Impact of supplementation with fermented dairy matrices on gut microbiota composition of hyperhomocysteinemic mice. MEDITO

Several studies highlighted a correlation between nutritional deficiencies (especially related to B-vitamins deficiencies, including folic acid) and a high plasma homocysteine concentration, which is considered as a risk factor for cardiovascular diseases. The present work was performed in a murine model of hyperhomocysteinemia with the aim of studying the impact of supplementation with dairy fermented foods enriched in natural folates produced by suitably selected lactic acid bacteria on faecal microbiota composition, compared to supplementation with synthetic folic acid. In order to induce hyperhomocysteinemia, a total of 40 6-weeks old C57BL/6J male mice were fed a diet depleted in folic acid and choline, and containing reduced levels of methionine. After one week of adaptation, animals were randomly divided into 6 groups (6-8 mice per group) and supplemented as follows: the first 2 groups were fed control diet or folate deficient diet for 10 weeks (C: Control and FD: Folate Deficient, respectively). The remaining 4 groups were fed folate deficient diet for the first 5 weeks and then shifted for additional 5 weeks to a folate deficient diet supplemented with: fermented milk enriched in folate (FFM: Folate Fermented Milk), obtained using 2 bacterial strains able to produce high folate levels; fermented milk (FM: Fermented Milk) obtained by a bacterial strain producing normal folate levels; unfermented milk (M: Milk); synthetic folic acid, choline and methionine in order to revert the diet to the standard composition (R: Repleted). Feces were collected from animals for each of the experimental groups at the end of treatments for microbiome analysis, which was performed by NGS on extracted DNA samples. LEfSe analysis was used to identify metagenomic biomarkers characterizing each group.