Dry mouth is in most cases due to iatrogenic causes, particularly drugs. The existing products such as saliva substitutes are often disappointing (bad taste, poor efficiency).

Our hypothesis has considered the "empirical" observations made by some patients with xerostomia who consumed milk products to relieve the dry mouth syndrome from which they suffered. With this clinical observation, a closer collaboration has been undertaken with research laboratories specialising in food and especially milk. Through its composition, the dairy product in itself provides relief for the patient, due both to its physical and biochemical properties, which could explain these observed improvements, and elements related to the phenomena of consumption of food as an alternative to medication. In the latter, hedonism takes on a role which has not been previously assessed. Initial work undertaken with the department of applied research at the National Dairy Industry School (ENIL) led to the prototyping of a new natural milk, which is the subject of this application for development, to qualify and adapt a product with a "health benefit" in patients suffering from xerostomia.

To further develop this project we will initiate a sequential clinical trial by groups of five ambulatory patients with xerostomia (patients taking antidepressants followed in psychiatry appointments). The clinical tests will be organised by the CIC with the psychiatric wards of the University Hospital of Besançon. Each group of 5 patients will test a similar product for 14 days. The information collected after a series of tests with a group of patients will be translated by changing the ENIL specifications to produce a new mini-series of products. This repetition will be carried out up to 3 times if necessary to help achieve a satisfactory product in terms of taste, texture and lubrication properties, which will then be tested in a randomized controlled cross-over study of the efficiency and acceptability of the new "LactoXeros" product versus a reference product (Aequasyal ®, Oxidized Glycerol Triester) on a group of 32 patients at the University hospital of Dijon.

A natural way to combat xerostomia at the interface of patient diet, such as we propose, could help improve quality of life for patients, minimize harmful effects (infection, decay) and promote adherence of patients to treatments which are responsible for xerostomia.

Inclusion Criteria:

• Patients over 18 years old
• Patients seen in the psychiatry department requiring the prescription of psychotropic drugs (antidepressants anxiolytics) for over 6 weeks
• Patients complaining of xerostomia
• Patients having not taken a palliative therapy against xerostomia for at least 2 weeks
• Patients having signed a free and informed consent form
• Patients affiliated to a social security system

Exclusion Criteria:

• Patients suffering from psychotic illness
• Patients suffering from Sjogren's syndrome
• Patients having been treated by radiation therapy for head or neck cancer
• Patients having stopped a palliative therapy against xerostomia for less than 2 weeks
• Patients under 18
• Pregnant or Breastfeeding women
• Incapacitated adults
• Patients placed under tutorship or curatorship
• Patients under judicial protection
• Patients suffering from milk allergy or lactose intolerance
• Patients allergic to curcumin