Wild-Mouse-Derived Gut Microbiome Transplantation in Laboratory Mice Partly Alleviates House-Dust-Mite-Induced Allergic Airway Inflammation.

Laboratory mice are instrumental for preclinical research but there are serious concerns that the use of a clean standardized environment for specific-pathogen-free (SPF) mice results in poor bench-to-bedside translation due to their immature immune system. The aim of the present study was to test the importance of the gut microbiota in wild vs. SPF mice for evaluating host immune responses in a house-dust-mite-induced allergic airway inflammation model without the influence of pathogens.

No association between the early-life gut microbiota and childhood body mass index and body composition.

Background: The gut microbiota has been implicated in adult obesity, but the causality is still unclear. It has been hypothesized that an obesity-prone gut microbiota can be established in infancy, but only few studies have examined the early-life gut microbiota in relation to obesity in childhood, and no consistent associations have been reported. Here, we examine the association between the early-life gut microbiota and body mass index (BMI) development and body composition throughout childhood.

Delayed Gut Colonization Changes Future Insulin Resistance and Hepatic Gene Expression but Not Adiposity in Obese Mice.

Objective: The importance of early microbial dysbiosis in later development of obesity and metabolic disorders has been a subject of debate. Here we tested cause and effect in mice.

Methods: Germ-free male Swiss Webster mice were colonized in a specific-pathogen-free (SPF) facility at 1 week (1W) and 3 weeks (3W) of age.

Probiotic treatment with viable α-galactosylceramide-producing Bacteroides fragilis reduces diabetes incidence in female nonobese diabetic mice.

Background: We aimed to investigate whether alpha-galactosylceramide (α-GalCer)-producing Bacteroides fragilis could induce natural killer T (NKT) cells in nonobese diabetic (NOD) mice and reduce their diabetes incidence.

Methods: Five-week-old female NOD mice were treated orally with B. fragilis, and islet pathology and diabetes onset were monitored.

Overcoming donor variability and risks associated with fecal microbiota transplants through bacteriophage-mediated treatments.

Background: Fecal microbiota transplantation (FMT) and fecal virome transplantation (FVT, sterile filtrated donor feces) have been effective in treating recurrent Clostridioides difficile infections, possibly through bacteriophage-mediated modulation of the gut microbiome. However, challenges like donor variability, costly screening, coupled with concerns over pathogen transfer (incl. eukaryotic viruses) with FMT or FVT hinder their wider clinical application in treating less acute diseases.

Transfer of modified gut viromes improves symptoms associated with metabolic syndrome in obese male mice.

Metabolic syndrome encompasses amongst other conditions like obesity and type-2 diabetes and is associated with gut microbiome (GM) dysbiosis. Fecal microbiota transplantation (FMT) has been explored to treat metabolic syndrome by restoring the GM; however, concerns on accidentally transferring pathogenic microbes remain. As a safer alternative, fecal virome transplantation (FVT, sterile-filtrated feces) has the advantage over FMT in that mainly bacteriophages are transferred.

Induction of CD8 immune memory and enhanced inflammation in a skin inflammation model through pre-immunization with inactivated pathogens.

Laboratory mice live in specific pathogen-free (SPF) conditions, resulting in an immature immune system comparable to that of newborns rather than adult humans or mice from pet shops. This condition may compromise their translational value. Reintroducing pathogens would lead to the uncontrolled spread of infections and associated diseases, so research facilities should seek safer alternatives.

Cesarean section induced dysbiosis promotes type 2 immunity but not oxazolone-induced dermatitis in mice.

Delivery by cesarean section (CS) is associated with an altered gut microbiota (GM) colonization and a higher risk of later chronic inflammatory diseases. Studies investigating the association between CS and atopic dermatitis (AD) are contradictive and often biased by confounding factors. The aim of this study was therefore to provide experimental evidence for the association between CS and AD in a mouse model and clarify the role of the GM changes associated with CS.

Fecal virome transfer improves proliferation of commensal gut and unexpectedly enhances the fertility rate in laboratory mice.

Probiotics are intended to improve gastrointestinal health when consumed. However, the probiotics marketed today only colonize the densely populated gut to a limited extent. Bacteriophages comprise the majority of viruses in the human gut virome and there are strong indications that they play important roles in shaping the gut microbiome.

Controlling the uncontrolled variation in the diet induced obese mouse by microbiomic characterization.

Group sizes in an animal study are calculated from estimates on variation, effect, power and significance level. Much of the variation in glucose related parameters of the diet-induced obese (DIO) mouse model is due to inter-individual variation in gut microbiota composition. In addition, standard tandem repeats (STRs) in the non-coding DNA shows that inbred mice are not always homogenic.

Gluten-free diet reduces autoimmune diabetes mellitus in mice across multiple generations in a microbiota-independent manner.

Experimental and clinical data suggest that a gluten-free diet attenuates the development of type 1 diabetes. A gluten-free diet changes the gut microbiota composition, and such microbial changes are expected to reduce the autoimmune responses. However, in experiments with laboratory mice, a gluten-free diet changes the gut microbiota differently under varying experimental settings, questioning the specific role of the gut microbes.

Delayed Gut Colonization Shapes Future Allergic Responses in a Murine Model of Atopic Dermatitis.

Epidemiological studies have long reported that perturbations of the childhood microbiome increase the risk of developing allergies, but a causal relationship with atopic dermatitis remains unclear. Here we colonized germ-free mice at birth or at one or eight week-of-age to investigate the role of prenatal and early postnatal microbial exposure on development of oxozolone-induced dermatitis later in life. We demonstrate that only one week delayed microbial colonization increased IgE levels and the total histological score of the inflamed ear compared to mice colonized throughout life.

The microbiome and rodent models of immune mediated diseases.

Over the last six decades production of laboratory rodents have been refined with the aim of eliminating all pathogens, which could influence research results. This has, however, also created rodents with little diversity in their microbiota. Until 10 years ago the impact of the microbiota on the outcome of rodent studies was ignored, but today it is clear that the phenotype of rodent models differs essentially in relation to the environment of origin, i.

Effects of delivery mode on behavior in mouse offspring.

Cesarean section (CS) has been associated with an increased risk of mental disorders in the offspring. This could possibly be explained by an inadequate microbial colonization early in life with a consequential disturbed gut-brain interaction. To investigate the link between delivery mode and behavior and develop a suitable animal model for further research of the gut-brain axis, the aim of this study was to characterize the gut microbiota (GM) together with the behavioral response in various behavioral tests in CS-delivered mice.

Dietary prebiotics promote intestinal Prevotella in association with a low-responding phenotype in a murine oxazolone-induced model of atopic dermatitis.

Atopic dermatitis is a chronic eczema commonly observed among children in Western countries. The gut microbiota is a significant factor in the pathogenesis, and ways to promote intestinal colonizers with anti-inflammatory capabilities are therefore favorable. The present study addressed the effects of a prebiotic, xylooligosaccharide (XOS), on the gut microbiota and ear inflammation in an oxazolone-induced dermatitis model in BALB/c mice.

A Humanized Diet Profile May Facilitate Colonization and Immune Stimulation in Human Microbiota-Colonized Mice.

Background: In spite of the importance of the use of gnotobiotic mice for human fecal transfer, colonization efficiency and immune stimulation after human microbiota inoculation in mice are poorly studied compared to mouse microbiota inoculation. We tested the colonization efficiency and immune responses in mice bred for one additional generation after inoculating the parent generation with either a human (HM) or a mouse microbiota (MM). Furthermore, we tested if colonization efficiency and immune stimulation could be improved in HM-colonized mice by dietary approaches: if these were fed a diet closer to the human diet either in its sources of animal fat and protein [the "animal source" (AS) diet] or in its proportions of macronutrients from the normal sources of a mouse diet [the "human profile" (HP) diet].

induces cell-surface expression of immune stimulatory NKG2D ligands on human monocytes.

is among the leading causes of bacterial infections worldwide. The pathogenicity and establishment of infections are tightly linked to its ability to modulate host immunity. Persistent infections are often associated with mutant staphylococcal strains that have decreased susceptibility to antibiotics; however, little is known about how these mutations influence bacterial interaction with the host immune system.

Human microbiota-transplanted C57BL/6 mice and offspring display reduced establishment of key bacteria and reduced immune stimulation compared to mouse microbiota-transplantation.

Transplantation of germ-free (GF) mice with microbiota from mice or humans stimulates the intestinal immune system in disparate ways. We transplanted a human microbiota into GF C57BL/6 mice and a murine C57BL/6 microbiota into GF C57BL/6 mice and Swiss-Webster (SW) mice. Mice were bred to produce an offspring generation.

TL1A regulates adipose-resident innate lymphoid immune responses and enables diet-induced obesity in mice.

Background/objectives: TL1A is a pro-inflammatory cytokine that is homologous to TNFα and connected with the development of several chronic inflammatory disorders. The preliminary results of this study indicated reduced fat accumulation in 9-month-old TL1A-deficient mice at steady state. Thus, the objective was to investigate whether TL1A-deficient mice are resistant to the development of high-fat (HF) diet-induced obesity and to investigate the impact on lymphocyte infiltration in adipose tissue.

Betamethasone Treatment for Atopic Dermatitis in Gut Microbiota Transplanted Mice.

Gut microbiota composition correlates strongly with essential disease parameters in the oxazolone-induced mouse model for atopic dermatitis. The phenotype of this model can be transferred to germ-free mice with a gut microbiota transplant to achieve high and low responding mice. Therefore, the production of high responding mice through gut microbiota transplantation may be seen as a tool to reduce group sizes or increase power in intervention studies by increasing effect size.

Cesarean section increases sensitivity to oxazolone-induced colitis in C57BL/6 mice.

Children born by cesarean section (CS) have an increased risk of developing inflammatory bowel disease (IBD), possibly due to skewed microbial colonization during birth and consequently impaired bacterial stimulation of the developing immune system. The aim of this study was to investigate the association between CS and experimental colitis in a murine model of IBD. It was hypothesized that CS aggravates colonic inflammation due to a change in gut microbiota (GM) composition.

Targeting gut microbiota and barrier function with prebiotics to alleviate autoimmune manifestations in NOD mice.

Aims/hypothesis: Adopting a diet containing indigestible fibre compounds such as prebiotics to fuel advantageous bacteria has proven beneficial for alleviating inflammation. The effect of the microbial changes on autoimmunity, however, remains unknown. We studied the effects of prebiotic xylooligosaccharides (XOS) on pancreatic islet and salivary gland inflammation in NOD mice and tested whether these were mediated by the gut microbiota.

Bacterial species to be considered in quality assurance of mice and rats.

Bacteria are relevant in rodent quality assurance programmes if (a) the animals are at risk and (b) presence in the animals makes a difference for animal research or welfare, for example because the agent regulates clinical disease progression or impacts its host in other ways. Furthermore, zoonoses are relevant. Some bacterial species internationally recommended for the health monitoring of rats and mice, that is, Citrobacter rodentium, Corynebacterium kutscheri, Salmonella spp.

Oral LPS Dosing Induces Local Immunological Changes in the Pancreatic Lymph Nodes in Mice.

Lacking the initial contact between the immune system and microbial-associated molecular patterns (MAMPs), such as lipopolysaccharides (LPS), early in life, may be regarded as one of the causal factors of the increasing global increase in the incidence of autoimmune diseases, such as type 1 diabetes (T1D). Previously, a reduced incidence of T1D accompanied by dramatically increased abundances of both the mucin-metabolising bacterium , and LPS-carrying Proteobacteria was observed, when vancomycin was given to pups of nonobese diabetic (NOD) mice. While the T1D incidence reducing effect of .