Brigham Research Institute Poster Session Site logo-1

Jennifer Lee, PhD

Pronouns:

She/Her/Hers

Rank:

Assistant Professor

Institution:

BIDMC

Department:

Endocrinology, Diabetes and Metabolism

Authors:

Jennifer Lee*, Kerry Wellenstein, Barbara B. Kahn

Principal Investigator:

Jennifer Lee

Bacteroides thetaiotaomicron has sex-specific effects on the intestinal mucosa and adiposity in Dietary Obese Mice

The global prevalence of obesity is greater in women compared to men. The gut microbiome is implicated in the sexual dimorphic nature of metabolic disease development. Understanding how the composition and function of the gut microbiome differs between sexes and determining the factors that regulate these differences is critical to develop improved gut-based therapeutic strategies to improve metabolic health for all. Here, we identify Bacteroides thetaiotaomicron (Bt) as a probiotic that associates with insulin sensitivity and report its beneficial effects on fortifying the gut epithelium and improving host metabolism when it is supplemented in HFD-fed female mice. This work highlights the therapeutic potential of leveraging the gut microbiome to improve metabolic health outcomes for women.

Overview

Disruption of the intestinal mucosa contributes to the development of obesity and Type 2 diabetes. Probiotic supplementation, which restores gut microbiota composition and fortifies intestinal barrier function, has therapeutic potential to treat metabolic disease. Treatment of mice on a chow diet or high fat diet (HFD) with Palmitic Acid Hydroxystearic Acids (PAHSAs) improves insulin sensitivity. Our data show that these effects are mediated, at least in part, by changes in the gut microbiome. We used this paradigm to identify new microbes that may have beneficial metabolic effects. Metagenome sequencing of the cecum from mice treated with PAHSAs identified Bacteroides thetaiotaomicron (Bt) to most strongly associate with insulin sensitivity. Here, we aimed to determine whether Bt supplementation in HFD-fed mice has beneficial effects on energy balance and/or glucose homeostasis. Bt supplementation in HFD-fed female mice resulted in less weight gain, lower adiposity, and improved glucose tolerance compared to vehicle-treated mice. Additionally, Bt supplementation preserved colonic mucus thickness which was reduced in control mice, an indicator of gut health; increased the number of Goblet cells which are the cells that secrete mucin2, the predominant mucus protein that forms the intestinal mucosal barrier; and increased protein levels of mucin2 in the distal gut versus vehicle-treated controls. These improvements in distal gut barrier architecture were associated with a reduction in circulating levels of pro-inflammatory lipopolysaccharide (LPS) and interleukin-6 (IL-6). These beneficial effects of Bt were observed in female and not in male HFD-fed mice. In current studies, we are determining the role of sex hormones in mediating Bt effects on gut and glucose homeostasis in ovariectomized HFD-fed female mice supplemented with Bt. These studies indicate that Bt has sex-specific effects to improve host metabolism in dietary obesity. Bt represents a next-generation probiotic and novel gut-based therapeutic strategy which could improve metabolic health in women.