Deer antler velvet is widely used in traditional medicine for its anti-aging,
antioxidant, and immunity-enhancing effects. However, few studies have reported
on the discovery of probiotic strains for deer antler fermentation to increase
functional ingredient absorption. This study evaluated the ability of probiotic
lactic acid bacteria to enhance the concentrations of bioactive molecules (e.g.,
sialic acid and gamma-aminobutyric acid [GABA]) in extracts of deer antler
velvet. Seventeen strains of
Lactobacillus
spp. that were
isolated from kimchi and infant feces, including
L. sakei
,
L. rhamnosus
,
L. brevis
, and
L.
plantarum
, and those that improved the life span of
Caenorhabditis elegans
were selected for evaluation. Of the
17 strains, 2 (
L. rhamnosus
LFR20-004 and
L.
sakei
LFR20-007) were selected based on data showing that these
strains increased both the sialic acid and GABA contents of deer antler extract
after fermentation for 2 d and significantly improved the life span of
C. elegans
. Co-fermentation with both strains further
increased the concentrations of sialic acid, GABA, and metabolites such as
short-chain fatty acids and amino acids. We evaluated the biological effects of
the fermented antler velvet (FAV) on the antibacterial immune response in
C. elegans
by assessing worm survival after pathogen
infection. The survival of the
C. elegans
conditioned with FAV
for 24 h was significantly higher compared with that of the control worm group
fed only normal feed (non-pathogenic
E. coli
OP50) exposed to
E. coli
O157:H7,
Salmonella typhi
, and
Listeria monocytogenes
. To evaluate the protective effects
of FAV on immune response, cyclophosphamide (Cy), an immune-suppressing agent
was treated to
in vitro
and
in vivo
. We found
that FAV significantly restored viability of mice splenocytes and immune
promoting-related cytokines (interleukin [IL]-6, IL-10, inducible nitric oxide
synthase [iNOS], interferon [IFN]-γ, and tumor necrosis factor
[TNF]-α) were activated compared to non-fermented deer antlers. This
finding indicated the protective effect of FAV against Cy-induced cell death and
immunosuppressed mice. Taken together, our study suggests that immune-promoting
antler velvet can be produced through fermentation using
L.
rhamnosus
LFR20-004 and
L. sakei
LFR20-007.