Ageing of the general population may be a risk factor for various complications, including sarcopenia. Sarcopenia is a progressive loss of muscle mass and muscle strength, leading to a decrease in functional capacities. It affects between 0.7% and 16% of European adults over 70 years of age (1). Recent studies suggest that the faecal microbiota may be altered with ageing but also according to sarcopenic status. Furthermore, no study has currently published data on the relationship between salivary microbiota and sarcopenic status. The main hypothesis of this study is that a decrease in salivary microbiota richness could be associated with impaired handgrip strength in the ageing subject.

Inclusion Criteria:

• Male or female adult volunteer, over 70 years of age
• Non-hospitalised
• Having read and understood the information letter and signed the consent form
• Affiliated with a Social Security scheme

Exclusion Criteria:

• Already included in an interventional drug clinical trial
• Unable to understand and complete the questionnaires
• Deprived of liberty by an administrative or judicial decision or protected adult subject (under guardianship, curatorship or judicial protection order)
• Receiving antibiotic treatment or having received antibiotic treatment during the previous 3 months
• Taking or having taken probiotics during the previous 3 months
• Having undergone colonic lavage/bowel cleansing during the previous 3 months
• Presenting one of the following situations likely to alter the microbiota: active cancer, eating disorders, exclusive vegetarian diet, history of digestive surgery
• Having a cardiac pacemaker
• Living in a nursing home for dependent elderly persons (EHPAD)