Biogeographical distribution of gut microbiome composition and function is partially recapitulated by fecal transplantation into germ-free mice.

Fecal microbiota transplantation has been vital for establishing whether host phenotypes can be conferred through the microbiome. However, whether the existing microbial ecology along the mouse gastrointestinal tract can be recapitulated in germ-free mice colonized with stool remains unknown. We first identified microbes and their predicted functions specific to each of six intestinal regions in three cohorts of specific pathogen-free mice spanning two facilities.

ZIP8 A391T Crohn's Disease-Linked Risk Variant Induces Colonic Metal Ion Dyshomeostasis, Microbiome Compositional Shifts, and Inflammation.

Background: The pathogenesis of Crohn's disease involves genetic and environmental factors, with the gut microbiome playing a crucial role. The Crohn's disease-associated variant rs13107325 in the SLC39A8 gene results in an A391T substitution in the ZIP8 metal ion transporter and has previously been linked to alterations in the colonic microbiome in variant carriers. We hypothesized that the A391T substitution alters metal ion homeostasis in the colonic mucosal-luminal interface, thereby inducing dysbiosis which may promote intestinal inflammation.

Bariatric-induced microbiome changes alter MASLD development in association with changes in the innate immune system.

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) affects nearly 25% of the population and is the leading cause for liver-related mortality. Bariatric surgery is a well-known treatment for MASLD and obesity. Understanding the fundamental mechanisms by which bariatric surgery can alter MASLD can lead to new avenues of therapy and research.

Ambient Particulate Matter Induces In Vitro Toxicity to Intestinal Epithelial Cells without Exacerbating Acute Colitis Induced by Dextran Sodium Sulfate or 2,4,6-Trinitrobenzenesulfonic Acid.

Inflammatory bowel disease (IBD) is an immunologically complex disorder involving genetic, microbial, and environmental risk factors. Its global burden has continued to rise since industrialization, with epidemiological studies suggesting that ambient particulate matter (PM) in air pollution could be a contributing factor. Prior animal studies have shown that oral PM exposure promotes intestinal inflammation in a genetic IBD model and that PM inhalation exposure can increase intestinal levels of pro-inflammatory cytokines.

Subchronic inhalation exposure to ultrafine particulate matter alters the intestinal microbiome in various mouse models.

Exposure to ultrafine particles (UFPs) has been associated with multiple adverse health effects. Inhaled UFPs could reach the gastrointestinal tract and influence the composition of the gut microbiome. We have previously shown that oral ingestion of UFPs alters the gut microbiome and promotes intestinal inflammation in hyperlipidemic Ldlr mice.

Microbial changes from bariatric surgery alters glucose-dependent insulinotropic polypeptide and prevents fatty liver disease.

Bariatric surgery remains a potent therapy for nonalcoholic fatty liver disease (NAFLD), but its inherent risk and eligibility requirement limit its adoption. Therefore, understanding how bariatric surgery improves NAFLD is paramount to developing novel therapeutics. Here, we show that the microbiome changes induced by sleeve gastrectomy (SG) reduce glucose-dependent insulinotropic polypeptide (GIP) signaling and confer resistance against diet-induced obesity (DIO) and NAFLD.

The Ocular Microbiome Is Altered by Sampling Modality and Age.

Background: Studies of the ocular microbiome have used a variety of sampling techniques, but no study has directly compared different sampling methods applied to the same eyes to one another or to a reference standard of corneal epithelial biopsy. We addressed this lack by comparing the microbiome from three conjunctival swabs with those of corneal epithelial biopsy.

Methods: Twelve eyes (11 patients) were swabbed by calcium alginate swab, cotton-tipped applicator, and Weck-Cel cellulose sponge before a corneal epithelial biopsy (48 samples).

The Intestinal Microbiome Predicts Weight Loss on a Calorie-Restricted Diet and Is Associated With Improved Hepatic Steatosis.

The microbiome has been shown in pre-clinical and epidemiological studies to be important in both the development and treatment of obesity and metabolic associated fatty liver disease (MAFLD). However, few studies have examined the role of the microbiome in the clinical response to calorie restriction. To explore this area, we performed a prospective study examining the association of the intestinal microbiome with weight loss and change in hepatic steatosis on a calorie-restricted diet.

Gut microbiome profiles associated with steatosis severity in metabolic associated fatty liver disease.

Aim: The microbiome has been shown to be pivotal in the development of metabolic associated fatty liver disease (MAFLD). Few have examined the relationship of the microbiome specifically with steatosis grade. Therefore, our aim was to characterize the association of the microbiome with MAFLD steatosis severity while adjusting for metabolic comorbidities including diabetes.

A High Protein Calorie Restriction Diet Alters the Gut Microbiome in Obesity.

Background: High protein calorie restriction diets have shown clinical efficacy for obesity, but the mechanisms are not fully known. The intestinal microbiome is a mediator of obesity and preclinical data support an effect of high protein diet (HPD) on the gut microbiome of obesity, but there are few studies in humans.

Methods: To address this, we conducted a dietary intervention trial of 80 overweight and obese subjects who were randomized to a calorie-restricted high protein diet (HPD) (30% calorie intake) or calorie-restricted normal protein diet (NPD) (15%) for 8 weeks.

Zebrafish Axenic Larvae Colonization with Human Intestinal Microbiota.

The human intestine hosts a vast and complex microbial community that is vital for maintaining several functions related with host health. The processes that determine the gut microbiome composition are poorly understood, being the interaction between species, the external environment, and the relationship with the host the most feasible. Animal models offer the opportunity to understand the interactions between the host and the microbiota.