Intestinal Dysfunction Research Articles

Intestinal Motility Dysfunction in Goto-Kakizaki Rats: Role of the Myenteric Plexus.

The morpho-quantitative analysis of myenteric plexus neurons in the small and large intestines of 120-day-old male GK rats was investigated. The diabetes was confirmed by high fasting blood glucose levels. The myenteric plexus was evaluated through wholemount immunofluorescence. The morpho-quantitative analyses included evaluating neuronal density (neurons per ganglion) of the total neuronal population, the cholinergic and nitrergic subpopulations, and enteric glial cells per ganglion. The cell body area of 100 neurons per segment per animal was measured. The total neurons and nitrergic subpopulation were unaltered in the GK rats' small and large intestines. The cholinergic subpopulation exhibited decreased density in the three segments of the small intestine and an increased number in the proximal colon of the GK rats. The number of enteric glial cells increased in the ileum of the GK rats, which could indicate enteric gliosis caused by the intestinal inflammatory state. The area of the cell body was increased in the total neuronal population of the jejunum and ileum of the GK rats. Frequency histograms of the cell body area distribution revealed the contribution of cholinergic neurons to larger areas in the jejunum and nitrergic neurons in the ileum. The constipation previously reported in GK rats might be explained by the decrease in the density of cholinergic neurons in the small intestine of this animal model.

Sinisan Alleviates Stress-Induced Intestinal Dysfunction and Depressive-like Behaviors in Mice with Irritable Bowel Syndrome by Enhancing the Intestinal Barrier and Modulating Central 5-Hydroxytryptamine

Irritable bowel syndrome (IBS) is a common chronic functional bowel disorder and is strongly associated with an increased risk of depression and anxiety. The brain–gut axis plays an important role in the pathophysiologic changes in IBS, yet effective treatments for IBS are still lacking. Sinisan, originating from the Treatise on Typhoid Fever by the medical sage Zhang Zhongjing, is a classic formula in the Eight Methods of Traditional Chinese Medicine (TCM) that focuses on dispersing the liver and regulating the spleen, relieving depression and transmitting evils, and has been widely used in the treatment of liver-depression and spleen-deficiency, diarrhea, and related liver and stomach disorders. However, the therapeutic effect of sinisan in IBS has not been clarified. The aim of this study was to investigate the effects of sinisan on stress-induced intestinal dysfunction and depressive behavior in IBS mice. We established a diarrhea-predominant irritable bowel syndrome (IBS-D) mouse model using a 4% acetic acid enema combined with restraint stress, and analyzed the results using behavioral tests, relevant test kits, hematoxylin-eosin (HE) staining, immunofluorescence (IF), Western blot (WB), and quantitative fluorescence polymerase chain reaction (qRT-PCR). The results showed that sinisan administration significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice, improved mild colonic inflammation and intestinal mucosal permeability, up-regulated the expression of tight junction proteins ZO-1 and occludin. Sinisan significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice by decreasing the expression of TNF-α, promoting the expression of tight junction proteins (occludin, ZO-1) expression, and inhibiting the Tlr4/Myd88 signaling pathway, thereby attenuating the inflammatory response, protecting the intestinal barrier, and alleviating symptoms in the IBS-D mouse model. Taken together, sinisan may ameliorate intestinal inflammation and the intestinal barrier by regulating 5-HT expression and the Tlr4/Myd88 pathway, thereby alleviating stress-induced intestinal dysfunction and depressive behaviors in IBS-D mice.

Effect of Morchella esculenta polysaccharides on the rectal microbiota of mice challenged with lipopolysaccharides.

Intestinal dysfunction poses a severe problem by preventing the digestion and absorption of nutrients. The gut, being the most vital organ for these processes, plays a crucial role in ensuring our body receives the nutrients it needs. We explored the mitigating effect of Morchella esculenta polysaccharides (MEP) on intestinal injury induced by lipopolysaccharides (LPS) through the modulation of intestinal flora. For this purpose, Kunming mice (KM) were divided into three groups, namely, PC, PM, and PY. Group PY was treated with MEP, while groups PM and PY were induced with LPS. The results showed that weight loss in the PM group was significantly greater than that in the PY group (P < 0.05), and the organ indexes of the lung and spleen in the PM group were significantly higher than those in the PC (P < 0.01) and PY (P < 0.05) groups. LPS caused severe injuries in KM mice in the PM group, characterized by broken villi. However, MEP treatment could alleviate this damage in the PY group, resulting in relatively intact villi. The serum analysis showed that tumor necrosis factor alpha (TNF-ɑ) (P < 0.01), interleukin 6 (IL-6) (P < 0.01), and 3,4-methylenedioxyamphetamine (MDA) (P < 0.05) levels were significantly higher in the PM group, while IL-10 (P < 0.001), superoxide dismutase (SOD) (P < 0.01) and glutathione peroxidase (GSH-Px) (P < 0.01) were significantly lower in that group. Interestingly, supplementation with MEP could lower the levels of TNF-ɑ, IL-10, IL-6, MDA while increasing the levels of superoxide dismutase (SOD) (P < 0.01) and GSH-Px. The gut microbiota analysis yielded 630,323 raw reads and 554,062 clean reads, identifying 3,390 amplicon sequencing variants (ASVs). One phylum and five genera were notably different among animal groups, including Escherichia_Shigella, Limosilactobacillus, unclassified_Geminicoccaceae, unclassified_Rhodobacteraceae, and Parabacteroides (P. distasonis). In conclusion, we found that MEP could mitigate the intestinal damage caused by LPS by modulating the inflammatory response, oxidative resistance, and intestinal flora of KM mice. Our results may provide insights into novel treatment options for intestine-related diseases.

Zonulin — effective biomarker for the diagnosis of intestinal lesions in patients with nonalcoholic fatty liver disease in COVID‑19

The SARS‑CoV‑2 virus mainly attacks the respiratory system, but can also affect several organs, in particular, causing gastrointestinal symptoms such as vomiting, diarrhea or abdominal pain in the early stages of the disease. Intestinal dysfunction leads to a change in intestinal microorganisms and an increase in the content of inflammatory cytokines. Liver dysfunction is also relatively common in patients with coronavirus disease 2019 (COVID19). Objective — to investigate the efficacy of zonulin in determining intestinal damage in patients with nonalcoholic fatty liver disease with COVID‑19. Materials and methods. The study included 76 patients with non‑alcoholic fatty liver disease (NAFLD) who had complaints indicating intestinal disorders during the outpatient stage of follow‑up after ­COVID‑19. From the anamnesis, it was found that all examined patients had a confirmed diagnosis of infection with SARS‑CoV‑2 virus. All patients had a mostly mild course of COVID‑19, which did not require hospitalization. Patients with NAFLD were divided into two groups depending on defecation violation: group I — 36 patients who, after an acute respiratory infection caused by the SARS‑CoV‑2 virus, developed periodic diarrhea (on average, in (38.7±5.2) days after a negative PCR result for SARS‑CoV‑2 virus); group II — 40 patients with constipation, which began to bother on average in (86.9±7.4) days after a negative PCR result. The control group included 20 practically healthy individuals. The level of zonulin was determined in blood serum and faeces by enzyme‑linked immunosorbent assay. Patients underwent faecal culture to assess the quantitative and qualitative composition of the colon microflora. Results. During the anthropometric examination, overweight and first‑degree obesity were detected more frequently in patients of both groups: overweight was diagnosed most frequently in patients of group I (38.9%) and first‑degree obesity in patients of group II (35.0%). The microbiological examination of faeces in both groups of patients revealed a decrease in the number of bifidus and lactobacilli, as well as Enterococcus and E. coli with normal enzymatic properties. In group I patients, Citrobacter and Staphylococcus were statistically significantly (p &lt;0.05) more often detected in increased concentrations in faeces, whereas in group II patients Enterobacter, Klebsiella and Clostridium were detected (p &lt;0.05). Significant changes were found in the analysis of zonulin levels in both serum and faeces in patients with NAFLD after COVID‑19. Serum zonulin levels in patients of group I increased 6.5‑fold, and in patients of group II—8.6‑fold (p &lt;0.001). An increase in the concentration of zonulin in the faeces was also detected — by 7.5 and 9.7 times, respectively (p &lt;0.001). A correlation was established between the level of zonulin in both blood serum and faeces and a decrease in the number of bifidus and lactobacilli in faeces in patients of both groups. Also, a strong correlation was found between the number of Enterobacter, Klebsiella and Clostridium and a medium intensity correlation between the number of Staphylococcus in the faeces in patients of group ІІ. In patients of group І, a correlation was found between the number of Staphylococcus and Citrobacter. The level of zonulin (both in blood serum and faeces) directly depended on changes in body mass index in the patients we examined, namely, overweight in patients of group І and obesity of the first degree in patients of group ІІ. Conclusions. In patients with NAFLD after COVID19, changes in the quantitative and qualitative composition of the colon microflora were found in the intestinal lesions, including a decrease in the number of bifidobacteria and lactobacilli, as well as an increase in the content of Staphylococcus and Citrobacter in the faeces in patients with predominant diarrhoea and Enterobacter, Klebsiella and Clostridium in patients with predominant constipation. An increase in the level of zonulin in the blood serum and faeces in patients with NAFLD after ­COVID‑19 was detected. A more pronounced deviation from the norm was found in patients of group ІІ (with complaints of constipation). A direct correlation was established between the level of zonulin in the blood serum and faeces and changes in the quantitative and qualitative composition of the colon microflora, as well as an increase in body mass index in patients with NAFLD after ­COVID‑19.

Enteric glial NLRP3 inflammasome contributes to gut mucosal barrier alterations in a mouse model of diet-induced obesity.

In the present study, we investigated the involvement of NLRP3 inflammasome in the intestinal epithelial barrier (IEB) changes associated with obesity, and its role in the interplay between enteric glia and intestinal epithelial cells (IECs). Wild-type C57BL/6J and NLRP3-KO (-/-) mice were fed with high-fat diet (HFD) or standard diet for 8 weeks. Colonic IEB integrity and inflammasome activation were assessed. Immunolocalization of colonic mucosal GFAP- and NLRP3-positive cells along with invitro coculture experiments with enteric glial cells (EGCs) and IECs allowed to investigate the potential link between altered IEB, enteric gliosis, and NLRP3 activation. HFD mice showed increased body weight, altered IEB integrity, increased GFAP-positive glial cells, and NLRP3 inflammasome hyperactivation. HFD-NLRP3-/- mice showed a lower increase in body weight, an improvement in IEB integrity and an absence of enteric gliosis. Coculture experiments showed that palmitate and lipopolysaccharide contribute to IEB damage and promote enteric gliosis with consequent hyperactivation of enteric glial NLRP3/caspase-1/IL-1β signaling. Enteric glial-derived IL-1β release exacerbates the IEB alterations. Such an effect was abrogated upon incubation with anakinra (IL-1β receptor antagonist) and with conditioned medium derived from silenced-NLRP3 glial cells. HFD intake elicits mucosal enteric gliotic processes characterized by a hyperactivation of NLRP3/caspase-1/IL-1β signaling pathway, that contributes to further exacerbate the disruption of intestinal mucosal barrier integrity. However, we cannot rule out the contribution of NLRP3 inflammasome activation from other cells, such as immune cells, in IEB alterations associated with obesity. Overall, our results suggest that enteric glial NLRP3 inflammasome might represent an interesting molecular target for the development of novel pharmacological approaches aimed at managing the enteric inflammation and intestinal mucosal dysfunctions associated with obesity.

Dexmedetomidine ameliorates diabetic intestinal injury by promoting the polarization of M2 macrophages through the MMP23B pathway.

Diabetes is often associated with gastrointestinal dysfunctions, which can lead to hypoglycemia. Dexmedetomidine (DEX) is a commonly used sedative in perioperative diabetic patients and may affect gastrointestinal function. To investigate whether sedative doses of DEX alleviate diabetes-caused intestinal dysfunction. Sedation/anesthesia scores and vital signs of streptozotocin (STZ)-induced diabetic mice under DEX sedation were observed. Diabetic mice were divided into saline and DEX groups. After injecting sedatives intraperitoneally, tight junctions (TJs) and apoptotic levels were evaluated 24 hours later to assess the intestinal barrier function. The role of DEX was validated using Villin-MMP23B flox/flox mice with intestinal epithelial deletion. In vitro, high glucose and hyperosmolarity were used to culture Caco-2 monolayer cells with STZ inter-vention. Immunofluorescence techniques were used to monitor the barrier and mitochondrial functions. MMP23B protein levels in the intestinal tissue of STZ-induced diabetic mice were significantly higher than those in the intestinal tissue of control mice, with the DEX group displaying decreased MMP23B levels. Diabetes-mediated TJ dis-ruption, increased intestinal mucosal permeability, and systemic inflammation in wild-type mice might be reversed by DEX. In Caco-2 cells, MMP23B was associated with increased reactive oxygen species accumulation, mitochondrial membrane potential depolarization, and TJ disruption. DEX reduces MMP23B, which may potentially contribute to STZ-induced intestinal barrier dysfunction, affecting TJ modification through mitochondrial dysfunction.

Gastrointestinal dysmotility is associated with proton pump inhibitor refractory esophagitis in patients with systemic sclerosis.

Patients with systemic sclerosis present with severe gastroesophageal reflux disease, often refractory to proton-pump inhibitors (PPI) treatment. The aim of the present study was to identify factors associated with PPI-refractory esophagitis. We performed a cross-sectional study in a single-center cohort of patients diagnosed with systemic sclerosis. We included patients who underwent an esophagogastroduodenoscopy while on PPI treatment. Patients with PPI-refractory erosive esophagitis were compared with those with endoscopically normal esophageal mucosa. A total of 69 patients were included, from these, 23 patients (33%) had PPI-refractory esophagitis (Grade A, n = 11; Grade B, n = 7; Grade C, n = 2; Grade D, n = 3) and 46 (67%) had an endoscopically normal esophageal mucosa. On univariate analysis, patients with PPI-refractory esophagitis were more frequently diffuse SSc subset (43% vs 17%; p= 0.041). Evaluating gastrointestinal motility tests, neither absent esophageal contractility (39% vs 25%, p= 0.292) nor hypotensive lower esophageal sphincter (47% vs 44%, p= 0.980) were significantly associated with PPI-refractory esophagitis. Gastrointestinal dysmotility, defined as abnormal gastric emptying and/or small bowel dilated loops, was significantly associated with PPI-refractory esophagitis (66 vs 8%, p = <0.001). On a multivariate regression model to evaluate the association between motility test results adjusted for the diffuse subset, gastrointestinal dysmotility (β = 0.751, p= 0.010) was independently associated with PPI-refractory esophagitis, while absent esophageal contractility (β = 0.044, p= 0.886) or a hypotensive LES were not (β=-0.131, p= 0.663). Our findings suggest that gastric and small intestinal motor dysfunction may be an important contributor to the development of PPI-refractory esophagitis in patients with systemic sclerosis.

ACSL4 mediates inflammatory bowel disease and contributes to LPS-induced intestinal epithelial cell dysfunction by activating ferroptosis and inflammation.

The pathogenesis of inflammatory bowel disease (IBD) is closely associated with the dysfunction of the intestinal epithelial barrier, leading to increased bacterial translocation, leukocyte infiltration, and mucosal injury, which may act as a pivotal or incipient event in the pathophysiology of the disorder. The primary objective of this study is to examine the key genes implicated in IBD and the perturbation of intestinal epithelial cell function. The genes associated with ferroptosis were identified through the utilization of the Gene Expression Omnibus (GEO) database and the GeneCard database. Additionally, an in vitro model of IBD was established by stimulating Caco-2 cells with lipopolysaccharides (LPSs) to investigate the molecular mechanisms underlying intestinal epithelial cell dysfunction. We discovered evidence that establishes a connection between ferroptosis and the inflammatory responses associated with the development of IBD. This evidence suggests that IBD patients who exhibit an inflammatory response have higher expression of the acyl-CoA synthetase long-chain family member 4 (ACSL4) gene compared to IBD patients without an inflammatory response or healthy individuals. Exposure to LPS at concentrations of 1 or 10 μg/mL resulted in a significant upregulation of ferroptosis-related genes ACSL4, GPX4, and SLC7A11, as well as an increase in ferroptosis biomarkers MDA and a decrease in CAT and GSH-Px levels compared to the control group. Inhibition of ACSL4 using si-ACSL4 or rosiglitazone demonstrated protective effects against LPS-induced ferroptosis and NF-κB-mediated inflammatory response. ACSL4 shows potential as a promising target for ferroptosis in the prevention and treatment of IBD and dysfunction of intestinal epithelial cells.

High-resolution versus conventional manometry for the diagnosis of small bowel motor dysfunction.

The diagnosis of small bowel motility disorders is performed by manometric evaluation of the contractile patterns of the small intestine. Conventional intestinal manometry systems include few pressure sensors at relatively long intervals. We have recently shown that high-resolution jejunal manometry, with multiple closely spaced recording sites, allows the analysis of propagation patterns of intestinal motility in healthy subjects that cannot be detected with conventional manometry. The objective of this pilot study was to explore the feasibility and diagnostic value of high-resolution intestinal manometry in patients with suspected small bowel dysmotility. Prospective pilot study evaluating intestinal motility patterns in 16 consecutive patients (16-61 years; 11 women) with severe, chronic digestive symptoms referred for the evaluation of intestinal motility and in 18 healthy controls (21-38 years; 8 women). A 36-channel high-resolution manometry catheter was orally placed under radiological guidance in the jejunum. Intestinal motility was continuously recorded for 3 h fasting and 2 h after a 450 kcal meal. The manometric recordings were analyzed in two formats: (a) with the high-resolution data from 34 channels and (b) showing only the recordings from 5 channels separated by 7 cm intervals, mimicking a conventional manometry recording. In the analysis mimicking conventional manometry, abnormal motility criteria were detected in six patients and in no healthy subject [bursts (n = 3), postprandial minute rhythm (n = 1) and myopathic pattern (n = 2)]. These classical dysmotility criteria were also detected by high-resolution manometry. High-resolution analysis detected one or more abnormal findings in seven additional patients that were not observed in any healthy subject, specifically: (a) abnormal propagation of Phase III (n = 3); (b) reduced propagated activity during Fasting Phase II (n = 4); (c) increased propagated activity during Fasting Phase II and postprandial phase (n = 1). This pilot study suggests that high-resolution intestinal manometry may improve the sensitivity of conventional manometry in the detection of intestinal motor dysfunction.

Network Pharmacology Analysis and Retrospective Cohort Study Revealing the Effect of Qingyi Decoction on Intestinal Paralysis in Patients with Severe Acute Pancreatitis.

Intestinal dysfunction plays an important role in the clinical progress and prognosis of severe acute pancreatitis (SAP). Qingyi decoction (QYD) has shown beneficial effects on intestinal function recovery, but the prevention actions of the QYD on intestinal paralysis and its mechanism have not been fully explored. The possible molecular mechanism was unraveled by network pharmacology, including active ingredients and potential target prediction, as well as GO, KEGG, and REATCOME pathway enrichment analyses. The potential interactions between the main active ingredients of the QYD and core genes were explored by molecular docking. A retrospective cohort study on 137 patients with SAP from Tianjin Nankai Hospital was conducted to evaluate the preventive effect of QYD on intestinal paralysis. A total of 110 active ingredients in QYD were screened out, and 37 key targets were predicted by network pharmacology. GO, KEGG, and REATCOME enrichment analyses showed that bioinformatics annotation of the hub genes was mainly involved in intestinal epithelial functions and inflammatory response pathways. The main components of QYD possessed good affinity with IL-6, TNF, CASP3, CXCL8, and CRP by molecular docking. Patients who used QYD plus usual care seemed to have fewer intestinal paralysis rates, lower risk of renal insufficiency, ARDS and blood purification therapy, and shorter hospital and ICU stays. The multivariable regression analyses indicated that the mode of nasogastric and enemas administration of QYD (P = 0.010) and timely intervention with QYD (P = 0.045) were the independent protective factors for intestinal paralysis prevention in patients with SAP. In conclusion, QYD can be used as an effective adjuvant procedure to prevent the occurrence and development of intestinal paralysis in patients with SAP. The mechanisms may be involved in the anti-inflammatory response and maintenance of intestinal epithelial function.

Nitric oxide in the mechanisms of inhibitory effects of sodium butyrate on colon contractions in a mouse model of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a multifactorial disorder, with altered intestinal motility, visceral hypersensitivity, and dysfunction of the gut-brain axis. The aim of our study was to analyze the role of nitric oxide (NO) in the inhibitory effects of sodium butyrate on spontaneous contractility of proximal colon in a mouse model of IBS. IBS was induced by intracolonic infusion of acetic acid in the early postnatal period. Spontaneous contractions of proximal colon segments were studied in isometric conditions. The amplitude and frequency of colon contractions were higher in the IBS group. Sodium butyrate exerted inhibitory effects on colon contractions, which were less pronounced in IBS group. NO donors decreased spontaneous colon contractility and prevented the inhibitory effects of sodium butyrate in control and IBS groups. Nitric oxide synthase (NOS) inhibition by L-NAME increased contractile activity more effective in the control group and decreased the inhibitory action of sodium butyrate. In IBS group, preliminary application of L-NAME did not prevent sodium butyrate action. Our data indicate that butyrate exerts its inhibitory effects on colon motility at least partially through activation of NO synthesis. In the IBS model group, the NO-dependent mechanisms were less effective probably due to downregulation of NOS.

Developing a novel hypothesis to enhance mental resilience via targeting Faecalibacterium prausnitzii in gut-brain axis

Social stress (SS) can lead to mental disorders (MD) in some people, such as depression and anxiety, while others who are resilient can handle SS without showing signs of mental illness. Resilience is characterized by human capacity to adapt to life’s adverse events without losing function or developing a mental disorder. Exploring molecular processes can help elucidate resilience mechanisms that counteract the pathophysiology of depression. Gut microbiome plays an essential role in the homeostasis of human body, especially the central nervous system (CNS). Therefore, it may support the counterbalance of certain disorders, such as depression, through the microbiota-gut-brain (MGB) axis. Short-chain fatty acids (SCFAs) produced by the gut microbiota, such as butyrate, increase the transmission activity of neurotransmitters, brain-derived neurotrophic factor (BDNF) expression and the regulation of microglia maturation enhances resilience in response to stress. Probiotics can be engineered to yield more butyrate. However, the overproduction of SCFAs is not necessarily beneficial and may lead to known side effects, such as intestinal dysbiosis or metabolic dysfunction. Herein, as we hypothesized the potential effect of the microbiome in resilience promotion, we have designed a cortisol-sensitive operon that allows gut microbiota to regulate the production of SCFAs according to the environmental demands which produces butyrate only when responding to stress. Amongst gut bacteria, Faecalibacterium prausnitzii (F. prausnitzii) has large amounts of butyrate and can be manipulated by designed plasmid, a process which makes it a suitable candidate to be translated into clinic.

Lonicerin alleviates intestinal myenteric neuron injury induced by hypoxia/reoxygenation treated macrophages by downregulating EZH2.

Intestinal ischemia-reperfusion (IR) injury is a common gastrointestinal disease that induces severe intestinal dysfunction. Intestinal myenteric neurons participate in maintaining the intestinal function, which will be severely injured by IR. Macrophages are widely reported to be involved in the pathogenesis of organ IR injury, including intestine, which is activated by NLRP3 signaling. Lonicerin (LCR) is a natural extracted monomer with inhibitory efficacy against the NLRP3 pathway in macrophages. The present study aims to explore the potential protective function of LCR in intestinal IR injury. Myenteric neurons were extracted from mice. RAW 264.7 cells were stimulated by H/R with or without 10 μM and 30 μM LCR. Remarkable increased release of IL-6, MCP-1, and TNF-α were observed in H/R treated RAW 264.7 cells, along with an upregulation of NLRP3, cleaved-caspase-1, IL-1β, and EZH2, which were sharply repressed by LCR. Myenteric neurons were cultured with the supernatant collected from each group. Markedly decreased neuron number and shortened length of neuron axon were observed in the H/R group, which were signally reversed by LCR. RAW 264.7 cells were stimulated by H/R, followed by incubated with 30 μM LCR with or without pcDNA3.1-EZH2. The inhibition of LCR on NLRP3 signaling in H/R treated RAW 264.7 cells was abolished by EZH2 overexpression. Furthermore, the impact of LCR on neuron number and neuron axon length in myenteric neurons in the H/R group was abated by EZH2 overexpression. Collectively, LCR alleviated intestinal myenteric neuron injury induced by H/R treated macrophages via downregulating EZH2.

Unraveling Cross-Organ Impacts of Airborne Pollutants: A Multiomics Study on Respiratory Exposure and Gastrointestinal Health.

Poor air quality is increasingly linked to gastrointestinal diseases, suggesting a potential correlation with human intestine health. However, this relationship remains largely unexplored due to limited research. This study used a controlled mouse model exposed to cooking oil fumes (COFs) and metagenomics, transcriptomics, and metabolomics to elucidate interactions between intestine microbiota and host metabolism under environmental stress. Our findings reveal that short-term COF inhalation induces pulmonary inflammation within 3 days and leads to gastrointestinal disturbances, elucidating a pathway connecting respiratory exposure to intestinal dysfunction. The exposure intensity significantly correlates with changes in intestinal tissue integrity, microbial composition, and metabolic function. Extended exposure of 7 days disrupts intestine microbiota and alters tryptophan metabolism, with further changes observed after 14 days, highlighting an adaptive response. These results highlight the vulnerability of intestinal health to airborne pollutants and suggest a pathway through which inhaled pollutants may affect distant organ systems.

Textbook anastomotic success in patients with low rectal cancer treated by intersphincteric resection: reappraising surgical, oncological, and functional outcomes.

Previous studies on successful anastomosis after intersphincteric resection (ISR) for low rectal cancer (LRC) primarily focused on anastomotic complications rather than functional outcomes. Here, we improved the anastomotic success criteria by considering surgical, oncological, and functional outcomes and proposed a new composite outcome, "textbook anastomotic success" (TASS). This retrospective single-center study included patients with LRC treated with ISR from January 2014 to April 2020. TASS was defined as (1) no anastomotic complications occurring after ISR; (2) ileostomy was closed and there was no severe intestinal dysfunction 2years after ISR; and (3) no local recurrence within 2years of surgery. TASS was achieved upon meeting all indicators. We analyzed 259 patients with LRC, with 125 (48.3%) achieving TASS. Multivariate analysis showed that male sex (OR 0.47; 95% CI 0.27-0.81; p = 0.007), hypertension (OR 0.48; 95% CI 0.24-0.97; p = 0.041), ASA score ≥ 3 (OR 0.28; 95% CI 0.10-0.81; p = 0.018), pre-treatment major low anterior resection syndrome (OR 0.37; 95% CI 0.15-0.94; p = 0.037), and preoperative neoadjuvant chemoradiotherapy (OR 0.41; 95% CI 0.22-0.77; p = 0.006) were independent risk factors for not achieving TASS. Conversely, transverse coloplasty pouch (OR 2.13; 95% CI 1.07-4.25; p = 0.032) and higher anastomosis level (OR 1.56; 95% CI 1.05-2.30; p = 0.026) were independent protective factors for achieving TASS. The nomogram constructed to evaluate the probability of achieving TASS demonstrated good accuracy in the dataset (area under curve, 0.737). TASS provides a comprehensive quality assessment for ISR in patients with LRC. The nomogram predicting TASS may assist surgeons in decision-making for managing LRC.

Nobiletin restores HFD-induced enteric nerve injury by regulating enteric glial activation and the GDNF/AKT/FOXO3a/P21 pathway

BackgroundTo explore whether nobiletin has a protective effect on high-fat diet (HFD)-induced enteric nerve injury and its underlying mechanism.MethodsAn obesity model was induced by a HFD. Nobiletin (100 mg/kg and 200 mg/kg) and vehicle were administered by gastric gavage for 4 weeks. Lee’s index, body weight, OGTT and intestinal propulsion assays were performed before sacrifice. After sampling, lipids were detected using Bodipy 493/503; lipid peroxidation was detected using MDA and SOD kits and the expression of PGP 9.5, Trem2, GFAP, β-tubulin 3, Bax, Bcl2, Nestin, P75 NTR, SOX10 and EDU was detected using immunofluorescence. The GDNF, p-AKT, AKT, p-FOXO3a, FOXO3a and P21 proteins were detected using western blotting. The relative mRNA expression levels of NOS2 were detected via qPCR. Primary enteric neural stem cells (ENSCs) were cultured. After ENSCs were treated with palmitic acid (PA) and nobiletin, CCK-8 and caspase-3/7 activity assays were performed to evaluate proliferation and apoptosis.ResultsHFD consumption caused colon lipid accumulation and peroxidation, induced enteric nerve damage and caused intestinal motor dysfunction. However, nobiletin reduced lipid accumulation and peroxidation in the colon; promoted Trem2, β-tubulin 3, Nestin, P75NTR, SOX10 and Bcl2 expression; inhibited Bax and GFAP expression; reduced NOS2 mRNA transcription; and regulated the GDNF/AKT/FOXO3a/P21 pathway. Nobiletin also promoted PA-induced impairment of ENSCs.ConclusionsNobiletin restored HFD-induced enteric nerve injury, which may be associated with inhibiting enteric nerve apoptosis, promoting enteric nerve survival and regulating the GDNF/AKT/FOXO3a/P21 pathway.

Identification of Antioxidant Methyl Derivatives of Ortho-Carbonyl Hydroquinones That Reduce Caco-2 Cell Energetic Metabolism and Alpha-Glucosidase Activity.

α-glucosidase, a pharmacological target for type 2 diabetes mellitus (T2DM), is present in the intestinal brush border membrane and catalyzes the hydrolysis of sugar linkages during carbohydrate digestion. Since α-glucosidase inhibitors (AGIs) modulate intestinal metabolism, they may influence oxidative stress and glycolysis inhibition, potentially addressing intestinal dysfunction associated with T2DM. Herein, we report on a study of an ortho-carbonyl substituted hydroquinone series, whose members differ only in the number and position of methyl groups on a common scaffold, on radical-scavenging activities (ORAC assay) and correlate them with some parameters obtained by density functional theory (DFT) analysis. These compounds' effect on enzymatic activity, their molecular modeling on α-glucosidase, and their impact on the mitochondrial respiration and glycolysis of the intestinal Caco-2 cell line were evaluated. Three groups of compounds, according their effects on the Caco-2 cells metabolism, were characterized: group A (compounds 2, 3, 5, 8, 9, and 10) reduces the glycolysis, group B (compounds 1 and 6) reduces the basal mitochondrial oxygen consumption rate (OCR) and increases the extracellular acidification rate (ECAR), suggesting that it induces a metabolic remodeling toward glycolysis, and group C (compounds 4 and 7) increases the glycolysis lacking effect on OCR. Compounds 5 and 10 were more potent as α-glucosidase inhibitors (AGIs) than acarbose, a well-known AGI with clinical use. Moreover, compound 5 was an OCR/ECAR inhibitor, and compound 10 was a dual agent, increasing the proton leak-driven OCR and inhibiting the maximal electron transport flux. Additionally, menadione-induced ROS production was prevented by compound 5 in Caco-2 cells. These results reveal that slight structural variations in a hydroquinone scaffold led to diverse antioxidant capability, α-glucosidase inhibition, and the regulation of mitochondrial bioenergetics in Caco-2 cells, which may be useful in the design of new drugs for T2DM and metabolic syndrome.

The 5HT4R agonist velusetrag efficacy on neuropathic chronic intestinal pseudo-obstruction in PrP-SCA7-92Q transgenic mice.

Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction with symptoms of intestinal blockage but without the actual mechanical obstruction. Currently, there are no drugs available to treat this disease. Herein, we report the characterization of the PrP-SCA7-92Q transgenic (Tg) line as a valuable CIPO mouse model and investigated the tolerability and efficacy of the 5-hydroxytryptamine type-4 receptor (5HT4R) agonist velusetrag as a promising pharmacological treatment for CIPO. To test the pharmacodynamics of velusetrag, 8-week-old SCA7 Tg mice, which express human mutated Ataxin-7 gene containing 92 CAG repeats under the mouse prion protein promoter, were treated for 5weeks by oral route with velusetrag at 1 and 3mg/kg doses or vehicle. Body weight was monitored throughout the treatment. After sacrifice, the small intestine and proximal colon were collected for whole-mount immunostaining. Untreated, age-matched, C57BL/6J mice were also used as controls in comparison with the other experimental groups. Analysis of SCA7 Tg mice showed tissue damage and alterations, mucosal abnormalities, and ulcers in the distal small intestine and proximal colon. Morphological changes were associated with significant neuronal loss, as shown by decreased staining of pan-neuronal markers, and with accumulation of ataxin-7-positive inclusions in cholinergic neurons. Administration of velusetrag reversed intestinal abnormalities, by normalizing tissue damage and re-establishing the normal level of glia/neuron's count in both the small and large intestines. We demonstrated that the PrP-SCA7-92Q Tg line, a model originally developed to mimic spinocerebellar ataxia, is suitable to study CIPO pathology and can be useful in establishing new therapeutic strategies, such as in the case of velusetrag. Our results suggest that velusetrag is a promising compound to treat patients affected by CIPO or intestinal dysmotility disease.

Arecoline inhibits the growth of Spodoptera litura by inducing intestinal metabolic dysfunction

Arecoline (ACL), an active constituent derived from Areca catechu L., exerts various pharmacological effects and serves as a potential plant-based insecticide. However, the effects of ACL on Spodoptera litura, an important and widely distributed agricultural pest, remain unknown. This study aimed to elucidate the mechanism underlying ACL-induced toxicity and its inhibitory effects on larval growth and development through intestinal pathology observations, intestinal transcriptome sequencing, intestinal digestive enzyme activity analysis. The results indicated that ACL exposure leads to pathological alterations in the S. litura midgut. Furthermore, the detection of digestive enzyme activity revealed that ACL inhibits the activities of acetyl CoA carboxylase, lipase, α-amylase, and trypsin. Simultaneously, upregulation of superoxide dismutase activity and downregulation of malondialdehyde levels were observed after ACL exposure. Transcriptome analysis identified 1118 genes that were significantly differentially expressed in the midgut after ACL exposure, potentially related to ACL toxic effects. Notably, ACL treatment downregulated key enzymes involved in lipid metabolism, such as fatty acid binding protein 2-like, pancreatic triacylglycerol lipase-like, pancreatic lipid-related protein 2-like, and fatty acid binding protein 1-like. Taken together, these results suggest that ACL induces midgut damage and impedes larval growth by suppressing digestive enzyme activity in the intestine. These findings can aid in the development of environmentally friendly plant-derived insecticides, utilizing ACL to effectively combat S. litura proliferation.

Bacillus coagulans restores pathogen-induced intestinal dysfunction via acetate-FFAR2-NF-κB-MLCK-MLC axis in Apostichopus japonicus.

Skin ulceration syndrome (SUS) is currently the main disease threatening Apostichopus japonicus aquaculture due to its higher mortality rate and infectivity, which is caused by Vibrio splendidus. Our previous studies have demonstrated that SUS is accompanied by intestinal microbiota (IM) dysbiosis, alteration of short-chain fatty acids (SCFAs) content and the damage to the intestinal barrier. However, the mediating effect of IM on intestine dysfunction is largely unknown. Herein, we conducted comprehensive intestinal microbiota transplantation (IMT) to explore the link between IM and SUS development. Furthermore, we isolated and identified a Bacillus coagulans strain with an ability to produce acetic acid from both healthy individual and SUS individual with IM from healthy donors. We found that dysbiotic IM and intestinal barrier function in SUS recipients A. japonicus could be restored by IM from healthy donors. The B. coagulans strain could restore IM community and intestinal barrier function. Consistently, acetate supply also restores intestinal homeostasis of SUS-diseased and V. splendidus-infected A. japonicus. Mechanically, acetate was found to specifically bind to its receptor-free fatty acid receptor 2 (FFAR2) to mediate IM structure community and intestinal barrier function. Knockdown of FFAR2 by transfection of specific FFAR2 siRNA could hamper acetate-mediated intestinal homeostasis in vivo. Furthermore, we confirmed that acetate/FFAR2 could inhibit V. splendidus-activated NF-κB-MLCK-MLC signaling pathway to restore intestinal epithelium integrity and upregulated the expression of ZO-1 and Occludin. Our findings provide the first evidence that B. coagulans restores pathogen-induced intestinal barrier dysfunction via acetate/FFAR2-NF-κB-MLCK-MLC axis, which provides new insights into the control and prevention of SUS outbreak from an ecological perspective.IMPORTANCESkin ulceration syndrome (SUS) as a main disease in Apostichopus japonicus aquaculture has severely restricted the developmental A. japonicus aquaculture industry. Intestinal microbiota (IM) has been studied extensively due to its immunomodulatory properties. Short-chain fatty acids (SCFAs) as an essential signal molecule for microbial regulation of host health also have attracted wide attention. Therefore, it is beneficial to explore the link between IM and SUS for prevention and control of SUS. In the study, the contribution of IM to SUS development has been examined. Additionally, our research further validated the restoration of SCFAs on intestinal barrier dysfunction caused by SUS via isolating SCFAs-producing bacteria. Notably, this restoration might be achieved by inhibition of NF-κB-MLCK-MLC signal pathway, which could be activated by V. splendidus. These findings may have important implications for exploration of the role of IM in SUS occurrence and provide insight into the SUS treatment.