Targeted FODMAP Degradation in Pea Substrate Fermentation by Selected Lactic Acid Bacteria

Raffinose-family oligosaccharides (RFOs) such as raffinose, stachyose and verbascose are abundant in legumes and are associated with gastrointestinal discomfort, particularly in individuals sensitive to FODMAPs. This study aimed to identify and characterize lactic acid bacteria capable of degrading RFOs in order to improve the tolerability of legume-based food products. Lactic acid bacteria were isolated from chicken feces and screened for α-galactosidase activity and raffinose utilization. Selected strains were further evaluated in a liquid medium containing raffinose as the single carbon source and in yellow pea flour fermentations to assess their RFO-degrading capacity. A total of 23 of 138 strains, including Limosilactobacillus reuteri (13), Ligilactobacillus salivarius (4), Leuconostoc mesenteroides (4), Lactiplantibacillus plantarum (1) and Weissella paramesenteroides (1), were identified as α-galactosidase-positive and capable of raffinose metabolism. In liquid culture, six L. reuteri showed particularly high efficiency, with complete raffinose depletion within 8 h. In pea flour fermentations, RFO reductions of up to 100% were achieved. However, RFO metabolism by L. reuteri was associated with mannitol formation, a sugar alcohol classified as a FODMAP. Overall, the results demonstrate that targeted fermentation with selected lactic acid bacteria enables effective RFO reduction in pea flour, highlighting their potential for the development of legume-based meat alternatives.