The trigger for infectious complications in patients following major abdominal operations is classically attributed to endogenous enteral bacterial translocation, due to the critical condition of the gut. Today, extensive gut microbiome analysis has enabled us to understand that almost all "evidence-based" surgical or medical intervention (antibiotics, bowel preparation, opioids, deprivation of nutrition), in addition to stress-released hormones, could affect the relative abundance and diversity of the enteral microbiome, allowing harmful bacteria to proliferate in the place of depressed beneficial species. Furthermore, these bacteria, after tight sensing of host stress and its consequent humoral alterations, can and do switch their virulence accordingly, towards invasion of the host. Probiotics are the exogenously given, beneficial clusters of live bacteria that, upon digestion, seem to succeed in partially restoring the distorted microbial diversity, thus reducing the infectious complications occurring in surgical and critically ill patients. This review presents the latest data on the interrelationship between the gut microbiome and the occurrence of complications after colon surgery, and the efficacy of probiotics as therapeutic instruments for changing the bacterial imbalance.

Six intragastric balloons: Which to choose?

The role of probiotics in the prevention of ventilator-associated pneumonia (VAP) remains inconclusive. The aim of this study was to assess the efficacy of a probiotic regimen for VAP prophylaxis in mechanically ventilated multi-trauma patients, intubated immediately after the injurious insult. In a randomized, placebo-controlled study enrolling multi-trauma patients, patients expected to require mechanical ventilation for >10 days were assigned at random to receive prophylaxis with a probiotic formula (n=59) or placebo (n=53). The probiotic formula was a preparation of Lactobacillus acidophilus LA-5 [1.75 × 10⁹ colony-forming units (cfu)], Lactobacillus plantarum (0.5 × 10⁹ cfu), Bifidobacterium lactis BB-12 (1.75 × 10⁹ cfu) and Saccharomyces boulardii (1.5 × 10⁹ cfu) in sachets. Each patient received two sachets twice daily for 15 days: one through the nasogastric tube and one spread on the oropharynx. The incidence of VAP was the primary endpoint. The incidence of other infections and sepsis, and the duration of hospital stay were the secondary endpoints. Administration of probiotics reduced the incidence of VAP [11.9% vs 28.3%, hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.13-0.92; P=0.034] and sepsis [6.8% vs 24.5%, odds ratio 0.22, 95% CI 0.07-0.74: P=0.016]. Furthermore, probiotic prophylaxis reduced the time of stay in the intensive care unit (ICU) and the length of hospital stay. The prophylactic use of probiotics with a combination of enteral and topical application to the oropharynx had a positive effect on the incidence of VAP and sepsis, as well as on ICU and total hospital stay in patients receiving protracted mechanical ventilation.

Obesity is a major public health concern, caused by a combination of increased consumption of energy-dense foods and reduced physical activity, with contributions from host genetics, environment, and adipose tissue inflammation. In recent years, the gut microbiome has also been found to be implicated and augmented research in mice and humans have attributed to it both the manifestation and/or exacerbation of this major epidemic and vice versa. At the experimental level, analysis of fecal samples revealed a potential link between obesity and alterations in the gut flora (drop in Bacteroidetes and increase in Firmicutes), the specific gut microbiome being associated with the obese phenotype. Conventionally raised mice were found to have over 40% more total body fat compared with those raised under germ-free conditions, while conventionalization of germ-free mice resulted in a significant increase in total body fat. Similarly, the sparse data in humans supports the fact that fat storage is favoured by the presence of the gut microbiota, through a multifaceted mechanism. Efforts to identify new therapeutic strategies to modulate gut microbiota would be of high priority for public health, and to date, probiotics and/or prebiotics seem to be the most effective tools.

Background: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are widely accepted indices positively correlated with disease severity, progression, and mortality. In this study, we tested whether NLR and PLR could predict mortality and length of hospital stay (LOS) after cardiac surgery. Methods: NLR and PLR were calculated on days 0, 3, 5, and 7 postoperatively. A ROC curve was generated to assess their prognostic value; multivariate logistic analysis identified independent risk factors for 90-day mortality. Results: Analysis was performed on 179 patients’ data, 11 of whom (6.15%) died within 90 days. The discriminatory performance for predicting 90-day mortality was better for NLR7 (AUC = 0.925, 95% CI:0.865–0.984) with the optimal cut-off point being 7.10. NLR5 and PLR3 also exhibited a significant strong discriminative performance. Similarly, a significant discriminative performance was prominent for PLR3, NLR5, and NLR7 with respect to LOS. Moreover, NLR7 (OR: 2.143, 95% CI: 1.076–4.267, p = 0.030) and ICU LOS (OR:1.361, 95% CI: 1.045–1.774, p = 0.022) were significant independent risk factors for 90-day mortality. Conclusions: NLR and PLR are efficient predictive factors for 90-day mortality and LOS in cardiac surgery patients. Owing to the simplicity of determining NLR and PLR, their postoperative monitoring may offer a reliable predictor of patients’ outcomes in terms of LOS and mortality.