Functional and Genomic Characterization of Ligilactobacillus salivarius TUCO-L2 Isolated From Lama glama Milk: A Promising Immunobiotic Strain to Combat Infections

QUILODRÁN-VEGA, SANDRA; ARCE, LORENA; TOMOKIYO, MIKADO; KITAZAWA, HARUKI; ALBARRACIN, LEONARDO; ZHOU, BINGHUI; AL KASSAA, IMAD; VILLENA, JULIO; MANSILLA, FLAVIA; ISLAM, MD AMINUL; SUDA, YOSHIHITO

Frontiers in Microbiology

Frontiers Media S.A.

Lugar: Lausana ; Año: 2020 vol. 11

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated fromthe milk of the South American camelid llama (Lama glama) have not been reported inpublished studies. The aim of the present work was to isolate beneficial LAB from llamamilk that can be used as potential probiotics active against bacterial pathogens. LABstrains were isolated from llama milk samples. In vitro functional characterization of thestrains was performed by evaluating the resistance against gastrointestinal conditionsand inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatoryproperties of the strains were assessed. The functional studies were complementedwith a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillussalivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared tothat of other tested strains. The TUCO-L2 strain was resistant to pH and high bile saltconcentrations and demonstrated antimicrobial activity against Gram-negative intestinalpathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulatedthe innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinalepithelial cells. This effect involved differential regulation of the expression of inflammatorycytokines and chemokines mediated by the modulation of the negative regulators of theTLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of miceto Salmonella infection. This is the first report on the isolation and characterization ofa potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and insilico investigation performed in this study reveals several research directions that areneeded to characterize the TUCO-L2 strain in detail to position this strain as a probiotic orimmunobiotic that can be used against infections in humans or animals, including llama.