Lactococcus lactis ssp. cremoris MRS47, a potential probiotic strain isolated from kefir grains, increases cis-9, trans-11-CLA and PUFA contents in fermented milk

Conjugated linoleic acid (CLA) has a number of beneficial health effects, including decreases in cancer incidence and atherosclerosis severity. However, dietary CLA intake is relatively low to promote the desired physiological effects. The CLA bacterial production in foods is a technological challenge besides the ability of probiotics to produce CLA is currently inconclusive. Therefore, the aim of the present study was to screen potential probiotic LAB strains isolated from Brazilian kefir grains able to produce CLA during the fermentation of whole cow milk. The selected strain, Lactococcus lactis ssp. cremoris MRS 47, increased CLA and polyunsaturated fatty acid content while at the same time significantly reducing saturated fatty acids and the thrombogenic index in fermented milk. These findings highlight the possibility of enriching CLA content in a dairy-fermented product if LAB were pre-selected by their capacity to produce CLA from milk fat, in what seems to be a strain-dependent ability.