Metabolic cross-feeding by human gut bacteria
Gut microbes cross-feed dietary macromolecules, yet whether similar pathways exist for antioxidant nutrients is unclear.
The researchers show that gut bacteria from different phyla cross-feed the antioxidant ergothioneine to produce energy under anaerobic conditions.
They demonstrate that the gut bacteria Clostridium symbiosum encodes ergothionases that transform ergothioneine, a mushroom-derived antioxidant, into the electron acceptor thiourocanic acid (TUA). TUA is reduced by another bacteria, Bacteroides xylanisolvens, increasing bacterial ATP synthesis and growth.
Furthermore, TUA is selectively produced and consumed by certain human fecal microbial communities. Consistent with emerging links between intestinal ergothioneine homeostasis and colorectal cancer, ergothionase is significantly enriched in fecal metagenomes from colorectal cancer patients.
This pathway is active in human fecal communities and may contribute to colorectal cancer risk.
https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(25)00280-X
