I have been taking care of patients since 1994 when I was a medic in the Air Force. I was taught in my training then, and again during Chiropractic college, that the appendix was a useless organ left over from some previous time in our evolutionary history. Darwin postulated that it was the remains of a larger structure called the cecum which was used by our ancestors to digest a diet much larger in fiber.
New research may be putting that old theory to the test. We may now know what the purpose of the appendix actually is. The next 2 articles will delve into this topic. Today’s article will focus on what the function of the appendix could actually be. The next article will focus on how this may may be influencing a surgery only approach with appendicitis.
The appendix is a finger like structure about four inches long located in the right lower abdomen attached to the large intestine at the junction of the small and large intestines. Researchers have been trying to find out what the function of the appendix may be for many years, and now there have been a few studies that all seem to point in the same direction. The appendix could be a reservoir for good bacteria that is responsible for repopulating the beneficial bacteria in our gut following certain illnesses.
We now know that healthy gut bacteria, also known as our microbiome, plays a crucial role for our immune systems. When illnesses accompanied by diarrhea wipe-out the good bacteria in our gut, some researchers believe that the appendix is responsible for repopulating the beneficial bacteria. There have been a few different studies that have come to this conclusion.
The 1st was in 2012. It was a records review of patients with Clostridium difficile colitis at Winthrop-University Hospital. They found that patients with C-diff had a re-occurrence rate of 45% if they had their appendix removed versus only 18% of the time if they had not. C-diff that reoccurs is often treated with a fecal transplant. Yes you read that right. The purpose of the fecal transplant is to repopulate the gut with beneficial bacteria. It was postulated that perhaps the appendix was serving the same purpose.
The next study was published in Nature Immunology in 2015 performed by French and Australian researchers. Their study showed that a group of white blood cells called innate lymphoid cells (ILC’s) help the appendix play a role in the body’s immune response to infection. “A balanced microbiome is essential for recovery from bacterial threats to gut health, such as food poisoning”. “We found that ILC’s may help the appendix to potentially re-seed good bacteria within the microbiome in the body” explained Gabrielle Belz, a professor at Melbourne’s Walter and Eliza Hall Institute.
The most recent study is being performed by Heather F. Smith PhD., an associate professor at Midwestern University Arizona College of osteopathic medicine. Her team is studying the evolution of the appendix in mammals. They found that the appendix has evolved in over 30 mammalian species independently, and almost never disappears once it has arrived. This suggests that the appendix does indeed have a function, or it would not keep showing up independently in evolutionary history. They also found that species with an appendix have a higher concentration of lymphoid (immune) tissue in their cecum. Lymphatic tissue can stimulate the growth of some types of beneficial gut bacteria. This provides further evidence that the appendix may be a storage facility for helpful gut bacteria.
We still cannot say with 100% certainty that the appendix is indeed a “safe house” for beneficial bacteria. However, more studies are underway testing this hypothesis. Dr. William Parker, an associate professor at the Duke University school of medicine states “It’s no question the idea that it (the appendix) was a vestige would never have been proposed if Darwin had the data that we have now” He also goes on to say “It turns out the appendix is perfectly located and situated to provide us with a backup source of bacteria in case of infection. The appendix… is a safe haven where good bacteria could hang out until they are needed to repopulate the gut after a nasty case of diarrhea.”
It is exciting to me that we have evidence pointing to a vital role that the appendix may play in our bodies. It always seemed odd to me that every other body parts seem to have a function, but because we simply did not know yet what the function of the appendix was, we considered it useless. In our next article we will discuss how this information, and other studies are changing a surgery always approach to appendicitis.
Yours in Health
Crick and Crack
Dr. Thomas Turek grew up in New Jersey and attended Rutgers University and New York Chiropractic College. He has practiced in St. Johnsbury for over 35 years, and lives in Waterford with his wife Dorothy. Dr. Travis Howard grew up in Rantoul, Ill. He was a medic in the Air Force for eight years. He attended University of Maryland European Division, Illinois State University, and Logan College of Chiropractic. He lives with his wife and three sons in Littleton, N.H. To submit a question for the column, email email@example.com.