The identified consortium increases the functional potential of fermented dairy products.

The metabolic capacity of probiotic mixed cultures formed by Lactobacillus and Bifidobacterium strains was assessed through the determination of the acidification profile and the production of amino acids and volatile compounds, during the fermentation of ultra-pasteurized skim milk. Two mixed cultures formed by [L. acidophilus + B. bifidum] and [L. acidophilus + B. animalis] stood out in the production of essential amino acids: His, Ile, Leu, Met, Thr, Trp and Val. As well as increased production of volatile compounds such as: acetoin, 2-heptanone, 2-nonanone, acetic acid, acid butanoic and hexanoic acid, in contrast to commercial fermented dairy products. Additionally, these bacterial mixed cultures were characterized by the production of distinctive volatile compounds: 1-heptanol, diisobutylcarninol, hemellitol, 1-dodecanol, acetone, 2-pentanone, 2-undecanone, ethyl acetate, benzaldehyde as well as valeric, acetyl valeric and isopropylpyruvic acids. Finally, the culture formed by [L. acidophilus + B. bifidum] presented a good acidification profile with a lactic acid production of 26.1 ± 0.1 g / L and pH 3.6 at the end of fermentation. This data suggests a great potential of these mixed cultures to improve the nutritional value and organoleptic characteristics of fermented dairy products, when added as starter or adjunct cultures in the fermentation process.

Targeted and non-targeted metabolite profiling can identify biomarkers after a dietary treatment leading to a better understanding of interactions between diet and health. This study was conducted to establish enriched or depleted metabolites in the feces of overweight mice after a diet shift plus agavins or inulins supplementation, and their possible association with beneficial effects on host health. Thirty-eight male C57BL/6 mice were fed with a high-fat diet for 5 weeks followed by a diet shift to a standard diet supplemented with agavins (HF-ST + A) or inulins (HF-ST + I) for five more weeks. Feces were collected before and after prebiotic supplementation for metabolomics analyses. HF-ST + I group increased the fecal excretion of two methyl esters: linoleic and oleic acid, while HF-ST + A mice showed a substantial augment of 2-decenal, fructose, cyclohexanol, and the acids: 10-undecenoic, 3-phenyllactic, nicotinic, 5-hydroxyvaleric, and lactic. From the metabolites identified in HF-ST + A, only lactic acid has been reported previously and associated with beneficial effects on host health. However, the identification of new metabolites, coming from the microbial fermentation of agavins, opens opportunities to transform this information into practical solutions to tackle overweight and associated metabolic syndrome.