Characterization of the gut microbiota in leptin deficient obese mice - Correlation to inflammatory and diabetic parameters.

Gut microbiota have been implicated as a relevant factor in the development of type 2 diabetes mellitus (T2DM), and its diversity might be a cause of variation in animal models of T2DM. In this study, we aimed to characterise the gut microbiota of a T2DM mouse model with a long term vision of being able to target the gut microbiota to reduce the number of animals used in experiments. Male B6.V-Lep(ob)/J mice were characterized according to a number of characteristics related to T2DM, inflammation and gut microbiota. All findings were thereafter correlated to one another in a linear regression model. The total gut microbiota profile correlated to glycated haemoglobin, and high proportions of Prevotellaceae and Lachnospiraceae correlated to impaired or improved glucose intolerance, respectively. In addition, Akkermansia muciniphila disappeared with age as glucose intolerance worsened. A high proportion of regulatory T cells correlated to the gut microbiota and improved glucose tolerance. Furthermore, high levels of IL-10, IL-12 and TNF-α correlated to impaired glucose tolerance, blood glucose or glycated haemoglobin. The findings indicate that gut microbiota may contribute to variation in various disease read-outs in the B6.V-Lep(ob)/J model and considering them in both quality assurance and data evaluation for the B6.V-Lep(ob)/J model may have a reducing impact on the inter-individual variation.

Ellekilde M ，Krych L ，Hansen CH ，Hufeldt MR ，Dahl K ，Hansen LH ，Sørensen SJ ，Vogensen FK ，Nielsen DS ，Hansen AK ... -  《-》

Manipulation of the gut microbiota in C57BL/6 mice changes glucose tolerance without affecting weight development and gut mucosal immunity.

Inflammatory diseases such as type 2 diabetes (T2D) in humans and mice are under the influence of the composition of the gut microbiota (GM). It was previously demonstrated that treating Lep(ob) mice with antibiotics improved glucose tolerance. However, wild type C57BL/6J mice may also exhibit plasma glucose intolerance reminiscent of human T2D. We hypothesized that antibiotic treatment in C57BL/6 mice would have an impact on glucose tolerance without affecting weight and gut immunology. When compared to mice treated with erythromycin or the controls, treatment for five weeks with ampicillin improved glucose tolerance without significantly affecting the weight or the number of gut mucosal regulatory T cells, tolerogenic dendritic cells or T helper cells type 1. 16S rRNA gene based denaturing gradient gel electrophoresis profiles clearly clustered according to treatment and showed that antibiotic treatment reduced GM diversity. It is concluded that antibiotic treatment changes glucose metabolism as well as the composition of the GM in C57BL/6 mice, and that this does not seem to be correlated to weight development in the mice.

Bech-Nielsen GV ，Hansen CH ，Hufeldt MR ，Nielsen DS ，Aasted B ，Vogensen FK ，Midtvedt T ，Hansen AK ... -  《-》

Managing the manager: gut microbes, stem cells and metabolism.

One major discovery of the last decade in the field of metabolic diseases is that the microorganisms comprising the gut microbiota are now considered a metabolic "organ", modulating multiple functions of the host, such as intestinal immune system maturation, adiposity, cardiac metabolism, liver triglyceride storage, and brain development and behaviour. The corresponding mechanisms involve increased energy harvesting through the production by microbiota of short-chain fatty acids for use by the host, and the release of pro-inflammatory compounds, such as lipopolysaccharide (LPS), flagellin and peptidoglycan. In particular, a high-fat diet (HFD) modifies gut microbiota, resulting in an increase of plasma LPS levels known as "metabolic endotoxaemia", a major driver of the onset of metabolic diseases through a CD14-dependent mechanism. The LPS-sensitive cell types can be seen within bone marrow-derived cells (BMC), which are involved in the development of inflammation in the adipose tissue of obese and type 2 diabetic mice. Furthermore, the expression of LPS receptor/cofactor CD14 cells from the stromal vascular fraction of adipose depots can also be directly targeted by LPS to initiate precursor cell development and adiposity. Moreover, data from the literature also indicate an impact of gut microbiota on intestinal stem cells. Thus, this mini review presents the experimental evidence supporting a relationship between gut microbiota and stem cells as a new axis of metabolic homoeostasis control.

Serino M ，Blasco-Baque V ，Nicolas S ，Burcelin R ... -  《-》

Gut decontamination with norfloxacin and ampicillin enhances insulin sensitivity in mice.

Chou CJ ，Membrez M ，Blancher F 《-》

Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics.

Geurts L ，Neyrinck AM ，Delzenne NM ，Knauf C ，Cani PD ... -  《-》