ObjectivesDysbiosis of the intestinal microbiota is associated with Crohn's disease (CD). Functional evidence for a causal role of bacteria in the development of chronic small intestinal inflammation is lacking. Similar to human pathology, TNFdeltaARE mice develop a tumour necrosis factor (TNF)-driven CD-like transmural inflammation with predominant ileal involvement.DesignHeterozygous TNFdeltaARE mice and wildtype (WT) littermates were housed under conventional (CONV), specific pathogen-free (SPF) and germ-free (GF) conditions. Microbial communities were analysed by high-throughput 16S ribosomal RNA gene sequencing. Metaproteomes were measured using LC-MS. Temporal and spatial resolution of disease development was followed after antibiotic treatment and transfer of microbial communities into GF mice. Granulocyte infiltration and Paneth cell function was assessed by immunofluorescence and gene expression analysis.ResultsGF-TNFdeltaARE mice were free of inflammation in the gut and antibiotic treatment of CONV-TNFdeltaARE mice attenuated ileitis but not colitis, demonstrating that disease severity and location are microbiota-dependent. SPF-TNFdeltaARE mice developed distinct ileitis-phenotypes associated with gradual loss of antimicrobial defence. 16S analysis and metaproteomics revealed specific compositional and functional alterations of bacterial communities in inflamed mice. Transplantation of disease-associated but not healthy microbiota transmitted CD-like ileitis to GF-TNFdeltaARE recipients and triggered loss of lysozyme and cryptdin-2 expression. Monoassociation of GF-TNFdeltaARE mice with the human CD-related Escherichia coli LF82 did not induce ileitis.ConclusionsWe provide clear experimental evidence for the causal role of gut bacterial dysbiosis in the development of chronic ileal inflammation with subsequent failure of Paneth cell function.

The gut microbiota generates a huge pool of unknown metabolites, and their identification and characterization is a key challenge in metabolomics. However, there are still gaps on the studies of gut microbiota and their chemical structures. In this investigation, an unusual class of bacterial sulfonolipids (SLs) is detected in mouse cecum, which was originally found in environmental microbes. We have performed a detailed molecular level characterization of this class of lipids by combining high-resolution mass spectrometry and liquid chromatography analysis. Eighteen SLs that differ in their capnoid and fatty acid chain compositions were identified. The SL called “sulfobacin B” was isolated, characterized, and was significantly increased in mice fed with high-fat diets. To reveal bacterial producers of SLs, metagenome analysis was acquired and only two bacterial genera, i.e., Alistipes and Odoribacter, were revealed to be responsible for their production. This knowledge enables explaining a part of the molecular complexity introduced by microbes to the mammalian gastrointestinal tract and can be used as chemotaxonomic evidence in gut microbiota.

These data suggest that factors other than evidence-based medicine have a dominant effect on the use of NSAIDs in Serbia. Targeted education from independent sources in the prescribing, dispensing, and use of drugs is important to improve the quality of the prescribing behavior and the use of NSAIDs.

There are opposite hypotheses on the effect of saccharin. Our aim was reviewing the influence of chronically ingested saccharin on the function and histological structure of liver and pancreas and all this in light of gender differences. The rats were divided into control group - (Group C) and saccharin-treated group - (Group S) which was given a normal diet and 0.0005% saccharin in drinking water for 6 weeks. Liver and pancreas were histologically processed and quantitative histological analysis was performed. Glucose blood levels and plasma activities of aspartate transaminase (AST) and alanine transaminase (ALT), body weight, and food intake were analyzed. Quantitative histological analysis determined that the values of diameter and volume density of both Langerhans islets and exocrine acini were significantly higher in S group, especially in males. AST levels were significantly higher in treated group. Glucose levels were higher in treated group, mainly due to the values of the female subgroup. Food intake was significantly higher in control group, while weight gain was higher in treated group. Treated males had significantly higher food intake and weight gain in comparison with treated females. The data presented here suggests that chronic saccharin intake affects the examined parameters. Reported facts reflect various metabolic, hormonal and neural responses in males and females.

Factors other than evidence-based medicine (such as poor health education in the past that led to long-lasting consequences on the cultural behaviour of the general population as well as on the prescribing habits of physicians) have a dominating impact on the use of NSAIDs in SBD. Targeted education from independent sources in the prescribing, dispensing and use of drugs is required to improve the quality of prescription and use of NSAIDs in Serbia.