RESUMEN
Industrialization has impacted the human gut ecosystem, resulting in altered microbiome composition and diversity. Whether bacterial genomes may also adapt to the industrialization of their host populations remains largely unexplored. Here, we investigate the extent to which the rates and targets of horizontal gene transfer (HGT) vary across thousands of bacterial strains from 15 human populations spanning a range of industrialization. We show that HGTs have accumulated in the microbiome over recent host generations and that HGT occurs at high frequency within individuals. Comparison across human populations reveals that industrialized lifestyles are associated with higher HGT rates and that the functions of HGTs are related to the level of host industrialization. Our results suggest that gut bacteria continuously acquire new functionality based on host lifestyle and that high rates of HGT may be a recent development in human history linked to industrialization.
Asunto(s)
Bacterias/genética , Microbioma Gastrointestinal , Transferencia de Gen Horizontal , Bacterias/clasificación , Bacterias/aislamiento & purificación , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/metabolismo , Heces/microbiología , Genoma Bacteriano , Humanos , Filogenia , Población Rural , Análisis de Secuencia de ADN , Población Urbana , Secuenciación Completa del GenomaRESUMEN
BACKGROUND: The ability of the pretreatment lymphocyte to monocyte ratio (LMR) to predict outcomes of patients with hepatocellular carcinoma (HCC) receiving sorafenib is not conclusively determined. METHODS: We retrospectively studied patients treated with sorafenib for HCC in two tertiary referral centres in Asia and North America. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Predictive factors for the outcomes were determined by Cox proportional hazards models. A risk assessment tool was developed. RESULTS: Compared to the North America cohort, the Asia cohort was more heavily pretreated (72.1% vs. 35.2%; p < 0.001), had higher hepatitis B virus infection (87.6% vs. 5.6%; p < 0.001), and more distant metastases (83.2% vs. 25.4%; p < 0.001). Lower monocyte count in the Asia cohort (median 462.7 vs. 600.0/µL; p = 0.023) resulted in a higher LMR (median 2.6 vs. 1.8; p < 0.001). High LMR was associated with a significantly higher OS [hazard ratio (HR) 0.88; 95% confidence interval (CI) 0.81â0.97; p = 0.007]. This was confirmed in a sensitivity analysis including patients treated in Asia only (HR 0.89; 95% CI 0.81â0.97; p = 0.010). An OS nomogram was constructed with the following variables selected in the multivariate Cox model: LMR, treatment location, previous treatment, performance status, alpha-fetoprotein, lymph node metastasis, and ChildâPugh score. The concordance score was 0.71 (95% CI, 0.67â0.75). LMR did not predict PFS. CONCLUSION: LMR measured before sorafenib administration predicts OS in advanced HCC patients. Our OS nomogram, incorporating LMR, can be offered to clinicians to improve their ability to assess prognosis, strengthen the prognosis-based decision-making, and inform patients in the clinic.