Optimizing Magnesium Uptake in Lacticaseibacillus Rhamnosus To Advance Nutribiotic Strategies

Magnesium is an essential mineral involved in more than 300 enzymatic reactions, including protein synthesis, neuromuscular function, and blood pressure regulation. Recent studies have highlighted the role of probiotics, beneficial microorganisms in the human gut, in enhancing mineral absorption. However, the interaction between magnesium and probiotic strains remains poorly understood. This study aimed to investigate the capacity of Lacticaseibacillus rhamnosus ATCC 53,103 to uptake and internalize magnesium ions, using MgSO₄ as a supplementation source. The bacterium was cultivated in MRS medium with varying concentrations of MgSO₄ (0, 0.1444, 0.722, and 1.444 g/L) over seven days. Quantitative analysis revealed that at 0.722 g/L MgSO₄, intracellular magnesium accumulation peaked at 0.7 mg/dL by Day 3, representing a 7-fold increase compared to the control (0.1 mg/dL). Scanning and transmission electron microscopy indicated essential morphological changes, including ruffled cell surfaces and enhanced ribosomal visibility. These findings suggest that L. rhamnosus can internalize magnesium under enriched conditions, supporting its potential as a microbial carrier for nutribiotic applications. This work contributes to the growing field of mineral-microbe interactions and may inform the development of probiotic-based strategies to improve magnesium bioaccessibility in the human gut.