Location: Immunity and Disease Prevention Research
Project Number: 2032-51530-026-023-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Jan 1, 2022
End Date: Mar 31, 2024
Objective:
1) Investigate the relationship between lactose consumption, lactase genotype, and fecal acetate.
2) Investigate the taxonomic sources of microbial lactase in lactase non-persisters (LNP) and lactase persisters (LP), and in Caucasians and non-Caucasians, in relationship to lactose intake and dairy product type.
Approach:
A California cohort (n=330) will be derived from the USDA Nutritional Phenotyping Study, which has completed enrollment with numerous outcomes already measured. Fecal samples were collected from participants in the period after completing two to three 24-hr dietary recalls using ASA24. Participants also completed the Block Food Frequency Questionnaire. The cohort has been genotyped for the lactase persistence SNP, rs4988235, and lactose intake has been estimated as part of a previous CDRF-funded study.
Fecal short chain fatty acids (SCFAs)—acetate, butyrate, and proprionate—will be assessed using GC-MS. Shotgun metagenomes will be sequenced for the remaining 40 samples for which we have extracted DNA of sufficient yield and quality for sequencing. Metagenomic sequences will be analyzed for beta-galactosidase (lactase) genes and these genes will be mapped to microbial taxonomy in the complete set of shotgun metagenomes (n=330). These data will then be used to determine differences in SCFA production and in microbial sources of lactase between lactose persisters and non-persisters in Caucasians and non-Caucasians with different habitual intakes of lactose.
