Influence of exopolysaccharide EPSKar1–iron complexation on iron bioavailability and alleviating iron deficiency anaemia in Wistar rats

The prevalence of iron deficiency anaemia is a significant issue worldwide, affecting individuals of all ages and often associated with inadequate iron bioavailability. Despite the use of ferrous salt supplements to address anaemia, their limited bioaccessibility and bioavailability in human GIT and adverse impact on food properties remain significant challenges. Hence, this study aims to explore the iron chelation mechanism of an exopolysaccharide EPSKar1 to enhance iron bioaccessibility, bioavailability, and anti-anaemic effects using cell culture and an anaemic rat model. EPSKar1 was extracted from Lacticaseibacillus rhamnosus Kar1 and complexed with FeSO₄ to form "EPSKar1-iron". This novel complex, besides being bio-accessible after in vitro gastric digestion, demonstrated 61.27 ± 1.96% iron bioavailability to the Caco-2 cells. In line with these in vitro findings, intragastric administration of the EPSKar1-iron complex to anaemic Wistar rats at 25 and 50 mg per kg body weight significantly restored blood haemoglobin levels and re-established the morphological features of red blood cells. Furthermore, the apparent digestibility co-efficient and iron uptake improved significantly without adversely affecting the serum biochemical parameters in these anaemic rats. The levels of iron-transport proteins including serum transferrin and ferritin in tissue and plasma have increased remarkably upon oral administration of EPSKar1-iron at a higher dose of 50 mg per kg body weight. Oral supplementation of EPSKar1-iron did not foster adverse histological changes in the liver, kidneys, and spleen. In fact, the treatment with the EPSKar1-iron complex had a restitution effect on the tissue architecture, thereby ameliorating the tissue lesions. These findings collectively indicate that the EPSKar1-iron complex shows nutraceutical potential in enhancing the bioavailability of iron and could be a promising approach to tackle iron deficiency anaemia.