Why are unripe, green bananas good for the intestines?

Initially rather accidentally, over the years I came to the conclusion that unripe, green bananas are good for the intestinal mucosa.

“You traded green banana”: serious or fun? 

How did it come about? Many years ago, I heard a lecture by an American at a congress on inflammatory bowel disease on the topic of “Inflammatory Bowel Disease and its Treatment.” To be more specific, he reported on the inflammation in the reconstruction reservoir of the intestine after colon removal for ulcerative colitis, called pouchitis. He said that conventional treatments with local administration of cortisone, antibiotics, probiotics, short-chain fatty acids, or mesalazine were without much efficacy.  But – he continued – you could also give straight green bananas. I was not sure if this was just an ironic remark or if there was something behind it. In the days that followed, I looked into the literature on green bananas, because there were indeed publications on the subject. In animal experiments, when stomach ulcers were treated with banana extract, the ulcers disappeared (1). Bananas have various ingredients. Among others, they are rich in lecithin, which biochemically corresponds to the phosphorus-containing fat phosphatidylcholine.

Phosphatidylcholine protects the mucous membrane

The idea matured in me that this phosphatidylcholine protects the mucous membrane in the stomach. It could lie like a protective film over the ulcer so that it can heal – shielded from the aggressive hydrochloric acid. It is known that gastric ulcers can occur not only after exposed ingestion of aspirin or ibuprofen, but much more frequently due to the bacterium Helicobacter pylori, which lives in the stomach. This discovery was made by two Australian scientists, Barry Marshall and Robin Warren, who were awarded the Nobel Prize for Medicine in 2005. Incidentally, they also found that the mineral bismuth helps against Helicobacter. Interestingly, the mineral bismuth also increases the concentration of phosphatidylcholine in its environment (2).

Bacteria eat phosphatidylcholine and thus perforate the mucus protector

It was later reported that Helicobacter pylori has an enzyme on its surface that can cleave phosphorus-containing fats, called ectophospholipase (3). Phosphatidylcholine is the protective factor in gastric mucus that prevents bacterial invasion. The sophisticated gastric germ called Helicobacter, with its ectophospholipase, manages to crack this protective phosphatidylcholine film and can thus penetrate the mucus to attach itself to the surface of the gastric mucosal cells. There it triggers an inflammation, which we know as gastritis. This eventually leads to gastric ulceration. Helicobacter pylori feeds on the lecithin in the mucus.

The administration of banana extract with its lecithin enrichment makes the lecithin easily accessible to the Helicobacter already in the gastric lumen, without having to laboriously break it out of the mucus. He is overfed with it and therefore abandons the mucus lecithin. The gastric inflammation recedes and the ulcer heals.

Why unripe bananas?

Giving unripe, green bananas may have the advantage that they are more difficult for the stomach to “digest”. In scientific terms, because they are unripe, they remain in the stomach longer, so exposure to the lecithin lasts longer. This would be an explanation for the particularly good efficacy in gastric ulcer disease. In further studies, phosphatidylcholine in orally administered form was shown to protect against gastric mucosal injury and gastric ulcers caused by stress or malnutrition (4).

The use of these simple and natural connections could also be of importance in the treatment of gastric inflammations. Thus, the thought matured in my mind whether the extract of green bananas could also be useful for the intestines.

  1. Hills BA, Kirwood CA. Surfactant approach to the gastric mucosal barrier: protection of rats by banana even when acidified. Gastroenterology. 1989;97(2):294-303.
  2. Ottlecz A, Romero JJ, Hazell SL, Graham DY, Lichtenberger LM. Phospholipase activity of Helicobacter pylori and its inhibition by bismuth salts. Biochemical and biophysical studies. Dig Dis Sci. 1993;38(11):2071-80.
  3. Weitkamp JH, Pérez-Pérez GI, Bode G, Malfertheiner P, Blaser MJ. Identification and characterization of Helicobacter pylori phospholipase C activity. Zentralbl Bakteriol. 1993;280(1-2):11-27.
  4. Dial EJ, Zayat M, Lopez-Storey M, Tran D, Lichtenberger L. Oral phosphatidylcholine preserves the gastrointestinal mucosal barrier during LPS-induced inflammation. Shock. 2008;30(6):729-33.