Investigation into In Vitro and In Vivo Caenorhabditis elegans Models to Select Cheese Yeasts as Probiotic Candidates for their Preventive Effects against Salmonella Typhimurium

Abstract

The design of multiscale strategies integrating in vitro and in vivo models is necessary for the selection of new probiotics. In this regard, we developed a screening assay based on the investigation of the potential of yeasts from cheese as probiotics against the pathogen Salmonella Typhimurium UPsm1 (ST). Two yeasts isolated from raw-milk cheese (Saccharomyces cerevisiae 16, Sc16; Debaryomyces hansenii 25, Dh25), as well as S. cerevisiae subspecies boulardii (CNCM I-1079, Sb1079), were tested against ST by applying in vitro and in vivo tests. Adherence measurements to Caco-2 and HT29-MTX intestinal cells indicated that the two tested cheese yeasts presented a better adhesion than the probiotic Sb1079 as the control strain. Further, the Dh25 was the cheese yeast most likely to survive in the gastrointestinal tract. What is more, the modulation of the TransEpithelial Electrical Resistance (TEER) of differentiated Caco-2 cell monolayers showed the ability of Dh25 to delay the deleterious effects of ST. The influence of microorganisms on the in vivo model Caenorhabditis elegans was evaluated by measuring the longevity of the worm. This in vivo approach revealed that this yeast increased the worm’s lifespan and protected it against ST infection, confirming that this in vivo model can be useful for screening probiotic cheese yeasts.

Development of an innovative methodology combining chemical fractionation and in vivo analysis to investigate the biological properties of cheese

“…The similarities in C. elegans and human genetics, as well as its short lifespan, make it a reliable experimental model to test the impact of such cheese extracts on the host [22]. Like Drosophila melanogaster this worm has become a rudimentary in vivo model used to characterise the probiotic properties of bacteria and yeasts [23][24][25] but its use has now been extended to the screening of the biological effects of plant extracts [26,27]. In this context, we decided to use C. elegans to investigate the impact of cheese fractions on the longevity.…”

Physiological and Genomic Analysis of Bacillus pumilus UAMX Isolated from the Gastrointestinal Tract of Overweight Individuals

“…Nonetheless, a variation in the experimental conditions may restrict data comparison within researchers [ 54 , 55 , 56 ]. Still, in vitro models are recommended for metabolic and biochemical experiments [ 57 ]. Therefore, this study was undertaken using an in vitro model based on the ability of B. pumilus UAMX (BP-UAMX) to survive at low pH or in the presence of bile salts that are related to the gastrointestinal transit from the gastric to the enteric sections, since the studied strain was previously isolated from the gut of overweight individuals.…”

Caenorhabditis elegans, a Host to Investigate the Probiotic Properties of Beneficial Microorganisms

“…Indeed yeasts can also play this role. The recent study by Veisseire and colleagues has thus demonstrated, in C. elegans , the probiotic properties of the cheese yeast Debaryomyces hansenii Dh25 ( 104 ). The authors showed that in its presence, the nematode had a significantly increased life expectancy and was able to resist to a S .…”