The hormone secretin produced by the digestive system stimulates the secretion of the following EXCEPT:

Secretin is a gastrointestinal hormone secreted by the S cells of the duodenum in response to low pH (acidic chyme).

It stimulates the exocrine pancreas to secrete a bicarbonate-rich pancreatic juice to neutralize the acidity.

It also stimulates the liver to secrete bicarbonate-rich bile juice and the Brunner's glands to secrete alkaline intestinal juice.

However, secretin inhibits the secretion of gastric acid (gastric juice) from the parietal cells of the stomach and reduces gastric motility.

Therefore, secretin does not stimulate the secretion of gastric juice.

Answer: Gastric juice