Associations Between Serum Lutein and Human Gut Microbiota (P02-004-19)

Abstract

ObjectivesLutein is a carotenoid found in green leafy vegetables, avocados, and eggs, and is purported to have protective effects against age-related macular degeneration (AMD) as well as benefits for visual and cognitive health. Recent studies have indicated significant variation in serum lutein among individuals and that gastrointestinal (GI) microbial profile may potentially contribute to lutein status. However, the extent to which the GI microbiota contribute to lutein is unclear. The current study aimed to determine GI microbial predictors of serum lutein in a healthy young adult population. MethodsAmong adults ages 25–45 years (N = 105), venous blood was collected following a 10-hour fast. Serum lutein was determined using HPLC. Fecal DNA was extracted and the V4 region of the 16S rRNA gene was amplified. Amplicon sequence variants were assigned using the GreenGenes 13-8 database and DADA2, followed by analysis in QIIME2 and LDA Effect Size (LEfSe). Participants underwent DXA scan for whole body % fat (%Fat) and completed a 7-day food record to assess lutein consumption. Demographic information on participant’s age and sex was also assessed and included in the statistical models. ResultsFour genera (Dialister, Ruminococcus, Gemmiger, and Phascolarctobacterium) and two species (Bacteroides eggerthii, Ruminococcus torques) were different between individuals in the highest and lowest quartiles of serum lutein. The genera Ruminococcus (Rho = –0.24, P = 0.02) and Phascolarctobacterium (Rho = –0.21, P = 0.03) and species R. torques (Rho = –0.35, P < 0.001) were inversely related to serum lutein. Linear regression modelling, adjusted for age, sex, %Fat, and dietary lutein, revealed that R. torques was the only significant predictor of serum lutein concentrations, accounting for 8.4% of the variance. ConclusionsOur results reveal that individuals with lower serum lutein concentrations have a higher relative abundance of R. torques than those with higher lutein concentrations. As R. torques has been shown to be elevated in those with AMD, it is possible the relationship between this microbe and lutein is evident earlier in adulthood. However, further dietary intervention trials are warranted to clarify the relations among R. torques and serum lutein concentrations. Funding SourcesThis work was supported by funds provided by the Department of Kinesiology and Community Health at the University of Illinois and the USDA National Institute of Food and Agriculture, Hatch Project 1009249. Partial support was also provided by the Hass Avocado Board.