Inhibitory Effect of Levilactobacillus brevis on Salivary α‐Amylase: Evidence From In Vivo and In Vitro Study

Scope Human salivary α‐amylase (sAA) is a therapeutic target for various pathological oral conditions. Several studies have reported that different probiotic strains can inhibit α‐amylase in vitro . However, the mechanisms behind remain largely unknown. To explore this topic, we focused on Levilactobacillus brevis (L. brevis) , a probiotic species known for its beneficial effects on oral health. Methods and Results The effect of L. brevis on sAA activity was evaluated in vivo by analyzing saliva samples from healthy subjects involved in a randomized, double‐blind, placebo‐controlled study. Additionally, we assessed the effects of probiotic lysate in vitro using a commercial sAA. An amylase‐binding assay was conducted to investigate the interaction between probiotic soluble components and the enzyme. Our findings demonstrate that L. brevis effectively inhibits α‐amylase activity, supporting its positive role in promoting both oral and systemic health. We also observed a similar effect on pancreatic α‐amylase. Conclusion Our data provide the first evidence of a direct interaction between α‐amylase and bioactive molecules from L. brevis , suggesting that the observed effects could be due to the ability of these probiotic‐derived molecules to bind and inhibit α‐amylase activity. This research expands our understanding of the anticariogenic and antihyperglycemic properties of specific probiotics. Trial Registration: ClinicalTrials.gov identifier: NCT06457724