Abstract
This study aims to characterize the microbiota and peptidomic composition of raw milk kefir, and to address the potential anti-allergic effects of raw milk kefir using validated research models for food allergy. Raw milk kefir was produced after incubation with a defined freeze-dried starter culture. Kefir was sampled during fermentation at seven time intervals. For comparison, kefir was also prepared from heat-treated milk. Peptide compositions were determined for the raw and heated milk, and kefir end products made from these milks. In a murine food allergy model, the two kefir end products were investigated for their allergy modulating effects. In both kefirs, we identified amplicon sequence variants identical to those in the starter culture, matching the bacteria Lactococcus lactis, Streptococcus thermophilus, Leuconostoc and the yeast Debaryomyces. In raw milk kefir, additional sequence variants of Lactococcus lactis and the yeasts Pichia and Galactomyces could be identified, which were absent in heated milk kefir. Analysis of peptide compositions in both kefirs indicated that the number and intensity of peptides drastically increased after fermentation. Heating of the milk negatively affected the diversity of the peptide composition in kefir. Only raw milk kefir suppressed the acute allergic skin response to the food allergen ovalbumin in sensitised mice. These effects coincided with differences in the T-cell compartment, with lower percentages of activated Th1 cells and IFNg production after treatment with kefir made from heated milk. The results of this study indicate specific properties of raw milk kefir that may contribute to its additional health benefits.
Original language | English |
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Pages (from-to) | 1648-1661 |
Number of pages | 14 |
Journal | Food and Function |
Volume | 14 |
Issue number | 3 |
DOIs | |
Publication status | Published - 24 Jan 2023 |
Bibliographical note
Publisher Copyright:© 2023 The Royal Society of Chemistry.
Funding
Software AG Stiftung, Darmstadt, Germany is acknowledged for funding the murine allergy study. Raw Milk Company, De Lutte, The Netherlands is acknowledged for providing the milk and kefir samples in this study as well as funding for the microbial enumeration experiments. Funding for microbiota profiling was obtained by R. K. from his NPN James Lind Award 2018.
Funders | Funder number |
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Software AG – Stiftung |