Limosilactobacillus fermentum SPC L75-1: a novel sourdough starter enhancing bread quality and exhibiting postbiotic immunomodulatory activity.

Sourdough is a mixture of water and flour fermented by yeast and lactic acid bacteria, enhancing its nutritional value, digestibility, shelf-life, and flavor. This study explored the potential of Limosilactobacillus fermentum SPC L75-1 as a novel sourdough starter by investigating its effects on baking characteristics and postbiotic properties. The SPC L75-1 strain utilized maltose, and its fermentation resulted in a volatile profile similar to that of the control bread. The application of SPC L75-1 to bread improved gas production by 18.5% and resulted in lower hardness compared to the control. Regarding its postbiotic potential, SPC L75-1 exhibited potent antioxidant and anti-inflammatory activities, reducing nitric oxide (NO) production by 42.1% and suppressing pro-inflammatory cytokines in an in vitro LPS-induced RAW 264.7 model. Furthermore, safety assessments, including hemolytic activity and antibiotic susceptibility tests, confirmed the strain’s suitability for food applications. Genome analysis further identified genes associated with these functional and safety traits. This study demonstrates that L. fermentum SPC L75-1 is a promising starter for sourdough fermentation, enhancing both bread quality and health benefits.