Acids produced by lactobacilli inhibit the growth of commensal and S24-7 bacteria.

The are an intensively studied family of bacteria widely used in fermented food and probiotics, and many are native to the gut and vaginal microbiota of humans and other animals. Various studies have shown that specific species produce metabolites that can inhibit the colonization of fungal and bacterial pathogens, but less is known about how affect individual bacterial species in the endogenous animal microbiota. Here, we show that numerous species inhibit the growth of the family and the S24-7 group, two dominant clades of bacteria within the gut.

The CIAMIB: a Large and Metabolically Diverse Collection of Inflammation-Associated Bacteria from the Murine Gut.

Gut inflammation directly impacts the growth and stability of commensal gut microbes and can lead to long-lasting changes in microbiota composition that can prolong or exacerbate disease states. While mouse models are used extensively to investigate the interplay between microbes and the inflamed state, the paucity of cultured mouse gut microbes has hindered efforts to determine causal relationships. To address this issue, we are assembling the Collection of Inflammation-Associated Mouse Intestinal Bacteria (CIAMIB).

Longitudinal Emergence of Concurrent Mental Health and Substance Use Concerns in an Ontario School-Based Sample: The Research and Action for Teens Study.

Objectives: This study characterizes patterns of mental health, substance use and their co-occurrence, and identifies developmental trajectories associated with progression from single to concurrent mental health and substance use concerns in an Ontario school-based population. It is a longitudinal extension of the Ontario Student Drug Use and Mental Health Survey, as part of the RAFT collaborative project.

Methods: In this study, an Ontario-wide survey was administered to students across three biennial waves starting in grades 7-8 (ages 12-14).

Early-life programming of mesenteric lymph node stromal cell identity by the lymphotoxin pathway regulates adult mucosal immunity.

Redundant mechanisms support immunoglobulin A (IgA) responses to intestinal antigens. These include multiple priming sites [mesenteric lymph nodes (MLNs), Peyer's patches, and isolated lymphoid follicles] and various cytokines that promote class switch to IgA, even in the absence of T cells. Despite these backup mechanisms, vaccination against enteric pathogens such as rotavirus has limited success in some populations.

Early Adolescent Substance Use and Mental Health Problems and Service Utilisation in a School-based Sample.

Objective: This paper reports on substance use, mental health problems, and mental health service utilisation in an early adolescent school-based sample.

Method: Participants were 1,360 grade 7 and 8 students from 4 regions of Ontario, Canada. Students completed an in-class survey on mental health and substance use.