Omega-3 and conjugated fatty acids impact on human microbiota modulation using an in vitro fecal fermentation model

Background& aims: Gut microbiota has been gaining increasing attention and itsimportant role in the maintenance of a general good health condition is alreadyestablished. The potential of gut microbiota modulation through diet is animportant research focus to be considered. Lipids, as omega-3 fatty acids, arewell known for their beneficial role on organs and corresponding diseases.However, their impact on gut microbiota is still poorly defined, and studies onthe role of other polyunsaturated fatty acids, such as conjugated linoleic andlinolenic acids, are even scarcer. Methods: By using an in vitro humanfermentation model, we assessed the effect of omega-3, CLA iso mers, andpunicic acid on microbiota modulation. Results: Fish oil, Omega-3, and CLAsamples positively impact Akkermansia spp. and Bifidobacterium spp. growth.Moreover, all the samples supported Roseburia spp. growth after 24 h offermentation and, importantly, they were able to maintain the Firmicutes:Bacteroidetes ratio near 1. All the bioactive fatty acid samples, exceptPomegranate oil, were able to significantly increase butyrate levels comparedto those found in the positive control (FOS) sample. Moreover, Fish oil andOmega-3 samples were able to increase the concentration of GABA, alanine,tyrosine, phenylalanine, isoleucine, and leucine between 12 and 24 h offermentation. Conclusions: The impact of the assessed polyunsaturated fattyacids in gut microbiota has been observed in its impact on key bacteria(Akkermansia, Bifidobacterium, and Roseburia) as well as their metabolic byproducts,including butyrate and amino acids, which could potentially play a role inmodulating the gut-brain axis.