Serotonin modulation of metabolism and stress response in Pseudomonas fluorescens

TY - JOUR

T1 - Serotonin modulation of metabolism and stress response in Pseudomonas fluorescens

AU - Waclawiková, Barbora

AU - Schwalbe, Markus

AU - Ilyaskina, Diana

AU - Toptas, Semih

AU - Thome, Nicola U.

AU - Du, Chao

AU - Elsayed, Somayah S.

AU - de Jong, Anne

AU - van Wezel, Gilles

AU - El Aidy, Sahar

PY - 2025/10/31

Y1 - 2025/10/31

N2 - Background Pseudomonas fluorescens is a Gram-negative bacterium with a remarkable metabolic and physiological versatility that enables it to adapt and colonize diverse ecological niches, including the human small intestine. While serotonin is primarily found in high concentrations in gut tissue, its levels in the lumen can be elevated in conditions such as celiac disease, where P. fluorescens is also found in increased abundance. The potential effects of serotonin on P. fluorescens in such contexts remain unclear. Results We demonstrate that P. fluorescens metabolizes serotonin primarily into 5-hydroxyindole-3-acetic acid (5-HIAA) and, to a lesser extent, into 5-hydroxytryptophol and N-acetylserotonin. Gene expression analysis revealed significant changes in oxidative stress-related pathways over time, and proteomic analysis confirmed the shifts seen particularly in amino acid catabolic pathways. Serotonin metabolism also enhanced bacterial resistance to oxidative stress, suggesting a protective role. Conclusions The findings reveal a novel mechanism by which serotonin modulates the metabolism and stress responses of P. fluorescens. This study provides insight into how P. fluorescens adapts to serotonin-rich environments, such as in celiac disease, and may inform future research on microbial interactions with host-derived metabolites in disease contexts.

AB - Background Pseudomonas fluorescens is a Gram-negative bacterium with a remarkable metabolic and physiological versatility that enables it to adapt and colonize diverse ecological niches, including the human small intestine. While serotonin is primarily found in high concentrations in gut tissue, its levels in the lumen can be elevated in conditions such as celiac disease, where P. fluorescens is also found in increased abundance. The potential effects of serotonin on P. fluorescens in such contexts remain unclear. Results We demonstrate that P. fluorescens metabolizes serotonin primarily into 5-hydroxyindole-3-acetic acid (5-HIAA) and, to a lesser extent, into 5-hydroxytryptophol and N-acetylserotonin. Gene expression analysis revealed significant changes in oxidative stress-related pathways over time, and proteomic analysis confirmed the shifts seen particularly in amino acid catabolic pathways. Serotonin metabolism also enhanced bacterial resistance to oxidative stress, suggesting a protective role. Conclusions The findings reveal a novel mechanism by which serotonin modulates the metabolism and stress responses of P. fluorescens. This study provides insight into how P. fluorescens adapts to serotonin-rich environments, such as in celiac disease, and may inform future research on microbial interactions with host-derived metabolites in disease contexts.

U2 - 10.1186/s12915-025-02434-1

DO - 10.1186/s12915-025-02434-1

M3 - Article

SN - 1741-7007

VL - 23

JO - BMC Biology

JF - BMC Biology

M1 - 330

ER -