Colon impairments and inflammation driven by an altered gut microbiota leads to social behavior deficits rescued by hyaluronic acid and celecoxib.

BACKGROUND: The exact mechanisms linking the gut microbiota and social behavior are still under investigation. We aimed to explore the role of the gut microbiota in shaping social behavior deficits using selectively bred mice possessing dominant (Dom) or submissive (Sub) behavior features. Sub mice exhibit asocial, depressive- and anxiety-like behaviors, as well as systemic inflammation, all of which are shaped by their impaired gut microbiota composition. METHODS: An age-dependent comparative analysis of the gut microbiota composition of Dom and Sub mice was performed using 16S rRNA sequencing, from early infancy to adulthood. Dom and Sub gastrointestinal (GI) tract anatomy, function, and immune profiling analyses were performed using histology, RT-PCR, flow cytometry, cytokine array, and dextran-FITC permeability assays. Short chain fatty acids (SCFA) levels in the colons of Dom and Sub mice were quantified using targeted metabolomics. To support our findings, adult Sub mice were orally treated with hyaluronic acid (HA) (30 mg/kg) or with the non-steroidal anti-inflammatory agent celecoxib (16 mg/kg). RESULTS: We demonstrate that from early infancy the Sub mouse gut microbiota lacks essential bacteria for immune maturation, including Lactobacillus and Bifidobacterium genera. Furthermore, from birth, Sub mice possess a thicker colon mucin layer, and from early adulthood, they exhibit shorter colonic length, altered colon integrity with increased gut permeability, reduced SCFA levels and decreased regulatory T-cells, compared to Dom mice. Therapeutic intervention in adult Sub mice treated with HA, celecoxib, or both agents, rescued Sub mice phenotypes. HA treatment reduced Sub mouse gut permeability, increased colon length, and improved mouse social behavior deficits. Treatment with celecoxib increased sociability, reduced depressive- and anxiety-like behaviors, and increased colon length, and a combined treatment resulted in similar effects as celecoxib administered as a single agent. CONCLUSIONS: Overall, our data suggest that treating colon inflammation and decreasing gut permeability can restore gut physiology and prevent social deficits later in life. These findings provide critical insights into the importance of early life gut microbiota in shaping gut immunity, functionality, and social behavior, and may be beneficial for the development of future therapeutic strategies.

Melatonin alleviates 3,3',4,4',5-pentachlorobenzene induced colon injury by relieving oxidative stress.

3,3',4,4',5-pentachlorobiphenyl (PCB126) is widely distributed, non-degradable and bioaccumulative, which can affect the function of tissues and organs of the living organisms. Melatonin (MT) is a sort of indole neurohormone that is mainly secreted by the pineal gland. Numerous studies have shown that MT can alleviate intestinal injury through various mechanisms such as antioxidant, anti-inflammatory, and anti-apoptosis. For the above reasons, the aim of this study is to explore the mechanism of intestinal injury in mice after exposure to PCB126 as well as the antagonistic effect of MT. Mice were respectively fed PCB126 (0.326 mg/kg) and/or MT (10 mg/kg) in vivo. In vitro, colonic epithelial cells (MCEC) were treated with PCB126 (150 µM) and/or MT (2 mM). We found that the microscopic structure of colon tissue was impaired after exposure to PCB126. The levels of oxidative stress, the protein and mRNA levels of expression of inflammatory related factors were significantly increased and the expression levels of intestinal tight junction protein were decreased. Notably, MT can promote Nrf2/HO-1 expression level and reduce the colonic injury caused by PCB126. Further in vitro treatment with reactive oxygen species inhibitors (NAC) showed that it significantly alleviated PCB126-induced in MCEC cell damage. In summary, the above results suggested that MT alleviates PCB126-induced colon inflammation by inhibiting the overproduction of reactive oxygen species (ROS) and up-regulating the expression level of intestinal tight junction protein. Our results contribute to the further comprehension of the intestinal toxicity effects of PCB126 and the significant role of MT in preserving the mechanisms of intestinal injury.

Acute Colon Inflammation Triggers Primary Motor Cortex Glial Activation, Neuroinflammation, Neuronal Hyperexcitability, and Motor Coordination Deficits.

Neuroinflammation underlies neurodegenerative diseases. Herein, we test whether acute colon inflammation activates microglia and astrocytes, induces neuroinflammation, disturbs neuron intrinsic electrical properties in the primary motor cortex, and alters motor behaviors. We used a rat model of acute colon inflammation induced by dextran sulfate sodium. Inflammatory mediators and microglial activation were assessed in the primary motor cortex by PCR and immunofluorescence assays. Electrophysiological properties of the motor cortex neurons were determined by whole-cell patch-clamp recordings. Motor behaviors were examined using open-field and rotarod tests. We show that the primary motor cortex of rats with acute colon inflammation exhibited microglial and astrocyte activation and increased mRNA abundance of interleukin-6, tumor necrosis factor-alpha, and both inducible and neuronal nitric oxide synthases. These changes were accompanied by a reduction in resting membrane potential and rheobase and increased input resistance and action potential frequency, indicating motor neuron hyperexcitability. In addition, locomotion and motor coordination were impaired. In conclusion, acute colon inflammation induces motor cortex microglial and astrocyte activation and inflammation, which led to neurons' hyperexcitability and reduced motor coordination performance. The described disturbances resembled some of the early features found in amyotrophic lateral sclerosis patients and animal models, suggesting that colon inflammation might be a risk factor for developing this disease.

Tissue-specific effect of colitis on protein synthesis in mice: impact of the dietary protein content.

PURPOSE: Inflammatory bowel diseases are associated with an increase in the whole-body protein turnover, thus possibly requiring an additional supply of dietary proteins. Our aim was to evaluate whether increasing dietary protein content could alleviate protein metabolism alterations in the injured splanchnic and peripheral tissues during colitis and spontaneous mucosal healing. METHODS: Mice with acute chemically induced colitis received either a normal protein (P14, 14% as energy), a moderately (P30, 30%) and a very high-protein (P53, 55%) diets. At different times after the challenge, protein synthesis rate was determined in tissues using a flooding dose of 13C valine. RESULTS: Colon, liver and spleen protein synthesis rates were significantly increased after colitis induction, while being decreased in the caecum, kidneys and muscle. Contrastingly to the two other diets, P30 diet consumption allowed faster recovery of the animals, and this coincided with a rapid resaturation of the initial protein synthesis in the colon. In the other tissues studied, the high-protein diets show different effects depending on the dietary protein content consumed and on the examined tissues, with a general trend of P53 in lowering anabolism rates. CONCLUSION: This study highlights the severe impact of acute colonic inflammation on protein metabolism in different organs. In addition, dietary protein content modulated the recovery of the initial protein synthesis rate in the various tissues following colitis induction. P30 diet consumption notably showed a better ability to alleviate protein metabolism perturbations induced by colitis, that may explain its documented beneficial effect on colon mucosal healing.

Betulinic acid hydroxamate prevents colonic inflammation and fibrosis in murine models of inflammatory bowel disease.

Intestinal fibrosis is a common complication of inflammatory bowel disease (IBD) and is defined as an excessive accumulation of scar tissue in the intestinal wall. Intestinal fibrosis occurs in both forms of IBD: ulcerative colitis and Crohn's disease. Small-molecule inhibitors targeting hypoxia-inducing factor (HIF) prolyl-hydroxylases are promising for the development of novel antifibrotic therapies in IBD. Herein, we evaluated the therapeutic efficacy of hydroxamate of betulinic acid (BHA), a hypoxia mimetic derivative of betulinic acid, against IBD in vitro and in vivo. We showed that BAH (5-20 µM) dose-dependently enhanced collagen gel contraction and activated the HIF pathway in NIH-3T3 fibroblasts; BAH treatment also prevented the loss of trans-epithelial electrical resistance induced by proinflammatory cytokines in Caco-2 cells. In two different murine models (TNBS- and DSS-induced IBD) that cause colon fibrosis, oral administration of BAH (20, 50 mg/kg·d, for 17 days) prevented colon inflammation and fibrosis, as detected using immunohistochemistry and qPCR assays. BAH-treated animals showed a significant reduction of fibrotic markers (Tnc, Col1a2, Col3a1, Timp-1, α-SMA) and inflammatory markers (F4/80+, CD3+, Il-1ß, Ccl3) in colon tissue, as well as an improvement in epithelial barrier integrity and wound healing. BHA displayed promising oral bioavailability, no significant activity against a panel of 68 potential pharmacological targets and was devoid of genotoxicity and cardiotoxicity. Taken together, our results provide evidence that oral administration of BAH can alleviate colon inflammation and colitis-associated fibrosis, identifying the enhancement of colon barrier integrity as a possible mechanism of action, and providing a solid rationale for additional clinical studies.

Acute infection with Strongyloides venezuelensis increases intestine production IL-10, reduces Th1/Th2/Th17 induction in colon and attenuates Dextran Sulfate Sodium-induced colitis in BALB/c mice.

Helminth infection can reduce the severity of inflammatory bowel disease. However, the modulatory mechanisms elicited by helminth infection are not yet fully understood and vary depending on the experimental model. Herein we evaluated the effect of acute infection of BALB/c mice with Strongyloides venezuelensis on the clinical course of ulcerative colitis induced by Dextran Sulfate Sodium (DSS) treatment of these animals. For the experiments, S. venezuelensis-infected BALB/c mice were treated orally with 4% DSS solution for seven days. As controls, we used untreated S. venezuelensis infected, DSS-treated uninfected, and untreated/uninfected BALB/c mice. During DSS treatment, mice from the different groups were compared with regards to the clinical signs related to the severity of colitis and intestinal inflammation. Mice acutely infected with S. venezulensis and treated with DSS had reduced clinical score, shortening of the colon, and tissue inflammation. Moreover, DSS-treated and infected mice showed reduced IL-4, INF-γ, and IL-17 levels and increase of IL-10 production in the colon and/or in the supernatant of mesenteric lymph nodes cell cultures that resulted in lower eosinophil peroxidase and myeloperoxidase activity in colon homogenates, when compared with DSS-treated uninfected mice. DSS-treated infected mice also preserved the intestine architecture and had normal differentiation of goblet cells and mucus production in the colon mucosa. In conclusion, the data indicate that the clinical improvement reported in DSS-treated infected mice was accompanied by the lower production of Th1/Th2/Th17 pro-inflammatory cytokines, stimulation of IL-10, and induction of mucosal repair mechanisms.

Sphingomyelin synthase 2 deficiency inhibits the induction of murine colitis-associated colon cancer.

Sphingomyelin synthase 2 (SMS2) is the synthetic enzyme of sphingomyelin (SM), which regulates membrane fluidity and microdomain structure. SMS2 plays a role in LPS-induced lung injury and inflammation; however, its role in inflammation-mediated tumorigenesis is unclear. We investigated the effect of SMS2 deficiency on dextran sodium sulfate (DSS)-induced murine colitis and found inhibition of DSS-induced inflammation in SMS2-deficient (SMS2-/-) mice. DSS treatment induced a significant increase in ceramide levels, with a decrease of SM levels in SMS2-/- colon tissue, and demonstrated attenuation of the elevation of both inflammation-related gene expression and proinflammatory cytokines and chemokines, leukocyte infiltration, and MAPK and signal transducer and activator of transcription 3 activation. After undergoing transplantation of wild-type bone marrow, SMS2-/- mice also exhibited inhibition of DSS-induced inflammation in the colon, which suggested that SMS2 deficiency in bone marrow-derived immune cells was not involved in the inhibition of colitis. Finally, in an azoxymethane/DSS-induced cancer model, SMS2 deficiency significantly decreased tumor incidence in the colon. Our results demonstrate that SMS2 deficiency inhibits DSS-induced colitis and subsequent colitis-associated colon cancer via inhibition of colon epithelial cell-mediated inflammation; therefore, inhibition of SMS2 may be a potential therapeutic target for human colitis and colorectal cancer.-Ohnishi, T., Hashizume, C., Taniguchi, M., Furumoto, H., Han, J., Gao, R., Kinami, S., Kosaka, T., Okazaki, T. Sphingomyelin synthase 2 deficiency inhibits the induction of murine colitis-associated colon cancer.

Correlation of Fecal Markers with Magnifying Endoscopic Stratification in Patients with Ulcerative Colitis Who Are in Clinical Remission.

BACKGROUND: Maintenance of mucosal healing is recommended during the treatment of ulcerative colitis (UC). However, symptoms of UC often do not reflect mucosal disease activity. Fecal markers such as calprotectin, lactoferrin, and hemoglobin have been reported to correlate well with the Mayo endoscopic subscore (MES) and are being considered alternative monitoring tools in endoscopy. Ulcerative Colitis Endoscopic Index of Severity (UCEIS) is a new and more detailed endoscopic scoring system compared to MES. Furthermore, magnifying endoscopic stratification (ME) based on alterations in the mucosal surface pit patterns is noted in UC. However, the association between fecal markers and UCIES and magnifying endoscopy is relatively unexplored. SUMMARY: This study investigated the association between the aforementioned fecal markers and MES, UCEIS, and ME in patients with UC in clinical remission. This prospective study included 60 patients with UC in clinical remission who underwent colonoscopy at the Nagasaki University Hospital between June 2015 and November 2016. A significant correlation was observed between MES and all fecal markers. Notably, the fecal markers correlated well with UCEIS (calprotectin Spearman's correlation coefficient [r] = 0.54, p < 0.0001; lactoferrin r = 0.56, p < 0.0001; and hemoglobin r = 0.43, p < 0.001). Furthermore, ME findings correlated significantly with calprotectin (r = 0.50, p = 0.0002) and lactoferrin (r = 0.46, p = 0.0006) levels and slightly with hemoglobin (r = 0.28, p = 0.043) levels. Moreover, each cutoff level of fecal calprotectin, lactoferrin, or hemoglobin had a high sensitivity and specificity for the detection of MES = 0, UCEIS = 0, ME = A, for predicting mucosa healing. Key Messages: Fecal markers correlated not only with MES but also with UCEIS and ME and should be useful for monitoring patients with UC in clinical remission.

Disruption of GPR35 Exacerbates Dextran Sulfate Sodium-Induced Colitis in Mice.

BACKGROUND: G protein-coupled receptor 35 (GPR35) is an orphan receptor and is vastly expressed in immune cells and gastrointestinal cells, suggesting the potential physiological importance of GPR35 in these cells. Here, we tested the hypothesis that the lack of GPR35 expression in the colon mucosa exacerbates the severity of dextran sulfate sodium (DSS)-induced experimental colitis in mice. METHODS: Colitis was induced in GPR35 wild-type (GPR35+/+) and GPR35 knockout (GPR35-/-) mice through the administration of DSS in drinking water for 5 days followed by regular facility water for 1 day. Induction of colitis was evaluated by measuring relative body weight loss, clinical illness scores, and morphological changes in the colon. Abolition of Gpr35 gene expression in the colon mucosa of GPR35-/- mice was confirmed by quantitative real-time PCR (qPCR). Gene expressions of inflammatory and tissue remodeling cytokines were detected by qPCR. Human colorectal epithelial Caco cells were transfected with siRNA against GPR35 before treated with 1% DSS in vitro. Protein expressions were measured using Western blot. RESULTS: GPR35-/- mice receiving DSS showed a significantly worsened colitis disease with profound loss of body weight and a considerable amount of severe clinical illness compared to GPR35+/+ mice that received DSS. The histology of colon sections from GPR35-/- mice showed extensive pathological changes including submucosal edema, diffuse ulcerations, and evidence of complete loss of crypts compared to wild-type mice. The mean histopathological score was significantly higher in GPR35-/- mice as compared to GPR35+/+ mice. The qPCR data revealed significant expression of pro-inflammatory and tissue remodeling cytokines in GPR35-/- colon mucosa, including IL-1ß, CXCL1, CXCL2, CCL2, HMGB1, TGFß1, TGFß3, MMP1/9/12. The protein expressions of Zonula occludens-1, E-cadherin, Claudin1 were decreased upon knocking down GPR35 with or without 1% DSS treatment. CONCLUSIONS: Our experimental data suggest that lack of GPR35 resulted in worsened disease outcome in DSS-induced experimental colitis, indicating that GPR35 could play a crucial role in protecting from colonic inflammation and serve as a therapeutic target.

Frondanol, a Nutraceutical Extract from Cucumaria frondosa, Attenuates Colonic Inflammation in a DSS-Induced Colitis Model in Mice.

Frondanol is a nutraceutical lipid extract of the intestine of the edible Atlantic sea cucumber, Cucumaria frondosa, with potent anti-inflammatory effects. In the current study, we investigated Frondanol as a putative anti-inflammatory compound in an experimental model of colonic inflammation. C57BL/6J male black mice (C57BL/6J) were given 3% dextran sodium sulfate (DSS) in drinking water for 7 days to induce colitis. The colitis group received oral Frondanol (100 mg/kg body weight/per day by gavage) and were compared with a control group and the DSS group. Disease activity index (DAI) and colon histology were scored for macroscopic and microscopic changes. Colonic tissue length, myeloperoxidase (MPO) concentration, neutrophil and macrophage marker mRNA, pro-inflammatory cytokine proteins, and their respective mRNAs were measured using ELISA and real-time RT-PCR. The tissue content of leukotriene B4 (LTB4) was also measured using ELISA. Frondanol significantly decreased the DAI and reduced the inflammation-associated changes in colon length as well as macroscopic and microscopic architecture of the colon. Changes in tissue MPO concentrations, neutrophil and macrophage mRNA expression (F4/80 and MIP-2), and pro-inflammatory cytokine content (IL-1β, IL-6 and TNF-α) both at the protein and mRNA level were significantly reduced by Frondanol. The increase in content of the pro-inflammatory mediator leukotriene B4 (LTB4) induced by DSS was also significantly inhibited by Frondanol. It was thus found that Frondanol supplementation attenuates colon inflammation through its potent anti-inflammatory activity.

Mesalamine did not prevent recurrent diverticulitis in phase 3 controlled trials.

BACKGROUND & AIMS: No therapy has been proven to prevent the recurrence of diverticulitis. Mesalamine has shown efficacy in preventing relapse in inflammatory bowel disease, and there is preliminary evidence that it might be effective for diverticular disease. We investigated the efficacy of mesalamine in preventing recurrence of diverticulitis in 2 identical but separate phase 3, randomized, double-blind, placebo-controlled, multicenter trials (identical confirmatory trials were conducted for regulatory reasons). METHODS: We evaluated the efficacy and safety of multimatrix mesalamine vs placebo in the prevention of recurrent diverticulitis in 590 (PREVENT1) and 592 (PREVENT2) adult patients with ≥1 episodes of acute diverticulitis in the previous 24 months that resolved without surgery. Patients received mesalamine (1.2 g, 2.4 g, or 4.8 g) or placebo once daily for 104 weeks. The primary end point was the proportion of recurrence-free patients at week 104. Diverticulitis recurrence was defined as surgical intervention at any time for diverticular disease or presence of computed tomography scan results demonstrating bowel wall thickening (>5 mm) and/or fat stranding consistent with diverticulitis. For a portion of the study, recurrence also required the presence of abdominal pain and an increase in white blood cells. RESULTS: Mesalamine did not reduce the rate of diverticulitis recurrence at week 104. Among patients in PREVENT1, 53%-63% did not have disease recurrence, compared with 65% of those given placebo. Among patients in PREVENT2, 59%-69% of patients did not have disease recurrence, compared with 68% of those given placebo. Mesalamine did not reduce time to recurrence, and the proportions of patients requiring surgery were comparable among treatment groups. No new adverse events were identified with mesalamine administration. CONCLUSIONS: Mesalamine was not superior to placebo in preventing recurrent diverticulitis. Mesalamine is not recommended for this indication. ClinicalTrials.gov ID: NCT00545740 and NCT00545103.

Effect of acute and chronic DSS induced colitis on plasma eicosanoid and oxylipin levels in the rat.

Eicosanoids and oxylipins are potent lipid mediators involved in the regulation of inflammation. In order to evaluate their role and suitability as biomarkers in colitis, we analyzed their systemic levels in the acute and chronic phase of dextran sulfate sodium (DSS) induced colitis. Male Fischer 344 rats were treated in three cycles with 4% DSS in the drinking water (4 days followed by 10 days recovery) and blood was drawn 3 days prior to the first DSS treatment and on days 4, 11, 32 and 39. Histopathological evaluation of the colon tissue after 42 days showed that the animals developed a mild to severe chronic colitis. Consistently, prostaglandin levels were massively (twofold) elevated in the colonic tissue. LC-MS based targeted metabolomics was used to determine plasma oxylipin levels at the different time points. In the acute phase of inflammation directly after DSS treatment, epoxy-fatty acid (FA), dihydroxy-FA and hydroxy-FA plasma concentrations were uniformly elevated. With each treatment cycle the increase in these oxylipin levels was more pronounced. Our data suggest that in the acute phase of colitis release of polyunsaturated FAs from membranes in the inflamed tissue is reflected by a uniform increase of oylipins formed in different branches of the arachidonic acid cascade. However, during the recovery phases the systemic oxylipin pattern is not or only moderately altered and does not allow to evaluate the onset of chronic inflammation in the colon.

Rice prolamin extract ameliorates acute murine colitis by inhibiting nuclear factor-kappa B and modulating intestinal apoptosis and cell proliferation.

We investigated the impact of rice prolamin extract (RPE) on lipopolysaccharide (LPS)-induced nuclear factor (NF)-κB signalling in intestinal epithelial cells and macrophages, and determined the therapeutic efficacy of RPE in acute murine colitis. The effect of RPE on LPS-induced NF-κB signalling and proinflammatory gene expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in-vivo efficacy of RPE was assessed in mice with 3% dextran sulphate sodium (DSS)-induced colitis. Apoptotic and cellular proliferative activities were evaluated by immunostaining with cleaved caspase-3 and proliferating cell nuclear antigen (PCNA) antibodies. RPE inhibited LPS-induced expression of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha and LPS-induced NF-κB signalling in intestinal epithelial cells and macrophages. RPE-fed, DSS-exposed mice showed less weight loss, longer colon length and lower histological score compared to control diet-fed, DSS-exposed mice. Immunostaining analysis revealed a significant decrease of cleaved caspase-3 positive cells in RPE-fed, DSS-exposed mice compared to DSS-exposed mice. Also, the number of PCNA-positive cells within intact colonic crypts decreased significantly in RPE-fed, DSS-exposed mice compared to control diet-fed, DSS-exposed mice. DSS-induced NF-κB signalling was inhibited by RPE. RPE ameliorates intestinal inflammation by inhibiting NF-κB activation and modulating intestinal apoptosis and cell proliferation in an acute murine colitis.

Highly Effective Nobiletin-MPN in Yeast Microcapsules for Targeted Modulation of Oxidative Stress, NLRP3 Inflammasome Activation, and Immune Responses in Ulcerative Colitis.

Inflammatory bowel disease (IBD) etiology is intricately linked to oxidative stress and inflammasome activation. Natural antioxidant nobiletin (NOB) contains excellent anti-inflammatory properties in alleviating intestinal injury. However, the insufficient water solubility and low bioavailability restrict its oral intervention for IBD. Herein, we constructed a highly efficient NOB-loaded yeast microcapsule (YM, NEFY) exhibiting marked therapeutic efficacy for dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) at a low oral dose of NOB (20 mg/kg). We utilized the metal polyphenol network (MPN) formed by self-assembly of epigallocatechin gallate (EGCG) and FeCl3 as the intermediate carrier to improve the encapsulation efficiency (EE) of NOB by 4.2 times. These microcapsules effectively alleviated the inflammatory reaction and oxidative stress of RAW264.7 macrophages induced by lipopolysaccharide (LPS). In vivo, NEFY with biocompatibility enabled the intestinal enrichment of NOB through controlled gastrointestinal release and macrophage targeting. In addition, NEFY could inhibit NLRP3 inflammasome and balance the macrophage polarization, which favors the complete intestinal mucosal barrier and recovery of colitis. Based on the oral targeted delivery platform of YM, this work proposes a novel strategy for developing and utilizing the natural flavone NOB to intervene in intestinal inflammation-related diseases.

Therapeutic Potential of Lactiplantibacillus plantarum FB091 in Alleviating AlcoholInduced Liver Disease through Gut-Liver Axis.

Alcoholic liver disease (ALD) poses a significant global health burden, often requiring liver transplantation and resulting in fatalities. Current treatments, like corticosteroids, effectively reduce inflammation but carry significant immunosuppressive risks. This study evaluates Lactiplantibacillus plantarum FB091, a newly isolated probiotic strain, as a safer alternative for ALD treatment. Using an in vivo mouse model, we assessed the effects of L. plantarum FB091 on alcohol-induced liver damage and gut microbiota composition. Alcohol and probiotics administration did not significantly impact water/feed intake or body weight. Histopathological analysis showed that L. plantarum FB091 reduced hepatocellular ballooning and inflammatory cell infiltration in liver tissues and mitigated structural damage in colon tissues, demonstrating protective effects against alcohol-induced damage. Biomarker analysis indicated that L. plantarum FB091 decreased aspartate aminotransferase levels, suggesting reduced liver damage, and increased alcohol dehydrogenase activity, indicating enhanced alcohol metabolism. Additionally, cytokine assays revealed a reduction in pro-inflammatory TNF-α and an increase in anti-inflammatory IL-10 levels in colon tissues of the L. plantarum FB091 group, suggesting an anti-inflammatory effect. Gut microbiota analysis showed changes in the L. plantarum FB091 group, including a reduction in Cyanobacteria and an increase in beneficial bacteria such as Akkermansia and Lactobacillus. These changes correlated with the recovery and protection of liver and colon health. Overall, L. plantarum FB091 shows potential as a therapeutic probiotic for managing ALD through its protective effects on liver and colon tissues, enhancement of alcohol metabolism, and beneficial modulation of gut microbiota. Further clinical studies are warranted to confirm these findings in humans.

Adverse effect of oxidized cholesterol exposure on colitis is mediated by modulation of gut microbiota.

Both cholesterol and oxidized cholesterol (OXC) are present in human diets. The incidence of inflammatory bowel diseases (IBDs) is increasing in the world. The present study was to investigate the mechanism by which OXC promotes colitis using C57BL/6 mice as a model. Results shown that more severe colitis was developed in OXC-treated mice with the administration of dextran sulfate sodium (DSS) in water. Direct effects of short-term OXC exposure on gut barrier or inflammation were not observed in healthy mice. However, OXC exposure could cause gut microbiota dysbiosis with a decrease in the relative abundance of short-train fatty acids (SCFAs)-producing bacteria (Lachnospiraceae_NK4A136_group and Blautia) and an increase in the abundance of some potential harmful bacteria (Bacteroides). OXC-induced symptoms of colitis were eliminated when mice were administered with antibiotic cocktails, indicating the promoting effect of OXC on DSS-induced colitis was mediated by its effect on gut microbiota. Moreover, bacteria-depleted mice colonized with gut microbiome from OXC-DSS-exposed mice exhibited a severe colitis, further proving the gut dysbiosis caused by OXC exposure was the culprit in exacerbating the colitis. It was concluded that dietary OXC exposure increased the susceptibility of colitis in mice by causing gut microbiota dysbiosis.

ROS-triggered self-disintegrating and pH-responsive astaxanthin nanoparticles for regulating the intestinal barrier and colitis.

Smart delivery systems with stimuli-responsive capability are able to improve the bioaccessibility through increasing the solubility, physicochemical stability and biocompatibility of bioactive compounds. In this study, the astaxanthin nanoparticles with reactive oxygen species (ROS) and pH dual-response function were design and constructed using poly (propylene sulfide) covalently modified sodium alginate as carriers based on ultrasonic assisted self-assembly strategy. Atomic force microscope and scanning electron microscope analysis showed that the nanoparticles were spherical in shape with a size of around 260 nm. Meanwhile, the astaxanthin nanoparticles showed both pH and ROS stimuli-responsive release characteristics. In vitro cell experiments showed that astaxanthin nanoparticles significantly inhibited the production of ROS and mitochondrial depolarization induced by oxidative stress. In vivo colitis experiment of mice revealed that astaxanthin nanoparticles could significantly relieve colitis, protect the integrity of colon tissue and restore the expression of tight junction proteins ZO-1 and occludin. The abundance of Lactobacillus and Lachnospiraceae, and the ratio of Firmicutes/Bacteroidota of gut microbiota were significantly improved after intervention of the stimuli-responsive astaxanthin nanoparticles. This work provided a simple strategy for constructing ROS/pH dual response delivery system, which provided an experimental basis for improving the oral bioavailability of hydrophobic active compounds.

Transient gestational hypothyroxinemia accelerates and enhances ulcerative colitis-like disorder in the male offspring.

Introduction: Gestational hypothyroxinemia (HTX) is a condition that occurs frequently at the beginning of pregnancy, and it correlates with cognitive impairment, autism, and attentional deficit in the offspring. Evidence in animal models suggests that gestational HTX can increase the susceptibility of the offspring to develop strong inflammation in immune-mediated inflammatory diseases. Ulcerative colitis (UC) is a frequent inflammatory bowel disease with unknown causes. Therefore, the intensity of ulcerative colitis-like disorder (UCLD) and the cellular and molecular factors involved in proinflammatory or anti-inflammatory responses were analyzed in the offspring gestated in HTX (HTX-offspring) and compared with the offspring gestated in euthyroidism (Control-offspring). Methods: Gestational HTX was induced by the administration of 2-mercapto-1-methylimidazole in drinking water to pregnant mice during E10-E14. The HTX-offspring were induced with UCLD by the acute administration of dextran sodium sulfate (DSS). The score of UCLD symptomatology was registered every day, and colon histopathology, immune cells, and molecular factors involved in the inflammatory or anti-inflammatory response were analyzed on day 6 of DSS treatment. Results: The HTX-offspring displayed earlier UCLD pathological symptoms compared with the Control-offspring. After 6 days of DSS treatment, the HTX-offspring almost doubled the score of the Control-offspring. The histopathological analyses of the colon samples showed signs of inflammation at the distal and medial colon for both the HTX-offspring and Control-offspring. However, significantly more inflammatory features were detected in the proximal colon of the HTX-offspring induced with UCLD compared with the Control-offspring induced with UCLD. Significantly reduced mRNA contents encoding for protective molecules like glutamate-cysteine ligase catalytic subunit (GCLC) and mucin-2 (MUC-2) were found in the colon of the HTX-offspring as compared with the Control-offspring. Higher percentages of Th17 lymphocytes were detected in the colon tissues of the HTX-offspring induced or not with UCLD as compared with the Control-offspring. Discussion: Gestational HTX accelerates the onset and increases the intensity of UCLD in the offspring. The low expression of MUC-2 and GCLC together with high levels of Th17 Lymphocytes in the colon tissue suggests that the HTX-offspring has molecular and cellular features that favor inflammation and tissue damage. These results are important evidence to be aware of the impact of gestational HTX as a risk factor for UCLD development in offspring.

Colonic mechanism of serum NAD+ depletion induced by DEHP during pregnancy.

Di (2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer in polyvinyl chloride products such as feed piping, packing bag, and medical consumable. Our previous studies have demonstrated that DEHP exposure reduced the concentration of nicotinamide adenine dinucleotide (NAD+) in pregnant mice serum, which cuts off the source of NAD+ to placenta and results fetal growth restriction. However, the mechanism of serum NAD+ depletion by DEHP remains elusive. This study investigated the intestinal mechanism of NAD+ shortage-induced by DEHP in pregnant mice. The transcriptome results implicated that the mRNA level of oxidative response genes Cyp1a1, Gsto2, Trpv1 and Trpv3 were upregulated in colon. These changes induced intestinal inflammation. Transmission Electron Microscopy results displayed that DEHP destroyed the tight junctions and cell polarity of colonic epithelial cells. These dysfunctions diminished the expression of NAD+ precursor transporters SLC12A8, SLC5A8, SLC7A5, and the NAD+ biosynthetic key enzymes NAMPT, NMNAT1-3, and TDO2 in colonic epithelial cells. Analysis of the gut microbiota showed that DEHP led to the dysbiosis of gut microbiota, reducing the relative abundance of Prevotella copri which possesses the VB3 biosynthetic pathway. Therefore, maternal DEHP exposure during pregnancy decreased the transportation of NAD+ precursors from enteric cavity to colonic epithelial cells, and inhibited the synthesis of NAD+ in colonic epithelial cells. Meanwhile, DEHP reduced the NAD+ precursors provided by gut microbiota. Eventually, serum NAD+ content was lowered. Taken together, our findings provide a new insight for understanding the intestinal mechanisms by which DEHP affects serum NAD+ levels.

Adding New Scientific Evidences on the Pharmaceutical Properties of Pelargonium quercetorum Agnew Extracts by Using In Vitro and In Silico Approaches.

Pelargonium quercetorum is a medicinal plant traditionally used for treating intestinal worms. In the present study, the chemical composition and bio-pharmacological properties of P. quercetorum extracts were investigated. Enzyme inhibition and scavenging/reducing properties of water, methanol, and ethyl acetate extracts were assayed. The extracts were also studied in an ex vivo experimental model of colon inflammation, and in this context the gene expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor α (TNFα) were assayed. Additionally, in colon cancer HCT116 cells, the gene expression of transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8), possibly involved in colon carcinogenesis, was conducted as well. The extracts showed a different qualitative and quantitative content of phytochemicals, with water and methanol extracts being richer in total phenols and flavonoids, among which are flavonol glycosides and hydroxycinnamic acids. This could explain, at least in part, the higher antioxidant effects shown by methanol and water extracts, compared with ethyl acetate extract. By contrast, the ethyl acetate was more effective as cytotoxic agent against colon cancer cells, and this could be related, albeit partially, to the content of thymol and to its putative ability to downregulate TRPM8 gene expression. Additionally, the ethyl acetate extract was effective in inhibiting the gene expression of COX-2 and TNFα in isolated colon tissue exposed to LPS. Overall, the present results support future studies for investigating protective effects against gut inflammatory diseases.