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Session: Personalizing Nutrition - Select Genetic, Epigenetic and Microbiome Interactions Influencing Diet and Diet-related Diseases (Oral 13)

(OR13-07-23) Enhanced Anthocyanin Metabolite Excretion in Adults With the Genotype for Persistent Lactase Expression

Sunday, July 23, 2023
5:12 PM – 5:24 PM ET
Location:  Constitution B

    Presenting Author(s)

  • Martin Kohlmeier, MD PhD

    Professor
    UNC Nutrition Research Institute
    Chapel Hill, North Carolina, United States

    Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • EB

    Emmanuel Baah, MD MPH

    Postdoctoral Research Associate
    UNC Nutrition Research Institute
    Kannapolis, North Carolina, United States

  • AL

    Anju Lula

    UNC Nutrition Research Institute

  • DD

    Daniele Del Rio

    University of Parma, Italy

  • Colin D. Kay, PhD

    Professor
    University of Arkansas Medical Sciences
    Little Rock, Arkansas, United States

  • KM

    Katie A. Meyer, Ph.D.

    Nutrition Department, University of North Carolina
    Chapel Hill, North Carolina, United States

Disclosure(s):
Martin Kohlmeier, MD PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Colin D. Kay, PhD: No relevant financial relationship(s) with ineligible companies to disclose.
Objectives: Removal of glucose from flavonoid glucosides by brush-border lactase is a critical step for their absorption from the small intestinal lumen. The amounts of metabolites excreted with urine reflect how much of ingested flavonoids have been absorbed. We tested the hypothesis that adults with the genotype associated with high lactase expression (LCT -13910 TT) excrete larger amounts of phenolic metabolites after a single dose of naturally anthocyanin-rich pomegranate juice than people with the non-persistent genotype (LCT -13910 CC).

Methods: Locally recruited healthy adult participants (23 women and 17 men) ingested after an overnight fast 500 ml pomegranate juice and then collected all urine for 24 hours. Urine samples were extracted on solid-phase columns and analyzed by HPLC-MS/MS (SCIEX 6500). Genotypes related to lactase-persistence were determined with a customized multiarray (Illumina). A two-sided t test was used to compare amounts by genotype.

Results: The 18 adults with the TT genotype (presumably with high lactase activity) excreted about twice the amount of anthocyanin-derived phenolic compounds than the 12 participants with the non-persistent CC genotype (787 versus 391 nmoles/24 hours, p=0.006). Similar genotype-related differences were seen for hippuric acid alone (360 versus 202 nmoles/24h, p=0.016), 3-OH hippuric acid (36.2 versus 12.7 nmoles/24h, p=0.017), and 3-OH phenylacetic acid (47.4 versus 32.9 nmoles/24h, p=0.077).

Conclusions: The observation that ingestion of the same dose of anthocyanins results in much higher excretion of the typical phenolic metabolites in adults with the high-lactase genotype than in those with the low-lactase genotype Is consistent with the initial hypothesis. Since it is likely that many of the benefits of anthocyanins and other glucoside flavonoids are related to small metabolites derived from the ingested bioactives, greater produced and excreted amounts may well indicate a greater health benefit.

Future investigations of relevant fruit and vegetable effects and of flavonoid intake recommendations must consider the likely consequence of presence versus absence of lactase persistence, particularly considering the greatly differing frequencies in diverse populations.

Funding Sources: Supported by a UNC Nutrition Research Institute pilot grant