Scientists are beginning to question the long-standing belief that the appendix serves no purpose and whether removing it is necessary for all people with appendicitis.
The appendix is a small tube-like structure attached to part of the digestive tract called the colon. It generally remains unnoticed unless it becomes painful due to a potentially dangerous condition known as appendicitis. Data suggests that about five to nine out of 100 people will experience appendicitis at some point in their lives.
Appendicitis happens when the appendix becomes blocked and inflamed. If left untreated, the inflamed organ can burst, resulting in a potentially fatal condition known as peritonitis. That's why a burst appendix is considered a medical emergency.
Symptoms of appendicitis include pain beginning around the belly button that may move to the lower right part of the abdomen, nausea, vomiting, and low-grade fever. Most often, surgeons will remove the appendix immediately after diagnosis through a procedure called appendectomy.
Does the appendix have essential functions?
Charles Darwin theorized that the appendix was a useless structure in the human body with no actual function. So, most people consider it an expendable part of human anatomy that can be surgically removed via appendectomy without consequence.
However, emerging research suggests that this tiny appendage on the large bowel may be more important than once thought, which has scientists second-guessing whether treating appendicitis with an appendectomy is necessary in all cases.
Heather F. Smith, Ph.D., FAAA, a Professor of Anatomy at Midwestern University, tells Healthnews that research shows the appendix is not useless and may actually serve two critical roles in the human body.
"In 2007, a team out of Duke University discovered that the appendix has a biofilm, a layer of beneficial gut bacteria," Smith explains. "They hypothesized that the appendix serves as a 'safe house' where good gut bacteria are protected during times of gastrointestinal (GI) distress when much of the gut's healthy bacteria gets flushed out of the rest of the large intestine. The reservoir of beneficial bacteria in the appendix can then repopulate the gut after the GI issue is over."
Smith says that besides serving as a reservoir for beneficial gut bacteria, the appendix contains a concentration of lymphoid tissue, which supports the immune system and helps the body defend against invading pathogens in the gut.
What happens if the appendix is removed?
Though people can function just fine without an appendix, some research implies that removing the organ may have negative consequences.
For example, research published in 2021 suggests that having an intact appendix may promote longevity. The study's authors found that compared to mammals of the same weight without an appendix, those with an appendix have a longer lifespan — likely due to a lower risk of acquiring fatal infectious diarrhea.
However, a 2017 study showed that having a personal history of appendicitis and appendectomy before age 20 was associated with a lower risk of ulcerative colitis.
Still, appendix removal may impact the gut biome, leading to a higher risk of specific diseases. For example, a 2022 study published in Oncogene found that appendectomy-induced microbial changes in the gut biome may play a role in the development of colorectal cancer.
"This is an area in which additional research is definitely needed," Smith tells Healthnews. "However, a few studies have found that rates of 'C-diff' (Clostridium difficile) infection are higher in people without an appendix, suggesting that the appendix may offer some protection against infections such as these. Further research is needed to further evaluate the range of medical issues associated with appendix removal."
Treating appendicitis with antibiotics
As scientists learn more about the appendix and its role in human health, some suggest that antibiotics could be a feasible treatment option for some people with appendicitis.
For example, in a 2021 review of research, scientists found evidence that antibiotics can successfully treat up to 70% of uncomplicated appendicitis cases. However, about 40% of patients treated with antibiotics end up experiencing another bout of appendicitis and eventually need surgery.
Therefore, whether to use antibiotics or surgery to treat appendicitis is a decision best made by a qualified healthcare provider or surgeon. This helps ensure a person receives the most appropriate treatment to prevent potentially deadly complications such as peritonitis.
- NIH. Definition & facts for appendicitis.
- Journal of Theoretical Biology. Biofilms in the large bowel suggest an apparent function of the human vermiform appendix.
- Gut. Reduced risk of UC in families affected by appendicitis: a Danish national cohort study.
- Journal of Anatomy. The cecal appendix is correlated with greater maximal longevity in mammals.
- MedlinePlus. Appendicitis.
- Oncogene. Altered gut microbiome composition by appendectomy contributes to colorectal cancer.
- JAMA. Diagnosis and management of acute appendicitis in adults: a review.