Brunner's glands

Brunner's glands (or duodenal glands) are compound tubuloalveolar submucosal glands found in that portion of the duodenum proximal to the hepatopancreatic sphincter (i.e sphincter of Oddi).

For decades, it was believed that the main function of the glands is to secrete alkaline (bicarbonate-containing) mucus in order to:

• protect the duodenum from the acidic content of chyme (which enters the duodenum from the stomach),
• provide an alkaline environment which promotes the activity of intestinal enzymes,
• lubricate the intestinal walls.

However, more recent studies have demonstrated that Brunner’s glands actually act as major modulators of the gut microbiome and systemic immunity.

They are the distinguishing feature of the duodenum, and are named for the Swiss physician who first described them, Johann Conrad Brunner.