Healthy dietary choices are associated with higher serum propionate and PGC1α expression in peripheral blood mononuclear cells in adult humans

•Dietary intake of study subjects was assessed by 24-h dietary recall, FFQ and a Mediterranean Diet Scale (MDS).•SCFAs and LPS were measured in serum and gene expression of PGC1α and HIF1α was assessed in PBMCs.•Lean subjects showed higher fiber intake, MDS scores, propionate levels, PGC1α and HIF1α expression and lower serum LPS.•Subjects consuming diet that is closer to Mediterranean diet had higher levels of serum propionate and PGC1α mRNA.