Bioconversion of Fe3O4 Nanoparticles by Probiotics

<b>Background/Objectives</b>: Iron deficiency anemia remains a primary global health concern, affecting millions worldwide. Despite the widespread availability of iron supplements, their efficacy is often hindered by poor bioavailability and adverse gastrointestinal effects. This study explores the potential of probiotics to enhance the bioavailability of Fe₃O₄ NPs through probiotic-mediated mechanisms. <b>Methods</b>: <i>Lactobacillus fermentum</i>, <i>Lactobacillus rhamnosus</i>, and <i>Lactobacillus plantarum</i> were utilized to investigate their interactions with Fe₃O₄ NPs, synthesized via co-precipitation and characterized using transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. <b>Results</b>: The results indicated that probiotics adhere to the nanoparticle surface, with <i>L. fermentum</i> exhibiting the highest adhesion and internalization capacity, leading to a significant increase in 4-hydroxyphenylacetic acid (4-HPLA) production (11.73 ± 0.09 mg/mL at 24 h, <i>p</i> < 0.05). Spectroscopic analyses further revealed that probiotic metabolism facilitates the oxidation of Fe₃O₄ to Fe₂O₃. Additionally, Fe₃O₄ nanoparticle-treated cultures demonstrated enhanced bacterial viability and metabolic activity, highlighting a synergistic effect between probiotics and iron nanoparticles. <b>Conclusions</b>: These findings provide compelling evidence for probiotic-assisted iron supplementation as a promising strategy to enhance iron bioavailability while mitigating the gastrointestinal side effects of conventional iron supplements.