The study tested a 20‑day course of friendly gut bacteria (Enterococcus) in people with metabolic syndrome and saw improvements in weight‑related markers and several blood and urine chemicals, but it does not involve the peptide palmitoyl‑dipeptide‑6.

The effectiveness of oral administration of autoprobiotic (nonpathogenic, indigenous) Enterococcus faecium or Enterococcus hirae for 20 days in patients with metabolic syndrome (MetS), characterized by obesity and impaired carbohydrate and lipid metabolism, was investigated. The dynamics of changes in anthropometric, biochemical parameters, and metabolism were monitored 14 and 28 days after the end of therapy. Clinical and laboratory changes after using autoprobiotics indicate a decrease in the severity of MetS. In the reversed-phase high-performance liquid chromatography-mass spectrometry analysis of blood serum metabolome, a significant decrease in the levels of all identified long-chain acylcarnitines - palmitoyl-L-carnitine (C16:0), stearoyl-L-carnitine (C18:0), and oleoyl-L-carnitine (C25), trimethylamine-N-oxide, and homocysteine 14 and 28 days after the end of therapy, and, conversely, a significant increase in L-histidine levels. The targeted gas-liquid chromatography showed an increase in the concentrations of hippuric, glycolic, methylmalonic acids, and 5-oxoproline at the same time. The effectiveness of therapy is confirmed by changes in serum and urinary metabolism, primarily aimed at correcting these and reducing signs characteristic of patients with obesity and impaired energy metabolism. The revealed positive changes in the concentration of individual serum and urine metabolites allow for their further use in a targeted study to predict the severity of MetS and the effectiveness of its therapy.