Eligibility Criteria:
Inclusion Criteria:
Patients with anorexia nervosa :
* female,
* living in Upper Normandy since 1 year at least,
* between 18 and 50 years of age
* with a BMI between 14 and 16 kg/m²,
* diagnosed as anorexia nervosa according to the DSM IV criteria
* hospitalised for the first time in the Nutrition Unit
* not being pregnant (effective contraception and negative pregnancy test)
* not breast-feeding,
* HIV-1 negative ,
* HIV-2 negative,
* HBV negative (hépatitis B virus),
* HCV negative (hépatitis C virus),
* Affiliated to the National Health Service,
* Giving a filled informed consent,
* Not included in other studies
Controls :
* female,
* living in Upper Normandy since 1 year at least,
* between 18 and 50 years of age,
* with a BMI between 20 and 24,9 kg/m²,
* without antecedent or current diagnosis of eating disorders (DSM IV criteria),
* without dyspepsia or irritable bowel syndrom for 6 month,
* not being pregnant (effective contraception and negative pregnancy test)
* not breast-feeding,
* HIV-1 negative ,
* HIV-2 negative,
* HBV negative (hépatitis B virus),
* HCV negative (hépatitis C virus),
* Affiliated to the National Health Service,
* Giving a filled informed consent,
* Not included in other studies
Exclusion Criteria:
Patients with anorexia nervosa :
* Adult under guardianship,
* Patient with inflammatory bowel disease and/or psychotic disorders,
* Antecedent of digestive surgery,
* Drug addiction for the last 6 month,
* Alcohol and/or other substance use disorder,
* Current immunological treatment, and/or non steroidal anti inflamatory and/or corticosteroids and/or anticoagulants and/or platelet antiaggregants
* galactosemia
* Lactulose intolerance,
* Laxatives intake in the last 3 days
* Antecedent of digestive surgery,
Controls :
* Adult under guardianship,
* Patient with inflammatory bowel disease and/or psychotic disorders,
* Antecedent of digestive surgery,
* Drug addiction for the last 6 month,
* Alcohol and/or other substance use disorder,
* Current immunological treatment, and/or non steroidal anti inflamatory and/or corticosteroids and/or anticoagulants and/or platelet antiaggregants
* galactosemia
* Lactulose intolerance,
* Laxatives intake in the last 3 days
* Antecedent of digestive surgery,