Multi-Omics Analysis Reveals Changes in the Intestinal Microbiome, Transcriptome, and Methylome in a Rat Model of Chronic Non-bacterial Prostatitis: Indications for the Existence of the Gut-Prostate Axis

Chronic non-bacterial prostatitis (CNP) is one of the most prevalent diseases in human males worldwide. In 2005, the prostate-gut axis was first proposed to indicate the close relationship between the prostate and the intestine. This study investigated CNP-induced changes of the gut microbiota, gene expression and DNA methylation in a rat model by using multi-omics analysis. Firstly, 16S rDNA sequencing presented an altered structure of the microbiota in cecum of CNP rats. Then, transcriptomic analysis revealed that the expression of 185 genes in intestinal epithelium was significantly changed by CNP. These changes can participate in the immune system, digestive system, metabolic process, etc. Finally, methylC-capture sequencing (MCC-Seq) found 73,232 differentially methylated sites (DMSs) in the DNA of intestinal epithelium between control and CNP rats. A combined analysis of methylomics and transcriptomics suggested an epigenetic mechanism for CNP-induced differential expression genes correlated with intestinal barrier function, immunity, metabolism, enteric infectious disease, etc. More importantly, the transcriptomic, methylomic and gut microbial changes were highly correlated with multiple processes including intestinal immunity, metabolism and epithelial barrier function. In this study, disrupted homeostasis in the gut microbiota, gene expression and DNA methylation were reported in CNP, which supports the existence of the gut-prostate axis.

Life Cycle and Transmission of Cyclospora cayetanensis: Knowns and Unknowns

Although infections with Cyclospora cayetanensis are prevalent worldwide, many aspects of this parasite’s life cycle and transmission remain unknown. Humans are the only known hosts of this parasite. Existing information on its endogenous development has been derived from histological examination of only a few biopsy specimens. Its asexual and sexual stages occur in biliary-intestinal epithelium. In histological sections, its stages are less than 10 μm, making definitive identification difficult. Asexual (schizonts) and sexual (gamonts) are located in epithelial cells. Male microgamonts have two flagella; female macrogametes contain wall-forming bodies. Oocysts are excreted in feces unsporulated. Sporulation occurs in the environment, but there are many unanswered questions concerning dissemination and survival of C. cayetanensis oocysts. Biologically and phylogenetically, C. cayetanensis closely resembles Eimeria spp. that parastize chickens; among them, E. acervulina most closely resembles C. cayetanensis in size. Here, we review known and unknown aspects of its life cycle and transmission and discuss the appropriateness of surrogates best capable of hastening progress in understanding its biology and developing mitigating strategies.

Stabilization but no functional influence of HIF-1α expression in the intestinal epithelium during Salmonella Typhimurium infection

The hypoxia-inducible transcription factor 1 (HIF-1) has been shown to enhance microbial killing and to ameliorate the course of bacterial infections. While the impact of HIF-1 on inflammatory diseases of the gut has been studied intensively, its function in bacterial infections of the gastrointestinal tract remains largely elusive. With the help of a publicly available gene expression data set, we could infer significant activation of HIF-1 after oral infection of mice with Salmonella Typhimurium. Immunohistochemistry and western blot analysis confirmed marked HIF-1α protein stabilization, especially in the intestinal epithelium. This prompted us to analyze conditional Hif1a -deficient mice to examine cell type-specific functions of HIF-1 in this model. Our results demonstrate enhanced non-canonical induction of HIF-1 activity upon Salmonella infection in the intestinal epithelium as well as in macrophages. Surprisingly, Hif1a deletion in intestinal epithelial cells did not impact on inflammatory gene expression, bacterial spread or disease outcome. In contrast, Hif1a deletion in myeloid cells enhanced intestinal Cxcl2 expression and reduced the cecal Salmonella load. In vitro , HIF-1α-deficient macrophages showed an overall impaired transcription of mRNA encoding pro-inflammatory factors, however, intracellular survival of Salmonella was not impacted by HIF-1α deficiency.

Myosin phosphatase target subunit 1 governs integrity of the embryonic gut epithelium to circumvent atresia development in medaka, Oryzias latipes

BackgroundIntestinal atresia (IA) is a congenital gut obstruction caused by the absence of gut opening. Genetic factors are assumed to be critical for the development of IA, in addition to accidental vascular insufficiency or mechanical strangulation. However, the molecular mechanism underlying IA remains poorly understood.ResultsIn this study, to better understand such a mechanism, we isolated a mutant of Oryzias latipes (the Japanese rice fish known as medaka) generated by N-ethyl-N-nitrosourea mutagenesis, in which IA develops during embryogenesis. Positional cloning identified a nonsense mutation in the myosin phosphatase target subunit 1 (mypt1) gene. Consistent with known Mypt1 function, the active form of myosin regulatory light chain (MRLC), which is essential for actomyosin contraction, and F-actin were ectopically accumulated in the intestinal epithelium of mutant embryos, whereas cell motility, proliferation and cell death were not substantially affected. Corresponding to the accumulation site of F-actin/active MRLC, the intestinal epithelium architecture was disordered. Importantly, blebbistatin, a non-muscle myosin inhibitor, attenuated the development of IA in the mutant.ConclusionsCytoskeletal contraction governed by mypt1 regulates the integrity of the embryonic intestinal epithelium. This study provides new insight into our understanding of the mechanism of IA development in humans.Bullet PointsMedaka mypt1 mutants display intestinal atresia.The level of phosphorylated myosin regulatory light chain was higher in mypt1 mutant embryos than in wild-type embryos.The levels of F-actin appeared elevated in the intestinal epithelium of mypt1 mutants.Blebbistatin, an inhibitor of non-muscle myosin II, rescued intestinal atresia in mypt1 mutant embryos.

Soluble Non-Starch Polysaccharides From Plantain (Musa x paradisiaca L.) Diminish Epithelial Impact of Clostridioides difficile

Clostridioides difficile infection (CDI) is a leading cause of antibiotic-associated diarrhoea. Adhesion of this Gram-positive pathogen to the intestinal epithelium is a crucial step in CDI, with recurrence and relapse of disease dependent on epithelial interaction of its endospores. Close proximity, or adhesion of, hypervirulent strains to the intestinal mucosa are also likely to be necessary for the release of C. difficile toxins, which when internalized, result in intestinal epithelial cell rounding, damage, inflammation, loss of barrier function and diarrhoea. Interrupting these C. difficile-epithelium interactions could therefore represent a promising therapeutic strategy to prevent and treat CDI. Intake of dietary fibre is widely recognised as being beneficial for intestinal health, and we have previously shown that soluble non-starch polysaccharides (NSP) from plantain banana (Musa spp.), can block epithelial adhesion and invasion of a number of gut pathogens, such as E. coli and Salmonellae. Here, we assessed the action of plantain NSP, and a range of alternative soluble plant fibres, for inhibitory action on epithelial interactions of C. difficile clinical isolates, purified endospore preparations and toxins. We found that plantain NSP possessed ability to disrupt epithelial adhesion of C. difficile vegetative cells and spores, with inhibitory activity against C. difficile found within the acidic (pectin-rich) polysaccharide component, through interaction with the intestinal epithelium. Similar activity was found with NSP purified from broccoli and leek, although seen to be less potent than NSP from plantain. Whilst plantain NSP could not block the interaction and intracellular action of purified C. difficile toxins, it significantly diminished the epithelial impact of C. difficile, reducing both bacteria and toxin induced inflammation, activation of caspase 3/7 and cytotoxicity in human intestinal cell-line and murine intestinal organoid cultures. Dietary supplementation with soluble NSP from plantain may therefore confer a protective effect in CDI patients by preventing adhesion of C. difficile to the mucosa, i.e. a “contrabiotic” effect, and diminishing its epithelial impact. This suggests that plantain soluble dietary fibre may be a therapeutically effective nutritional product for use in the prevention or treatment of CDI and antibiotic-associated diarrhoea.

Developmental Stage, Solid Food Introduction and Suckling Cessation Differentially Influence the Co-maturation of the Gut Microbiota and Intestinal Epithelium in Rabbits

Background In mammals, the establishment around weaning of a symbiotic relationship between the gut microbiota and its host determines long-term health. Objective The aim of this study was to identify the factors driving the co-maturation of the gut microbiota and intestinal epithelium at the suckling-to-weaning transition. We hypothesized that developmental stage, solid food ingestion and suckling cessation contribute to this process. Methods From birth to day 18, Hyplus rabbits were exclusively suckling. From day 18 to day 25, rabbits were i) exclusively suckling or ii) suckling and ingesting solid food or iii) exclusively ingesting solid food. The microbiota (16S amplicon sequencing), metabolome (nuclear magnetic resonance) and epithelial gene expression (high-throughput qPCR) were analyzed in the caecum at day 18 and 25. Results The microbiota structure and metabolic activity were modified with age when rabbits remained exclusively suckling. The epithelial gene expression of nutrient transporters, proliferation markers and innate immune factors were also regulated with age (e.g., 1.5-fold decrease of TLR5). Solid food ingestion by suckling rabbits had a major effect on the gut microbiota by increasing its α-diversity, remodeling its structure (e.g., 6.3-fold increase of Ruminococcaceae) and metabolic activity (e.g., 4.6-fold increase of butyrate). Solid food introduction also regulated the gene expression of nutrient transporters, differentiation markers and innate immune factors in the epithelium (e.g., 3-fold increase of NOS2). Suckling cessation had no effect on the microbiota while it regulated the expression of genes involved in epithelial differentiation and immunoglobulin transport (e.g., 2.5-increase of PIGR). Conclusion In rabbits, the maturation of the microbiota at the suckling-to-weaning transition is driven by the introduction of solid food and to a lesser extent by developmental stage. In contrast, the maturation of the intestinal epithelium at the suckling-to-weaning transition is under the influence of developmental stage, solid food introduction and suckling cessation.

Intestinal Stem Cell-on-Chip to Study Human Host-Microbiota Interaction

The gut is a tubular organ responsible for nutrient absorption and harbors our intestinal microbiome. This organ is composed of a multitude of specialized cell types arranged in complex barrier-forming crypts and villi covered by a mucosal layer controlling nutrient passage and protecting from invading pathogens. The development and self-renewal of the intestinal epithelium are guided by niche signals controlling the differentiation of specific cell types along the crypt-villus axis in the epithelium. The emergence of microphysiological systems, or organ-on-chips, has paved the way to study the intestinal epithelium within a dynamic and controlled environment. In this review, we describe the use of organ-on-chip technology to control and guide these differentiation processes in vitro. We further discuss current applications and forthcoming strategies to investigate the mechanical processes of intestinal stem cell differentiation, tissue formation, and the interaction of the intestine with the microbiota in the context of gastrointestinal diseases.