Glutathione

Glutathione is capable of preventing damage to important cellular components caused by reactive oxygen species such as Free radicals, peroxides, lipid peroxides, and heavy metals.

One metabolite present in particularly high abundance inside host cells is the tripeptide glutathione (g-L-glutamyl-L-cysteinyl-glycine, GSH)
Wang et al. 2023b Cell Host & Microbe 31(8): 1359–1370

Glutathione (GSH) is an abundant metabolite within eukaryotic cells that can act as a signal, a nutrient source, or serve in a redox capacity for intracellular bacterial pathogens
Wang et al. 2023b Cell Host & Microbe 31(8): 1359–1370

Perhaps as a result of the ubiquity and high concentration of Glutathione in the cytosol of eukaryotic cells, certain intracellular pathogens couple Glutathione sensing to virulence factor induction
Ku & Gan 2019 Curr. Opin. Microbiol. 47: 8–13

Glutathione and its oxidized counterpart GSSG play crucial roles in multiple essential processes, including maintaining redox homeostasis, defense against reactive oxygen species, and protein iron-sulfur cluster synthesis
Meister & Anderson 1983 Annu. Rev. Biochem. 52: 711–760

see also:
Glutathione & Virulence
Pathogens / Pathobionts / Pathogenic Bacteria