<i>Lactobacillus paracasei</i> ZJUZ2-3 inhibits gastrointestinal tumors via the IAA-induced AHR/MTDH/NF-κB axis.

ABSTRACT: Lactobacillus paracasei abundance is markedly reduced in gastric cancer (GC) tissues, suggesting its potential protective role. From healthy gastric tissue of a GC patient, we isolated a novel strain, L. paracasei ZJUZ2-3, which exerted potent antitumor effects. Intratumoral injection of live ZJUZ2-3, but not heat-killed bacteria, attenuated gastrointestinal tumor growth in mice. Conditioned medium from ZJUZ2-3 similarly inhibited cancer cell proliferation, implicating a secreted metabolite. Metabolomic profiling identified indole-3-acetic acid (IAA) as the key bioactive compound. Consistent with this, genetic knockout of trpA (essential for IAA biosynthesis) in ZJUZ2-3 abolished its antitumor efficacy. IAA alone recapitulated the tumor-suppressive effects both in v

SUBMITTER: Yang R 

PROVIDER: S-EPMC12594602 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature