(P20-037-23) Prebiotic and Synbiotic Supplementation Impact on the Iron Status and Gut Microbiota in a Neonatal Piglet Model

Objectives: Iron-fortified infant formula contains 30 to 60 times more iron than breastmilk, while the mechanisms revolving iron metabolism in infancy are not fully understood. We hypothesized that dietary iron overexposure negatively affects gut microbiota and compromises absorption of other trace minerals. Using a piglet model, the study investigated the effects of iron-fortified milk replacer on gut microbiome and trace mineral status and whether the use of inulin or inulin and Ligilactobacillus agilis YZ050 (L. agilis YZ050) would alleviate adverse effects of iron overexposure.

Methods: Twenty-four neonatal pigs (n = 6/treatment) were fed with an iron-adequate formula (AI), a high-iron formula (HI), the HI formula supplemented with 5% inulin (HIP), the HIP formula with oral administration of L. agilis YZ050 every third day (HIS). Fecal and blood samples were collected weekly. On postnatal day 29, piglets were euthanized for intestinal tissue, colon content, and organ samples, which were analyzed for trace minerals using inductively coupled plasma atomic emission spectroscopy. The colon and fecal microbiome were analyzed using 16S rRNA sequencing.

Results: High-iron formula resulted in tissue iron overload and iron accumulation in colon and feces compared to AI (P < 0.001), while both HIP and HIS formulas diminished iron deposition in the liver (P ≤ 0.05), colon (P ≤ 0.001), and feces (P ≤ 0.05). The AI pigs had the highest zinc and copper in duodenum, liver and spleen, whereas HIP and HIS had the lowest zinc and copper in liver. High iron intake and inulin differently modulated colon and fecal microbiota compositions in comparison with AI pigs.

Conclusions: Excess iron fortification in formula caused tissue iron overload and an iron overflow to large intestine where it modulated microbial profile. Both high iron intake and inulin reduced zinc and copper absorption and 5% inulin (in milk diet) had a marked effect on gut microbiome.

Funding Sources: NIFA Hatch/multistate funding