Gastrointestinal complications after ischemic stroke

The gut-immune axis during hypertension and cardiovascular diseases

The gut-immune axis is a relatively novel phenomenon that provides mechanistic links between the gut microbiome and the immune system. A growing body of evidence supports it is key in how the gut microbiome contributes to several diseases, including hypertension and cardiovascular diseases (CVDs). Evidence over the past decade supports a causal link of the gut microbiome in hypertension and its complications, including myocardial infarction, atherosclerosis, heart failure, and stroke. Perturbations in gut homeostasis such as dysbiosis (i.e., alterations in gut microbial composition) may trigger immune responses that lead to chronic low-grade inflammation and, ultimately, the development and progression of these conditions. This is unsurprising, as the gut harbors one of the largest numbers of immune cells in the body, yet is a phenomenon not entirely understood in the context of cardiometabolic disorders. In this review, we discuss the role of the gut microbiome, the immune system, and inflammation in the context of hypertension and CVD, and consolidate current evidence of this complex interplay, whilst highlighting gaps in the literature. We focus on diet as one of the major modulators of the gut microbiota, and explain key microbial-derived metabolites (e.g., short-chain fatty acids, trimethylamine N-oxide) as potential mediators of the communication between the gut and peripheral organs such as the heart, arteries, kidneys, and the brain via the immune system. Finally, we explore the dual role of both the gut microbiome and the immune system, and how they work together to not only contribute, but also mitigate hypertension and CVD.

From Gut to Brain: Unraveling the Intricate Link Between Microbiome and Stroke

Stroke, a neurological disorder, is intricately linked to the gut microbiota, influencing microbial composition and elevating the risk of ischemic stroke. The neuroprotective impact of short-chain fatty acids (SCFAs) derived from dietary fiber fermentation contrasts with the neuroinflammatory effects of lipopolysaccharide (LPS) from gut bacteria. The pivotal role of the gut-brain axis, facilitating bidirectional communication between the gut and the brain, is crucial in maintaining gastrointestinal equilibrium and influencing cognitive functions. An in-depth understanding of the interplay among the gut microbiota, immune system, and neurological outcomes in stroke is imperative for devising innovative preventive and therapeutic approaches. Strategies such as dietary adjustments, probiotics, prebiotics, antibiotics, or fecal transplantation offer promise in modulating stroke outcomes. Nevertheless, comprehensive research is essential to unravel the precise mechanisms governing the gut microbiota's involvement in stroke and to establish effective therapeutic interventions. The initiation of large-scale clinical trials is warranted to assess the safety and efficacy of interventions targeting the gut microbiota in stroke management. Tailored strategies that reinstate eubiosis and foster a healthy gut microbiota hold potential for both stroke prevention and treatment. This review underscores the gut microbiota as a promising therapeutic target in stroke and underscores the need for continued research to delineate its precise role and develop microbiome-based interventions effectively.

The Involvement of Immune Cells Between Ischemic Stroke and Gut Microbiota

Ischemic stroke, a disease with high mortality and disability rate worldwide, currently has no effective treatment. The systemic inflammation response to the ischemic stroke, followed by immunosuppression in focal neurologic deficits and other inflammatory damage, reduces the circulating immune cell counts and multiorgan infectious complications such as intestinal and gut dysfunction dysbiosis. Evidence showed that microbiota dysbiosis plays a role in neuroinflammation and peripheral immune response after stroke, changing the lymphocyte populations. Multiple immune cells, including lymphocytes, engage in complex and dynamic immune responses in all stages of stroke and may be a pivotal moderator in the bidirectional immunomodulation between ischemic stroke and gut microbiota. This review discusses the role of lymphocytes and other immune cells, the immunological processes in the bidirectional immunomodulation between gut microbiota and ischemic stroke, and its potential as a therapeutic strategy for ischemic stroke.

Immune regulation of the gut-brain axis and lung-brain axis involved in ischemic stroke

Local ischemia often causes a series of inflammatory reactions when both brain immune cells and the peripheral immune response are activated. In the human body, the gut and lung are regarded as the key reactional targets that are initiated by brain ischemic attacks. Mucosal microorganisms play an important role in immune regulation and metabolism and affect blood-brain barrier permeability. In addition to the relationship between peripheral organs and central areas and the intestine and lung also interact among each other. Here, we review the molecular and cellular immune mechanisms involved in the pathways of inflammation across the gut-brain axis and lung-brain axis. We found that abnormal intestinal flora, the intestinal microenvironment, lung infection, chronic diseases, and mechanical ventilation can worsen the outcome of ischemic stroke. This review also introduces the influence of the brain on the gut and lungs after stroke, highlighting the bidirectional feedback effect among the gut, lungs, and brain.

Gastrointestinal Bleeding in Patients With Acute Ischemic Stroke: A Literature Review

Stroke is an infarction of the central nervous system (brain, spinal cord, or retina) that results from a disruption in cerebral blood flow either due to ischemia or hemorrhage. Complications of acute stroke are common and include pneumonia, urinary tract infection, myocardial infarction, deep vein thrombosis, and pulmonary embolism, among several others, all of which increase the risk of poor clinical outcomes. Gastrointestinal bleeding is a well-known complication that can occur during the acute phase of stroke. In this review, we have summarized the existing data regarding the incidence, pathophysiology, risk factors, morbidity, mortality, and management strategies for gastrointestinal bleeding in patients with acute ischemic stroke.

Post-stroke immunosuppression: Exploring potential implications beyond infections

Stroke is a leading cause of mortality and disability. It occurs when cerebral blood flow is disrupted via vascular occlusion or rupture, causing tissue damage. Research has extensively examined the role of the immune response in stroke pathophysiology, focusing on infiltrated immune cells and inflammatory molecules. However, the stroke's impact on immune physiology remains underexplored. While initially stroke triggers the activation of peripheral inflammation, a subsequent profound immunosuppression occurs in a matter of hours/days. This response, potentially shielding the brain from excessive inflammation, significantly affects stroke patients. Beyond rendering patients more susceptible to infections, immunosuppression generates diverse consequences by disrupting immune system functions that are crucial for organ homeostasis. This review explores the effects of immunosuppression on stroke patients, shedding light on potential issues in immune organs such as the spleen and bone marrow, as well as non-immune organs like the small intestine, liver and heart. By synthesizing existing literature and offering additional insights, this manuscript highlights the multifaceted impact of post-stroke immunosuppression.

Sympathetic-Mediated Intestinal Cell Death Contributes to Gut Barrier Impairment After Stroke

Tissue injury induced by stroke is traditionally thought to be localised to the brain. However, there is an accumulating body of evidence to demonstrate that stroke promotes pathophysiological consequences in peripheral tissues including the gastrointestinal system. In this study, we investigated the mechanisms underlying gut permeability after stroke. We utilised the clinically relevant experimental model of stroke called permanent intraluminal middle cerebral artery occlusion (pMCAO) to examine the effect of cerebral ischaemia on the gut. We detected stroke-induced gut permeability at 5 h after pMCAO. At this timepoint, we observed significantly elevated intestinal epithelial cell death in post-stroke mice compared to their sham-operated counterparts. At 24 h after stroke onset when the gut barrier integrity is restored, our findings indicated that post-stroke intestinal epithelium had higher expression of genes associated with fructose metabolism, and hyperplasia of intestinal crypts and goblet cells, conceivably as a host compensatory mechanism to adapt to the impaired gut barrier. Furthermore, we discovered that stroke-induced gut permeability was mediated by the activation of the sympathetic nervous system as pharmacological denervation decreased the stroke-induced intestinal epithelial cell death, goblet cell and crypt hyperplasia, and gut permeability to baseline levels. Our study identifies a previously unknown mechanism in the brain-gut axis by which stroke triggers intestinal cell death and gut permeability.

Chrono-Gerontology: Integrating Circadian Rhythms and Aging in Stroke Research

Stroke is a significant public health concern for elderly individuals. However, the majority of pre-clinical studies utilize young and healthy rodents, which may result in failure of candidate therapies in clinical trials. In this brief review/perspective, the complex link between circadian rhythms, aging, innate immunity, and the gut microbiome to ischemic injury onset, progression, and recovery is discussed. Short-chain fatty acids and nicotinamide adenine dinucleotide+ (NAD+ ) production by the gut microbiome are highlighted as key mechanisms with profound rhythmic behavior, and it is suggested to boost them as prophylactic/therapeutic approaches. Integrating aging, its associated comorbidities, and circadian regulation of physiological processes into stroke research may increase the translational value of pre-clinical studies and help to schedule the optimal time window for existing practices to improve stroke outcome and recovery.

Imaging and clinical predictors of acute constipation in patients with acute ischemic stroke

Background

Constipation symptoms are highly prevalent in acute ischemic stroke, but the clinical and neuroimaging predictors are unknown. This study aimed to identify lesions and clinical features associated with acute constipation.

Methods

Data from patients with acute ischemic stroke registered in a hospital-based stroke registry between January 2018 and December 2019 were analyzed. Clinical, laboratory, and imaging features were examined for associations with acute constipation. Using the topographic lesion on diffusion-weighted images, multivariate support vector regression-based lesion-symptom mapping (SVR-LSM) was conducted and compared between the non-constipation and acute constipation groups.

Results

A total of 256 patients (mean age 67 years, men: 64%) were included. Acute constipation was noted in 81 patients (32%). Initial stroke severity, represented by initial National Institutes of Health and Stroke Scale (NIHSS) scores, was associated with acute constipation. Laboratory parameters, including fibrin degradation products (FDP), fibrinogen, D-dimer, lipoprotein (a), and free fatty acid levels, also showed statistically significant differences between the non-constipation and constipation groups. FDP, D-dimer, and free fatty acid levels were independently associated with acute constipation in the logistic regression model after adjusting for initial NIHSS scores and potassium levels. SVR-LSM revealed that bilateral lesions in the precentral gyrus, insula, opercular part of the inferior frontal gyrus, the inferior parietal lobule, and lesions in the right middle frontal gyrus were significantly associated with acute constipation. The results were consistent after controlling for the initial NIHSS scores and poststroke potassium levels. When cardioembolic stroke subjects were excluded, the right insular and prefrontal cortex lesions lost their association with acute constipation.

Conclusion

Acute constipation symptoms after acute ischemic stroke are mainly related to bilateral lesions in the insula, precentral gyrus, postcentral gyrus, and inferior parietal lobule. Clinically important predictors of acute constipation include initial neurological severity and thromboembolic markers of stroke.

Ischemic Stroke Shifts the Protein and Metabolite Profiles of Colon in Mice

Over half of all stroke patients present gastrointestinal complications. It has been speculated that there is an intriguing brain-gut connection. However, molecular mechanisms of the connection remain poorly illuminated. Thus, this study is aimed to investigate molecular alternations regarding proteins and metabolites in the colon upon ischemic stroke using multi-omics analyses. Here, stroke mouse model was induced by means of transient middle cerebral artery occlusion. After the confirmation of successful model evaluated as evidenced by neurological deficit and cerebral blood flow decrease, the proteins and metabolites of colon and brain were respectively measured using multiple omics. Functional analysis of differentially expressed proteins (DEPs) and differential metabolites was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. There were 434 common DEPs in the colon and brain after stroke. The DEPs in the two tissues displayed common enrichment in several pathways upon GO/KEGG analyses. The common KEGG pathways of DEPs were mainly linked to the inflammation and immune network. Although there was no common differential metabolite and its corresponding pathway in the two tissues, several metabolism pathways in the colon were also changed after stroke. In conclusion, we have demonstrated that the proteins and metabolites in the colon are significantly changed after ischemic stroke, which provides molecular-level evidence regarding the brain-gut connection. In this light, several common enriched pathways of DEPs may become potential therapeutic targets for stroke upon the brain-gut axis. Notably, we have discovered a promising colon-derived metabolite enterolactone possibly beneficial for tackling stroke.

Gastrointestinal Dysfunction in Stroke

Gastrointestinal (GI) complications are seen in over 50% of ischemic stroke survivors; the most common complications are dysphagia, constipation, and GI bleeding. The bidirectional relationship of the gut-brain axis and stroke has recently gained traction, wherein stroke contributes to gut dysbiosis (alterations in the normal host intestinal microbiome) and gut dysbiosis perpetuates poor functional neurologic outcomes in stroke. It is postulated that the propagation of proinflammatory cells and gut metabolites (including trimethylamine N-oxide and short-chain fatty acids) from the GI tract to the central nervous system play a central role in gut-brain axis dysfunction. In this review, we discuss the known GI complications in acute ischemic stroke, our current knowledge from experimental stroke models for gut-brain axis dysfunction in stroke, and emerging therapeutics that target the gut-brain axis.

A study of the correlation between stroke and gut microbiota over the last 20years: a bibliometric analysis

Purpose

This study intends to uncover a more thorough knowledge structure, research hotspots, and future trends in the field by presenting an overview of the relationship between stroke and gut microbiota in the past two decades.

Method

Studies on stroke and gut microbiota correlations published between 1st January 2002 and 31st December 2021 were retrieved from the Web of Science Core Collection and then visualized and scientometrically analyzed using CiteSpace V.

Results

A total of 660 papers were included in the study, among which the United States, the United Kingdom, and Germany were the leading research centers. Cleveland Clinic, Southern Medical University, and Chinese Academy of Science were the top three institutions. The NATURE was the most frequently co-cited journal. STANLEY L HAZEN was the most published author, and Tang WHW was the most cited one. The co-occurrence analysis revealed eight clusters (i.e., brain-gut microbiota axis, fecal microbiome transplantation, gut microbiota, hypertension, TMAO, ischemic stroke, neuroinflammation, atopobiosis). "gut microbiota," "Escherichia coli," "cardiovascular disease," "risk," "disease," "ischemic stroke," "stroke," "metabolism," "inflammation," and "phosphatidylcholine" were the most recent keyword explosions.

Conclusion

Findings suggest that in the next 10 years, the number of publications produced annually may increase significantly. Future research trends tend to concentrate on the mechanisms of stroke and gut microbiota, with the inflammation and immunological mechanisms, TMAO, and fecal transplantation as hotspots. And the relationship between these mechanisms and a particular cardiovascular illness may also be a future research trend.

The gastrointestinal-brain-microbiota axis: a promising therapeutic target for ischemic stroke

Ischemic stroke is a highly complex systemic disease characterized by intricate interactions between the brain and gastrointestinal tract. While our current understanding of these interactions primarily stems from experimental models, their relevance to human stroke outcomes is of considerable interest. After stroke, bidirectional communication between the brain and gastrointestinal tract initiates changes in the gastrointestinal microenvironment. These changes involve the activation of gastrointestinal immunity, disruption of the gastrointestinal barrier, and alterations in gastrointestinal microbiota. Importantly, experimental evidence suggests that these alterations facilitate the migration of gastrointestinal immune cells and cytokines across the damaged blood-brain barrier, ultimately infiltrating the ischemic brain. Although the characterization of these phenomena in humans is still limited, recognizing the significance of the brain-gastrointestinal crosstalk after stroke offers potential avenues for therapeutic intervention. By targeting the mutually reinforcing processes between the brain and gastrointestinal tract, it may be possible to improve the prognosis of ischemic stroke. Further investigation is warranted to elucidate the clinical relevance and translational potential of these findings.

Global cerebral ischemia followed by long-term reperfusion promotes neurodegeneration, oxidative stress, and inflammation in the small intestine in Wistar rats

AIMS

Brain ischemia and reperfusion may occur in several clinical conditions that have high rates of mortality and disability, compromising an individual's quality of life. Brain injury can affect organs beyond the brain, such as the gastrointestinal tract. The present study investigated the effects of cerebral ischemia on the ileum and jejunum during a chronic reperfusion period by examining oxidative stress, inflammatory parameters, and the myenteric plexus in Wistar rats.

MAIN METHODS

Ischemia was induced by the four-vessel occlusion model for 15 min with 52 days of reperfusion. Oxidative stress and inflammatory markers were evaluated using biochemical techniques. Gastrointestinal transit time was evaluated, and immunofluorescence techniques were used to examine morpho-quantitative aspects of myenteric neurons.

KEY FINDINGS

Brain ischemia and reperfusion promoted inflammation, characterized by increases in myeloperoxidase and N-acetylglycosaminidase activity, oxidative stress, and lipid hydroperoxides, decreases in superoxide dismutase and catalase activity, a decrease in levels of reduced glutathione, neurodegeneration in the gut, and slow gastrointestinal transit.

SIGNIFICANCE

Chronic ischemia and reperfusion promoted a slow gastrointestinal transit time, oxidative stress, and inflammation and neurodegeneration in the small intestine in rats. These findings indicate that the use of antioxidant and antiinflammatory molecules even after a long period of reperfusion may be useful to alleviate the consequences of this pathology.

Gut microbiota-derived melatonin from Puerariae Lobatae Radix-resistant starch supplementation attenuates ischemic stroke injury via a positive microbial co-occurrence pattern

Ischemic stroke is closely associated with gut microbiota dysbiosis and intestinal barrier dysfunction. Prebiotic intervention could modulate the intestinal microbiota, thus considered a practical strategy for neurological disorders. Puerariae Lobatae Radix-resistant starch (PLR-RS) is a potential novel prebiotic; however, its role in ischemic stroke remains unknown. This study aimed to clarify the effects and underlying mechanisms of PLR-RS in ischemic stroke. Middle cerebral artery occlusion surgery was performed to establish a model of ischemic stroke in rats. After gavage for 14 days, PLR-RS attenuated ischemic stroke-induced brain impairment and gut barrier dysfunction. Moreover, PLR-RS rescued gut microbiota dysbiosis and enriched Akkermansia and Bifidobacterium. We transplanted the fecal microbiota from PLR-RS-treated rats into rats with ischemic stroke and found that the brain and colon damage were also ameliorated. Notably, we found that PLR-RS promoted the gut microbiota to produce a higher level of melatonin. Intriguingly, exogenous gavage of melatonin attenuated ischemic stroke injury. In particular, melatonin attenuated brain impairment via a positive co-occurrence pattern in the intestinal microecology. Specific beneficial bacteria served as leaders or keystone species to promoted gut homeostasis, such as Enterobacter, Bacteroidales_S24-7_group, Prevotella_9, Ruminococcaceae and Lachnospiraceae. Thus, this new underlying mechanism could explain that the therapeutic efficacy of PLR-RS on ischemic stroke at least partly attributed to gut microbiota-derived melatonin. In summary, improving intestinal microecology by prebiotic intervention and melatonin supplementation in the gut were found to be effective therapies for ischemic stroke.

Benefits of Biotics for Cardiovascular Diseases

Cardiovascular diseases are the main cause of death in many countries, and the better prevention and prediction of these diseases would be of great importance for individuals and society. Nutrition, the gut microbiota, and metabolism have raised much interest in the field of cardiovascular disease research in the search for the main mechanisms that promote cardiovascular diseases. Understanding the interactions between dietary nutrient intake and the gut microbiota-mediated metabolism may provide clinical insight in order to identify individuals at risk of cardiometabolic disease progression, as well as other potential therapeutic targets to mitigate the risk of cardiometabolic disease progression. The development of cardiometabolic diseases can be modulated by specific beneficial metabolites derived from bacteria. Therefore, it is very important to investigate the impact of these metabolites on human health and the possibilities of modulating their production with dietary supplements called biotics.

Tanshinone IIA-loaded nanoparticles and neural stem cell combination therapy improves gut homeostasis and recovery in a pig ischemic stroke model

Impaired gut homeostasis is associated with stroke often presenting with leaky gut syndrome and increased gut, brain, and systemic inflammation that further exacerbates brain damage. We previously reported that intracisternal administration of Tanshinone IIA-loaded nanoparticles (Tan IIA-NPs) and transplantation of induced pluripotent stem cell-derived neural stem cells (iNSCs) led to enhanced neuroprotective and regenerative activity and improved recovery in a pig stroke model. We hypothesized that Tan IIA-NP + iNSC combination therapy-mediated stroke recovery may also have an impact on gut inflammation and integrity in the stroke pigs. Ischemic stroke was induced, and male Yucatan pigs received PBS + PBS (Control, n = 6) or Tan IIA-NP + iNSC (Treatment, n = 6) treatment. The Tan IIA-NP + iNSC treatment reduced expression of jejunal TNF-α, TNF-α receptor1, and phosphorylated IkBα while increasing the expression of jejunal occludin, claudin1, and ZO-1 at 12 weeks post-treatment (PT). Treated pigs had higher fecal short-chain fatty acid (SCFAs) levels than their counterparts throughout the study period, and fecal SCFAs levels were negatively correlated with jejunal inflammation. Interestingly, fecal SCFAs levels were also negatively correlated with brain lesion volume and midline shift at 12 weeks PT. Collectively, the anti-inflammatory and neuroregenerative treatment resulted in increased SCFAs levels, tight junction protein expression, and decreased inflammation in the gut.

Risk factors and predictors of acute gastrointestinal injury in stroke patients

PURPOSE

This prospective study investigates the incidence, risk factors, biological markers, and predictors of acute gastrointestinal injury (AGI) in patients with stroke.

METHODS

The study involved a total of 98 patients with acute cerebrovascular disease were included. According to the ESICM, the definition of AGI in intensive care patients is classified as grade 0, I, II and III. Patients' demographics, serological indicators (e.g., urea nitrogen, albumin, D-lactate, α-GST, neutrophil count and lymphocyte count), relevant scores (NIHSS score, GCS score, APACHE II score), length of hospital stay as well as the 7-day and 28-day mortality were recorded.

RESULTS

In 98 patients, the incidence of AGI was 90.8 %. The APACHE II, NIHSS, GCS and Hs-mGPS scores significantly increased the odds of a higher AGI grade (P < 0.05). Also, current use of antibiotics and the presence of pneumonia significantly increased the probability of a higher AGI grade (P < 0.05). NLR, diabetes and dehydrating drugs increased the probability of AGI grade II and III (P < 0.05). Finally, an early commencement of endovascular treatment significantly reduced the incidence of AGI class III (P < 0.05). Patients with higher AGI grades had longer hospital stays and higher 28-day mortality (P < 0.05).

CONCLUSION

The degree of the neurological deficit in stroke patients (high NIHSS score, low GCS score) in this study was associated with the development of AGI. The patients' gastrointestinal barrier function continued to deteriorate during the week of onset. The APACHE II score, NRL score and HS-mGPS score have some predictive value for the occurrence of AGI in stroke patients.

Imbalance of Microbacterial Diversity Is Associated with Functional Prognosis of Stroke

Objectives

There is mounting evidence to suggest that the pathophysiology of stroke is greatly influenced by the microbiota of the gut and its metabolites, in particular short-chain fatty acids (SCFAs). The primary purpose of the study was to evaluate whether the levels of SCFAs and the gut microbiota are altered in poststroke patients and to examine the relationship between these alterations and the physical condition, intestinal health, pain, or nutritional status of patients.

Methods

Twenty stroke patients and twenty healthy controls were enrolled in the current study, and their demographics were matched. Gas chromatography was used to determine the fecal SCFAs, and 16S rRNA gene sequencing was used to evaluate their fecal microbiota. Microbial diversity and richness were examined using the diversity indices alpha and beta, and taxonomic analysis was utilized to determine group differences. The relationships between the gut microbiome and fecal SCFAs, discriminant bacteria, and poststroke clinical outcomes were analyzed.

Results

Less community richness (ACE and Chao) was observed in the poststroke patients (P < 0.05), but the differences between the poststroke group and the healthy control group in terms of species diversity (Shannon and Simpson) were not statistically significant. The makeup of the poststroke gut microbiota was distinct from that of the control group, as evidenced by beta diversity. Then, the relative abundances of the taxa in the poststroke and control groups were compared in order to identify the specific microbiota changes. At the level of phylum, the poststroke subjects showed a significant increase in the relative abundances of Akkermansiaceae, Fusobacteriota, Desulfobacterota, Ruminococcaceae, and Oscillospirales and a particularly noticeable decrease in the relative abundance of Acidobacteriota compared to the control subjects (P < 0.05). In regard to SCFA concentrations, lower levels of fecal acetic acid (P = 0.001) and propionic acid (P = 0.049) were found in poststroke subjects. Agathobacter was highly correlated with acetic acid level (r = 0.473, P = 0.002), whereas Fusobacteria (r = -0.371, P = 0.018), Flavonifractor (r = -0.334, P = 0.034), Desulfovibrio (r = -0.362, P = 0.018), and Akkermansia (r = -0.321, P = 0.043) were negatively related to acetic acid levels. Additionally, the findings of the correlation analysis revealed that Akkermansia (r = -0.356, P = 0.024), Desulfovibrio (r = -0.316, P = 0.047), and Alloprevotella (r = -0.366, P = 0.020) were significantly negatively correlated with high-density lipoprotein cholesterol. In addition, the Neurogenic Bowel Dysfunction score (r = 0.495, P = 0.026), Barthel index (r = -0.531, P = 0.015), Fugl-Meyer Assessment score (r = -0.565, P = 0.009), Visual Analogue Scale score (r = 0.605, P = 0.005), and Brief Pain Inventory score (r = 0.507, P = 0.023) were significantly associated with alterations of distinctive gut microbiota.

Conclusions

Stroke generates extensive and substantial alterations in the gut microbiota and SCFAs, according to our findings. The differences of intestinal flora and lower fecal SCFA levels are closely related to the physical function, intestinal function, pain, or nutritional status of poststroke patients. Treatment strategies aimed at modulating the gut microbiota and SCFAs may have the potential to enhance the clinical results of patients.

Palliative care approaches to acute stroke in the hospital setting

Stroke is a prevalent neurologic condition that portends a high risk of morbidity and mortality such that patients impacted by stroke and their caregivers can benefit from palliative care at the time of diagnosis and throughout the disease trajectory. Clinicians who care for stroke patients should be adept at establishing rapport with patients and caregivers, delivering serious news, responding to emotions, discussing prognosis, and establishing goals of care efficiently in an acute stroke setting. Aggressive stroke care can be integrated with a palliative approach to care that involves aligning the available treatment options with a patient's values and goals of care. Reassessing the goals throughout the hospitalization provides an opportunity for continued shared decision-making about the intensity of poststroke interventions. The palliative needs for stroke patients may increase over time depending on the severity of disease, poststroke complications, stroke-related symptoms, and treatment intensity preferences. If the decision is made to transition the focus of care to comfort, the support of an interdisciplinary palliative care or hospice team can be beneficial to the patient, family members, and surrogate decision makers.

Fecal microbiota transplantation and replenishment of short-chain fatty acids protect against chronic cerebral hypoperfusion-induced colonic dysfunction by regulating gut microbiota, differentiation of Th17 cells, and mitochondrial energy metabolism

BACKGROUND

Little is known about the association between gut microbiota and intestinal injury under a state of chronic cerebral hypoperfusion (CCH). Here, the effects of gut microbiota and short-chain fatty acids (SCFAs), as important metabolic products, on intestinal function and potential mechanisms after CCH were investigated.

METHODS

Rats were subjected to bilateral common carotid artery occlusion (BCCAo) to induce CCH. The gut microbiota and metabolites of SCFAs were assessed by 16S rRNA sequencing and targeted metabolomics, respectively. Transcriptomic analysis of colon tissues was also conducted. Subsequently, potential molecular pathways and differentially expressed genes were verified by western blot, immunoprecipitation, and immunofluorescence analyses. Furthermore, the integrity of the colonic barrier was evaluated by hematoxylin and eosin and mucin 2 staining and expression levels of tight junction proteins. Besides, colonic inflammation was further assessed by flow cytometry and expression levels of inflammatory cytokines. In addition, colonic mitochondrial dysfunction was analyzed via membrane potential, reactive oxygen species, electron transport chain (ETC) activities, adenosine triphosphate content, and mitochondrial ultrastructure.

RESULTS

CCH modified gut microbial composition and microbial metabolism of SCFAs, which may be associated with inhibition of mitochondrial ETC activities and oxidative phosphorylation, leading to dysregulation of mitochondrial energy metabolism. Furthermore, CCH induced differentiation of pathogenic Th17 cells, promoted the formation of complexes of interferon regulatory factor 4 and signal transducer and activator of transcription 3 (STAT3), and increased the phosphorylation of STAT3. This was associated with an impairment of colonic barrier function and chronic colonic inflammation. In contrast, FMT and SCFA replenishment ameliorated CCH-induced gut microbial dysbiosis by increasing the intestinal content of Ruminococcus_sp_N15_MGS_57 and modulating microbial metabolism of SCFAs by increasing acetic acid contents associated with an improvment of the balance between Tregs and Th17 cells, mitochondrial ETC activities, and oxidative phosphorylation to prevent colonic inflammation and dysregulation of mitochondrial energy metabolism.

CONCLUSION

These findings indicate that FMT and SCFA replenishment present a promising therapeutic strategy against colonic dysfunction under a state of chronic cerebral ischemia.

Inflammasome-Regulated Pyroptotic Cell Death in Disruption of the Gut-Brain Axis After Stroke

Approximately 50% of stroke survivors experience gastrointestinal complications. The innate immune response plays a role in changes to the gut-brain axis after stroke. The purpose of this study is to examine the importance of inflammasome-mediated pyroptosis in disruption of the gut-brain axis after experimental stroke. B6129 mice were subjected to a closed-head photothrombotic stroke. We examined the time course of inflammasome protein expression in brain and intestinal lysate using western blot analysis at 1-, 3-, and 7-days post-injury for caspase-1, interleukin-1β, nod-like receptor protein 3 (NLRP3), and apoptosis speck-like protein containing a caspase-recruiting domain (ASC) and gasdermin-D (GSDMD) cleavage. In a separate group of mice, we processed brain tissue 24 and 72 h after thrombotic stroke for immunohistochemical analysis of neuronal and endothelial cell pyroptosis. We examined intestinal tissue for morphological changes and pyroptosis of macrophages. We performed behavioral tests and assessed gut permeability changes to confirm functional changes after stroke. Our data show that thrombotic stroke induces inflammasome activation in the brain and intestinal tissue up to 7-day post-injury as well as pyroptosis of neurons, cerebral endothelial cells, and intestinal macrophages. We found that thrombotic stroke leads to neurocognitive and motor function deficits as well as increased gut permeability. Finally, the adoptive transfer of serum-derived EVs from stroke mice into naive induced inflammasome activation in intestinal tissues. Taken together, these results provide novel information regarding possible mechanisms underlying gut complications after stroke and the identification of new therapeutic targets for reducing the widespread consequences of ischemic brain injury.

Crosstalk between the aging intestinal microflora and the brain in ischemic stroke

Aging is an inevitable phenomenon experienced by animals and humans, and its intensity varies from one individual to another. Aging has been identified as a risk factor for neurodegenerative disorders by influencing the composition of the gut microbiota, microglia activity and cognitive performance. The microbiota-gut-brain axis is a two-way communication path between the gut microbes and the host brain. The aging intestinal microbiota communicates with the brain through secreted metabolites (neurotransmitters), and this phenomenon leads to the destruction of neuronal cells. Numerous external factors, such as living conditions and internal factors related to the age of the host, affect the condition of the intestinal microflora in the form of dysbiosis. Dysbiosis is defined as changes in the composition and function of the gut microflora that affect the pathogenesis, progress, and response to treatment of a disease entity. Dysbiosis occurs when changes in the composition and function of the microbiota exceed the ability of the microflora and its host to restore equilibrium. Dysbiosis leading to dysfunction of the microbiota-gut-brain axis regulates the development and functioning of the host’s nervous, immune, and metabolic systems. Dysbiosis, which causes disturbances in the microbiota-gut-brain axis, is seen with age and with the onset of stroke, and is closely related to the development of risk factors for stroke. The review presents and summarizes the basic elements of the microbiota-gut-brain axis to better understand age-related changes in signaling along the microbiota-gut-brain axis and its dysfunction after stroke. We focused on the relationship between the microbiota-gut-brain axis and aging, emphasizing that all elements of the microbiota-gut-brain axis are subject to age-related changes. We also discuss the interaction between microbiota, microglia and neurons in the aged individuals in the brain after ischemic stroke. Finally, we presented preclinical and clinical studies on the role of the aged microbiota-gut-brain axis in the development of risk factors for stroke and changes in the post-stroke microflora.

Diet-microbiome-gut-brain nexus in acute and chronic brain injury

In recent years, appreciation for the gut microbiome and its relationship to human health has emerged as a facilitator of maintaining healthy physiology and a contributor to numerous human diseases. The contribution of the microbiome in modulating the gut-brain axis has gained significant attention in recent years, extensively studied in chronic brain injuries such as Epilepsy and Alzheimer’s Disease. Furthermore, there is growing evidence that gut microbiome also contributes to acute brain injuries like stroke(s) and traumatic brain injury. Microbiome-gut-brain communications are bidirectional and involve metabolite production and modulation of immune and neuronal functions. The microbiome plays two distinct roles: it beneficially modulates immune system and neuronal functions; however, abnormalities in the host’s microbiome also exacerbates neuronal damage or delays the recovery from acute injuries. After brain injury, several inflammatory changes, such as the necrosis and apoptosis of neuronal tissue, propagates downward inflammatory signals to disrupt the microbiome homeostasis; however, microbiome dysbiosis impacts the upward signaling to the brain and interferes with recovery in neuronal functions and brain health. Diet is a superlative modulator of microbiome and is known to impact the gut-brain axis, including its influence on acute and neuronal injuries. In this review, we discussed the differential microbiome changes in both acute and chronic brain injuries, as well as the therapeutic importance of modulation by diets and probiotics. We emphasize the mechanistic studies based on animal models and their translational or clinical relationship by reviewing human studies.

Peripheral Organ Injury After Stroke

Stroke is a disease with high incidence, mortality and disability rates. It is also the main cause of adult disability in developed countries. Stroke is often caused by small emboli on the inner wall of the blood vessels supplying the brain, which can lead to arterial embolism, and can also be caused by cerebrovascular or thrombotic bleeding. With the exception of recombinant tissue plasminogen activator (rt-PA), which is a thrombolytic drug used to recanalize the occluded artery, most treatments have been demonstrated to be ineffective. Stroke can also induce peripheral organ damage. Most stroke patients have different degrees of injury to one or more organs, including the lung, heart, kidney, spleen, gastrointestinal tract and so on. In the acute phase of stroke, severe inflammation occurs in the brain, but there is strong immunosuppression in the peripheral organs, which greatly increases the risk of peripheral organ infection and aggravates organ damage. Nonneurological complications of stroke can affect treatment and prognosis, may cause serious short-term and long-term consequences and are associated with prolonged hospitalization and increased mortality. Many of these complications are preventable, and their adverse effects can be effectively mitigated by early detection and appropriate treatment with various medical measures. This article reviews the pathophysiological mechanism, clinical manifestations and treatment of peripheral organ injury after stroke.

Herb Formula (GCis) Prevents Pulmonary Infection Secondary to Intracerebral Hemorrhage by Enhancing Peripheral Immunity and Intestinal Mucosal Immune Barrier

Lung infection is a common complication induced by stroke and seriously affects the prognosis and life quality of patients. However, effective therapeutic strategies are still lacking. In the present study, the herb formula GCis was confirmed to prevent pulmonary infection induced by intracerebral hemorrhage (ICH). The animal model of lung infection induced by ICH, GCis (Ginseng Radix et Rhizoma, Aconiti Lateralis Radix Praeparata, and Cistanches Herba) was orally administrated every day for 7 days. Lung microbial biomass and pathological results showed that the GCis formula pretreatment significantly reduced lung bacterial biomass and alleviated pathological abnormalities. These results indicated that the GCis formula has a clear pharmacological effect on preventing lung infection induced by ICH. Immunosuppression induced by ICH seemed to be the main mechanism of lung infection. Our results showed that the spleen and thymus indexes, WBC, and LY% contents were significantly increased in the GCis formula group. Moreover, bone marrow cells were further analyzed by transcriptome sequencing, and GO and KEGG enrichment analysis results showed that immune function was the main pathway enriched by differential genes after GCis formula intervention. More importantly, our results showed that GCis pretreatment had no significant effect on the mRNA expression of IL-1β, IL-6, and TNF-α in the brain. These results indicated that the GCis formula could enhance immunity after ICH. The intestinal barrier function was further investigated in the present study, considering the origin of the source of infection. Our results showed that the mRNA expressions of intestinal ZO-1, SIgA, and MUC2 were significantly increased, villi structure was intact, inflammatory cell infiltration was reduced, and goblet cell number was increased after GCis formula treatment. These results suggest that the GCis formula can enhance the intestinal mucosal immune barrier. This study provides a herb formula (GCis) that could enhance peripheral immunity and intestinal mucosal immune barrier to prevent pulmonary infection induced by ICH. It would be beneficial in the prevention of severe clinical infections.

Aging Microbiota-Gut-Brain Axis in Stroke Risk and Outcome

The microbiota-gut-brain-axis (MGBA) is a bidirectional communication network between gut microbes and their host. Many environmental and host-related factors affect the gut microbiota. Dysbiosis is defined as compositional and functional alterations of the gut microbiota that contribute to the pathogenesis, progression and treatment responses to disease. Dysbiosis occurs when perturbations of microbiota composition and function exceed the ability of microbiota and its host to restore a symbiotic state. Dysbiosis leads to dysfunctional signaling of the MGBA, which regulates the development and the function of the host's immune, metabolic, and nervous systems. Dysbiosis-induced dysfunction of the MGBA is seen with aging and stroke, and is linked to the development of common stroke risk factors such as obesity, diabetes, and atherosclerosis. Changes in the gut microbiota are also seen in response to stroke, and may impair recovery after injury. This review will begin with an overview of the tools used to study the MGBA with a discussion on limitations and potential experimental confounders. Relevant MGBA components are introduced and summarized for a better understanding of age-related changes in MGBA signaling and its dysfunction after stroke. We will then focus on the relationship between the MGBA and aging, highlighting that all components of the MGBA undergo age-related alterations that can be influenced by or even driven by the gut microbiota. In the final section, the current clinical and preclinical evidence for the role of MGBA signaling in the development of stroke risk factors such as obesity, diabetes, hypertension, and frailty are summarized, as well as microbiota changes with stroke in experimental and clinical populations. We conclude by describing the current understanding of microbiota-based therapies for stroke including the use of pre-/pro-biotics and supplementations with bacterial metabolites. Ongoing progress in this new frontier of biomedical sciences will lead to an improved understanding of the MGBA's impact on human health and disease.

The effectiveness of acupoint herbal patching for constipation after stroke: A protocol for systematic review and meta-analysis

BACKGROUND

Constipation is one of the common problems in stroke patients, which seriously affects the life quality of patients and even leads to the recurrence of cerebrovascular disease. The clinical trials of acupoint herbal patching (AHP) in the adjuvant treatment of constipation after stroke (CAS) is currently in progress. However, there is no systematic review or meta-analysis to evaluate the effects of AHP on CAS.

METHODS

We will search articles in 8 electronic databases including the Cochrane Central Register of Controlled Trials, PubMed, Embase, the Web of Science, China National Knowledge Infrastructure, the Chinese Biomedical Literature Database, Wanfang Database, and the Chinese Scientific Journal Database for randomized controlled trials of CAS treated by AHP from their inception to November 1, 2021. The primary outcome measures will be clinical effective rate, defecation frequency, improvement of clinical symptoms including complete spontaneous bowel movements. The data meeting the inclusion criteria were analyzed by RevMan V.5.4 software. Two authors evaluated the study using the Cochrane collaborative risk bias tool. We will use a scoring method to assess the overall quality of evidence supporting the main results.

RESULTS

This study will analyze the clinical effective rate, defecation frequency, improvement of clinical symptoms including complete spontaneous bowel movements after stroke.

CONCLUSION

The findings of this systematic review will provide evidence to evaluate the effectiveness and safety of AHP for CAS.

INPLASY REGISTRATION NUMBER

INPLASY202210065.

Evaluation of Mannitol Intervention Effects on Ischemic Cerebral Edema in Mice Using Swept Source Optical Coherence Tomography

Cerebral edema is a serious complication of ischemic cerebrovascular disease and mannitol is a commonly used dehydrating agent for relieving cerebral edema. However, the edema state and surrounding vascular perfusion level during mannitol treatment remains unclear, which affects the clinical application of the medicine. In this paper, we demonstrated the role of swept-source optical coherence tomography (OCT) in the evaluation of mannitol efficacy using mouse models. The OCT-based angiography and attenuation imaging technology were used to obtain the cerebral vascular perfusion level and cerebral edema state at different times. Vascular parameters and edema parameters were quantified and compared. Experimental results show that mannitol can significantly reduce the water content in the central region of edema, effectively inhibiting the rapid growth of the edema area, and restoring cerebral blood flow. On average, the edema area decreased by 33% after 2 h, and the vascular perfusion density increased by 12% after 5 h. This work helps to provide a valuable theoretical basis and research ideas for the clinical treatment of cerebral edema.

Recent Advances in the Impact of Infection and Inflammation on Stroke Risk and Outcomes

PURPOSE OF THE REVIEW

Inflammation is a key component in the pathogenesis of cerebrovascular diseases. In the past few years, the role of systemic infection and gut dysbiosis in modulating inflammation and stroke risk has been increasingly acknowledged. In this review, we synthesize contemporary literature on the effects of infection and inflammation on stroke risk and outcomes, with a focus on periodontal disease, COVID-19 infection, and gut dysbiosis.

RECENT FINDINGS

Chronic and acute infections such as periodontitis and COVID-19 induce systemic inflammation that cause atherogenesis and increase cardiac injury and arrhythmias. These infections also directly injure the endothelium leading to worsened secondary inflammation after stroke. Gut dysbiosis engenders a pro-inflammatory state by modulating intestinal lymphocyte populations that can traffic directly to the brain. Additionally, post-stroke immune dysregulation creates a compounding feedback loop of further infections and gut dysbiosis that worsen outcomes. Recent advances in understanding the pathophysiology of how infection and dysbiosis affect the progression of stroke, as well as long-term recovery, have revealed tantalizing glimpses at potential therapeutic targets. We discuss the multidirectional relationship between stroke, infection, and gut dysbiosis, and identify areas for future research to further explore therapeutic opportunities.

Fecal Calprotectin Is Increased in Stroke

Background: While there have been major advances in unveiling the mechanisms comprising the ischemic cascade of CNS, stroke continues to be a significant burden. There is a need to extend the focus toward peripheral changes, and the brain–gut axis has recently gained much attention. Our study aimed to evaluate gut inflammation and its association with blood variables in stroke using fecal calprotectin (FC). Methods: Fecal samples were obtained from 27 stroke patients and 27 control subjects. FC was quantitatively measured using a commercial ELISA. Laboratory data on the fecal sample collection were also collected, including CBC, ESR, glucose, creatinine, total protein, albumin, transaminases, and CRP. Results: There was a significant increase in FC levels in stroke patients compared to the controls. Furthermore, FC in stroke patients was negatively correlated with the Glasgow Coma Scale. Moreover, FC in stroke patients was positively correlated with CRP and negatively correlated with lymphocyte count and albumin. Conclusions: Our findings show that increased FC is associated with consciousness and systemic response in stroke and warrants further studies to elucidate the usefulness of FC in the management of stroke.

Current Incidence and Risk Factors of Fecal Incontinence After Acute Stroke Affecting Functionally Independent People

Background: Previously published retrospective series show a high prevalence of fecal incontinence (FI) in stroke patients. We aimed to analyze in a prospective series the current incidence of FI in acute stroke in functionally independent patients and its evolution over time and the patient characteristics associated with the appearance of FI in acute stroke. Methods: We included consecutive patients with acute stroke admitted in our stroke unit who fulfilled the following inclusion criteria: a first episode of stroke, aged >18 years, with no previous functional dependency [modified Rankin Scale (mRS) ≤ 2] and without previous known FI. FI was assessed by a multidisciplinary trained team using dedicated questionnaires at 72 ± 24 h (acute phase) and at 90 ± 15 days (chronic phase). Demographic, medical history, clinical and stroke features, mortality, and mRS at 7 days were collected. Results: Three hundred fifty-nine (48.3%) of 749 patients (mean age 65.9 ± 10, 64% male, 84.1% ischemic) fulfilled the inclusion criteria and were prospectively included during a 20-month period. FI was identified in 23 patients (6.4%) at 72 ± 24 h and in 7 (1.9%) at 90 days ± 15 days after stroke onset. FI was more frequent in hemorrhagic strokes (18 vs. 5%, p 0.007) and in more severe strokes [median National Institute of Health Stroke Scale (NIHSS) 18 (14-22) vs. 5 (3-13), p < 0.0001]. No differences were found regarding age, sex, vascular risk factors, or other comorbidities, or affected hemisphere. Patients with NIHSS ≥12 (AUC 0.81, 95% CI 0.71 to 0.89) had a 17-fold increase for the risk of FI (OR 16.9, IC 95% 4.7-60.1) adjusted for covariates. Conclusions: At present, the incidence of FI in acute stroke patients without previous functional dependency is lower than expected, with an association of a more severe and hemorrhagic stroke. Due to its impact on the quality of life, it is necessary to deepen the knowledge of the underlying mechanisms to address therapeutic strategies.

Brain to periphery in acute ischemic stroke: Mechanisms and clinical significance

The social and public health burdens of ischemic stroke have been increasing worldwide. In addition to focal brain damage, acute ischemic stroke (AIS) provokes systemic abnormalities across peripheral organs. AIS profoundly alters the autonomic nervous system, hypothalamic-pituitary-adrenal axis, and immune system, which further yield deleterious organ-specific consequences. Poststroke systemic pathological alterations in turn considerably contribute to the progression of ischemic brain injury, which accounts for the substantial impact of systemic complications on stroke outcomes. This review provides a comprehensive and updated pathophysiological model elucidating the systemic effects of AIS. To address their clinical significance and inform stroke management, we also outline the resulting systemic complications at particular stages of AIS and highlight the mechanisms. Future therapeutic strategies should attempt to integrate the treatment of primary brain lesions with interventions for secondary systemic complications, and should be tailored to patient individualized characteristics to optimize stroke outcomes.

Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke

Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.

Potential Benefits of Probiotics and Prebiotics for Coronary Heart Disease and Stroke

Among cardiovascular diseases (CVDs), a major cause of morbidity and mortality worldwide, coronary heart disease and stroke are the most well-known and extensively studied. The onset and progression of CVD is associated with multiple risk factors, among which, gut microbiota has received much attention in the past two decades. Gut microbiota, the microbial community colonizing in the gut, plays a prominent role in human health. In particular, gut dysbiosis is directly related to many acute or chronic dysfunctions of the cardiovascular system (CVS) in the host. Earlier studies have demonstrated that the pathogenesis of CVD is strongly linked to intestinal microbiota imbalance and inflammatory responses. Probiotics and prebiotics conferring various health benefits on the host are emerging as promising therapeutic interventions for many diseases. These two types of food supplements have the potential to alleviate the risks of CVD through improving the levels of several cardiovascular markers, such as total and low-density lipoprotein (LDL) cholesterol, high sensitivity C-reactive protein (hs-CRP), and certain cytokines involved in the inflammatory response. In this review, we focus mainly on the preventive effects of probiotics and prebiotics on CVD via rebalancing the structural and functional changes in gut microbiota and maintaining immune homeostasis.

Microbiota dysbiosis and functional outcome in acute ischemic stroke patients

Currently, few studies are reported on the composition of microbiota in stroke patients and the association with stroke prognosis. This study investigated the differing microbiota composition in stroke patients and confirmed the association of microbiota composition with poor functional outcome. Between January of 2018 and December of 2019, 198 patients with acute cerebral infarction were included in this study. For the case–control study, age and sex-matched normal healthy subjects (n = 200) were included when receiving their health screening examinations. We isolated bacterial extracellular membrane vesicles and extracted DNA from blood samples. Taxonomic assignments were performed by using the sequence reads of 16S rRNA genes following blood microbiota analysis. Statistical analysis was conducted appropriately by using Statistical Analysis System software. The mean age of the stroke patients were 63.7 ± 12.5 years, and the male sex was 58.5%. Of the total enrolled patients, poor functional outcome (modified Rankin Score ≥ 3) was noted in 19.7%. The principal component analysis of microbiota composition revealed significant differences between healthy control subjects and stroke patients. At the genus level, Aerococcaceae(f), ZB2(c), TM7-1(c), and Flavobacterium were significantly increased in stroke patients compared to the healthy controls, whereas Mucispirillum, rc4-4, Akkermansia, Clostridiales(o), Lactobacillus, and Stenotrophomonas were decreased considerably. For the functional outcome after ischemic stroke, Anaerococcus, Blautia, Dialister, Aerococcaceae(f), Propionibacterium, Microbacteriaceae(f), and Rothia were enriched in the group with good outcomes, whereas Ruminococcaceae(f) and Prevotella were enriched in the group with poor outcome. There was apparent dysbiosis of blood microbiota in patients with acute ischemic stroke compared to healthy people. Ruminococcaceae(f) and Prevotella were elevated in stroke patients with poor functional outcome.

Could the Gut Microbiota Serve as a Therapeutic Target in Ischemic Stroke?

The brain-gut axis is a relatively recent discovery of a two-way regulation system between the gut and brain, suggesting that the gut microbiota may be a promising targeted prevention and treatment strategy for patients with a high risk of acute cerebral ischemia/reperfusion injury. There are many risk factors for ischemic stroke, and many studies have shown that the gut microbiota affects the absorption and metabolism of the body, as well as the risk factors of stroke, such as blood pressure, blood glucose, blood lipids, and atherosclerosis, either directly or indirectly. Furthermore, the gut microbiota can affect the occurrence and prognosis of ischemic stroke by regulating risk factors or immune responses. Therefore, this study aimed to collect evidence of the interaction between gut microbiota and ischemic stroke, summarize the interaction mechanism between the two, and explore the gut microbiota as a new targeted prevention and treatment strategy for patients with high ischemic risk.

Traditional East Asian herbal medicines for the treatment of poststroke constipation: A protocol for systematic review and meta analysis

BACKGROUND

Post-stroke constipation is a major complication of stroke and increases the incidence of poor neurological outcomes and infectious complications and, therefore, warrants active and prompt treatment. In East Asian countries, several types of herbal medicines have been used for the treatment of post-stroke constipation because they are considered safer than existing pharmacotherapies. However, no systematic review has investigated the efficacy and safety of traditional East Asian herbal medicine in the treatment of post-stroke constipation. With this systematic review and meta-analysis, we aimed to evaluate the efficacy and safety of traditional East Asian herbal medicines for the treatment of post-stroke constipation.

METHODS AND ANALYSIS

Eight electronic databases will be searched for relevant studies published from inception to April 2021. Only randomized controlled trials (RCTs) that assess the efficacy and safety of traditional East Asian herbal medicines for the treatment of post-stroke constipation will be included in this study. The methodological qualities, including the risk of bias, will be evaluated using the Cochrane risk of bias assessment tool. After screening the studies, a meta-analysis of the RCTs will be performed, if possible.

RESULTS

This study is expected to generate high-quality evidence of the efficacy and safety of herbal medicines to treat post-stroke constipation.

CONCLUSION

Our systematic review will provide evidence to determine whether herbal medicines can be effective interventions for patients with post-stroke constipation.

ETHICS AND DISSEMINATION

Ethical approval is not required, as this study was based on a review of published research. This review will be published in a peer-reviewed journal and disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

Research registry reviewregistry1117.

D-Lactate and intestinal fatty acid-binding protein are elevated in serum in patients with acute ischemic stroke

Experimental studies suggest that the intestinal barrier is affected in ischemic stroke. D-Lactate and intestinal fatty acid-binding protein (IFABP) are markers of intestinal mucosa integrity and barrier function. Our purpose was to evaluate the serum concentrations of these markers in patients with acute ischemic stroke (AIS). We included patients with AIS and used healthy subjects as controls. Clinical, demographic and outcome measures were recorded. Blood was drawn within 24 h of symptom onset. Serum concentrations of D-Lactate and IFABP were determined using commercially available colorimetric and ELISA kits, respectively. We included a total of 61 patients (median age of 64 years). The majority of patients were male (57.4%). The most common cause of stroke was atherosclerosis (34.4%), followed by small-vessel disease and cardioembolic (32.7% each). Mean admission NIHSS score was 8. Median IFABP and D-Lactate concentrations were significantly higher in patients than in controls. Concentrations were not associated with stroke severity or 3-month outcome. Patients with large-artery atherosclerosis and cardioembolic etiology had higher D-Lactate values than patients with small-vessel disease. D-Lactate and IFABP were significantly elevated in patients with AIS. This suggests that there is disruption of the intestinal barrier in patients with AIS.

The Role of Gut Microbiota in an Ischemic Stroke

The intestinal microbiome, the largest reservoir of microorganisms in the human body, plays an important role in neurological development and aging as well as in brain disorders such as an ischemic stroke. Increasing knowledge about mediators and triggered pathways has contributed to a better understanding of the interaction between the gut-brain axis and the brain-gut axis. Intestinal bacteria produce neuroactive compounds and can modulate neuronal function, which affects behavior after an ischemic stroke. In addition, intestinal microorganisms affect host metabolism and immune status, which in turn affects the neuronal network in the ischemic brain. Here we discuss the latest results of animal and human research on two-way communication along the gut-brain axis in an ischemic stroke. Moreover, several reports have revealed the impact of an ischemic stroke on gut dysfunction and intestinal dysbiosis, highlighting the delicate play between the brain, intestines and microbiome after this acute brain injury. Despite our growing knowledge of intestinal microflora in shaping brain health, host metabolism, the immune system and disease progression, its therapeutic options in an ischemic stroke have not yet been fully utilized. This review shows the role of the gut microflora-brain axis in an ischemic stroke and assesses the potential role of intestinal microflora in the onset, progression and recovery post-stroke.

The effects of abdominal "I LOV U" massage along with lifestyle training on constipation and distension in the elderly with stroke

INTRODUCTION

Constipation and distension are dominant gastrointestinal problems after stroke in the elderly. Always they are treated by the use of laxatives and fibers. Abdominal massage along with a healthy lifestyle can be a solution.

PURPOSE

This study aimed to investigate the effect of abdominal massage and lifestyle training on constipation and distention of the elderly with stroke.

METHOD

This study was a randomized clinical trial that was conducted on elderly patients with stroke at Qaem hospital of Mashhad, Iran. 68 patients were randomly allocated into control (n = 34) and intervention (n = 34) groups in 2017-2018. Finally 29 elderly in the intervention and 34 in the control group completed the study. Intervention included the abdominal massage by using "I LOV U" method along with lifestyle education. Each abdominal massage lasted for 15 min, twice daily for ten days that was performed at first session by the researcher and then continued by the key care giver. Data were collected by the demographic form, constipation assessment score (CAS), distension measurement tool (meter), and food tolerance evaluation checklist.

RESULTS

The results indicated that both groups were homogeneous in demographic variables (P > 0.05). The repeated ANOVA showed a more significant decrease in abdominal circumference of the intervention group during the 10- days study (P = 0.029).The Friedman test showed a significant difference in frequency of defecation in two groups in 10- day study (P < 0.0001). Therefore the CAS Score was significantly decreased in intervention group more than the control group (0.30 < 0.98 < 1.59, P = 0.001, EF = 0.44). The food tolerance frequencies through Gavage (P = 0.20), and also orally (P < 0.001) were significantly improved in the intervention group.

CONCLUSION

According to results, the abdominal massage along with lifestyle training could improve constipation and distension and also increase food intake tolerance in the elderly patients with stroke.

Identification of Gut Microbiome Signatures in Patients With Post-stroke Cognitive Impairment and Affective Disorder

Stroke (ST), endangering human health due to its high incidence and high mortality, is a global public health problem. There is increasing evidence that there is a link between the gut microbiota (GM) and neuropsychiatric diseases. We aimed to find the GM of ST, post-ST cognitive impairment (PSCI), and post-ST affective disorder (PSTD). GM composition was analyzed, followed by GM identification. Alpha diversity estimation showed microbiota diversity in ST patients. Beta diversity analysis showed that the bacterial community structure segregated differently between different groups. At the genus level, ST patients had a significantly higher proportion of Enterococcus and lower content of Bacteroides, Escherichia-Shigella, and Megamonas. PSCI patients had a significantly higher content of Enterococcus, Bacteroides, and Escherichia-Shigella and a lower proportion of Faecalibacterium compared with patients with ST. Patients with PSTD had a significantly higher content of Bacteroides and Escherichia-Shigella and lower content of Enterococcus and Faecalibacterium. Parabacteroides and Lachnospiraceae were associated with Montreal cognitive assessment score of ST patients. Our study indicated that the characteristic GM, especially Bacteroidetes, could be used as clinical biomarkers of PSCI and PSTD.

CNS and peripheral immunity in cerebral ischemia: partition and interaction

Stroke elicits excessive immune activation in the injured brain tissue. This well-recognized neural inflammation in the brain is not just an intrinsic organ response but also a result of additional intricate interactions between infiltrating peripheral immune cells and the resident immune cells in the affected areas. Given that there is a finite number of immune cells in the organism at the time of stroke, the partitioned immune systems of the central nervous system (CNS) and periphery must appropriately distribute the limited pool of immune cells between the two domains, mounting a necessary post-stroke inflammatory response by supplying a sufficient number of immune cells into the brain while maintaining peripheral immunity. Stroke pathophysiology has mainly been neurocentric in focus, but understanding the distinct roles of the CNS and peripheral immunity in their concerted action against ischemic insults is crucial. This review will discuss stroke-induced influences of the peripheral immune system on CNS injury/repair and of neural inflammation on peripheral immunity, and how comorbidity influences each.

Effects of uncomfortable care and histamine H2-antagonists on delirium in acute stroke: A propensity score analysis

BACKGROUND AND PURPOSE

Uncomfortable care and histamine H2 antagonist (H2A) are implicated in precipitating delirium. In acute stroke, however, the need for them depends on stroke severity, an established risk factor for delirium. So, it is unclear whether care or H2A itself is responsible for delirium. We aimed to evaluate their causal effects on delirium in acute stroke patients.

METHODS

This is a prospective cohort study on acute stroke patients admitted to a stroke care unit. Patients without stupor, coma, sedation, or delirium upon admission were enrolled. The treatment was H2A and five care modalities given during the first 24 h: restraint use, prohibited self-transfer, no oral feeding, indwelling catheters, and frequent nighttime care. The outcome was delirium within 5 days defined as Intensive Care Delirium Screening Checklist ≥4 points. We estimated the relative risk (RR) for delirium with regression models weighted by overlap weights using propensity scores estimated through logistic models incorporating known and potential confounders, including stroke severity.

RESULTS

Of the 387 participants, 188 were given at least one care modality and 130 were given H2A. A total of 42 developed delirium. Delirium was significantly associated with prohibited self-transfer (RR 1.7, 95% CI 1.0-3.0), frequent nighttime care (RR 2.1, 95% CI 1.2-3.7), and multiple care modalities (RR 2.4, 95% CI 1.3-4.4), while other care modalities and H2A were not.

CONCLUSIONS

This study showed possible causal effects of uncomfortable care on delirium and suggests that minimizing it could prevent delirium in acute stroke.

Does overground robotic gait training improve non-motor outcomes in patients with chronic stroke? Findings from a pilot study

Stroke is the leading cause of disability among the elderly in the industrialized world. No more than 40% of stroke survivors walk independently, and only after receiving appropriate rehabilitation treatment; many stroke patients have also non-motor symptoms. The aim of this pilot study is to evaluate the effects of Ekso-training on non-motor outcomes, including gastrointestinal function and psychological well-being, in post stroke patients. We enrolled 30 post-stroke subjects, which were randomized into two groups in order of recruitment: 15 patients were trained with the overground exoskeleton Ekso-GT (experimental group, EG), whereas 15 patients were submitted to a standard gait training (control group, CG). Both the groups underwent the same amount of physiotherapy. At the end of the training, only in the EG we observed a significant improvement in constipation, mood, and coping strategies, with regard to social support, as well as in the perception of quality of life (as per SF-12). According to these preliminary data, overground robotic gait training can be considered a valuable tool in improving non-motor symptoms, including constipation and behavioral disorders in patients with chronic stroke.

Dysbiosis is one of the risk factor for stroke and cognitive impairment and potential target for treatment

More than 50 million people have various forms of cognitive impairment basically caused by neurodegenerative diseases, such as Alzheimer's, Parkinson's, and cerebrovascular diseases as well as stroke. Often these conditions coexist and exacerbate one another. The damaged area in post-stroke dementia may lead to neurodegenerative lesions. Gut microbiome functions like an endocrine organ by generating bioactive metabolites that can directly or indirectly impact human physiology. An alteration in the composition and function of intestinal flora, i.e. gut dysbiosis, is implicated in neurodegenerative and cerebrovascular diseases. Additionally, gut dysbiosis may accelerate the progression of cognitive impairment. Dysbiosis may result from obesity; metabolic disorders, cardiovascular disease, and sleep disorders, Lack of physical activity is associated with dysbiosis as well. These may coexist in various patterns in older people, enhancing the risk, incidence, and progression of cerebrovascular lesions, neurodegenerative disorders, and cognitive impairment, creating a vicious circle. Recently, it has been reported that several metabolites produced by gut microbiota (e.g., trimethylamine/trimethylamine N-oxide, short-chain fatty acids, secondary bile acids) may be linked to neurodegenerative and cerebrovascular diseases. New treatment modalities, including prebiotic and probiotics, may normalize the gut microbiota composition, change the brain-gut barrier, and decrease the risk of the pathology development. Fecal microbiota transplantation, sometimes in combination with other methods, is used for remodeling and replenishing the symbiotic gut microbiome. This promising field of research is associated with basic findings of bidirectional communication between body organs and gut microbiota that creates new possibilities of pharmacological treatments of many clinical conditions. The authors present the role of gut microbiota in physiology, and the novel therapeutic targets in modulation of intestinal microbiota Personalized therapies based on their personal genome make up could offer benefits by modulating microbiota cross-talk with brain and cardiovascular system. A healthy lifestyle, including pre and probiotic nutrition is generally recommended. Prevention may also be enhanced by correcting gut dysbiosis resulting a reduced risk of post-stroke cognitive impairment including dementia.

Clinical Effects and Safety of Electroacupuncture for the Treatment of Poststroke Dysphagia: A Comprehensive Systematic Review and Meta-Analysis

Objectives

Electroacupuncture (EA), an extension of acupuncture, which is based on traditional acupuncture combined with modern electrotherapy, is commonly used for poststroke dysphagia (PSD) in clinical treatment and research. However, there is still a lack of sufficient evidence to recommend the routine use of EA for PSD. The aim of this study was to assess the efficacy and safety of EA in the treatment of PSD.

Methods

Randomized controlled trials (RCTs) evaluating the effects of EA on PSD were identified through a comprehensive literature search of the PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure, Chinese Biomedical Database, and VIP databases from their inception to July 2020. The quality assessment of the included trials was performed based on the guidance of the Cochrane Reviewers' Handbook, and meta-analysis (MA) was performed by using the RevMan 5.3 software.

Results

Sixteen trials were identified, and these included 1,216 patients with PSD. The results demonstrated that EA in combination with swallowing rehabilitation training (SRT) was significantly superior to SRT alone with regard to effective rate (OR 5.40, 95% CI [3.78, 7.72], P < 0.00001, water swallow test (WST) (MD −0.78, 95% CI [−1.07, −0.50], P < 0.00001), the video fluoroscopic swallowing study (VFSS) (MD 1.47, 95% CI [1.11, 1.84], P < 0.00001), the Ichiro Fujishima Rating Scale (IFRS) (MD 1.94, 95% CI [1.67, 2.22], P < 0.00001), and the incidence of aspiration pneumonia (IAP) (OR 0.20, 95% CI [0.06, 0.61], P=0.005).

Conclusions

The results showed that EA was better than the control treatment in terms of the effective rate, WST, VFSS, IFRS, and IAP of dysphagia after stroke. Strict evaluation standards and high-quality RCT designs are necessary for further exploration.

Immune responses to stroke: mechanisms, modulation, and therapeutic potential

Stroke is the second leading cause of death worldwide and a leading cause of disability. Most strokes are caused by occlusion of a major cerebral artery, and substantial advances have been made in elucidating how ischemia damages the brain. In particular, increasing evidence points to a double-edged role of the immune system in stroke pathophysiology. In the acute phase, innate immune cells invade brain and meninges and contribute to ischemic damage, but may also be protective. At the same time, danger signals released into the circulation by damaged brain cells lead to activation of systemic immunity, followed by profound immunodepression that promotes life-threatening infections. In the chronic phase, antigen presentation initiates an adaptive immune response targeted to the brain, which may underlie neuropsychiatric sequelae, a considerable cause of poststroke morbidity. Here, we briefly review these pathogenic processes and assess the potential therapeutic value of targeting immunity in human stroke.