INTRODUCTION: The disruption of microbiota metabolism, measured by changes in the serum concentrations of clinically relevant aromatic metabolites, appears to play a crucial role in the occurrence of complications following cardiac surgery [DOI:10.3390/biomedicines11051335].
The aim of this study was to assess the potential of modulating the microbial metabolism using specific antibiotics to prevent infectious and inflammatory complications after cardiac surgery.
MATERIAL AND METHODS: Patients (n = 58) who underwent cardiac surgeries under artificial circulation were involved in a randomized prospective interventional study [ClinicalTrials.gov identifier: NCT04921436. Registered May 24, 2021].
Patients in group I (n = 30) received modulation of microbial metabolism through antibiotics that inhibited protein synthesis (a combination of semi-synthetic antibiotics from the tetracycline and macrolide groups); the patients in group II did not experience such modulation (n = 28).
Blood serum samples were collected three times, prior to and on the 3rd and 6th days after the surgery, and analyzed for their clinical parameters and concentrations of clinically significant aromatic acids.
RESULTS: Six and eight patients developed postoperative complications, including zero and five cases of pneumonia, in groups I and II, respectively. The range of identified microorganisms in group II was considerably broader. Group I (compared to group II) exhibited a more pronounced reduction in the concentration of 4-hydroxyphenylacetic acid when comparing the values prior to surgery to those on the third and sixth days (p = 0.016 and 0.005, respectively). The total concentration of aromatic metabolites on the third day, as well as 4-hydroxyphenylacetic acid on the sixth day, showed strong predictive value concerning the occurrence of complications (sensitivity of 100% for both parameters; specificity of 82% and 93%, respectively).
CONCLUSIONS: The preventive administration of antibiotics that inhibit microbial protein synthesis effectively diminishes the severity of microbiota metabolic dysfunction and lowers pneumonia incidence in the early stages following surgery.
