Cereal alkylresorcinols are absorbed by humans

Area of Science:

• Human nutrition and metabolism
• Dietary biomarkers
• Gastroenterology

Background:

• Whole grain consumption is linked to health benefits, but lacks a specific biomarker.
• Alkylresorcinols (AR) are phenolic lipids found in whole wheat and rye, proposed as potential biomarkers.
• Understanding AR absorption is crucial for validating their use as biomarkers.

Purpose of the Study:

• To investigate the ileal digestibility and absorption of alkylresorcinols (AR) in humans.
• To determine if meal frequency (nibbling vs. ordinary) affects AR uptake.
• To assess the potential of AR as a biomarker for whole grain wheat and rye intake.

Main Methods:

• Human ileostomy subjects consumed controlled diets: AR-free (white wheat bread) and AR-rich (rye bran-enriched bread).
• Diets were administered with two meal frequencies: nibbling (7 meals/day) and ordinary (3 meals/day) in a crossover design.
• Ileostomy effluent and food samples were analyzed for AR concentration to calculate ileal recovery and digestibility.

Main Results:

• Approximately 40% of ingested AR was recovered in ileostomy effluent, indicating 60% ileal digestibility.
• AR absorption showed no significant difference between nibbling and ordinary meal frequencies.
• High recovery of AR in ileostomy samples confirmed significant uptake within the small intestine.

Conclusions:

• Alkylresorcinols (AR) are substantially absorbed in the human small intestine.
• AR absorption is independent of meal frequency, supporting their role as reliable biomarkers.
• AR show promise as validated biomarkers for assessing whole grain wheat and rye consumption.