Butyrivibrio fibrisolvens F7 dietary supplementation increases levels of cis 9-trans 11 conjugated linoleic acid in gut and adipose tissue in mice

Ruminant-origin food products are the richest source of natural conjugated linoleic acid (CLA) in human diets, and cis-9, trans-11 (c9, t11) is the most abundant isomer of CLA. Butyrivibrio fibrisolvens, a rumen microbe, is considered responsible to have the highest CLA-producing potential. The present study was carried out to identify and characterize a rumen-origin B. fibrisolvens strain that can produce high levels of c9, t11 CLA, as well as to evaluate how dietary supplementation with the strain influenced c9, t11 CLA levels in the gut and adipose tissue in mice. A total of 257 anaerobic strains were isolated from buffalo, cattle, and goat rumen samples, and 24 isolates were identified as Butyrivibrio spp. based on 16S rRNA sequencing. 22 isolates of Butyrivibrio spp. were found to be B. fibrisolven-like. These strains were tested for their potential to produce CLA at varied concentrations (0, 100, 200, 300, 400, 500 μg/mL) of linoleic acid (LA) as substrate after incubating for different durations (0, 2, 4, 6, 12, 24 and 36 h). Results of the study reflected that Butyrivibrio fibrisolvens F7 converted almost 74% of LA of 200 μg/mL concentration to c9, t11 CLA after 24 h and formed the maximum CLA (147.39 μg/mL). B. fibrisolvens F7 (GenBank Accession No: KU507371) was found to be acid and bile tolerant and exhibited good cell surface hydrophobicity in n-hexadecane and toluene. B. fibrisolvens F7 dietary supplementation in mice, combined with a high-LA diet, increases c9, t11 CLA levels in adipose tissue and gut by more than three folds. The results of this study significantly increase the possibility of employing B. fibrisolvens F7 as a probiotic supplement for animals to maintain a steady supply of natural c9, t11 CLA in the host.