Comparative Analysis of 16S rRNA Gene and Metagenome Sequencing in Pediatric Gut Microbiomes

The colonization of the human gut microbiome begins at birth, and over time, these microbial communities become increasingly complex. Most of what we currently know about the human microbiome, especially in early stages of development, was described using culture-independent sequencing methods that allow us to identify the taxonomic composition of microbial communities using genomic techniques, such as amplicon or shotgun metagenomic sequencing. Each method has distinct tradeoffs, but there has not been a direct comparison of the utility of these methods in stool samples from very young children, which have different features than those of adults. We compared the effects of profiling the human infant gut microbiome with 16S rRNA amplicon vs. shotgun metagenomic sequencing techniques in 338 fecal samples; younger than 15, 15-30, and older than 30 months of age. We demonstrate that observed changes in alpha-diversity and beta-diversity with age occur to similar extents using both profiling methods. We also show that 16S rRNA profiling identified a larger number of genera and we find several genera that are missed or underrepresented by each profiling method. We present the link between alpha diversity and shotgun metagenomic sequencing depth for children of different ages. These findings provide a guide for selecting an appropriate method and sequencing depth for the three studied age groups.

A non-interventional comparison of rivaroxaban with standard of care for thromboprophylaxis after major orthopaedic surgery in 17,701 patients with propensity score adjustment

Rivaroxaban demonstrated superior efficacy and a similar safety profile to enoxaparin for the prevention of venous thromboembolism in the phase III RECORD programme in patients undergoing elective hip or knee replacement surgery. The XAMOS study investigated adverse events, including bleeding and thromboembolic events, in patients receiving rivaroxaban for thromboprophylaxis in routine clinical practice. XAMOS was a non-interventional, open-label cohort study in patients undergoing major orthopaedic surgery of the hip or knee (predominantly elective arthroplasty), in which rivaroxaban was compared with other pharmacological thromboprophylaxis. All adverse events were documented, including symptomatic thromboembolic and bleeding events. Crude and adjusted incidences based on propensity score subclasses were calculated and compared between the rivaroxaban and standard-of-care groups. A total of 17,701 patients were enrolled from 252 centres in 37 countries. Crude incidences of symptomatic thromboembolic events three months after surgery in the safety population were 0.89% in the rivaroxaban group (n=8,778) and 1.35% in the standard-of-care group (n=8,635; odds ratio [OR] 0.65; 95% confidence interval [CI] 0.49-0.87), and 0.91% and 1.31% (weighted) in the propensity score-adjusted analysis (OR 0.69; 95% CI 0.56-0.85), respectively. Treatment-emergent major bleeding events (as defined in the RECORD studies) occurred in 0.40% and 0.34% of patients in the rivaroxaban and standard-of-care groups in the safety population (OR 1.19; 95% CI 0.73-1.95), and in 0.44% versus 0.33% (weighted) in the propensity score-adjusted analysis (OR 1.35; 95% CI 0.94-1.93), respectively.This study in unselected patients confirmed the favourable benefit-risk profile of rivaroxaban seen in the RECORD programme.