Oxidative, Inflammatory, and Constipation Stress Modulation by a Heteropolysaccharide from Lacticaseibacillus rhamnosus CRL75

LOBO, RENÉ EMANUEL; ÁVILA, ANA MAGDALENA; LAIÑO, JONATHAN; MOLINA, VERÓNICA; NAVARRO, DIEGO; GÓMEZ, MARÍA INÉS; TORINO, MARÍA INÉS; TARANTO, MARÍA PÍA

Fermentation

MDPI

Año: 2025 vol. 11 p. 224 - 245

Abstract: Lacticaseibacillus (L.) rhamnosus CRL75 is a lactic acid bacterium (LAB) isolatedfrom local dairy products, demonstrating significant adaptation in skimmed milk (FM75).In this context, CRL75 exhibited high microbial growth (3.63 ± 0.18 log CFU·mL−1), strongacidification (9.20 ± 0.10 g·L−1 lactic acid, and 2.40 ± 0.10 pH units), and increased viscosityin FM75 after 16 h of fermentation. Additionally, this LAB strain produces both capsularpolysaccharides (CPS+) and extracellular polysaccharides (EPS75), contributing to a ropyphenotype (>10 cm). The purified EPS75 (70.70 ± 3.25 mg·L−1) displayed low molecularweight (12.7 kDa), with galactose and glucose as its primary monomers in a 4:1 ratio. Inaqueous environments, EPS75 exhibited an extended size (147 nm), a random coil structure,and macromolecular aggregation. Furthermore, vibrational spectroscopy confirmed thepresence of a neutral EPS with high thermal stability. Additionally, EPS75 exhibited dosedependentantioxidant activity, effectively reducing metal ions (Fe3+, Mo6+, and Mn7+) andstabilizing radicals (ABTS•+, HO•, O2•−, and HOO•). The biopolymer also demonstratedimmunostimulatory and anti-inflammatory effects in RAW 264.7 cells. In vivo assaysusing Balb/c mice indicated that both EPS75 and FM75 prevented constipation, suggestingtheir potential as natural and safe agents for constipation-related disorders. Due to itsviscosifying and health-promoting attributes, CRL75 offers promising applications forfunctional dairy products.