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

With the ever-increasing human lifespan, age-related affections have become a public health issue. The health sector is looking for new bioactive compounds to respond to this demand. The unexplored microbial biodiversity and its metabolites represent a major source of innovative bioactive molecules with health potential. Fermented foods, such as raw-milk cheese, have already been investigated for their rich microbial environment, especially for their organoleptic qualities. But studies remain limited regarding their effects on health and few metabolites of microbial origin have been identified. An efficient methodology was developed in this study to investigate the biological effect of raw-milk cheese, combining a chemical fractionation, to isolate the most metabolites from the cheese matrix, and an in vivo biological test using Caenorhabditis elegans. C. elegans was brought into contact with cheese extracts, obtained by means of chemical fractionation, and with freeze-dried whole cheese by supplementing the nematode growth medium. A longevity assay was performed to evaluate the effects of the extracts on the worms. Our results demonstrate the feasibility of the method developed to bring the worms into contact of the cheese extracts. The evaluation of the effects of the extracts on the longevity was possible. Some extracts showed a beneficial effect as extract W70 for example, obtained with water, which increases the mean lifespan by 16% and extends the longevity by 73% (p < 0.0001).