Carbon source, cell density, and the microbial community control inhibition of surface colonization by environmental nitrate.

Unlabelled: The intestinal diarrheal pathogen colonizes the host terminal ileum, a microaerophilic, glucose-poor, nitrate-rich environment. In this environment, respires nitrate and increases transport and utilization of alternative carbon sources via the cAMP receptor protein (CRP), a transcription factor that is active during glucose scarcity. Here we show that nitrate respiration in aerated cultures is under control of CRP and, therefore, glucose availability.

Testosterone treatment impacts the intestinal microbiome of transgender individuals.

Medical modulation of sex hormone levels is a cornerstone of treatment for many conditions that impact well-being, including cancer, fertility/infertility, gender dysphoria, and chronic metabolic diseases such as diabetes and obesity. The microbial residents of the intestine, known as the microbiota, interact with sex hormones in the intestine, and there is correlative evidence that this interaction is bidirectional. Based on these published findings, we hypothesized that transgender individuals receiving exogenous testosterone as part of their gender-affirming medical treatment might undergo changes in their intestinal microbiome.

Sequestration of a dual function DNA-binding protein by CRP.

Although the mechanism by which the cyclic AMP receptor protein (CRP) regulates global gene transcription has been intensively studied for decades, new discoveries remain to be made. Here, we report that, during rapid growth, CRP associates with both the well-conserved, dual-function DNA-binding protein peptidase A (PepA) and the cell membrane. These interactions are not present under nutrient-limited growth conditions, due to post-translational modification of three lysines on a single face of CRP.

Bioengineered 3D Tissue Model of Intestine Epithelium with Oxygen Gradients to Sustain Human Gut Microbiome.

The human gut microbiome is crucial to hosting physiology and health. Therefore, stable in vitro coculture of primary human intestinal cells with a microbiome community is essential for understanding intestinal disease progression and revealing novel therapeutic targets. Here, a three-dimensional scaffold system is presented to regenerate an in vitro human intestinal epithelium that recapitulates many functional characteristics of the native small intestines.