Intestinal health plays a critical role in the absorption and utilization of various micronutrients, including zinc. At the same time, some micronutrient interventions (particularly those containing high doses of iron) may have negative effects on the gut microbiome. In this new technical brief, we explore the intersection of gut health and the efficacy and safety of micronutrient interventions. We used data from the Zinc in Powders Trial (ZiPT) to assess the prevalence of elevated fecal calprotectin and myeloperoxidase, biomarkers of environmental enteric dysfunction (EED), and to assess their associations with indicators of child growth, micronutrient status, and inflammation among young children in Dhaka, Bangladesh. We also used data from our recently completed trial of quintuply-fortified salt to explore potential changes in the gut microbiome among mother-child pairs in Punjab, India that received quintuply-fortified salt vs. iodized salt for 12 months.

Key takeaways include:

  • The burden of zinc and other micronutrient deficiencies is high among young children and women in resource-limited settings, and interventions to effectively prevent deficiencies are needed.

  • The high prevalence of intestinal inflammation among young children in Bangladesh highlights a need to reduce the burden of EED and integrate gut health assessment into intervention design. This is critical to improving the effectiveness and targeting of zinc and multi-micronutrient intervention strategies.

  • Quintuply-fortified salt containing iron, zinc, vitamin B12, folic acid, and iodine, can be safely delivered without disrupting the gut microbiome of women or young children, supporting its use as a large-scale food fortification intervention.

  • Future research should focus on evaluating the interactions between zinc status, gut health, and intervention strategies in real-world settings to inform formulation, policy, and scale-up decisions.

This research was made possible through support from the Gates Foundation, the Thrasher Research Fund, the Waterloo Foundation, and the International Zinc Association. Read the full brief here.