Commensal fungi are an important part of human microbial community, among which
Candida albicans
and
Candida glabrata
are two common opportunistic pathogens. Unlike the high pathogenicity of
C. albicans, C. glabrata
is reported to show low pathogenicity to the host. Here, by using a
Galleria mellonella
infection model, we were able to confirm the much lower virulence of
C. glabrata
than
C. albicans
. Interestingly, pre-exposure to live
C. glabrata
(LCG) protects the larvae against subsequent various lethal fungal infections, including
C. albicans, Candida tropicalis,
and
Cryptococcus neoformans
. Inconsistently, heat-inactivated
C. glabrata
(HICG) pre-exposure can only protect against
C. albicans
or
C. tropicalis
re-infection, but not
C. neoformans
. Mechanistically, LCG or HICG pre-exposure enhanced the fungicidal activity of hemocytes against
C. albicans
or
C. tropicalis
. Meanwhile, LCG pre-exposure enhanced the humoral immunity by modulating the expression of fungal defending proteins in the cell-free hemolymph, which may contribute to the protection against
C. neoformans
. Together, this study suggests the important role of
C. glabrata
in enhancing host immunity, and demonstrates the great potential of
G. mellonella
model in studying the innate immune responses against infections.