Multi-omics Unveils Strain-specific Neuroactive Metabolite Production Linked to Inflammation Modulation by and Their Extracellular Vesicles

Overview

Journal Curr Res Microb Sci

Specialty Microbiology

Date 2025 Mar 3

PMID 40027450

Authors

Basit Yousuf

Walid Mottawea

Galal Ali Esmail

Nazila Nazemof

Nour Elhouda Bouhlel

Emmanuel Njoku

Yingxi Li

Xu Zhang

Zoran Minic

Riadh Hammami

Affiliations

Soon will be listed here.

Abstract

species are key members of the human gut microbiome and play crucial roles in gut ecology, metabolism, and host-microbe interactions. This study investigated the strain-specific production of neuroactive metabolites by 18 Bacteroidetes (12 , 4 , and 2 ) using multi-omics approaches. Genomic analysis revealed a significant potential for producing GABA, tryptophan, tyrosine, and histidine metabolism-linked neuroactive compounds. Using untargeted and targeted metabolomics, we identified key neurotransmitter-related or precursor metabolites, including GABA, l-tryptophan, 5-HTP, normelatonin, kynurenic acid, l-tyrosine, and norepinephrine, in a strain- and media-specific manner, with GABA (1-2 mM) being the most abundant. Additionally, extracellular vesicles (EVs) produced by harbor multiple neuroactive metabolites, mainly GABA, and related key enzymes. We used CRISPR/Cas12a-based gene engineering to create a knockout mutant lacking the glutamate decarboxylase gene () to demonstrate the specific contribution of -derived GABA in modulating intestinal homeostasis. Cell-free supernatants from wild-type (WT, GABA+) and Δ (GABA-) provided GABA-independent reinforcement of epithelial membrane integrity in LPS-treated Caco-2/HT29-MTX co-cultures. EVs from WT and Δ attenuated inflammatory immune response of LPS-treated RAW264.7 macrophages, with reduced pro-inflammatory cytokines (IL-1β and IL-6), downregulation of TNF-α, and upregulation of IL-10 and TGF-β. GABA production by had a limited impact on gut barrier integrity but a significant role in modulating inflammation. This study is the first to demonstrate the presence of a myriad of neuroactive metabolites produced by species in a strain- and media-specific manner in supernatant and EVs, with GABA being the most dominant metabolite and influencing immune responses.

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