Gut brain axis

# Overview

# Historical Perspective
- The gutbrain axis is the biochemical signaling between the central nervous system (CNS) and the gastrointestinal tract (GI tract). Gut brian axis was first used to refer  bidirectional communication network that links between the GI tract and CNS.
- Gut brian axis was first discovered by , a , in  during/following .
- In ,  mutations were first identified in the pathogenesis of .
- In , the first  was developed by  to treat/diagnose .

# Classification
-  may be classified according to  into  subtypes/groups:
- Other variants of  include , , and .

# Pathophysiology
- The pathogenesis of  is characterized by , , and .
- The  gene/Mutation in  has been associated with the development of , involving the  pathway.
- On gross pathology, , , and  are characteristic findings of .
- On microscopic histopathological analysis, , , and  are characteristic findings of .

# Causes
Disease name] may be caused by , , or .
OR
Common causes of  include , , and .
OR
The most common cause of  is . Less common causes of  include , , and .
OR
The cause of  has not been identified. To review risk factors for the development of , click here.

# Differentiating  from other Diseases
-  must be differentiated from other diseases that cause , , and , such as:

# Epidemiology and Demographics
- The prevalence of  is approximately  per 100,000 individuals worldwide.
- In , the incidence of  was estimated to be  cases per 100,000 individuals in .

## Age
- Patients of all age groups may develop .
-  is more commonly observed among patients aged  years old.
-  is more commonly observed among .

## Gender
-  affects men and women equally.
-  are more commonly affected with  than .
- The  to  ratio is approximately  to 1.

## Race
- There is no racial predilection for .
-  usually affects individuals of the  race.
-  individuals are less likely to develop .

# Risk Factors
- Common risk factors in the development of  are , , , and .

# Natural History, Complications and Prognosis
- The majority of patients with  remain asymptomatic for .
- Early clinical features include , , and .
- If left untreated,  of patients with  may progress to develop , , and .
- Common complications of  include , , and .
- Prognosis is generally , and the  of patients with  is approximately .

# Diagnosis

## Diagnostic Criteria
- The diagnosis of  is made when at least  of the following  diagnostic criteria are met:

## History and Symptoms
-  is usually asymptomatic.
- Symptoms of  may include the following:

## Physical Examination
- Patients with  usually appear .
- Physical examination may be remarkable for:

## Laboratory Findings
- There are no specific laboratory findings associated with .
- A    is diagnostic of .
- An  concentration of   is diagnostic of .
- Other laboratory findings consistent with the diagnosis of  include , , and .

## Electrocardiogram
There are no ECG findings associated with .
OR
An ECG may be helpful in the diagnosis of . Findings on an ECG suggestive of/diagnostic of  include , , and .

## X-ray
There are no x-ray findings associated with .
OR
An x-ray may be helpful in the diagnosis of . Findings on an x-ray suggestive of/diagnostic of  include , , and .
OR
There are no x-ray findings associated with . However, an x-ray may be helpful in the diagnosis of complications of , which include , , and .

## Echocardiography or Ultrasound
There are no echocardiography/ultrasound  findings associated with .
OR
Echocardiography/ultrasound  may be helpful in the diagnosis of . Findings on an echocardiography/ultrasound suggestive of/diagnostic of  include , , and .
OR
There are no echocardiography/ultrasound  findings associated with . However, an echocardiography/ultrasound  may be helpful in the diagnosis of complications of , which include , , and .

## CT scan
There are no CT scan findings associated with .
OR
 CT scan may be helpful in the diagnosis of . Findings on CT scan suggestive of/diagnostic of  include , , and .
OR
There are no CT scan findings associated with . However, a CT scan may be helpful in the diagnosis of complications of , which include , , and .

## MRI
There are no MRI findings associated with .
OR
 MRI may be helpful in the diagnosis of . Findings on MRI suggestive of/diagnostic of  include , , and .
OR
There are no MRI findings associated with . However, a MRI may be helpful in the diagnosis of complications of , which include , , and .

## Other Imaging Findings
There are no other imaging findings associated with .
OR
 may be helpful in the diagnosis of . Findings on an  suggestive of/diagnostic of  include , , and .

## Other Diagnostic Studies
There are no other diagnostic studies associated with .
OR
 may be helpful in the diagnosis of . Findings suggestive of/diagnostic of  include , , and .
OR
Other diagnostic studies for  include , which demonstrates , , and , and , which demonstrates , , and .

# Treatment

## Medical Therapy
- There is no treatment for ; the mainstay of therapy is supportive care.
- The mainstay of therapy for  is  and .
-  acts by .
- Response to  can be monitored with  every .

## Surgery
- Surgery is the mainstay of therapy for .
-  in conjunction with  is the most common approach to the treatment of .
-  can only be performed for patients with  .

## Prevention
- There are no primary preventive measures available for .
- Effective measures for the primary prevention of  include , , and .
- Once diagnosed and successfully treated, patients with  are followed-up every . Follow-up testing includes , , and .