What is the optimal pH of stomach?

The optimal pH of the stomach is highly acidic, typically ranging between 1 and 2. This extreme acidity is necessary for several important physiological functions within the stomach:

1. Activation of Pepsin: Pepsin is the primary enzyme responsible for breaking down proteins in the stomach. It is optimally active at a pH of around 1.5-2.0. The highly acidic environment of the stomach provides the ideal conditions for pepsin to work efficiently.

2. Denaturation of Proteins: The acidic pH of the stomach helps to denature proteins, disrupting their structure and making them more susceptible to enzymatic digestion. Denaturation exposes more sites on the protein for enzymes like pepsin to bind and break down.

3. Absorption of Nutrients: Certain nutrients, such as iron and vitamin B12, are more readily absorbed in an acidic environment. The low pH of the stomach facilitates the absorption of these nutrients by promoting their solubility and conversion into forms that can be more easily taken up by the intestinal lining.

4. Protection Against Pathogens: The acidic environment of the stomach acts as a natural defense mechanism against harmful microorganisms. Most bacteria and other pathogens cannot survive in such a highly acidic environment, which helps to protect the body from infections.

It's important to note that the stomach is able to withstand these extreme levels of acidity due to its specialized protective mechanisms, including the thick mucus layer lining its walls and the continuous secretion of bicarbonate ions to neutralize acids.

The regulation of stomach pH is crucial for maintaining proper digestion and overall health. Deviations from the optimal pH, such as conditions like hypochlorhydria (low stomach acid) or achlorhydria (absence of stomach acid), can impair digestion, absorption of nutrients, and increase the risk of infections.