Cecum Feces Research Articles

Sex-specific effects of gut microbiome on shaping bile acid metabolism.

Gut microbiome is a group of microorganisms that plays important roles in contributing to health and diseases. These bacterial compositions have been demonstrated to impact bile acids (BAs) profiles, either by directly metabolizing primary BAs to secondary BAs or indirect ways through host metabolism by influencing BAs synthesis, transportation and conjugation in liver. It has been observed sexually dimorphic gut microbiome and bile acids composition, with variations in expression levels of bile acid metabolizing genes in the liver. However, associations between sex-specific differences in gut microbiome and BAs profiles are not well understood. This study aimed to investigate whether gut microbiome could influence BAs profiles in host in a sexspecific manner. We transplanted cecum feces of male and female C57BL/6 mice to male mice and measured BAs concentrations in feces, serum and liver samples 7 days after fecal transplantation. We found different BAs profiles between mice with male and female gut microbiome, including altering levels and proportions of secondary BAs. We also observed varied expression levels of genes related to bile acid metabolism in the liver and distal ileum. Our results highlight sex-specific effects of gut microbiome on shaping bile acid metabolism through gut bacteria and regulation of host genes.

In Vivo Healthy Benefits of Galacto-Oligosaccharides from Lupinus albus (LA-GOS) in Butyrate Production through Intestinal Microbiota.

Animal digestive systems host microorganism ecosystems, including integrated bacteria, viruses, fungi, and others, that produce a variety of compounds from different substrates with healthy properties. Among these substrates, α-galacto-oligosaccharides (GOS) are considered prebiotics that promote the grow of gut microbiota with a metabolic output of Short Chain Fatty Acids (SCFAs). In this regard, we evaluated Lupinus albus GOS (LA-GOS) as a natural prebiotic using different animal models. Therefore, the aim of this work was to evaluate the effect of LA-GOS on the gut microbiota, SCFA production, and intestinal health in healthy and induced dysbiosis conditions (an ulcerative colitis (UC) model). Twenty C57BL/6 mice were randomly allocated in four groups (n = 5/group): untreated and treated non-induced animals, and two groups induced with 2% dextran sulfate sodium to UC with and without LA-GOS administration (2.5 g/kg bw). We found that the UC treated group showed a higher goblet cell number, lower disease activity index, and reduced histopathological damage in comparison to the UC untreated group. In addition, the abundance of positive bacteria to butyryl-CoA transferase in gut microbiota was significantly increased by LA-GOS treatment, in healthy conditions. We measured the SCFA production with significant differences in the butyrate concentration between treated and untreated healthy groups. Finally, the pH level in cecum feces was reduced after LA-GOS treatment. Overall, we point out the in vivo health benefits of LA-GOS administration on the preservation of the intestinal ecosystem and the promotion of SCFA production.

Alleviation of Neuronal Cell Death and Memory Deficit with Chungkookjang Made with Bacillus amyloliquefaciens and Bacillus subtilis Potentially through Promoting Gut-Brain Axis in Artery-Occluded Gerbils.

Short-term fermented soybeans (chungkookjang) with specific Bacillus (B.) spp. have anti-obesity, antidiabetic, and anti-stroke functions. We examined the hypothesis that the long-term consumption of B. amyloliquefaciens SCGB 1 fermented (CKJ1) and B. subtilis SCDB 291 (CKJ291) chungkookjang can alleviate clinical symptoms and hyperglycemia after ischemic stroke by promoting the gut microbiota–brain axis. We examined this hypothesis in Mongolian male gerbils with stroke symptoms induced by carotid artery occlusion. The artery-occluded gerbils were divided into five groups: no supplementation (Control, Normal-control), 4% cooked soybeans (CSB), CKJ1, or CKJ291 in a high-fat diet for 3 weeks. The carotid arteries of gerbils in the Control, CSB, CKJ1, and CKJ291 groups were occluded for 8 min and they then continued on their assigned diets for an additional 3 weeks. Normal-control gerbils had no artery occlusion. The diets in all groups contained an identical macronutrient composition using starch, casein, soybean oil, and dietary fiber. The CSB, CKJ1, and CKJ291 groups exhibited less neuronal cell death than the Control group, while the CKJ1 group produced the most significant reduction among all groups, as much as 85% of the Normal-control group. CKJ1 and CKJ291 increased the blood flow and removal of blood clots, as determined by Doppler, more than the Control. They also showed more improvement in neurological disorders from ischemic stroke. Their improvement showed a similar tendency as neuronal cell death. CKJ1 treatment improved memory impairment, measured with Y maze and passive avoidance tests, similar to the Normal-control. The gerbils in the Control group had post-stroke hyperglycemia due to decreased insulin sensitivity and β-cell function and mass; the CKJ291, CSB, and CKJ1 treatments protected against glucose disturbance after artery occlusion and were similar to the Normal-control. CKJ1 and CKJ291 also reduced serum tumor necrosis factor-α concentrations and hippocampal interleukin-1β expression levels, compared to the Control. CKJ1 and CKJ291 increased the contents of Lactobacillus, Bacillus, and Akkermansia in the cecum feces, similar to the Normal-control. Picrust2 analysis showed that CKJ1 and CKJ291 increased the propionate and butyrate metabolism and the starch and glucose metabolism but reduced the lipopolysaccharide biosynthesis and fatty acid metabolism compared to the Control. In conclusion, daily CKJ1 and CKJ291 intake prevented neuronal cell death and memory dysfunction from the artery occlusion by increasing blood flow and β-cell survival and reducing post-stroke-hyperglycemia through modulating the gut microbiome composition and metabolites to influence the host metabolism, especially inflammation and insulin resistance, protecting against neuronal cell death and brain dysfunction. CKJ1 had better effects than CKJ291.

Obese rats intervened with Rhizoma coptidis revealed differential gene expression and microbiota by serum metabolomics

BackgroundIntegrating systems biology is an approach for investigating metabolic diseases in humans. However, few studies use this approach to investigate the mechanism by which Rhizoma coptidis (RC) reduces the effect of lipids and glucose on high-fat induced obesity in rats.MethodsTwenty-four specific pathogen-free (SPF) male Sprague–Dawley rats (80 ± 10 g) were used in this study. Serum metabolomics were detected by ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry. Liver tissue and cecum feces were used for RNA-Seq technology and 16S rRNA gene sequencing, respectively.ResultsWe identified nine potential biomarkers, which are differential metabolites in the Control, Model and RC groups, including linoleic acid, eicosapentaenoic acid, arachidonic acid, stearic acid, and L-Alloisoleucine (p < 0.01). The liver tissue gene expression profile indicated the circadian rhythm pathway was significantly affected by RC (Q ≤ 0.05). A total of 149 and 39 operational taxonomic units (OTUs), which were highly associated with biochemical indicators and potential biomarkers in the cecum samples (FDR ≤ 0.05), respectively, were identified.ConclusionThis work provides information to better understand the mechanism of the effect of RC intervention on hyperlipidemia and hypoglycemic effects in obese rats. The present study demonstrates that integrating systems biology may be a powerful tool to reveal the complexity of metabolic diseases in rats intervened by traditional Chinese medicine.

Illumina MiSeq Sequencing Investigation of Microbiota in Bronchoalveolar Lavage Fluid and Cecum of the Swine Infected with PRRSV.

Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant animal morbidity and mortality and economic losses worldwide. In this study, we analyzed the microbiota in bronchoalveolar lavage fluid (BAL), mucosa, and feces in cecum of the PRRSV-challenged pigs using the Illumina MiSeq sequencing platform, to investigate the role of microbiota in the pathogenesis and development of porcine reproductive and respiratory syndrome (PRRS). Quantitative insights into microbial ecology analyses indicated that the dominant bacterial groups in the lung from the PRRSV-challenged pigs were Haemophilus parasuis and Mycoplasma hyorhinis, with a relative abundance of 35-48% and 27-41%, respectively. Our results were consistent with the clinical observation that the PRRSV-infected pigs are always co-infected with other bacteria, such as Haemophilus and Mycoplasma. On the other hand, Campylobacter and Clostridium became the two most abundant bacteria in the mucosal and luminal microbiota of the cecum of the PRRSV-challenged pigs, and the relative abundance was four times higher than that in the healthy pigs. This suggested that Campylobacter and Clostridium might be associated with the pathogenesis of diarrhea in PRRS. Linear discriminant analysis effect size reveals significant microbial dysbiosis of BAL, mucosa, and feces in cecum of the PRRSV-challenged pigs. We have identified a structural imbalance of the microbiota, characterized by a reduced diversity of microbiota and abundance alterations of certain bacteria in the PRRSV-challenged pigs. The observed microbiota dysbiosis in this study provides insight into the roles of the microbiota in the complications of the PRRSV infection.

Cyp7a1 is continuously increased with disrupted Fxr-mediated feedback inhibition in hypercholesterolemic TALLYHO/Jng mice

TALLYHO/Jng (TH) mice reveal hypercholesterolemia at an early age before their plasma glucose levels have increased. The increased plasma cholesterol should be related to bile acids (BAs) metabolism, because cholesterol is the precursor of BAs and BAs change cholesterol metabolism in a feedback manner. We analyzed the BAs pool size, BAs composition, and expression levels of several proteins that have key roles in BAs synthesis, excretion, and reabsorption and compared them to those of C57BL/6 (B6) mice to study BAs metabolism in TH mice. TH mice exhibited an increased total BAs pool size, increased BAs content in the cecum feces, and an increased ratio of muricholic acid (MCA)/cholic acid (CA). The mRNA and protein levels of cholesterol 7 alpha-hydroxylase (Cyp7a1) and the ATP-binding cassette sub-family G member 5 (Abcg5) were elevated in the liver but not in the apical sodium bile acid transporter (Asbt) and organic solute transporters (Osts) in the ileum. These results indicate that synthesis and the excretion of BAs from the liver to the gallbladder might be elevated, but the reabsorption rate of BAs in the ileum might be reduced. The declined expression of fibroblast growth factor 15 (Fgf15) and fibroblast growth factor receptor 4 (Fgfr4) was respectively identified in the ileum and the liver, indicating the disrupted feedback inhibition of Cyp7a1. Consequently, hypercholesterolemia in TH mice might increase the BAs amounts via the interrupted Fxr/Fgf15/Fgfr4-mediated feedback regulation of Cyp7a1.

The bacterial microbiota in the ceca of Capercaillie ( Tetrao urogallus) differs between wild and captive birds

The diet of wild capercaillie differs strongly between seasons. Particularly during winter, when energy demands are high and the birds forage solely on coniferous needles, microbial fermentations in the ceca are considered to contribute significantly to the energy requirement and to the detoxification of the resinous diet. Here, we present the first cultivation-independent analysis of the bacterial community in the cecum of capercaillie, using the 16S rRNA gene as a molecular marker. Cloning and fingerprinting analyses of cecum feces show distinct differences between wild and captive birds. While certain lineages of Clostridiales, Synergistetes, and Actinobacteria are most prevalent in wild birds, they are strongly reduced in individuals raised in captivity. Most striking is the complete absence of Megasphaera and Synergistes species in captive capercaillie, which are characterized by a large abundance of Gammaproteobacteria closely related to members of the genus Anaerobiospirillum, bacteria that are commonly connected with intestinal dysfunction. The community profiles of cecum content from wild birds differed between summer and winter season, and the cecum wall may be an important site for bacterial colonization. Our results corroborate the hypothesis that the bacterial community in the ceca of tetraonid birds changes in response to their highly specialized seasonal diets. Moreover, we propose that the observed differences in community profiles between wild and captive capercaillie reflects a disturbance in the bacterial microbiota that compromises the performance of the cecum and may be responsible for the high mortality of captive birds released into nature.

Influence of ecoimmunonutrition supplement on intestinal mucosa morphology and gut barrier function in rats after operative stress

To investigate the effects of ecoimmunonutrition supplement on intestinal microecology, epithelial tight junctions, and barrier function in rats with surgical stress. Seventy SD rats after surgical trauma were randomly divided into four groups:(1) placebo group,(2)total parenteral nutrition(TPN) group,(3)enteral nutrition(EN) group and (4)ecoimmunonutrition (EEN)group respectively. Rats received isocaloric and isonitrogenous nutrition. Nutrients were administered via the neck vein and the needle jejunostomy for five days. The homogenated tissues of liver, lung, and mesenteric lymph nodes were cultured to determine the bacterial translocation rate. The transmembrane binding proteins(occludin) was measured by immunohistochemistry. The ultrastructure and morphology of intestinal epithelial tight junctions in the intestine were observed by electron microscope. The feces in cecum was cultured for anaerobic bacterial growth and analysed. The amounts of lactobacteria and bifidobacteria in EEN group were significantly higher than those in TPN group(P<0.05). The expression levels of occludin in the intestine was significantly higher in EEN group than that in TPN and EN group. Furthermore, the intestinal epithelial tight junction and microvilli of EEN group were more intact compared with those of TPN group. The bacterial translocation rates of liver, lung and mesenteric lymph nodes were significantly lower in EEN and EN group than those in TPN group(P<0.05). Application of ecoimmunonutrition can protect intestinal mucosal barrier in rats with operative stress, increase the expression of occludin, maintain the gut epithelial tight junction, and eliminate gut bacterial translocation.

Influences of enteral nutrition combined with probiotics on the gut microecology and barrier function of the rats with abdominal infection

To investigate the influences of enteral nutrition (EN), parenteral nutrition (PN) and probiotics supplement on the intestinal microecology, and barrier function of the rats with abdominal infection. Twenty-one Sprague-Dawley (SD) rats with abdominal infection were randomly divided into three groups, and received PN (PN group, n=7), PN+ EN (PN+ EN group, n=7) or PN+ EN+ probiotics (probiotics group, n=7) respectively with isonitrogen and isocaloric nutrition. The rats were sacrificed after six days. The feces in cecum were cultured for anaerobic bacterial growth and DNA fingerprint spectrum was analyzed by randomly amplified polymorphic DNA technique. The transmembrane binding protein (occludin) and IgA levels in colon and terminal ileum were detected by immunohistochemistry method. The bacterial translocation rate and endotoxin level were also measured. The germ numbers of different species were both higher in PN+ EN and probiotic group than those in PN group. The bands of DNA fingerprint spectrum were significantly decreased in PN group, but the bands in both PN+ EN group and probiotic group were similar to that in the normal rats. The expression levels of occludin and IgA in the intestine and colorectum were higher in both PN+ EN group and probiotic group compared with those of PN group (P< 0.05, P< 0.01, respectively), the expression level of occludin was higher in probiotic group than that in PN+ EN group (P< 0.05). The overall bacterial translocation rates and endotoxin levels were significantly reduced in both probiotic and PN+ EN group (P< 0.05), but there was no difference between probiotic group and EN group. EN combined with probiotics can increase occluding and IgA expressions, improve the intestinal microecology,maintain the gut barrier function, and decrease the incidence of gut bacterial translocation.

Alterations of intestinal immune function and regulatory effects of L-arginine in experimental severe acute pancreatitis rats

To discuss the changes of intestinal mucosal immune function in rats with experimental severe acute pancreatitis (SAP) and the regulatory effect of L-arginine. Male adult Wistar rats were randomly divided into pancreatitis group, sham-operation group, and L-arginine treatment group. Animals were killed at 24, 48, and 72 h after SAP models were developed and specimens were harvested. Endotoxin concentration in portal vein was determined by limulus endotoxin analysis kit. CD3+, CD4+, CD8+ T lymphocytes in intestinal mucosal lamina propria were examined by immunohistochemistry. Secretory immunoglobulin A (SIgA) in cecum feces was examined by radioimmunoassay. Compared to the control group, plasma endotoxin concentration in the portal vein increased, percentage of CD3+ and CD4+ T lymphocyte subsets in the end of intestinal mucosal lamina propria reduced significantly, CD4+/CD8+ ratio decreased, and SIgA concentrations in cecum feces reduced at 24, 48, and 72 h after SAP developed. Compared to SAP group, the L-arginine treatment group had a lower level of plasma endotoxin concentration in the portal vein, a higher CD3+ and CD4+ T lymphocyte percentage in the end of intestinal mucosal lamina propria, an increased ratio of CD4+/CD8+ and a higher SIgA concentration in cecum feces. Intestinal immune suppression occurs in the early stage of SAP rats, which may be the main reason for bacterial and endotoxin translocation. L-arginine can improve the intestinal immunity and reduce bacterial and endotoxin translocation in SAP rats.