Project description:Complex gut microbiota increases chicken resistance to enteric diseases. However, the principles of this phenomenon are not understood in detail. One of the possibilities how to decipher the role of gut microbiota in chicken resistance to enteric pathogens is to gradually characterise gene expression of individual gut microbiota members when colonising chicken caecum. To reach this aim, newly hatched chicks were inoculated with bacterial species with known whole genomic sequence. Total protein purified from the chicken caecum was analysed by mass spectrometry and obtained spectra were searched against strain-specific protein databases generated from known genomic sequences.
Project description:This study investigated whether dietary poricoic acid A (PAA) alleviates chronic unpredictable stress (CUS)-induced depressive-like behaviors in mice by modulating the gut microbiota-immune axis. Male C57BL/6J mice were subjected to CUS and treated with PAA. Results showed that PAA alleviated depressive- and anxiety-like behaviors, reduced hippocampal neuronal damage, and restored gut microbiota composition by suppressing harmful bacteria like Ligilactobacillus murinus while promoting beneficial taxa such as Akkermansia muciniphila and Lactobacillus reuteri. Hippocampal transcriptomics revealed that PAA modulated immune cell infiltration by reducing M1 and restoring M2 macrophages, with significant correlations between gut microbial taxa and hippocampal immune gene expression. Functional analyses indicated that PAA regulated pathways related to synaptic plasticity and neuroinflammation, which was confirmed by qPCR and Western blot showing restored expression of HSP90B1, RPS6KB2, IGF2BP2, and COL4A5. In conclusion, dietary PAA alleviates depressive-like behaviors in CUS mice by remodeling the gut microbiota and modulating the hippocampal M1/M2 macrophage balance via the gut-brain axis, supporting its potential as a prebiotic-like nutritional agent for major depressive disorder.
Project description:Human diet emerges as a pivotal determinant of gut microbiota composition and function. Identification of the bacterial taxa targeted by diet derived factors with causal beneficial rather than detrimental effects on therapy and their mechanism of action is challenging but necessary for future clinical progress. The germ free mice colonized with human gut bacteria and four-plants derived nanoparticles uptaking bacteria were sorted with flow cytometry and identified with 16s rRNA next-generation sequencing.
Project description:Gut microbiota are known to influence oral drug disposition, yet the specific host pathways they affect remain poorly characterized. This study provides a transcriptome-wide characterization of how physiological gut microbiota regulate the expression of intestinal transporters, phase I and phase II metabolic enzymes, and barrier machinery relevant to oral drug disposition. By identifying microbiota-responsive processes, this work defines the scope of inter-individual variability attributable to gut microbial effects.
Project description:<p>There are few studies that have characterized maternal gut microbiota and fetal methylmercury exposure, yet microbes likely modulate this relationship. The primary objective of our pilot study was to determine associations between gut microbial taxa and mercury concentrations in multiple biomarkers (stool, hair, and cord blood). Our secondary objective was to determine the contribution of gut microbial mercury methylation to stool methylmercury.</p>
Project description:Elucidating the role of gut microbiota in physiological and pathological processes has recently emerged as a key research aim in life sciences. In this respect, metaproteomics (the study of the whole protein complement of a microbial community) can provide a unique contribution by revealing which functions are actually being expressed by specific microbial taxa. However, its wide application to gut microbiota research has been hindered by challenges in data analysis, especially related to the choice of the proper sequence databases for protein identification. Here we present a systematic investigation of variables concerning database construction and annotation, and evaluate their impact on human and mouse gut metaproteomic results. We found that both publicly available and experimental metagenomic databases lead to the identification of unique peptide assortments, suggesting parallel database searches as a mean to gain more complete information. Taxonomic and functional results were revealed to be strongly database-dependent, especially when dealing with mouse samples. As a striking example, in mouse the Firmicutes/Bacteroidetes ratio varied up to 10-fold depending on the database used. Finally, we provide recommendations regarding metagenomic sequence processing aimed at maximizing gut metaproteome characterization, and contribute to identify an optimized pipeline for metaproteomic data analysis.
Project description:The link between the gut microbiota of a human being (a complex group of microorganism including not only bacteria but also fungi, viruses, etc.,) that form an ecosystem in his gastrointestinal tract and his physiological state is nowadays unquestionable. Metaproteomics has emerged as a useful technique to characterize this microbial community, not just taxonomically, but also focusing on specific biological processes carried out by gut microbiota that may have an effect in the host health or pathological state. In order to characterize this host-microbiota inter-relation, we carried out the metaproteomic study of 6 stool samples from 6 healthy adults. A total of 37 080 peptide sequences and 10 686 protein groups were identified in this study. Regarding taxonomic information, we found a total of 247 taxa among 105 were species. Interesting contributions of microbiota metabolism to human host physiology has also been described.
Project description:This study investigated the impact of a high cellulose diet (HCD) on intestinal homeostasis and food allergy development in BALB/c mice. While soluble fibers are known to mitigate FA via short-chain fatty acid (SCFA) production, the role of insoluble fibers like cellulose remains unclear. Mice fed HCD exhibited gut dysbiosis, characterized by increased Proteobacteria, decreased tight junction protein expression, and intestinal barrier impairment, despite unchanged SCFA levels. RNA sequencing revealed HCD-induced upregulation of immune pathways, including the positive regulation of B and T cells differentiation and antigen receptor-mediated signaling pathway. Following ovalbumin (OVA) sensitization, HCD-fed mice displayed exacerbated allergic symptoms, including elevated OVA-specific IgE, IgG, histamine, and mMCP-1 levels. Gut microbiota analysis highlighted enrichment of potentially pathogenic taxa in HCD+OVA groups. Fecal microbiota transplantation (FMT) from HCD donors to antibiotic-treated recipients showed severe food allergy responses, confirming microbiota-mediated effects. These findings demonstrate that HCD exacerbates food allergy through gut microbial dysbiosis, intestinal barrier disruption, and intestinal immune disorder.
Project description:The gut microbiota, immune system, and enteric nervous system interact to regulate adult gut physiology. Yet the mechanisms establishing gut physiology during development remain unknown. We report that in developing zebrafish, enteroendocrine cells produced IL-22 in response to microbial signals before lymphocytes populate the gut. In larvae, IL-22 shaped the gut microbiota, increased Lactobacillaceae abundance and ghrelin expression to promote gut motility. Impaired motility and ghrelin expression were restored in il22-/- zebrafish by transfer of microbiota from wild-type zebrafish or by monoassociation with Lactobacillus plantarum. IL-22-deficient mice had impaired gut motility and reduced ghrelin expression in early life too, indicating a conserved function. Thus, before immune system maturation, enteroendocrine cells regulate early-life gut function by controlling the microbiota via IL-22.
Project description:Several studies have established a link between high-salt diet, inflammation, and hypertension. Vitamin D supplementation has shown anti-inflammatory effects in many diseases; gut microbiota is also associated with a wide variety of cardiovascular diseases, but potential role of vitamin D and gut microbiota in high-salt diet-induced hypertension remains unclear. Therefore, we used rats with hypertension induced by a high-salt diet as the research object and analyzed the transcriptome of their tissues (kidney and colon) and gut microbiome to conduct an overall analysis of the gut–kidney axis. We aimed to confirm the effects of high salt and calcitriol on the gut–kidney immune system and the composition of the intestinal flora. We demonstrate that consumption of a high-salt diet results in hypertension and inflammation in the colon and kidney and alteration of gut microbiota composition and function. High-salt diet-induced hypertension was found to be associated with seven microbial taxa and mainly associated with reduced production of the protective short-chain fatty acid butyrate. Calcitriol can reduce colon and kidney inflammation, and there are gene expression changes consistent with restored intestinal barrier function. The protective effect of calcitriol may be mediated indirectly by immunological properties. Additionally, the molecular pathways of the gut microbiota-mediated BP regulation may be related to circadian rhythm signals, which needs to be further investigated. An innovative association analysis of the microbiota may be a key strategy to understanding the association between gene patterns and host.