen (>25 ppm) and experienced greater digestive symptoms after milk and lactose ingestion compared to CT13910/GA22018 or TT13910/AA22018 genotypes. There was also a difference in the breath hydrogen and digestive symptoms between lactose and milk ingestion in CC13910/GG22018 individuals that was absent in the other genotypes. In addition, CC13910/GG22018 genotypes reported reduced fecal urgency after a2 Milk™ compared to conventional milk.
Conclusions: Lactase genotype influences both malabsorption and digestive discomfort in response to lactose and milk, with the intensity being higher for lactose compared to milk. Furthermore, digestive responses to milk may depend on lactase genotype and milk β-casein content.
Supplementary Materials
The poster is available online at www.mdpi.com/2504-3900/8/1/21/s1.
© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
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MDPI and ACS Style
Shrestha, A.; Martinsson, J.A.; Karlström, H.J.; Nilsson, N.J.; Barnett, M.P.G.; Perry, J.K.; Milan, A.M.; Cameron-Smith, D. Evaluation of Milk and Lactose Sensitivity in Lactase Non-Persistence Genotypes. Proceedings 2019, 8, 21. https://doi.org/10.3390/proceedings2019008021
AMA Style
Shrestha A, Martinsson JA, Karlström HJ, Nilsson NJ, Barnett MPG, Perry JK, Milan AM, Cameron-Smith D. Evaluation of Milk and Lactose Sensitivity in Lactase Non-Persistence Genotypes. Proceedings. 2019; 8(1):21. https://doi.org/10.3390/proceedings2019008021
Chicago/Turabian StyleShrestha, Aahana, Jakob André Martinsson, Helga Josefin Karlström, Nils Jimmy Nilsson, Mathew Philip Greig Barnett, Jo Kate Perry, Amber Marie Milan, and David Cameron-Smith. 2019. "Evaluation of Milk and Lactose Sensitivity in Lactase Non-Persistence Genotypes" Proceedings 8, no. 1: 21. https://doi.org/10.3390/proceedings2019008021
