Rat Cecum Research Articles

Physical and biological properties of a novel anti-adhesive punctate uneven gelatin film.

Since abdominal adhesion are quite problematic in abdominal and pelvic surgery, the conventional HA/CMC film are commonly used as an anti-adhesive material. However, such types are difficult to be rolled and delivered through the port of laparoscopic surgical devices due to adherence to the laparoscopic port or other parts of the films. To create an anti-adhesion film with more favorable handling properties and anti-adhesive effect, we developed a novel punctate uneven gelatin film (PU GF). In this study, we examined the physical strength, flexibilities and adhesiveness between film to tissues or film each other, compared to the conventional film and the flat gelatin film (Flat GF). In addition, we investigated the cell proliferation on each film and the anti-adhesive effect of the films and those reattachment possibility using a rat cecum abrasion model. The PU GF showed excellent tensile strength, ductility, and adherence to tissue compared to Flat GF and the conventional film. Moreover, the adherence of PU GF to the other film and to a silicon sheet were much lower than those of the Flat GF and conventional film. The proliferation of cells in PU GF and Flat GF were suppressed compared with control, though increased with time. The anti-adhesive scores of the PU GF after one time and re-attachment were significantly higher than that of non-covered control, although there was no significant difference between that of the conventional film and control. Our findings suggest that PU GF improve handling properties of laparoscopic surgery as it has excellent physical strength, ductility, and adherence to tissue, and low adherence to trocar. In addition, the punctate film may be more useful with the re-attachability without tearing and to retained sufficient anti-adhesion effect.

Effects of 3,4-methylenedioxymethamphetamine on the gut microbiota and metabolites in the small intestine, cecum, and colon of male rats.

3,4-Methylenedioxymethamphetamine (MDMA; Ecstasy) is a widely abused recreational drug that has also gained interest for potential clinical applications in mental health. With the growing recognition of gut microbiota's role in mental health, this study examined whether repeated oral MDMA administration could affect gut microbiota in the small intestine, cecum, and colon of male rats. Repeated oral MDMA administration (10mg/kg/day for 14days) caused significant changes in the gut microbiota across these regions, with distinct effects observed in each. PICRUSt2 analysis revealed significant alterations in several metabolic pathways in these regions, indicating potential shifts in microbial functional capabilities associated with MDMA treatment. Untargeted metabolomics analysis revealed that MDMA significantly altered levels of two metabolites-ferulic acid and methylmalonic acid-in the colon, without changes in the blood, small intestine, or cecum. Notably, methylmalonic acid levels in the colon positively correlated with Lawsonibacter and Oscillibacter. These findings suggest that repeated oral MDMA treatment can alter gut microbiota composition across intestinal regions, potentially contributing to its pharmacological effects.

Anti-Bacterial Potential of Multi-strain Probiotics Lactiplantibacillus plantarum (Strain Dad-13 and FNCC-0250) and Lacticaseibacillus paracasei GMRMP-001 against Escherichia coli FNCC-0091 In Vitro and In Vivo

Lactiplantibacillus plantarum Dad-13, Lactiplantibacillus plantarum FNCC-0250 and Lacticaseibacillus paracasei GMRMP-001 are probiotics strain isolated from Indonesian local and traditional fermented foods. This study aims to evaluate the administration of multi-strain probiotics at dose of 109 CFU/mL/day for 14 days against the diarrhea-causing bacteria Escherichia coli FNCC-0091 at a dose of 1011 CFU/mL/day. Thirty rats were randomized and the divided into 5 groups, including control group, skim milk group, single-strain group, multi-strain group and E. coli group. Antibacterial activity was analyzed in vitro, feed intake, body weight were analyzed, microbial analysis was carried out on feces and cecum, short chain fatty acids were analyzed and intestinal morphology was measured. The result showed that the single-strain and multi-strain inhibition zone in in vitro test produces a very strong inhibitory potential (> 9 mm). The number of L. plantarum and L. paracasei increased and the number of E. coli decreased significantly in the feces and cecum of Rat indicating the survival rate of the probiotic bacteria in the digestive tract and their ability to fight pathogenic bacteria. The concentration of acetic acid, propionic acid and butyric acid compounds also increased, indicating that the digestive tract is at a low pH so that it can inhibit the growth of pathogenic bacteria in rats. In addition, consumption of multi-strain probiotics does not have a negative effect on intestinal morphology. The conclusion is that multi-strain probiotics are able to inhibit pathogenic bacteria in vivo and in vitro. HIGHLIGHTS Multi-strain probiotics isolated from traditional Indonesian fermented foods can reduce the potential for diarrhea. Single-strain and multi-strain have the same effectiveness in inhibiting pathogenic bacteria as seen from the growth of the bacteria. Digestive conditions were damaged in rat that were not given probiotic intervention, but when they received probiotic intervention, digestive conditions improved. GRAPHICAL ABSTRACT

Whole-body mass spectrometry imaging reveals the systemic metabolic disorder and catecholamines biosynthesis alteration on heart-gut axis in heart failure rat

IntroductionHeart failure (HF) is a systemic metabolic disorder disease, across multiorgan investigations advancing knowledge of progression and treatment of HF. Whole-body MSI provides spatiotemporal information of metabolites in multiorgan and is expected to be a potent tool to dig out the complex mechanism of HF. ObjectivesThis study aimed at exploring the systemic metabolic disorder in multiorgan and catecholamines biosynthesis alteration on heart-gut axis after HF. MethodsWhole-body MSI was used to characterize metabolic disorder of the whole rat body after HF. An integrated method by MSI, LC-MS/MS and ELISA was utilized to analyze key metabolites and enzymes on heart, small intestine, cecum and colon tissues of rat. Gut microbiota dysbiosis was investigated by 16S rDNA sequencing and metagenomic sequencing. Validation experiments and in vitro experiments were performed to verify the effect of catecholamines biosynthesis alteration on heart-gut axis after HF. ResultsWhole-body MSI exhibited varieties of metabolites alteration in multiple organs. Remarkably, catecholamine biosynthesis was significantly altered in the serum, heart and intestines of rats. Furthermore, catecholamines and tyrosine hydroxylase were obviously upregulated in heart and colon tissue. Turicibacter_sanguinis was relevant to catecholamines of heart and colon. Validation experiments demonstrated excessive norepinephrine induced cardio-intestinal injury, including significantly elevating the levels of BNP, pro-BNP, LPS, DAO, and increased the abundance of Turicibacter_sanguinis. These alterations could be reversed by metoprolol treatment blocking the effect of norepinephrine. Additionally, in vitro studies demonstrated that norepinephrine promoted the growth of Turicibacter_sanguinis and Turicibacter_sanguinis could import and metabolize norepinephrine. Collectively, excessive norepinephrine exerted bidirectional effects on cardio-intestinal function to participate in the progression of HF. ConclusionOur study provides a new approach to elucidate multiorgan metabolic disorder and proposes new insights into heart-gut axis in HF development.

Effect of Raw and Cooked Green Bananas on Cecal Fermentation Characteristics in Rats

AbstractRaw and cooked (autoclaved) green bananas are fed to rats for 4 weeks and their effects on cecal microbiota and biomarkers of fermentation are evaluated and compared with those of potato starch, which is rich in RS. Relative abundances of genera Lachnospiraceae_NK4A136_group and Roseburia, and species Bifidobacterium pseudolongum in rat cecum are higher in the raw green banana group with higher RS consumption than in the control group. The raw green banana group shows higher cecal acetate production and similarly high levels of cecal n‐butyrate production than that in the potato starch group. In the autoclaved green banana group, the cecal microbial composition is altered and the relative abundance of family Ruminococcaceae increased. Additionally, the molar proportion of n‐butyrate in the cecum of the autoclaved green banana group is higher than that in the control group. The levels of cecal mucin and IgA in the raw green banana and potato starch groups are found to be higher compared to those observed in the control and autoclaved green banana groups. Therefore, raw and autoclaved green bananas can alter cecal microbial composition and thus exhibit beneficial intestinal fermentation characteristics.

The Comparison of the Effects of Platelet Rich Plasma and Streptokinase on Intra-Abdominal Adhesion: In the Rat Cecum Model

The Comparison of the Effects of Platelet Rich Plasma and Streptokinase on Intra-Abdominal Adhesion: In the Rat Cecum Model

N-Succinylaspartic-Acid-Conjugated Riluzole Is a Safe and Potent Colon-Targeted Prodrug of Riluzole against DNBS-Induced Rat Colitis.

In our previous study, riluzole azo-linked to salicylic acid (RAS) was prepared as a colon-targeted prodrug of riluzole (RLZ) to facilitate the repositioning of RLZ as an anticolitic drug. RAS is more effective against rat colitis than RLZ and sulfasalazine, currently used as an anti-inflammatory bowel disease drug. The aim of this study is to further improve colon specificity, anticolitic potency, and safety of RAS. N-succinylaspart-1-ylRLZ (SAR) and N-succinylglutam-1-ylRLZ (SGR) were synthesized and evaluated as a "me-better" colon-targeted prodrug of RLZ against rat colitis. SAR but not SGR was converted to RLZ in the cecal contents, whereas both conjugates remained intact in the small intestine. When comparing the colon specificity of SAR with that of RAS, the distribution coefficient and cell permeability of SAR were lower than those of RAS. In parallel, oral SAR delivered a greater amount of RLZ to the cecum of rats than oral RAS. In a DNBS-induced rat model of colitis, oral SAR mitigated colonic damage and inflammation and was more potent than oral RAS. Moreover, upon oral administration, SAR had a greater ability to limit the systemic absorption of RLZ than RAS, indicating a reduced risk of systemic side effects of SAR. Taken together, SAR may be a "me-better" colon-targeted prodrug of RLZ to improve the safety and anticolitic potency of RAS, an azo-type colon-targeted prodrug of RLZ.

Obstructive Sleep Apnea-Induced Hypertension Is Associated With Increased Gut and Neuroinflammation.

Background Obstructive sleep apnea (OSA) is an independent risk factor for the development of hypertension. We have demonstrated that OSA induces gut dysbiosis, and this dysbiotic microbiota contributes to hypertension. However, the mechanisms linking gut dysbiosis to blood pressure regulation remain unclear. Recent studies demonstrate that gut dysbiosis can induce a proinflammatory response of the host resulting in peripheral and neuroinflammation, key factors in the development of hypertension. We hypothesized that OSA induces inflammation in the gut that contributes to neuroinflammation and hypertension. Methods and Results OSA was induced in 8-week-old male rats. After 2 weeks of apneas, lymphocytes were isolated from aorta, brain, cecum, ileum, mesenteric lymph node, and spleen for flow cytometry. To examine the role of interleukin-17a, a monoclonal antibody was administered to neutralize interleukin-17a. Lymphocytes originating from the gut were tracked by labeling with carboxyfluorescein succinimidyl ester dye. OSA led to a significant decrease in T regulatory cells along with an increase in T helper (TH) 17 cells in the ileum, cecum, and brain. Interleukin-17a neutralization significantly reduced blood pressure, increased T regulatory cells, and decreased TH1 cells in the ileum, cecum, and brain of OSA rats. TH1, TH2, and TH17 cells from the gut were found to migrate to the mesenteric lymph node, spleen, and brain with increased frequency in rats with OSA. Conclusions OSA induces a proinflammatory response in the gut and brain that involves interleukin-17a signaling. Gut dysbiosis may serve as the trigger for gut and neuroinflammation, and treatments to prevent or reverse gut dysbiosis may prove useful in reducing neuroinflammation and hypertension.

Feeding Australian Acacia Gums and Gum Arabic Leads to Non-Starch Polysaccharide Accumulation in the Cecum of Rats

Exudative gums from two Australian Acacia species (A. pycnantha and A. baileyana) and gum arabic (from A. senegal) were fed to rats at graded levels (0, 20, 40, 80 g/kg), replacing cellulose in purified diets containing cholesterol plus cholic acid. Compared with consumption of the control diet containing cellulose only, consumption of the gums had no significant effects on concentrations of plasma or liver cholesterol. Plasma triacylglycerol concentrations were higher in rats fed gum arabic, whereas liver triacylglycerols were lower in rats fed the gums. The gums did not affect the total pool of volatile fatty acids in the ceca, as compared with results in controls, but did promote the relative contribution of propionate at the expense of acetate. In rats fed the diet containing cellulose (80 g/kg) the proportions of cecal acetate:propionate:butyrate were 76:15:9, whereas in the rats fed A. pycnantha gum, gum arabic and A. baileyana gum (80 g/kg) the ratios were 42:54:4, 35:46:19 and 43:53:4, respectively. The low apparent fermentability of the gums was confirmed by the accumulation of non-starch polysaccharides in cecal digesta. In rats fed 80 g/kg A. pycnantha gum, 3.44 g of soluble non-starch polysaccharides was measured in the ceca, which was 58% of the dry weight of the cecal contents. We conclude that the biological activities of the Australian Acacia gums were similar to those of gum arabic and that these gums may have potential value as human food ingredients.

Fermentable Fibers or Oligosaccharides Reduce Urinary Nitrogen Excretion by Increasing Urea Disposal in the Rat Cecum

The availability of fermentable carbohydrates could influence the digestive degradation and disposal of blood urea. The effects of a poorly fermented cellulosic oat fiber, a soluble fermentable fiber (gum arabic) or one of two oligosaccharides (fructooligosaccharide or xylooligosaccharide) on nitrogen excretion were compared with a wheat starch-based control diet in male Wistar rats. The fibers and oligosaccharides were added to the semipurified diets at 7.5 g/100 g in place of wheat starch. The diets contained 13 g casein/100 g. Oat fiber did not cause an enlargement of the cecum. In contrast, gum arabic and the oligosaccharides elicited a 35–60% enlargement of the cecal wall and a 2 to 2.6-fold mean increase in the cecal pool of short chain fatty acids. Compared with rats fed the oat fiber-based diet, urea flux from blood to cecum was nearly 50% greater and more than 120% greater in those fed the gum arabic and oligosaccharide diets, respectively. In those groups, net nitrogen retention in the cecum more than doubled (nitrogen retention was calculated as the difference between net urea nitrogen flux into the cecum and ammonia nitrogen reabsorption). As a percentage of total excreted nitrogen, fecal nitrogen was 20% in the oat fiber group and 27–29% in the gum arabic and oligosaccharide groups, compared with only 10% in fiber-free controls. Results indicate that under these dietary conditions, the addition of oligosaccharides to the diet induced a 20 to 30% decrease in blood urea and renal nitrogen excretion relative to the control, indicating a potential for oligosaccharide diet therapy in chronic renal disease.

S-57-6: OBSTRUCTIVE SLEEP APNEA INDUCED GUT DYSBIOSIS STIMULATES A PROINFLAMMATORY RESPONSE THAT PROMOTES NEUROINFLAMMATION AND HYPERTENSION

Objective: Obstructive sleep apnea (OSA) is an independent risk factor for hypertension (HT). We have demonstrated that OSA induces gut dysbiosis, and a dysbiotic microbiota is causal in the development of HT. The mechanisms linking gut dysbiosis to blood pressure (BP) regulation are unclear. Recent studies demonstrate gut dysbiosis induces a pro-inflammatory host response resulting in peripheral- and neuro-inflammation, key factors in the development of HT. We hypothesized that OSA induced gut dysbiosis elicits a pro-inflammatory response that promotes neuroinflammation and HT. Methods: OSA was induced in 8-week-old male rats by repeatedly inflating a surgically implanted tracheal balloon. Sham rats underwent balloon implantation without inflations. After two weeks of apneas, lymphocytes were isolated from aorta, brain, cecum, ileum, mesenteric lymph node, and spleen for assessment by flow cytometry. In studies examining IL-17, a monoclonal antibody to neutralize IL-17 was injected every 48 hours during the 2 weeks of OSA. To track lymphocytes originating from the gut, cells in the Peyers patches of the small intestine were labelled by injection of carboxyfluorescein succinimidyl ester (CFSE) dye. Results: Two weeks of OSA significantly decreased anti-inflammatory regulatory T (Treg) cells and increased TH17 (IL-17+) in the brain, cecum, and ileum (n = 7, p < 0.05). A significant increase in the Th17/Treg ratio was observed in brain, cecum and ileum of OSA, versus sham, rats (n = 7, p < 0.05). To examine the role of TH17 cells, we injected an IL-17 neutralizing antibody or control IgG antibody during the 2 weeks of OSA. Compared to OSA rats receiving IgG control, neutralization of IL-17 significantly reduced BP of OSA rats (n = 6, p < 0.05). Additionally, neutralization of IL-17 resulted in a significant increase of Tregs and decreased Th1 cells in brain, cecum and ileum of OSA rats (n = 6, p < 0.01). To examine the distribution of lymphocytes originating from the gut, cells in the Peyers patches of sham and OSA rats were labelled with CFSE. We observed significant increases in CFSE+ Th1, Th2, and Th17 cells in the brain, MLN and spleen of OSA as compared to sham rats (n = 6, p < 0.05). Conclusion: Overall, we found that OSA induced gut dysbiosis is associated with a pro-inflammatory response in the gut and brain that involves IL-17 signaling. Our findings suggest that gut dysbiosis may serve as the trigger for widespread inflammation, and treatment strategies to prevent or reverse gut dysbiosis may prove useful in reducing neuroinflammation and HT.

Induction mechanism of cigarette smoke components (CSCs) on dyslipidemia and hepatic steatosis in rats

ObjectiveThe purpose of this study was to explore the effect of cigarette smoke component (CSC) exposure on serum lipid levels in rats and the underlying molecular mechanism.MethodsMale SPF-grade SD rats were randomly divided into a control group and a CSC exposure group, with the CSC group being exposed to CSC for 6 weeks. RT–PCR and Western blotting methods were used to detect lipid metabolism gene expression in rats, and 16S RNA gene sequencing was used to detect the gut microbiota in the rat cecum. Rat serum exosomes were prepared and identified, and the interaction of exosomal miR-291a-3p and miR-126a-5p with AMPK and CYP7A1 was detected by a dual luciferase reporter gene assay (DLRG).ResultsSerum indicators, including cholesterol levels and trimethylamine oxide (TMAO) content, were significantly affected in the CSC exposure group compared with the control group (P < 0.05), and the expression levels of adenylate-activated protein kinase (AMPK), acetyl-coenzyme A carboxylase (ACC) and HMG-CoA reductase (HMG-CoAR) genes were significantly increased (P < 0.05) in the liver, while the expression level of cholesterol 7α-hydroxylase (CYP7A1) was markedly decreased (P < 0.01). 16S rRNA gene sequencing of the gut microbiota in the rat cecum showed that the abundance of Firmicutes in the CSC group increased significantly at the phylum level, while the abundances of Bacteroidota and Spirochaetota were reduced significantly (P < 0.01). The relative abundance of Romboutsia, Turicibacter, and Clostridium sensu stricto increased significantly (P < 0.01), and the relative abundance of Prevotella, Muribaculaceae_norank, Lachnospiraceae NK4A136 group, Roseburia, Treponema, and Ruminococcus significantly decreased (P < 0.01) at the genus level. In addition, the exosome miR-291a-3p and miR-126a-5p levels were markedly regulated by CSC exposure (P < 0.01). The interactions of miR-291a-3p and miR-126a-5p with AMPK and CYP7A1 mRNA were also validated by the DLRG method.ConclusionsIn summary, the rat dyslipidemia induced by CSC exposure may be related to the interference of gut microbiota structure and interaction of miRNAs from serum exosomes with target mRNAs, which further regulated AMPK-ACC/CYP7A1 signaling in rats.

Abstract 095: Obstructive Sleep Apnea Induced Gut Dysbiosis Stimulates A Proinflammatory Response In Gut And Brain That Contribute To Hypertension

Objective: Obstructive sleep apnea (OSA) is an independent risk factor for the development of hypertension (HT). OSA induces gut dysbiosis, and a dysbiotic microbiota is causal in the development of HT. The mechanisms linking gut dysbiosis to blood pressure (BP) regulation remain unclear. Gut dysbiosis can induce a pro-inflammatory response of the host resulting in peripheral- and neuro-inflammation, key factors in the development of HT. We hypothesized that OSA induced gut dysbiosis elicits a pro-inflammatory response that promotes neuroinflammation and HT. Methods: OSA was induced in 8-week-old male rats (60 apneas/hr for 8 hrs during sleep) by inflating a tracheal balloon. Sham rats underwent balloon implantation without inflations. After 2 weeks of apneas, lymphocytes were isolated from brain, cecum, ileum, mesenteric lymph node (MLN), and spleen for flow cytometry. The role of IL-17 was tested by treating rats with a monoclonal antibody to IL-17 to neutralize circulating IL-17. To track the distribution of lymphocytes originating from the gut, cells in the Peyer’s patches of the small intestine were labelled by injection of carboxyfluorescein succinimidyl ester (CFSE) dye. Results: Following 2 weeks of OSA we found a significant decrease in anti-inflammatory regulatory T (Treg) cells along with an increase in T H 17 (IL-17+) in the brain, cecum, and ileum (n=7, p&lt;0.05 for each). To examine the role of T H 17, we injected an IL-17 neutralizing antibody or control IgG during the 2 weeks of OSA. Compared to OSA rats receiving IgG control, neutralization of IL-17 significantly reduced BP of OSA rats (n=6, p&lt;0.05). IL-17 neutralization also resulted in a significantly increased Tregs and decreased Th1 cells in brain, cecum and ileum of OSA rats (n=6, p&lt;0.01 for each). To examine the distribution of lymphocytes originating from the gut, cells in the Peyer’s patches were labelled with CFSE. We observed significant increases in CFSE+ Th1, Th2, and Th17 cells in the brain, MLN and spleen of OSA as compared to sham rats (n=6, p&lt;0.05). Conclusion: OSA induced gut dysbiosis is associated with a pro-inflammatory response in the gut and brain that involves IL-17 signaling. Treatment strategies to prevent gut dysbiosis may prove useful in reducing neuroinflammation and HT.

Olanzapine-induced lipid disturbances: A potential mechanism through the gut microbiota-brain axis.

Objective: Long-term use of olanzapine can induce various side effects such as lipid metabolic disorders, but the mechanism remains to be elucidated. The gut microbiota-brain axis plays an important role in lipid metabolism, and may be related to the metabolic side effects of olanzapine. Therefore, we explored the mechanism by which olanzapine-induced lipid disturbances through the gut microbiota-brain axis. Methods: Sprague Dawley rats were randomly divided into two groups, which underwent subphrenic vagotomy and sham surgery. Then the two groups were further randomly divided into two subgroups, one was administered olanzapine (10 mg/kg/day) by intragastric administration, and the other was administered normal saline by intragastric administration (4 ml/kg/day) for 2 weeks. The final changes in lipid parameters, gut microbes and their metabolites, and orexin-related neuropeptides in the hypothalamus were investigated among the different groups. Results: Olanzapine induced lipid disturbances as indicated by increased weight gain, elevated ratio of white adipose tissue to brown adipose tissue, as well as increased triglyceride and total cholesterol. Olanzapine also increased the Firmicutes/Bacteroides (F/B) ratio in the gut, which was even aggravated by subphrenic vagotomy. In addition, olanzapine reduced the abundance of short-chain fatty acids (SCFAs) metabolism related microbiome and 5-hydroxytryptamine (5-HT) levels in the rat cecum, and increased the gene and protein expression of the appetite-related neuropeptide Y/agouti-related peptide (NPY/AgRP) in the hypothalamus. Conclusion: The abnormal lipid metabolism caused by olanzapine may be closely related to the vagus nerve-mediated gut microbiota-brain axis.

Casein and red meat proteins differentially affect the composition of the gut microbiota in weaning rats

Casein and meat are food sources providing high-quality animal proteins for human consumption. However, little is known concerning potentially different effects of these animal protein sources during early stages of life. In the present study, casein and red meat proteins (beef and pork) were fed to young postweaning rats for 14 days based on the AIN-93G diet formula. Casein and red meat protein-based diets did not differentially affect the overall growth performance. However, they discriminately modulated the abundances of different potentially beneficial bacteria belonging to genus Lactobacillus. Intake of the casein-based diet increased the intestinal abundance of Lactococcus lactis with a pronounced potential for galactose utilization via the Tag6P pathway, and it also resulted in lower amounts of toxic ammonia in the rat cecum compared to red meat protein-based diets. We observed no adverse effects on colonic tissue in response to any of the protein-based diets based on histological observations.

Obstructive Sleep Apnea Induced Gut Dysbiosis Stimulates a Proinflammatory Response that Promotes Neuroinflammation and Hypertension Sriram Ayyaswamy, Bojun Zhang, Huanan Shi, Sharon Phillips, Robert Bryan and David Durgan Baylor College of Medicine, Department of Anesthesiology, Houston, Texas, United States

Background and HypothesisObstructive sleep apnea (OSA) is an independent risk factor for the development of hypertension (HT). We have previously demonstrated that OSA induces gut dysbiosis, and a dysbiotic microbiota is causal in the development of HT. However, the mechanisms linking gut dysbiosis to blood pressure (BP) regulation are unclear. Recent studies have demonstrated that gut dysbiosis can induce a pro‐inflammatory response of the host resulting in peripheral‐ and neuro‐inflammation, key factors in the development of HT. We therefore hypothesized that OSA induced gut dysbiosis elicits a pro‐inflammatory response that promotes neuroinflammation and hypertension.MethodsOSA was induced in 8‐week‐old male rats (60 apneas/hour for 8 hours during the sleep phase) by repeatedly inflating a surgically implanted tracheal balloon. Sham rats underwent balloon implantation without inflations. After two weeks of apneas, lymphocytes were isolated from aorta, brain, cecum, ileum, mesenteric lymph node, and spleen for assessment by flow cytometry. In studies examining the role of IL‐17, a monoclonal antibody to IL‐17 was injected every 48 hours during the 2 weeks of apneas to neutralize circulating IL‐17. To track the distribution of lymphocytes originating from the gut, cells in the Peyer’s patches of the small intestine were labelled by microinjection of carboxyfluorescein succinimidyl ester (CFSE) dye.Summary of resultsFollowing 2 weeks of OSA we found a significant decrease in anti‐inflammatory regulatory T (Treg) cells along with an increase in TH17 (IL‐17+) in the brain, cecum, and ileum and TH1 (IFN‐γ+) in cecum and ileum (n=7, p&lt;0.05 for each). A significant increase in the Th17/Treg ratio, a sign of inflammation associated with hypertension, was observed in brain, cecum and ileum of OSA, versus sham, rats (n=7, p&lt;0.05 for each). To examine the role of TH17 cells, we injected an IL‐17 neutralizing antibody or control IgG antibody during the 2 weeks of OSA. Compared to OSA rats receiving IgG control, neutralization of IL‐17 significantly reduced BP of OSA rats after 1 and 2 weeks (n=6, p&lt;0.05 for each). Additionally, neutralization of IL‐17 resulted in a significant increase of Tregs and decreased Th1 cells and TNFα expressing cells in brain, cecum and ileum of OSA rats (n=6, p&lt;0.01 for each). To examine the distribution of lymphocytes originating from the gut, cells in the Peyer’s patches of sham and OSA rats were labelled with CFSE. We observed significant increases in CFSE+ Th1, Th2, and Th17 cells in the brain, MLN and spleen of OSA as compared to sham rats (n=6, p&lt;0.05).ConclusionOverall, we found that OSA induced gut dysbiosis is associated with a pro‐inflammatory response in the gut and brain that involves IL‐17 signaling. Our findings suggest that gut dysbiosis may serve as the trigger for widespread inflammation, and treatment strategies to prevent or reverse gut dysbiosis may prove useful in reducing neuroinflammation and HT.

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.

ОСОБЕННОСТИ ГИСТОЛОГИЧЕСКОГО СТРОЕНИЯ СЛЕПОЙ КИШКИ И ЧЕРВЕОБРАЗНОГО ОТРОСТКА КРЫСЫ И ЧЕЛОВЕКА В СРАВНИТЕЛЬНОМ АСПЕКТЕ

Background. In recent years, there have emerged new directions in the study of the histological structure of the digestive tract in humans and mammals and, in particular, white rats, since non-inbred white rats are the main model for reproducing human pathology under experimental conditions as well as for preclinical testing of new drugs. Objective. A comparative study of the histological features of the cecum and appendix in rats and humans by means of bibliographic analysis. Material and methods. Bibliographic analysis is based on published peer-reviewed articles, books, textbooks, monographs, dissertation abstracts. For the purposes of a systematic review, the literature search (concerning the study of the histological structure of the cecum and appendix) was carried out on the Internet, in native literature sources, the scientific and electronic library of Poltava State Medical University using the following keywords: “histology”, “microscopic structure”, "digestive system", "cecum", "appendix", "white rats", "rat anatomy". Results. The mucous membrane of the gastrointestinal tract of white rats, in terms of its histological structure, is similar enough to that of humans to serve as an object in the experimental modeling of certain pathological conditions of the digestive system. Conclusions. There has been found an increased concentration of lymphoid nodules in cecal mucosa of white rats. In white rats and humans, the cecum and the appendix in humans are endowed with the same immune defense structures, which together represent the immune system of the digestive tract mucosa.

Development of a 3D-Printed High Temperature Resin Cecal Fistula Implant for Long-Term and Minimally Invasive Access to the Gut Microbiome

Microbiota dysbiosis has been associated with chronic diseases ranging from gastrointestinal inflammatory and metabolic conditions to neurological changes affecting the gut-brain neural axis, mental health, and general well-being. However, current animal studies using oral gavage and gnotobiotic animals do not allow for non-invasive long-term access to gut microbiome. The purpose of the present study was to evaluate the feasibility of 3D-printed fistula implants through the body wall and into the cecum of rats to obtain long-term access to gut microbiome. Cecal fistulas were designed and 3D-printed using a high temperature resin (Formlabs; acrylic and methacrylic mixture). Nine male Sprague-Dawley rats underwent the fistula implantation. Food intake, body weight, and body fat were measured to determine the impact of fistula manipulation. Gut microbiome, vagal afferents in the hindbrain, and microglia activation were analyzed to determine if fistula implantation disrupted the gut-brain neural axis. We found that the procedure induced a transient decrease in microbial diversity in the gut that resolved within a few weeks. Fistula implantation had no impact on food intake, body weight, fat mass, or microglia activation. Our study shows that 3D-printed cecal fistula implantation is an effective procedure that allows long-term and minimally invasive access to gut microbiome.

Influence of Prebiotic Activity of Agave salmiana Fructans on Mucus Production and Morphology Changes in Colonic Epithelium Cell of Healthy Wistar Rats.

The beneficial health of evaluating prebiotic effect by the consumption of Agave salmiana fructans (A. salmiana fructans) was assessed in the epithelium of the cecum and proximal colon of Wistar rats fed at different doses for 35 days with regards to mucus production, morphological cell changes, and the serum concentration of tumor necrosis factor-α (TNF-α). Results showed a significant increase in mucus-secreting cells (P < 0.05) and a normal structure with preserved crypts, without morphological damage to colonic cells for a dose of 12.5% (w/w) with respect to the control and the other doses evaluated. The concentration of pro-inflammatory cytokine TNF-α was decreased significantly (P < 0.05) in the groups with doses of 10 and 12.5% (w/w) at 7 and 35 days, respectively. This effect was positively correlated with the reduction of inflammation in epithelial cells. This study provides direct evidence of the effects of the A. salmiana fructans on the colonic epithelium, demonstrating that a diet supplemented with 12.5% of fructans for 35 days exerts health benefits through the strengthening of the mucosa layer, which favors the adherence of the bacterial population and suppresses inflammation.