As we have previously reported in this publication, and at educational events, the human body relies on multitudes of bacteria within the colon – that colonize from the moment of birth – to help with the digestion of food. Research out of St. Louis, MO, in 2002 showed that bacteria living in the intestine play an essential role in the development of blood vessels within the gut.

Mice raised in a bacteria-free environment did not develop blood vessels in the gut until they were exposed to bacteria. The investigators made this discovery when they compared blood vessel growth in normal mice and mice that grew up without any bacteria in the small intestine.

Interestingly, within 10 days after the researchers colonized the germ-free mice with a common human and mouse gut bacteria called Bacteroides thetaiotaomicron, normal vessel development was restored.

They also discovered that antibacterial intestinal cells called Paneth cells interact with bacteria to promote the growth of blood vessels. When mice were genetically engineered to lack Paneth cells, blood vessel growth was considerably less extensive.

The researchers hope to discover the pathway by which bacteria are able to stimulate the formation of new blood vessels (angiogenesis). The hope is that by understanding how gut bacteria promote angiogenesis in the gut, compounds and targets will be identified that might be useful for treating illnesses that affect the gut.

First published in the Inside Tract® newsletter issue – 137 May/June 2003
T S Stappenbeck, L V Hooper, J I Gordon. Developmental regulation of intestinal angiogenesis by indigenous microbes via Paneth cells. Proceedings of the National Academy of Sciences Early Edition. 2002;10.1073/pnas.202604299.