Rat Gut Research Articles

Yeast Extract Peptides Alleviate Depression in Chronic Restraint Stress Rats by Alleviating Hippocampal Neuronal Apoptosis and Dysbiosis of the Gut Microbiota.

Depression as a global neurological disorder, and hippocampal neuronal apoptosis and disorders of the gut microbiota are closely related to it. This study aims to expose the ameliorative effect of enzyme peptides (AP) from brewer's yeast on depressive behavior caused by chronic restraint stress (CRS) in rats. After 4 weeks of AP intervention, a significant alleviation of depressive behavior in the sucrose preference test (SPT), forced swim test (FST), and light-dark test (LDT) is observed in depressed rats. AP ameliorates neuronal damage with increased the expression of the key CREB/BDNF/TrkB/Akt signaling pathway, which increases the levels of the monoamine neurotransmitters 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in the hippocampus, buffering hyperactivity of the hypothalamo-pituitary-adrenal axis (HPA), and decreasing the serum cortisol (CORT) and adrenocorticotropic hormone (ACTH) levels in rats. In addition, AP modulates the disruption of the rat gut microbiota by chronic restraint stress (CRS), and the changes in the abundance of Lactobacillus animalis and Lactobacillus johnsonii are probably the key for AP performing antidepressant benefits. A strong correlation is found between gut microbiota and biochemical markers of depression. AP, as a natural and safe active substance, has a positive effect in the treatment of depression.

Relationship of Salmonella Typhimurium 14028 strain and its dam and seqA mutants with gut microbiota dysbiosis in rats.

Introduction. Disruptions in gut microbiota, known as dysbiosis, have been increasingly linked to pathogenic infections, with Salmonella Typhimurium being a notable contributor to these disturbances.Hypothesis. We hypothesize that the S. Typhimurium 14028 WT strain induces significant dysbiosis in the rat gut microbiota and that the dam and seqA genes play crucial roles in this process.Aim. In this study, it was aimed at investigating the dysbiotic activity of the S. Typhimurium 14028 WT strain on the rat gut microbiota and the roles of dam and seqA genes on this activity.Method. Changes in the rat gut microbiota were determined by examining the anal swap samples taken from the experimental groups of these animals using 16S rRNA high-throughput sequencing technology.Results. In the experimental groups, the dominant phyla were determined to be Firmicutes and Bacteroidetes (P<0.05). However, while the rate of Bacteroidetes was significantly reduced in those treated with the WT and seqA mutants, no significant difference was observed in the dam mutant compared to the control group (P<0.05). In all experimental animals, the dominant species was determined to be Prevotella copri, regardless of the experiment time and application. The analysis results of the samples taken on the third day from the rat groups infected with the S. Typhimurium 14028 WT strain (W2) presented the most striking data of this study.Conclusion. Through distance analysis, we demonstrated that a successful Salmonella infection completely changes the composition of the microbiota, dramatically reduces species diversity and richness in the microbiota and encourages the growth of opportunistic pathogens.

The Effects of 1-Kestose on the Abundance of Inflammation-Related Gene mRNA in Adipose Tissue and the Gut Microbiota Composition in Rats Fed a High-Fat Diet.

Chronic inflammation in adipose tissue is thought to contribute to insulin resistance, which involves the gut microbiota. Our previous studies have demonstrated that ingestion of 1-kestose can alter the gut microbiota composition, increase cecal butyrate levels, and improve insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Additionally, we found that 1-kestose supplementation ameliorated insulin resistance in obese rat models fed a high-fat diet (HFD), although the effects of 1-kestose on the abundance of inflammation-related gene in adipose tissue and gut microbiota composition in these rats were not explored. This study aimed to investigate the impact of 1-kestose on these parameters in HFD-fed rats, compared to OLETF rats. Male Sprague-Dawley rats were divided into two dietary groups, control or HFD, for 19 wk. Each group was further subdivided to receive either tap water or tap water supplemented with 2% (w/v) 1-kestose throughout the study. We evaluated gene expression in adipose tissue, as well as short-chain fatty acids (SCFAs) levels and microbial composition in the cecum contents. 1-Kestose intake restored the increased relative abundance of tumor necrosis factor (Tnf) mRNA in adipose tissue and the reduced level of butyrate in the cecum contents of HFD-fed rats to those observed in control diet-fed rats. Additionally, 1-kestose consumption changed the composition of the gut microbiota, increasing Butyricicoccus spp., decreasing UGC-005 and Streptococcus spp., in the cecum contents of HFD-fed rats. Our findings suggest that 1-kestose supplementation reduces adipose tissue inflammation and increases butyrate levels in the gut of HFD-fed rats, associated with changes in the gut microbiota composition, distinct from those seen in OLETF rats.

An in situ bioadhesive foam as a large intestinal delivery platform for antibody fragment to treat inflammatory bowel disease

Biologics have been widely used as injectables in the treatment of inflammatory bowel disease (IBD). Different local treatment attempts have been developed in recent years. However, maintaining systemic levels of biologics is still crucial for achieving colitis remission. An equilibrium between systemic and local concentrations of biologics is therefore essential for treatment of colitis. Current formulations struggle to create optimal balance between drug concentrations in plasma and the colonic wall. Addressing this challenge, we developed a rectally delivered in situ foam that generates CO2via a reaction between potassium bicarbonate (PB) and citric acid (CA) without the aid of an external device. An anti-TNF-α antibody fragment (Fab) was loaded into the foam formulation, which promoted prolonged colon retention and improved Fab distribution up to proximal colon following rectal administration to mice. In addition, we observed increased plasma Fab concentrations in mice receiving the rectal Fab foam compared to a Fab solution. In a non-everted rat gut ex vivo model, a single exposure to the CO2-containing foam improved macromolecule transepithelial flux across colonic tissue by over ten-fold. Foam efficacy for Fab was investigated in a range of colitis mouse models, from acute to chronic. This non-invasive formulation platform demonstrates potential to overcome existing limitations in delivering biologics to inflamed colonic tissue.

Somatostatin-immunoreactive neurons of the rat gut during the development.

Somatostatin (SST) is a peptide expressed in the peripheral and central nervous systems, as well as in endocrine and immune cells. The aim of the current study is to determine the percentage of SST immunoreactive (IR) neurons and their colocalization with choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), neuropeptide Y (NPY), and glial fibrillary acidic protein (GFAP) in the myenteric plexus (MP) and submucous plexus (SP) of the small intestine (SI) and large intestine (LI) of rats across different age groups from newborn to senescence using immunohistochemistry. In the MP of the SI and LI, the percentage of SST-IR neurons significantly increased during early postnatal development from 12 ± 2.4 (SI) and 13 ± 3.0 (LI) in newborn rats to 23 ± 1.5 (SI) and 18 ± 1.6 (LI) in 20-day-old animals, remaining stable until 60days of age. The proportion of SST-IR cells then decreased in aged 2-year-old animals to 14 ± 2.0 (SI) and 10 ± 2.6 (LI). In the SP, the percentage of SST-IR neurons significantly rose from 22 ± 3.2 (SI) and 23 ± 1.7 (LI) in newborn rats to 42 ± 4.0 in 20-day-old animals (SI) and 32 ± 4.9 in 30-day-old animals (LI), before declining in aged 2-year-old animals to 21 ± 2.6 (SI) and 28 ± 7.4 (LI). Between birth and 60days of age, 97-98% of SST-IR neurons in the MP and SP colocalized with ChAT in both plexuses of the SI and LI. The percentage of SST/ChAT neurons decreased in old rats to 85 ± 5.0 (SI) and 90 ± 3.8 (LI) in the MP and 89 ± 3.2 (SI) and 89 ± 1.6 (LI) in the SP. Conversely, in young rats, only a few SST-IR neurons colocalized with nNOS, but this percentage significantly increased in 2-year-old rats. The percentage of SST/NPY-IR neurons exhibited considerable variation throughout postnatal development, with no significant differences across different age groups in both the MP and SP of both intestines. No colocalization of SST with GFAP was observed in any of the studied animals. In conclusion, the expression of SST in enteric neurons increases in young rats and decreases in senescence, accompanied by changes in SST colocalization with ChAT and nNOS.

A novel Bacillus aerolatus CX253 attenuates inflammation induced by Streptococcus pneumoniae in childhood and pregnant rats by regulating gut microbiome

Streptococcus pneumoniae (Spn) is the predominant pathogen responsible for community-acquired pneumonia (CAP) in children under five years old, and it can induce over 17% of pregnant women. However, no more effective measures exist to prevent infection induced by Spn in these two special populations. The beneficial microbes can antagonize Spn and provide new targets for preventing pneumococcal infections. This study used 16S rRNA gene sequencing and targeted metabolomics to evaluate the role of the Bacillus aerolatus CX253 (CX253) in alleviating Spn infection. Additionally, the colonization of CX253 was observed in nose, trachea, and lung by using confocal laser scanning microscopy and fluorescent labeling techniques. Compared with the model group, the expression level of interleukin-1β was dropped 1.81-fold and 2.22-fold, and interleukin-6 was decreased 2.39-fold and 1.84-fold. The express of tumor necrosis factor-α was down 2.30-fold and 3.84-fold in prevention group of childhood and pregnant rats, respectively. The 16S rRNA sequencing results showed that CX253 administration alone significantly increased the abundance of Lactobacillus, Limosilactobacillus, and Prevotella in the gut of childhood and pregnant rats. Furthermore, the CX253 increased propionate in the gut of childhood rats and increased propionate and butyrate in the gut of pregnant rats to inhibit pulmonary inflammation. In summary, CX253 attenuated Spn-induced inflammation by regulating the gut microbiota and SCFAs. The research provides valuable information for the prevention of pneumonia.Graphical

Modified Zhizhu Pill improves the loperamide-induced slow transit constipation via gut microbiota and neurotransmitters in microbiota-gut-brain axis

BackgroundSlow-transmission constipation is a type of intractable constipation with unknown etiology and unclear pathogenesis. ObjectiveThe intention of this study was to evaluate the therapeutic effect and possible mechanism of Modified Zhizhu Pills on loperamide-induced slow transit constipation. MethodsThe effects of the Modified Zhizhu Pill were evaluated in a rat model of constipation induced by subcutaneous administration of loperamide. Fecal parameters (fecal count, fecal water content, and fecal hardness) were measured in constipated rats. The substance, target, and pathway basis of the Modified Zhizhu Pill on constipation was investigated using network pharmacology. The microflora in rats was determined. Serum neurotransmitters (acetylcholine and 5-hydroxytryptamine) were measured in rats and their relationship with the gut microbiota was assessed. ResultsModified Zhizhu Pill increased the number of bowel movements and fecal water content, and decreased fecal hardness and transit time. Network pharmacological analysis showed that Modified Zhizhu Pill can target multiple constipation-related targets and pathways through multiple potential active ingredients. Modified Zhizhu Pill alleviated loperamide-induced microbiota dysbiosis. Modified Zhizhu Pill increased serum 5-hydroxytryptamine and acetylcholine. The increase in serum 5-hydroxytryptamine and acetylcholine was associated with rat gut microbiota. ConclusionThese results suggest that Modified Zhizhu Pill may increase intestinal motility and ultimately relieve constipation by improving microecological dysbiosis and neurotransmission.

METTL3 Promotes Nucleus Pulposus Cell Senescence in Intervertebral Disc Degeneration by Regulating TLR2 m6A Methylation and Gut Microbiota.

Nucleus pulposus cell (NPC) senescence in intervertebral disc (IVD) tissue is the major pathological cause of intervertebral disc degeneration (IDD). N6-methyladenosine (m6A) methylation and gut microbiota play important roles in the progression of IDD. This study investigated whether methyltransferase-like 3 (METTL3) regulates TLR2 m6A modification and gut microbiota to influence NPC senescence. An IDD rat model was established by lumbar IVD puncture and NPCs were challenged with IL-1β to mimic IVD injury. IDD rats and IL-1β-exposed NPCs were treated with METTL3-interfering lentivirus and the TLR2 agonist Pam3CSK4. Compositional changes in the rat gut microbiota were analyzed and fecal microbiota transplantation procedures were used. NPC senescence, cell cycle, and the expression of senescence-associated secretory phenotype (SASP) factors were assessed. The m6A enrichment of TLR2 and the binding of IGF2BP1 to TLR2 mRNA were examined. METTL3 and TLR2 were highly expressed in IDD rats. METTL3 silencing attenuated senescent phenotypes and reduced secretion of SASP factors. Pam3CSK4 reversed the beneficial effects of METTL3 silencing on NPC senescence and IVD injury. METTL3 stabilized TLR2 mRNA in an IGF2BP1-dependent manner. METTL3 silencing restored specific gut microbiota levels in IDD rats, which was further reversed by administration of Pam3CSK4. Fecal microbiota from METTL3 silenced IDD rats altered the pathological phenotypes of IDD rats. These results demonstrate the beneficial effects of METTL3 silencing on NPC senescence and amelioration of IVD injury, involving modulation of TLR2 m6A modification and gut microbiota. These findings support METTL3 silencing as a potential therapeutic target for IDD.

Controlled dual release of phenol compounds from phospholipid complexes of short-chain lipophenols

Ethanol evaporation method was applied to synthesize phospholipid complexes from phosphatidylcholine (PC) and short-chain alkyl gallates (A-GAs, a typical representative of lipophenols) including butyl-, propyl- and ethyl gallates. 1H NMR, UV and FTIR showed that A-GAs were interacted with PC through weak physical interaction. Through the analysis of concentrations of A-GAs and gallic acid (GA) by an everted rat gut sac model coupled with HPLC-UV detection, phospholipid complexes were found to gradually release A-GAs. These liberated A-GAs were further hydrolyzed by intestinal lipases to release GA. Both of GA and A-GAs could cross intestinal membrane. Especially, the transmembrane A-GAs could also be hydrolyzed to produce GA. Undoubtedly, the dual release of phenol compounds from phospholipid complexes of short-chain lipophenols will be effective to extend the in vivo residence period of phenol compounds. More importantly, such behavior is easily adjusted by changing the acyl chain lengths of lipophenols in phospholipid complexes.

Exploring the gut microbiota mediated biotransformation of Senecio scandens Buch.-Ham.: Insights from metabolite spectrum with UHPLC-Q-Orbitrap HRMS and bioinformatics analysis of gut microbiota metabolites

Senecio scandens Buch.-Ham., a traditional Chinese medicine commonly used clinically, exhibits various pharmacological properties, including anti-inflammatory, anti-tumor, antiviral, and antibacterial activities. However, its water extracts' chemical components and metabolites are inadequately understood, limiting further research. In this study, the chemical components and metabolism processes of Senecio scandens, both in vivo (plasma, feces, urine, and bile) and in vitro (gut microbiota and liver microsomes), were characterized based on ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry. Additionally, metabolites detectable in fecal samples and intestinal microbiota incubated but absent in liver microsomes were identified as characteristic metabolites of intestinal microbiota. The targets of the characteristic metabolites of intestinal microbiota were collected, followed by exploration of potential pathways through KEGG enrichment analysis. As a result, a total of 133 chemical components were preliminarily identified, including 35 organic acids, 21 alkaloids, 19 flavonoids and their glycosides, 17 phenylpropanoids, 10 jacaranda ketones, and 31 other compounds. Notably, 12 of these were potentially novel compounds. In addition, 39 prototype components in rats and 109 metabolites were identified and characterized, including 102 in vivo and 52 metabolites in vitro (51 in rat gut microbiota and 24 in rat liver microsomes). The main metabolic pathways include oxidation, reduction, hydrolysis, methylation, glucuronidation, sulfonation, and acetylation reactions. Furthermore, KEGG enrichment analysis revealed that the characteristic metabolites of intestinal microbiota may be related to the ErbB, FoxO, mTOR, and MAPK signaling pathways, exhibiting anti-inflammatory and anti-tumor effects. In summary, the chemical components and metabolites of Senecio scandens were comprehensively identified using a rapid and accurate method, providing a scientific basis for the in-depth study of the material basis and its clinical application of Senecio scandens.

Chronic exposure to tris(1,3-dichloro-2-propyl) phosphate: Effects on intestinal microbiota and serum metabolism in rats

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate ester that can adversely affect animal or human health. The intestinal microbiota is critical to human health. High-dose exposure to TDCIPP can markedly affect the intestinal ecosystem of mice, but the effects of long-term exposure to lower concentrations of TDCIPP on the intestinal flora and body metabolism remain unclear. In this study, TDCIPP was administered to Sprague–Dawley rats by gavage at a dose of 13.3 mg/kg bw/day for 90 days. TDCIPP increased the relative weight of the kidneys (P = 0.017), but had no effect on the relative weight of the heart, liver, spleen, lungs, testes, and ovaries (P > 0.05). 16 S rRNA gene sequencing revealed that long-term TDCIPP exposure affected the diversity, relative abundance, and functions of rat gut microbes. The serum metabolomics of the rats showed that TDCIPP can disrupt the serum metabolic profiles, result in the up-regulation of 26 metabolites and down-regulation of 3 metabolites, and affect multiple metabolic pathways in rat sera. In addition, the disturbed genera and metabolites were correlated. The functions of some disturbed gut microbes were consistent with the affected metabolic pathways in the sera, and these metabolic pathways were all associated with kidney disease, suggesting that TDCIPP may cause kidney injury in rats by affecting the intestinal flora and serum metabolism.

Hyperbaric Oxygen Therapy Reduces the Traumatic Brain Injury-Mediated Neuroinflammation Through Enrichment of Prevotella Copri in the Gut of Male Rats.

Gastrointestinal dysfunction frequently occurs following traumatic brain injury (TBI) and significantly increases posttraumatic complications. TBI can lead to alterations in gut microbiota. The neuroprotective effects of hyperbaric oxygen (HBO) have not been well recognized after TBI. The study''s aim was to investigate the impact of HBO on TBI-induced dysbiosis in the gut and the pathological changes in the brain following TBI. Anesthetized male Sprague-Dawley rats were randomly assigned to three groups: sham surgery plus normobaric air (21% oxygen at 1 atmospheres absolute), TBI (2.0atm) plus normobaric air, and TBI (2.0atm) plus HBO (100% oxygen at 2.0 atmospheres absolute) for 60min immediately after TBI, 24h later, and 48h later. The brain injury volume, tumor necrosis factor-α expression in microglia and astrocytes, and neuronal apoptosis in the brain were subsequently determined. The V3-V4 regions of 16S ribosomal rRNA in the fecal samples were sequenced, and alterations in the gut microbiome were statistically analyzed. All parameters were evaluated on the 3rd day after TBI. Our results demonstrated that HBO improved TBI-induced neuroinflammation, brain injury volume, and neuronal apoptosis. HBO appeared to increase the abundance of aerobic bacteria while inhibiting anaerobic bacteria. Intriguingly, HBO reversed the TBI-mediated decrease in Prevotella copri and Deinococcus spp., both of which were negatively correlated with neuroinflammation and brain injury volume. TBI increased the abundance of these gut bacteria in relation to NOD-lik0065 receptor signaling and the proteasome pathway, which also exhibited a positive correlation trend with neuro inflammation and apoptosis. The abundance of Prevotella copri was negatively correlated with NOD-like receptor signaling and the Proteasome pathway. Our study demonstrated how the neuroprotective effects of HBO after acute TBI might act through reshaping the TBI-induced gut dysbiosis and reversing the TBI-mediated decrease of Prevotella copri.

Modulation of the rat intestinal microbiota in the course of Anisakis pegreffii infection.

Anisakis are globally distributed, marine parasitic nematodes that can cause human health problems, including symptoms such as vomiting, acute diarrhea, and allergic reactions. As parasitic nematodes that primarily affect the patient's digestive tract, intestinal helminths can interact directly with the host microbiota through physical contact, chemicals, or nutrient competition. It is widely accepted that the host microbiota plays a crucial role in the regulation of immunity. Nematodes collected from the abdominal cavity of marine fish were identified by molecular biology and live worms were artificially infected in rats. Infection was determined by indirect ELISA based on rat serum and worm extraction. Feces were collected for 16S rDNA-based analysis of microbiota diversity. Molecular biology identification based on ITS sequences identified the collected nematodes as A. pegreffii. The success of the artificial infection was determined by indirect ELISA based on serum and worm extraction from artificially infected rats. Microbiota diversity analysis showed that a total of 773 ASVs were generated, and PCoA showed that the infected group was differentiated from the control group. The control group contained five characterized genera (Prevotellaceae NK3B31 group, Turicibacter, Clostridium sensu stricto 1, Candidatus Stoquefichus, Lachnospira) and the infected group contained nine characterized genera (Rodentibacter, Christensenella, Dubosiella, Streptococcus, Anaeroplasma, Lactococcus, Papillibacter, Desulfovibrio, Roseburia). Based on the Wilcoxon test, four processes were found to be significant: bacterial secretion system, bacterial invasion of epithelial cells, bacterial chemotaxis, and ABC transporters. This study is the first to analyze the diversity of the intestinal microbiota of rats infected with A. pegreffii and to determine the damage and regulation of metabolism and immunity caused by the infection in the rat gut. The findings provide a basis for further research on host-helminth-microbe correlationships.

PSVI-11 Effects of S-Abscisic Acid administration on the antioxidative status and glucose absorption in the gut of rats

Abstract S-Abscisic Acid (S-ABA) is known to show various physiological functions in plants, but little information is available regarding the role of S-ABA in animals. Two experiments were conducted to investigate the effects of S-ABA administration on the antioxidative status and the function of the gut in rats. In the Experiment 1, male 5-wk-old Sprague-Dawley (SD) rats (n = 40) were randomly divided into the four groups. All groups were fed a common basal diet (MF, Oriental Yeast Co., Ltd., Tokyo, Japan). After a week of acclimation, either saline (CON) or S-ABA at 0.002 (LOW), 0.02 (MID), or 0.2 (HIGH) mg/kg body weight (BW) was administered intragastrically for 14 d. On d 14, all rats were weighed and euthanized for collection of plasma and gut mucosal tissues. The plasma concentration of superoxide dismutase (SOD) and the content of glutathione in a reduced (GSH) and an oxidized (GSSG) form in the gut mucosa was determined. The BW gain during the experimental period was significantly greater for LOW, MID and HIGH than for CON (P &amp;lt; 0.01). The plasma SOD concentration did not differ among the treatments. The mucosal GSH was greater for LOW, MID and HIGH than for CON (P &amp;lt; 0.01). In the Experiment 2, male 4-week-old SD rats (n = 36) were randomly allotted into three groups. The control (CON) was fed the AIN-93G diet while the other two groups received the diet supplemented with either 1 ppm (LOW) or 5 ppm (HIGH) S-ABA. The experimental diets were fed for 56 d. On d 21, 4 rats per treatment were employed for the intraperitoneal glucose tolerant test (IPGTT). The remainder of the animals were euthanized on d 56 for determination of the content of GSH and GSSG in the gut mucosa, the glycogen content in the liver, and the serum insulin concentration. There was no significant difference in the BW gain during the experimental period. In the IPGTT, HIGH showed greater blood glucose concentrations than CON (P &amp;lt; 0.05) at 30 and 60 min after administration. Although there was no statistical significance, the mucosal GSH was numerically greater (P = 0.11) for HIGH than for CON or LOW. The liver glycogen or serum insulin did not differ among the treatments. Those results suggest that dietary S-ABA supplementation could improve the antioxidative status through stimulating the GSH production in the gut and consequently increase the absorption of glucose in animals. Although S-ABA was indicated to be beneficial in animals, further investigations are required to verify the practical benefits of feeding S-ABA to production animals.

β-cyclodextrin inclusion complexes with short-chain phenolipids: An effective formulation for the dual sustained-release of phenolic compounds

The β-cyclodextrin and short-chain alkyl gallates (A-GAs), which are representative of phenolipids, such as butyl, propyl, ethyl, and methyl gallates, were chosen to form inclusion complexes by the use of the freeze-drying process. In the everted rat gut sac model, HPLC-UV analysis demonstrated that the released A-GAs from inclusion complexes were degraded to yield free gallic acid (GA) (sustained-release function 1). The small intestine membrane may be crossed by both the GA and the A-GAs. A-GAs may also undergo hydrolysis to provide GA (sustained-release function 2) following transmembrane transfer. Clearly, a helpful technique for the dual sustained-release of phenolic compounds is to produce β-cyclodextrin inclusion complexes with short-chain phenolipids. This will increase the bioactivities of phenolic compounds and prolong their in vivo residence length. Moreover, changing the carbon-chain length of these β-cyclodextrin inclusion complexes would readily modify the dual sustained-release behavior of the phenolic compounds. Thus, our work effectively established a theoretical foundation for the use of β-cyclodextrin inclusion complexes containing short-chain phenolipids as new source of functional food components to provide the body with phenolic compounds more efficiently.

Effect of the consumption of brazzein and monellin, two recombinant sweet-tasting proteins, on rat gut microbiota.

Sweet-tasting proteins (SPs) are proteins of plant origin initially isolated from tropical fruits. They are thousands of times sweeter than sucrose and most artificial sweeteners. SPs are a class of proteins capable of causing a sweet taste sensation in humans when interacting with the T1R2/T1R3 receptor. SP thaumatin has already been introduced in the food industry in some countries. Other SPs, such as monellin and brazzein, are promising products. An important stage in researching SPs, in addition to confirming the absence of toxicity, mutagenicity, oncogenicity, and allergenic effects, is studying their influence on gut microbiota. In this paper we describe changes in the composition of rat gut microbiota after six months of consuming one of two recombinant SPs-brazzein or monellin. A full length 16S gene sequencing method was used for DNA library barcoding. The MaAsLin2 analysis results showed noticeable fluctuations in the relative abundances of Anaerocella delicata in brazzein-fed rat microbiota, and of Anaerutruncus rubiinfantis in monellin-fed rat microbiota, which, however, did not exceed the standard deviation. The sucrose-fed group was associated with an increase in the relative abundance of Faecalibaculum rodentium, which may contribute to obesity. Overall, prolonged consumption of the sweet proteins brazzein and monellin did not significantly change rat microbiota and did not result in the appearance of opportunistic microbiota. This provides additional evidence for the safety of these potential sweeteners.

Role of nitric oxide in determination of large intestinal contractility in neonatal rats

Objectives: Nitric oxide (NO) plays a key role in inhibiting the contractility of gut smooth muscles in various species, and NG-nitro-L-arginine methyl ester (L-NAME) is a critical NO synthase inhibitor. Previous research investigating the role of NO in regulating gut motility focused on adult animals. Therefore, more research is needed to determine their status in the gut of newborns. Our study intended to understand how NO impacts the large gut contractility, in vitro, in rats, both neonates and adults, to get a better insight into the physiological role of NO in regulating large gut motility, particularly in neonates. Materials and Methods: In an organ bath preparation, the segments of a large gut (colon and rectum) were subjected to various concentrations of nitroglycerin (NG) (0.01–100 mM), a NO donor, cumulatively. In another group, pre-treatment with L-NAME (100 mM) was done to evaluate the blocking effect of NO on the contractile tension and frequency. Results: NG induced relaxation in the colon and rectum of adult rats in a similar manner. NG caused significantly greater relaxation in neonates’ rectums than in their colons. In neonatal and adult rats, L-NAME pre-application inhibited NG-induced relaxation in contractile tension. Exposure to different concentrations of NG decreased contractile frequency in adult rats’ colons and rectum. However, L-NAME pre-treatment did not affect the decrease in contractile frequency caused by NG. In neonates, NG caused a concentration-dependent reduction in contractile frequency, and a decrease in contractile frequency in the rectum was more than that in the colon. However, L-NAME pre-treatment did not affect the reduction in contractile frequency caused by NG. Conclusion: Nitrergic mechanisms have possibly been present since birth. The intensity of control by NO may be different in the colon and rectum. The differences in NO sensitivity in adults and neonates demonstrated the changes during development.

Intestinal Flora Imbalance Induced by Antibiotic Use in Rats.

This study aims to explore the effect of different doses of antibiotics on rats in order to observe alterations in their fecal microbiota, inflammatory changes in the colonic mucosa and four types of inflammatory markers in blood serum. Our methodology involved separating 84 female Sprague Dawley rats into groups A-G, with each group consisting of 12 rats. We collected the rat feces for analysis, using a distinct medium for bacterial cultivation and counting colonies under a microscope. On the 11th and 15th days of the experiment, half of the rats from each group were euthanized and 5 mL of abdominal aortic blood and colon tissues were collected. Inflammations changes of colon were observed and assessed by pathological Hematoxylin Eosin (HE) staining. Enzyme-linked immune sorbent assay (ELISA) was adopted for detecting C-reactive protein (CRP), IL-6, IL1-β and TNF-α. Our findings revealed that the initial average weight of the rats did not differ between groups (p>0.05); but significant differences were observed between stool samples, water intake, food intake and weight (p=0.009, <0.001, 0.016 and 0.04, respectively) within two hours after the experiment. Additionally, there were notable differences among the groups in nine tested microbiota before and after weighting methods (all p<0.001). There were no difference in nine microbiota at day 1 (all p>0.05); at day 4 A/B (p=0.044), A/D (p<0.001), A/E (p=0.029); at day 8, all p<0.01, at day 11, only A/F exist significant difference (p<0.001); at day 14 only A/D has difference (p=0.045). Inflammation changes of colon were observed between groups A-G at days 11 and 15. Significant differences between all groups can be observed for CRP, IL-6, IL1-β and TNF-α (p<0.001). This study suggests that antibiotics administration can disrupt the balance of bacteria in the rat gut ecosystem, resulting in an inflammatory response in their bloodstream and inducing inflammation changes of colon.

Gut microbiota and host metabolizing enzymes co‐contribute to pharmacokinetic variability in type 2 diabetes mellitus rats

AbstractThis study aimed to investigate the pharmacokinetic difference of quercetin between normal and type 2 diabetes mellitus (T2DM) rats. Our results showed that the mean residence time and half time were significantly increased, while the peak concentration was significantly reduced in T2DM rats, compared to the control rats. In addition, quercetin remained a high concentration in the liver for a long time with the highest concentration (13.51 ± 4.66 μg/mL) at 4 h after oral administration in T2DM rats. Furthermore, the CYP3A4 messenger RNA (mRNA) levels were downregulated and UGT1A1 mRNA levels in liver were upregulated in T2DM rats. In addition, the relative abundances of Bacteroides, norank, Parabacteroides, and Alistipes were decreased, while the relative abundances of Acrococcus, Frisingicoccus, Romboutsia, and Clostridium_sensu_stricto_1 were increased in the T2DM rats. The metabolism of quercetin in T2DM rats was slower compared to the normal group, which may be related to the lower level of CYP3A4 and the higher level of UGT1A1 in T2DM, as well as the significant enrichment of Acrococcus and other bacteria in the gut of T2DM rats.

The Effects of Short- and Long-Term Ingestion of Plastic Toxin Bisphenol A on Gastrointestinal Transit Time in Rats.

Introduction Exposure to bisphenol A (BPA), a toxic chemical released from plastic, affects various body functions, including reproduction, metabolism, and development. The most common route of exposure to BPA is oral, and the gastrointestinal(GI) tract is, therefore, the first body system to be exposed to BPA. BPA has been well-documented to impair gut contractility in rats, in vitro. It may therefore be hypothesized that BPA may adversely affect GI motility and hence slow down the movement of food, resulting in the increased transit of food bolus in the GI tract. There are no reports so far on the effects of BPA on GI transit time. Objectives The present study was undertaken to examine the impact of exposure to BPA by a single oral dose (termed as short-term ingestion of BPA) and chronic (28-day) oral dose (termed as long-term ingestion of BPA) on the transit time of food bolus in the gut of adult male albino rats. Methods and materials The study was conducted in the Department of Physiology,Institute of MedicalSciences,Banaras Hindu University, Varanasi,Uttar Pradesh, India. In one set of experiments, each animal was fed a food pellet, once (short-term ingestion) containing BPA (2 µg/kg and 50 µg/kg in different groups), and in another set of experiments, each animal was fed a food pellet containing BPA (50 µg/kg/day) for 28 consecutive days (long-term ingestion). Control rats in both sets were fed food pellets without BPA. Subsequently, the gastric transit index (GTI), ileocecal transit index (ICTI), and colonic transit time (CTT) were determined by the standard charcoal marker method. Results One-time ingestion of a food pellet containing BPA caused a significant (p < 0.05) drop in the GTI and ICTI and an increase in the CTT with both doses of BPA (2 and 50 µg/kg). Similarly, after chronic (28-day), oral BPA exposure, a significant decrease in the GTI and ICTT and an increase in CTT were observed. Conclusion Both short-term (one-time) and long-term (28-day) oral exposure to BPA-containing food harmed GI transit. Slow GI transit may lead to metabolic disorders and GI motility disorders, such as constipation.