The role of the brain-gut microbiota axis in functional gastrointestinal diseases has been gradually recognized. According to the ROME IV diagnostic criteria, functional gastrointestinal diseases are classified as diseases caused by abnormal brain-gut interaction. This concept is of great significance to the change of diagnosis and treatment paradigm of functional gastrointestinal diseases. Chronic constipation is the most common functional gastrointestinal disease. The pathogenesis of chronic constipation is closely related to the imbalance of intestinal flora, the abnormality of enteric nervous system and neurotransmitter in brain. Therefore, in the diagnosis and treatment of chronic constipation, enough attention should be paid to the concept of integration of brain-gut microflora axis, but the clinical application of brain-gut microflora axis is still limited. This may be one of the factors for high incidence but poor treatment efficacy of chronic constipation. Based on the global research progress and our clinical experience, this article expounds the clinical significance of the brain-gut microbiota axis in chronic constipation.
Brain ; Constipation ; Enteric Nervous System ; Gastrointestinal Microbiome ; Humans

Enteric nervous system (ENS) is composed of intestinal submucosal and myenteric plexuses. ENS may independently regulate intestinal digestive and absorptive function, and it is also known as "the second brain" or gut brain. ENS has significant specificity relative to central nervous system (CNS) in properties and functional activities of neurons and neural circuits. ENS is connected with CNS through the feedback pathway (brain-gut-axis) of sympathetic and parasympathetic nerves and peripheral primary sensory afferent nerves to form the bidirectional brain-gut-axis, which may affect emotion, appetite and behavioral states of individuals. Gastrointestinal functional disorder (GIFD) induced by ENS dysfunction may not only cause abnormal gastrointestinal function but also has been implicated in cognitive and mood disorders, such as irritable bowel syndrome (IBS). GIFD would influence deeply the quality of life in patients. Nevertheless, in the worldwide, ENS has so far received much less attention as compared with CNS. The depth of research and scale of investment in ENS studies have been much lower than those in CNS studies. The situation in China is even more evident. From ENS research history, an outstanding problem is to ignore largely the unique properties of ENS and apply mechanically the hypotheses formed in CNS studies to ENS researches. In this review, the structure and function of ENS are briefly introduced, and the importance of extraordinary characteristics of ENS is illustrated by the problems encountered in our studies.
Brain ; China ; Enteric Nervous System ; Humans ; Quality of Life

Interactions among the nervous, the endocrine and the immune systems enable the gut to respond to the dietary products, pathogens and microbiota, which maintains the homeostasis of the body. However, dysbiosis may induce or aggravate the gastrointestinal (GI) and extra-GI diseases through changing the activities of enteric nervous system (ENS), enteroendocrine cells and enteric immune cells. Here we review recent advances in the understandings on how intestinal flora may impact the enteric neuro-endocrine-immune system in the gut, thereby contributing to the regulation of pathophysiological processes.
Enteric Nervous System ; Gastrointestinal Diseases ; Gastrointestinal Microbiome ; Humans ; Immune System

Parkinson's disease (PD) is a common neurodegenerative disorder arising from an interplay between genetic and environmental risk factors. Studies have suggested that the pathological hallmarks of intraneuronal α-synuclein aggregations may start from the olfactory bulb and the enteric nervous system of the gut and later propagate to the brain via the olfactory tract and the vagus nerve. This hypothesis correlates well with clinical symptoms, such as constipation, that may develop up to 20 years before the onset of PD motor symptoms. Recent interest in the gut–brain axis has led to vigorous research into the gastrointestinal pathology and gut microbiota changes in patients with PD. In this review, we provide current clinical and pathological evidence of gut involvement in PD by summarizing the changes in gut microbiota composition and gut inflammation associated with its pathogenesis.
Brain ; Constipation ; Enteric Nervous System ; Gastrointestinal Microbiome ; Humans ; Inflammation ; Microbiota ; Neurodegenerative Diseases ; Olfactory Bulb ; Parkinson Disease ; Pathology ; Risk Factors ; Vagus Nerve

The role of the microbiome in health and human disease has emerged at the forefront of medicine in the 21st century. Over the last 2 decades evidence has emerged to suggest that inflammation-derived oxidative damage and cytokine induced toxicity may play a significant role in the neuronal damage associated with Parkinson's disease (PD). Presence of pro-inflammatory cytokines and T cell infiltration has been observed in the brain parenchyma of patients with PD. Furthermore, evidence for inflammatory changes has been reported in the enteric nervous system, the vagus nerve branches and glial cells. The presence of α-synuclein deposits in the post-mortem brain biopsy in patients with PD has further substantiated the role of inflammation in PD. It has been suggested that the α-synuclein misfolding might begin in the gut and spread “prion like” via the vagus nerve into lower brainstem and ultimately to the midbrain; this is known as the Braak hypothesis. It is noteworthy that the presence of gastrointestinal symptoms (constipation, dysphagia, and hypersalivation), altered gut microbiota and leaky gut have been observed in PD patients several years prior to the clinical onset of the disease. These clinical observations have been supported by in vitro studies in mice as well, demonstrating the role of genetic (α-synuclein overexpression) and environmental (gut dysbiosis) factors in the pathogenesis of PD. The restoration of the gut microbiome in patients with PD may alter the clinical progression of PD and this alteration can be accomplished by carefully designed studies using customized probiotics and fecal microbiota transplantation.
Animals ; Anti-Bacterial Agents ; Biopsy ; Brain ; Brain Stem ; Cytokines ; Deglutition Disorders ; Dysbiosis ; Enteric Nervous System ; Fecal Microbiota Transplantation ; Gastrointestinal Microbiome ; Humans ; In Vitro Techniques ; Inflammation ; Mesencephalon ; Mice ; Microbiota ; Neuroglia ; Neurons ; Parkinson Disease ; Probiotics ; Vagus Nerve

Pediatric chronic intestinal pseudo-obstruction is a rare disorder characterized by a severe impairment of gastrointestinal motility leading to intestinal obstruction symptoms in the absence of mechanical causes. The diagnosis is usually clinical and diagnostic work is usually aimed to rule out mechanical obstruction and to identify any underlying diseases. Treatment is challenging and requires a multidisciplinary effort. In this manuscript we describe the youngest child successfully treated with the orally administrable, long-acting, reversible anti-cholinesterase drug, pyridostigmine. Like other drugs belonging to cholinesterase inhibitors, pyridostigmine enhances gut motility by increasing acetylcholine availability in the enteric nervous system and neuro-muscular junctions. Based on the direct evidence from the reported case, we reviewed the current literature on the use of pyridostigmine in severe pediatric dysmotility focusing on intestinal pseudo-obstruction. The overall data emerged from the few published studies suggest that pyridostigmine is an effective and usually well tolerated therapeutic options for patients with intestinal pseudo-obstruction. More specifically, the main results obtained by pyridostigmine included marked reduction of abdominal distension, reduced need of parenteral nutrition, and improvement of oral feeding. The present case and review on pyridostigmine pave the way for eagerly awaited future randomized controlled studies testing the efficacy of cholinesterase inhibitors in pediatric severe gut dysmotility.
Acetylcholine ; Child ; Cholinesterase Inhibitors ; Diagnosis ; Enteric Nervous System ; Female ; Gastrointestinal Motility ; Humans ; Intestinal Obstruction ; Intestinal Pseudo-Obstruction ; Parenteral Nutrition ; Pyridostigmine Bromide

BACKGROUND/AIMS: α-Synucleinopathy in the brain is the neuropathological hallmark of Parkinson’s disease (PD). However, the functional impact of α-synucleinopathy in the enteric nervous system remains unknown. We aim to evaluate the association between gastrointestinal (GI) dysfunction and α-synuclein (αSYN) pathology in the stomach and colon of PD patients and controls, as well as to investigate the association between the αSYN pathology in GI tract and future PD risk. METHODS: A total of 35 PD patients and 52 neurologically intact subjects were enrolled in this study. Endoscopic biopsies were performed, and then immunohistochemical staining for αSYN was performed. All subjects completed the validated Rome III questionnaire for the assessment of GI symptoms. The association between GI symptoms and the αSYN pathology in GI mucosa was evaluated. Incident PD cases were assessed during a median follow-up of 46 months. RESULTS: The proportion of self-reported constipation and functional constipation through the Rome III questionnaire was significantly higher in PD patients than in controls (P < 0.001 and P = 0.015). However, no significant association was found between the αSYN pathology in the stomach and colon mucosa and constipation, as well as other GI symptoms including dyspepsia symptoms and abdominal discomfort or pain, regardless of the presence or absence of clinical PD (P > 0.05). No incident PD cases were diagnosed during study period. CONCLUSIONS: Our present study suggests that the deposition of αSYN in the mucosal enteric nervous system may not be reflected by functional impairment of the affected segment of the gut.
Biopsy ; Brain ; Colon ; Constipation ; Dyspepsia ; Enteric Nervous System ; Follow-Up Studies ; Gastrointestinal Tract ; Humans ; Mucous Membrane ; Parkinson Disease ; Pathology ; Stomach

Ganglioneuroma of the gastrointestinal tract is a rare tumor that consists of ganglion cells, nerve fibers, and supporting cells of the enteric nervous system. Ganglioneuromas are usually associated with genetic disorders such as the multiple endocrine neoplasia syndrome or neurofibromatosis. Ganglioneuromas of the gastrointestinal tract predominantly involve the colon and rectum, and reports about duodenal ganglioneuromas are few. Herein, we report a case of duodenal ganglioneuroma treated with endoscopic resection. A 56-year-old female patient visited our hospital because of a subepithelial tumor in the second portion of the duodenum. She had no remarkable medical or family history and revealed no history of genetic disorders. Endoscopic ultrasonography and abdominal computed tomography revealed a tumor located mainly in the submucosal layer, without any regional lymph node involvement. Endoscopic resection of the lesion was performed, and the pathological examination confirmed a duodenal ganglioneuroma.
Colon ; Duodenum ; Endosonography ; Enteric Nervous System ; Female ; Ganglion Cysts ; Ganglioneuroma ; Gastrointestinal Tract ; Humans ; Lymph Nodes ; Middle Aged ; Multiple Endocrine Neoplasia ; Neurofibromatoses ; Neurons ; Rectum

BACKGROUND/AIMS: Myenteric plexus interstitial cells of Cajal (ICC-MY) are involved in the generation of gut pacemaker activity and neuronal communication. We performed patch clamp on ICC-MY in situ to observe the changes of pacemaker activity in response to neural modulations. METHODS: A fresh longitudinal muscle with myenteric plexus (LMMP) from mouse jejunum was prepared. ICC-MY and ganglion neurons embedded in the layer of longitudinal muscles were targeted by patch clamping in whole-cell configuration in a model of current or voltage clamp. Neurogenic modulators were applied to evaluate their effects on ICC pacemaker activity. RESULTS: In situ ICC-MY showed spontaneous and rhythmical voltage oscillations with a frequency of 27.2 ± 3.9 cycles/min, amplitude of 32.6 ± 6.3 mV, and resting membrane potential of −62.2 ± 2.8 mV. In situ neurons showed electrically evocable action potential in single or multiple spikes. Pacemaker activity was modulated by neuronal activators through receiving a neuronal input. Application of tetrodotoxin depolarized pacemaker potentials in a dose dependent manner, and decreased the amplitude at tetrodotoxin 0.3 μM for about 40 ± 10%; capsaicin (1 μM) ameliorated ICC-MY K+ current for about 49 ± 14.8%; and, nitric oxide hyperpolarized pacemaker potential and decreased the amplitude and frequency. CONCLUSIONS: The in situ preparation patch clamp study further demonstrates that the pacemaker activity is an intrinsic property of ICC. The neurogenic activators change and shape pacemaker potential and activity in situ. LMMP preparation in situ patch clamp provides an ideal platform to study the functional innervation of the ICC and the enteric neural system, thereby, for evaluating the neural regulation of pacemaker activity, especially in disorder models.
Action Potentials ; Animals ; Capsaicin ; Constriction ; Enteric Nervous System ; Ganglion Cysts ; Interstitial Cells of Cajal ; Jejunum* ; Membrane Potentials ; Mice* ; Muscles ; Myenteric Plexus* ; Neurons ; Nitric Oxide ; Tetrodotoxin

Gastroparesis (Gp) is a chronic disease that presents with clinical symptoms of early satiety, bloating, nausea, vomiting, and abdominal pain. Along with these symptoms, an objective finding of delayed gastric emptying, along with a documented absence of gastric outlet obstruction, are required for diagnosis. This article focuses on updates in the pathogenesis and management of Gp. Recent studies on full thickness biopsies of Gp patients have shed light on the complex interactions of the central, autonomic, and enteric nervous systems, which all play key roles in maintaining normal gut motility. The management of Gp has evolved beyond prokinetics and antiemetics with the use of gastric electrical stimulators (GES). In addition, this review aims to introduce the concept of gastroparesis-like syndrome (GLS). GLS helps groups of patients who have the cardinal symptoms of Gp but have a normal or rapid emptying test. Recent tests have shown that patients with Gp and GLS have similar pathophysiology, benefit greatly from GES placement, and likely should be treated in a similar manner.
Abdominal Pain ; Antiemetics ; Biopsy ; Chronic Disease ; Diagnosis ; Enteric Nervous System ; Gastric Emptying ; Gastric Outlet Obstruction ; Gastroparesis* ; Humans ; Nausea ; Vomiting