Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.

On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals

Prostate-Specific Antigen, Digital Rectal Examination and Transrectal Ultrasonography: A Meta-Analysis for This Diagnostic Triad of Prostate Cancer in Symptomatic Korean Men

We conducted a meta-analysis using results from the Korean literature to determine whether prostate-specific antigen (PSA) or digital rectal examination (DRE) or transrectal ultrasonography (TRUS) provides a better diagnostic outcome for possible prostate cancer patients. An extensive literature search of MedRIC database et al. (1980 to 2003) was performed using the medical subject headings "PSA", "DRE", "TRUS" and "prostate cancer". Of the 108 articles that we retrieved, 13 studies (2,029 subjects) were selected for this meta-analysis. The criteria for quality evaluation were as follows: the study subjects must have been compared clinically for suspected prostate cancer, and the articles must have included individual data about sensitivity and specificity for this diagnostic triad based on the biopsy results as a reference standard. For the quantitative meta-analysis process the Hasselblad method was utilized. The pooled sensitivity and specificity for a PSA level greater than 4 ng/mL were 91.3% and 35.9%, respectively; and those for a PSA level greater than 10 ng/mL were 77.3% and 67.5%, respectively; and those for DRE were 68.4% and 71.5%, respectively; and those for TRUS were 73.6% and 61.3%, respectively. According to the results in a fixed effect model for PSA criteria, the estimates of d for PSA4 and PSA10 were 0.8517 [95% confidence interval (CI): 0.6694, 1.0340] and 1.0996 (95% CI: 0.9459, 1.2534), respectively. Also, according to the results using a random effect model for both DRE and TRUS criteria, the estimates of d for DRE and TRUS were 0.8398 (95% CI: 0.7169, 0.9627) and 0.8002 (95% CI: 0.6714, 0.9289), respectively. The detection rate for combination testing of PSA, DRE and TRUS for the diagnosis of prostate cancer jumped further to 68.3% or to 76.8%. In conclusion, this study suggests that this diagnostic triad for prostate cancer was noneffective when they were used separately. Therefore, we recommend that the urologists should use PSA together with DRE and TRUS for the primary diagnosis of prostate cancer in men with lower urological symptoms

The impact of mass gatherings and holiday traveling on the course of an influenza pandemic: a computational model

<p>Abstract</p> <p>Background</p> <p>During the 2009 H1N1 influenza pandemic, concerns arose about the potential negative effects of mass public gatherings and travel on the course of the pandemic. Better understanding the potential effects of temporal changes in social mixing patterns could help public officials determine if and when to cancel large public gatherings or enforce regional travel restrictions, advisories, or surveillance during an epidemic.</p> <p>Methods</p> <p>We develop a computer simulation model using detailed data from the state of Georgia to explore how various changes in social mixing and contact patterns, representing mass gatherings and holiday traveling, may affect the course of an influenza pandemic. Various scenarios with different combinations of the length of the mass gatherings or traveling period (range: 0.5 to 5 days), the proportion of the population attending the mass gathering events or on travel (range: 1% to 50%), and the initial reproduction numbers R₀(1.3, 1.5, 1.8) are explored.</p> <p>Results</p> <p>Mass gatherings that occur within 10 days before the epidemic peak can result in as high as a 10% relative increase in the peak prevalence and the total attack rate, and may have even worse impacts on local communities and travelers' families. Holiday traveling can lead to a second epidemic peak under certain scenarios. Conversely, mass traveling or gatherings may have little effect when occurring much earlier or later than the epidemic peak, e.g., more than 40 days earlier or 20 days later than the peak when the initial R₀= 1.5.</p> <p>Conclusions</p> <p>Our results suggest that monitoring, postponing, or cancelling large public gatherings may be warranted close to the epidemic peak but not earlier or later during the epidemic. Influenza activity should also be closely monitored for a potential second peak if holiday traveling occurs when prevalence is high.</p

Short term effects of weather on hand, foot and mouth disease

Background: Hand, foot, and mouth disease (HFMD) outbreaks leading to clinical and fatal complications have increased since late 1990s; especially in the Asia Pacific Region. Outbreaks of HFMD peaks in the warmer season of the year, but the underlying factors for this annual pattern and the reasons to the recent upsurge trend have not yet been established. This study analyzed the effect of short-term changes in weather on the incidence of HFMD in Singapore. Methods: The relative risks between weekly HFMD cases and temperature and rainfall were estimated for the period 20012008 using time series Poisson regression models allowing for over-dispersion. Smoothing was used to allow non-linear relationship between weather and weekly HFMD cases, and to adjust for seasonality and long-term time trend. Additionally, autocorrelation was controlled and weather was allowed to have a lagged effect on HFMD incidence up to 2 weeks. Results: Weekly temperature and rainfall showed statistically significant association with HFMD incidence at time lag of 1-2 weeks. Every 1 degrees C increases in maximum temperature above 32 degrees C elevated the risk of HFMD incidence by 36% (95% CI = 1.341-1.389). Simultaneously, one mm increase of weekly cumulative rainfall below 75 mm increased the risk of HFMD by 0.3% (CI = 1.002-1.003). While above 75 mm the effect was opposite and each mm increases of rainfall decreased the incidence by 0.5% (CI = 0.995-0.996). We also found that a difference between minimum and maximum temperature greater than 7 degrees C elevated the risk of HFMD by 41% (CI = 1.388-1.439). Conclusion: Our findings suggest a strong association between HFMD and weather. However, the exact reason for the association is yet to be studied. Information on maximum temperature above 32 degrees C and moderate rainfall precede HFMD incidence could help to control and curb the up-surging trend of HFMD

Medical tourism and the state in Malaysia and Singapore

10.1177/1468018110379978Global Social Policy103336-35