PH value in saliva


The pH value is a measure of how acidic or basic a liquid or substance is. A pH value of 7 is called a neutral substance. Values below 7 are acidic and values above 7 are basic liquids. Since saliva consists of different components and is produced by different glands, its pH value can vary depending on its composition.

What is the normal pH value in saliva?

The saliva in our mouth consists of over 99% water and is produced by various salivary glands located in the throat and mouth area. These include the parotid gland (Parotis), the sublingual gland (Glandula Sublingualis) and the mandibular gland (Glandula Submandibularis). Each of these glands opens into the mouth with one or more excretory ducts.

They produce saliva, which is important for moistening our food so that we can swallow it more easily. For this purpose, mucins are contained in the saliva, and there are also digestive enzymes, such as alpha-amylase. It starts digesting carbohydrates right in the mouth.

Lysozyme is a bactericide in saliva that directly fights bacteria in the mouth. Another component of saliva is bicarbonate. It provides a slightly alkaline environment, so the alpha-amylase is particularly active and the tooth enamel is protected. Normally, saliva has a pH value that is relatively neutral (varies between 6.5 – 7.2 depending on saliva secretion).

Does the pH value in saliva change during the day?

Since the pH value of saliva is influenced by food intake, it is no wonder that it is subject to fluctuations over the course of a day. In the morning before breakfast, for example, it tends to be rather low, as people have not eaten for a long time overnight. After each meal, more saliva is suddenly produced and it becomes more alkaline.

If the salivary flow is shut down again after the end of the meal and the new saliva replaces the old, the pH value drops again. Nowadays, we generally eat more acidic foods (e.g. fruit juices, etc. ), so it is an advantage that alkaline saliva can balance the pH value in the mouth.

In addition, the fluctuation of the pH-value depends on what the meal contains. A carbohydrate-rich diet (especially sugar) is more likely to lead to an acidic environment in the mouth than protein-rich food. It therefore causes greater fluctuations during the day.