(P27-004-24) Investigating the Nexus Between Zinc Intake and Blood Lead Levels on Gut Microbiome Diversity: A Secondary Analysis of NHANES Data

Objectives: A healthy gut microbiome is composed of a complex and diverse bacterial ecosystem in which heavy metals can employ contrasting influences on its delicate balance . Zinc, an essential micronutrient, is required in many biological processes that may help to support microbiome diversity. In contrast, lead, a toxic heavy metal, has shown to cause dysbiosis in the gut. This study aims to determine if zinc intake impacts gut microbiome diversity and if the micronutrient aids in the preservation of diversity when blood lead levels (BLL) are elevated.

Methods: NHANES 2009-2010 data was uploaded and analyzed in SPSS. A one-way ANOVA was used to first determine if daily zinc intake at low (0-5.59 mg/day), adequate (5.6-40 mg/day), and high (≥ 40.01 mg/day) had significantly different concentrations of enterolactone (ENL), a microbiome diversity biomarker. Data was then divided into high and low BLL ( ≥1 µg/dl and < 1 µg/dl, respectively). To determine if ENL concentrations were significantly different among the three zinc ranges after the data was divided, one-way ANOVAs were run for both high and low BLL. To determine if zinc intake inhibited the impact of BLL on microbiome diversity, ENL concentrations were compared between high and low BLL for each zinc intake range using a 2x3 factorial ANOVA. The same ANOVA tests were run again with high BLL defined as ≥ 2 µg/dl.

Results: Adequate zinc intake had significantly higher ENL levels compared to high intakes (p=0.034) No significant differences between ENL concentrations for ≥1 µg/dl and < 1 µg/dl BLL at low, adequate, or high zinc ranges were observed (p = 0.81, 0.152, 0.27). When BLL toxicity was increased to ≥ 2 µg/dl, ENL concentrations were significantly lower at high BLL for adequate and high zinc intake ranges (p=0.034 and p = 0.041 respectively).

Conclusions: Adequate zinc intake is important in maintaining microbiome diversity. High zinc intakes can lead to a decrease in microbiome diversity. The data suggests that BLL ≥ 2 µg/dl are associated with a decrease in microbiome diversity, regardless of zinc intake. This indicates that as BLL approach 2 µg/dl the protective mechanisms become overwhelmed and as a result diversity is impacted.

Funding Sources: Florida International University