Author Interviews, JAMA, Smoking, Tobacco Research / 29.03.2019

MedicalResearch.com Interview with: Jidong Huang, PhD Associate Professor Department of Health Policy & Behavioral Sciences School of Public Health, Georgia State University Atlanta, GA 30303 MedicalResearch.com: What is the background for this study?   Response: The US tobacco market has been transformed in the past decade by a rapid increase in awareness and use of e-cigarettes among youth and adults. This transformation has been accelerated in recent years by the emergence of new generations of e-cigarettes, such as JUUL e-cigarettes. The exponential growth in e-cigarettes has prompted a renewed interest in the tobacco harm reduction approach, which aims to rapidly curbing the smoking epidemic by encouraging smokers to switch to low risk tobacco products, such as e-cigarettes. There is an ongoing debate about whether the scientific evidence on the health risks of e-cigarettes in comparison with combustible cigarettes has been accurately communicated to the public. Large representative surveys are needed to examine how the public perceives the health risk of e-cigarettes and how their perception change over time.
Author Interviews, Infections, MRSA, NIH, Probiotics / 12.10.2018

MedicalResearch.com Interview with: "staph aureus on blood agar" by Iqbal Osman is licensed under CC BY 2.0Pipat Piewngam Postdoctorol fellow Pathogen Molecular Genetics Section, Laboratory of Bacteriology, NIAID/NIH Bethesda, MD, USA 20892  MedicalResearch.com: What is the background for this study? What are the main findings?  Response: Our team at National Institutes of health, Mahidol University and Rajamangala University of Technology in Thailand has reported that the consumption of probiotic Bacillus bacteria comprehensively abolishes colonization with the dangerous pathogen, Staphylococcus aureus. We hypothesized that the composition of the human gut microbiota affects intestinal colonization with S. aureus. We collected fecal samples from 200 healthy individuals from rural populations in Thailand and analyzed the composition of the gut microbiome by 16S rRNA sequencing. Surprisingly, we did not detect significant differences in the composition of the microbiome between S. aureus carriers and non-carriers. We then sampled the same 200 people for S. aureus in the gut (25 positive) and nose (26 positive). Strikingly, we found no S. aureus in any of the samples where Bacillus were present. In mouse studies, we discovered S. aureus Agr quorum-sensing signaling system that must function for the bacteria to grow in the gut. Intriguingly, all of the more than 100 Bacillus isolates we had recovered from the human feces efficiently inhibited that system. Then, we discovered that the fengycin class of Bacillus lipopeptides achieves colonization resistance by inhibiting that system. To further validate their findings, we colonized the gut of mice with S. aureus and fed them B. subtilis spores to mimic probiotic intake. Probiotic Bacillus given every two days eliminated S. aureus in the guts of the mice. The same test using Bacillus where fengycin production had been removed had no effect, and S. aureus grew as expected. This is one of the first study that provide human evidence supporting the biological significance of probiotic bacterial interference and show that such interference can be achieved by blocking a pathogen’s signaling system.