Reduced immunomodulatory metabolite concentrations in peri-transplant fecal samples from heart allograft recipients.

Background: Emerging evidence is revealing the impact of the gut microbiome on hematopoietic and solid organ transplantation. Prior studies postulate that this influence is mediated by bioactive metabolites produced by gut-dwelling commensal bacteria. However, gut microbial metabolite production has not previously been measured among heart transplant (HT) recipients.

Parvovirus B19 in Pregnancy.

Importance: Although the risk of parvovirus B19 infection during pregnancy and subsequent risk of adverse fetal outcome are low, understanding management practices is essential for proper treatment of fetuses with nonimmune hydrops fetalis. In addition, continued investigation into delivery management, breastfeeding recommendations, and congenital abnormalities associated with pregnancies complicated by parvovirus B19 infection is needed.

Objective: This review describes the risks associated with parvovirus B19 infection during pregnancy and the management strategies for fetuses with vertically transmitted infections.

Fecal metabolite profiling identifies liver transplant recipients at risk for postoperative infection.

Metabolites produced by the intestinal microbiome modulate mucosal immune defenses and optimize epithelial barrier function. Intestinal dysbiosis, including loss of intestinal microbiome diversity and expansion of antibiotic-resistant pathobionts, is accompanied by changes in fecal metabolite concentrations and increased incidence of systemic infection. Laboratory tests that quantify intestinal dysbiosis, however, have yet to be incorporated into clinical practice.

Bifidobacteria metabolize lactulose to optimize gut metabolites and prevent systemic infection in patients with liver disease.

Progression of chronic liver disease is precipitated by hepatocyte loss, inflammation and fibrosis. This process results in the loss of critical hepatic functions, increasing morbidity and the risk of infection. Medical interventions that treat complications of hepatic failure, including antibiotic administration for systemic infections and lactulose treatment for hepatic encephalopathy, can impact gut microbiome composition and metabolite production.

Immunomodulatory fecal metabolites are associated with mortality in COVID-19 patients with respiratory failure.

Respiratory failure and mortality from COVID-19 result from virus- and inflammation-induced lung tissue damage. The intestinal microbiome and associated metabolites are implicated in immune responses to respiratory viral infections, however their impact on progression of severe COVID-19 remains unclear. We prospectively enrolled 71 patients with COVID-19 associated critical illness, collected fecal specimens within 3 days of medical intensive care unit admission, defined microbiome compositions by shotgun metagenomic sequencing, and quantified microbiota-derived metabolites (NCT #04552834).