(P08-027-23) Associations of Fecael Short-Chain Fatty Acids With Lactose Intake and Lactase Genotype in US Adults

Objectives: We investigated the relationship between lactase persistent (LP) genotype, dairy/lactose consumption, and fecal short-chain fatty acid (SCFA) levels. We hypothesized that higher lactose consumption and/or higher intake of dairy products by adults with the lactase non- persistence (LNP) genotype will be associated with elevated fecal SCFA levels.

Methods: The USDA Nutritional Phenotyping Study is a cross-sectional observational study designed to assess how dietary factors impact human health. Participants with fecal samples whose lactose intake could be estimated from ASA24 dietary recalls (n=275) or a food frequency questionnaire (FFQ) (n=331) were included in this study. Fecal SCFA levels were analyzed using GC-MS. Lactose consumption and dairy product intake were estimated based on dietary data. LP/LNP was assessed by the single nucleotide polymorphism (SNP ID: rs4988235).

Results: LNP genotype was associated with higher fecal SCFAs than LP on average. The interactions between recent milk consumption and LPG were associated with fecal acetate, butyrate, and total SCFA levels. The interaction effects, however, disappeared when only Caucasian and Hispanic subjects were included, which suggested these effects may be driven by ethnicity. Relative to the expected ratio of acetate:butyrate:propionate, habitual cheese intake was negatively associated with a shift toward increased fecal butyrate; recent yogurt consumption was negatively correlated with a shift toward acetate level but positively toward fecal butyrate.

Conclusions: The association of dairy intake and measured fecal SCFAs by healthy adults varied, in part, as a function of the lactase persistent genotype and dairy product type.

Funding Sources: This study was funded by the California Dairy Research Foundation and by USDA ARS 2032-51530-026-000-D.