Mammalian species have co-evolved with intestinal microbial communities that can shape development and adapt to environmental changes, including antibiotic perturbation or nutrient flux. In humans, especially children, microbiota disruption is common, yet the dynamic microbiome recovery from early-life antibiotics is still uncharacterized. Here we use a mouse model mimicking pediatric antibiotic use and find that therapeutic-dose pulsed antibiotic treatment (PAT) with a beta-lactam or macrolide alters both host and microbiota development. Early-life PAT accelerates total mass and bone growth, and causes progressive changes in gut microbiome diversity, population structure, and metagenomic content, with microbiome effects dependent on the number of courses and class of antibiotic. Whereas control microbiota rapidly adapts to a change in diet, PAT slows the ecological progression, with delays lasting several months with previous macrolide exposure. This study identifies key markers of disturbance and recovery, which may help provide therapeutic targets for microbiota restoration following antibiotic treatment.

C oronavirus disease 2019 (COVID-19) is a pandemic characterized by a high fatality rate. 1 The incidence of COVID-19 has risen dramatically in the United States since March 2020, with the highest number of cases in the country present in New York City. 2 As health care systems rise to the challenge of unprecedented demands, there is an urgent need to characterize the spectrum of clinical presentations of this disease to allow early identification, isolation, and triage of affected patients.Although fever, cough, and shortness of breath are among the most common presenting symptoms, gastrointestinal symptoms are increasingly recognized among patients with COVID-19. [3][4][5][6][7] This case-control study aimed to describe gastrointestinal symptomatology-including diarrhea and nausea/vomiting-in US patients with COVID-19 compared to patients presenting under similar circumstances who tested negative for COVID-19. The secondary aims were to characterize the associations of gastrointestinal symptoms with total illness duration and early clinical outcomes. MethodsThis was a retrospective case-control study. Adults 18 years of age were considered for the study if they underwent nasopharyngeal swab testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between March 10, 2020, and March 21, 2020, at outpatient settings, including clinics or the emergency departments, of New York-Presbyterian-Columbia or the medical center's affiliates in New York. Indications for testing during this period were respiratory symptoms (cough, fever, shortness of breath) with intent to hospitalize or the same symptoms in essential personnel. Patients were excluded if insufficient data were available in the electronic medical record or if testing was performed during a preexisting inpatient admission. This study was approved by the Columbia University Irving Medical Center institutional review board.Manual chart review of randomly selected patients was performed by 3 investigators (YRN, MP, DEF) blinded to SARS-CoV-2 test result. The primary exposure was presence of gastrointestinal symptoms, including diarrhea or nausea/

Obesity has been associated with COVID-19 and with pneumonia and acute respiratory distress syndrome but is also associated with comorbidities that place patients at higher risk. This study examines whether obesity is associated with intubation or death—as well as biomarkers of inflammation, cardiac injury, or fibrinolysis—in the context of COVID-19 disease independent of obesity-related comorbidities.

Background: The incidence of esophageal adenocarcinoma has risen dramatically over the past half century, and the underlying reasons are incompletely understood. Broad shifts to the upper gastrointestinal microbiome may be partly responsible. The goal of this study was to describe alterations in the esophageal microbiome that occur with progression from Barrett's esophagus to esophageal adenocarcinoma.Methods: A case-control study was performed of patients with and without Barrett's esophagus who were scheduled to undergo upper endoscopy. Demographic, clinical, and dietary intake data were collected, and esophageal brushings were collected during the endoscopy. 16S rRNA gene sequencing was performed to characterize the microbiome.Results: A total of 45 patients were enrolled and included in the analyses [16 controls; 14 Barrett's esophagus without dysplasia (NDBE); 6 low-grade dysplasia (LGD); 5 highgrade dysplasia (HGD); and 4 esophageal adenocarcinoma]. There was no difference in alpha diversity between non-Barrett's esophagus and Barrett's esophagus, but there was evidence of decreased diversity in patients with esophageal adenocarcinoma as assessed by Simpson index. There was an apparent shift in composition at the transition from LGD to HGD, and patients with HGD and esophageal adenocarcinoma had decreased Firmicutes and increased Proteobacteria. In addition, patients with HGD or esophageal adenocarcinoma had increased Enterobacteriaceae and Akkermansia muciniphila and reduced Veillonella. In the study population, patients taking proton pump inhibitors had increased Streptococcus and decreased Gram-negative bacteria overall.Conclusions: Shifts in the Barrett's esophagus-associated microbiome were observed in patients with HGD and esophageal adenocarcinoma, with increases in certain potentially pathogenic bacteria.Impact: The microbiome may play a role in esophageal carcinogenesis.