Commonly considered a vestigial organ with no real purpose, the human appendix may actually be more important to you than you think, particularly when it comes to your gut bacteria. Learn more about the link between the appendix and probiotics below.
What is the Appendix?
The appendix is a small, finger-shaped pouch that connects to the cecum, which is a tubelike structure found at the junction between the small and large intestines.
Prior to current research on its functions, the appendix mainly had a reputation for becoming inflamed, and developing appendicitis. When doctors diagnose appendicitis they usually recommended its removal in a process called an appendectomy because of the risk of perforation and rupture. A perforated or ruptured appendix leads to the release of microbes into the abdomen which may become life threatening.1
A perforated appendix that is not treated surgically with removal has been found to have a 20% chance of developing into an appendiceal neoplasm or appendiceal cancer. This risk increases to 29% in those aged 40 or more.7
What is the Function of the Appendix?
The appendix is home to the highest concentration of gut-associated lymphoid tissue (GALT), more so than in the entire digestive system. This lymphoid tissue is where immune cells are trained as they get exposed to bacteria within the gut. The GALT is also believed to assist in the maturation of antibodies and certain white blood cells, like B lymphocytes.2
The Appendix and Gut Bacteria
Further studies suggest that the appendix may function as a safe house for good bacteria. Bacteria in the appendix form resilient biofilms. Biofilms are made up of gut microbes that secrete an extracellular polymeric substance (EPS).6 These biofilms allow gut bacteria to live undisturbed in the appendix, occasionally exiting the appendix to colonize the gut.
This can play an important role in maintaining a healthy, balance gut microbiome. For example, during bouts of diarrhea that cause an evacuation of the intestines’ contents, beneficial gut bacteria can survive within the appendix and repopulate the gut once the diarrhea has subsided.3
Side Effects of an Appendectomy
Given its effects on immune functions and gut bacteria, the appendix may be more beneficial than initially thought.
Mixed Risk for Inflammatory Bowel Diseases
While removing the appendix has been associated with a lower risk of ulcerative colitis, studies have found that an appendectomy may increase the risk of Crohn’s disease. A study followed-up on 212,218 patients who had undergone an appendectomy before the age of 50. The results found that the patients collectively showed an increased risk of Crohn’s disease for more than 20 years following their appendectomy procedures. Patients with a history of perforated appendicitis had a worse prognosis.4
Increased Risk of Reoccuring C diff
Studies have also found that people without an appendix have an increased risk of recurrent Clostridium difficile-associated colitis. C. diff infections most often occur in long-term medical care facilities and usually come as a result of antibiotic medications that neutralize good bacteria in the gut.
Use of antibiotics that wipes out good gut bacteria allows for C. diff bacteria to grow out of control. Strong evidence suggests that the appendix may play a protective role in recurrent C. diff infections. Studies have found that patients without an appendix are 2.5 times more likely to experience recurring C. diff colitis compared to those with an appendix.5
The appendix appears to modulate and interact with the immune system and has roles that researchers have not fully elucidated. The appendix’s relationship with the rest of the immune system is complex, and it is theorized that the appendix is ill-suited to modern life because the incidence of appendicitis is correlated with the availability of clean running water.
According to the hygiene hypothesis, a lack of exposure of the immune system to microbes and parasites has led to the development of overactive immune systems that are more prone to autoimmune diseases, allergies, asthma, and inflammatory reactions, such as appendicitis. More research is necessary to determine the role of the appendix in the immune system.
The existing research shows that people without an appendix may have trouble maintaining healthy gut bacteria levels and are prone to recurring C. diff, along with a potentially increased risk of Crohn’s disease. Taking a probiotic supplement, like DrFormulas® Nexabiotic®, may help to support a diverse, robust, and healthy gut microbiome. One of the 23 probiotics in the formula is the probiotic Saccharomyces boulardii, which has been shown to reduce recurring C. diff.
Read next: Probiotic Side Effects | Here's How to Avoid Them