Dynamic genetic adaptation of Bacteroides thetaiotaomicron during murine gut colonization.

To understand how a bacterium ultimately succeeds or fails in adapting to a new host, it is essential to assess the temporal dynamics of its fitness over the course of colonization. Here, we introduce a human-derived commensal organism, Bacteroides thetaiotaomicron (Bt), into the guts of germ-free mice to determine whether and how the genetic requirements for colonization shift over time. Combining a high-throughput functional genetics assay and transcriptomics, we find that gene usage changes drastically during the first days of colonization, shifting from high expression of amino acid biosynthesis genes to broad upregulation of diverse polysaccharide utilization loci. Within the first week, metabolism becomes centered around utilization of a predominant dietary oligosaccharide, and these changes are largely sustained through 6 weeks of colonization. Spontaneous mutations in wild-type Bt also evolve around this locus. These findings highlight the importance of considering temporal colonization dynamics in developing more effective microbiome-based therapies.

Trust in Health Information Sources among Underserved and Vulnerable Populations in the U.S.

The purpose of this study was to examine trust in health information sources among underserved and vulnerable populations. Data (N=8,759) were from the Health Information National Trends Survey. Differences were assessed across the following subgroups: ethnoracial minorities, immigrants, rural residence, people with limited English proficiency, and sexual minorities. Trust was highest for doctors, followed by government, family/friends, charities, and religious organizations. In adjusted regression models, trusting health information from charitable and religious organizations was higher in ethnoracial minorities and immigrants. Individuals with limited English proficiency also had higher trust in religious organizations compared with those fluent in English. Trusting health information from doctors was lower among individuals with limited English proficiency. There was evidence in support of additive and multiplicative intersectional frameworks for understanding trust in vulnerable and underserved populations; however, the extent to which differences in trust explain disparities in health behaviors and outcomes should be examined.