Effects of synbiotic supplementation on the serum endotoxin level, inflammatory status, and clinical outcomes of adult patients with critical illness: A randomized controlled trial.

Background:  Gutmicrobiota dysbiosis, endotoxemia, and systemic inflammation are major factors contributing to disease pathophysiology in patients with critical illness. The present study aimed to assess the effects of synbiotic supplementation on serum endotoxin and inflammationof adult patients with critical illness.

Methods:  This double-anonymized, randomized controlled trial was conducted at the intensive care unit (ICU) of Imam Reza Hospital in Mashhad, Iran. In the intervention group, 20 patients received synbiotic capsules (containing a combination of Lactobacillus, Bifidobacterium, Streptococcus, and fructooligosaccharides) twice per day for a maximum of 14 days. In the control group, 18 patients received placebo capsules. The serum levels of endotoxin and C-reactive protein and the neutrophil to lymphocyte ratio (NLR) were measured before and after the intervention. In addition, clinical outcomes and Acute Physiology and Chronic Health Evaluation and Sequential Organ Failure Assessment scores were recorded.

Results:  Basic characteristics were similar in the intervention and control groups. The NLR and serum endotoxin levels (median [IQR]) significantly declined in the synbiotic group (7.83 [4.58-12.57] to 6.01 [4.25-9.38]; P = .04; and 11.98 [10.64-12.65] to 10.58 [9.41-12.34]; P = .03, respectively). However, no significant changes were observed in the mentioned parameters in the placebo group. The clinical outcomes were also similar in the study groups, such as the length of hospital/ICU stay and hospital/28-day mortality rate.

Conclusion:  Although synbiotic supplementation (500 mg twice daily for 14 days) could reduce serum endotoxin and inflammatory markers, it had no effects on the clinical outcomes of the patients.