Your Appendix Isn’t Useless: New Scientific Theory Gains Ground

appendix useful bacteria beneficial

Remembering back to my days as a student of human anatomy and physiology, I recall clearly our lecture on the human appendix. The appendix was basically seen as a benign, but essentially useless leftover of human evolution.

In some people, at some times, it would inexplicably grow inflamed and acutely painful. The remedy? Surgical removal. And guess what? Unlike removing an organ like the gallbladder, no one missed their appendix. Removal didn’t seem to cause any adverse health effects.

Then, back in 2007, researchers put forward an interesting theory about the appendix. They argued that it did serve a purpose. The appendix, they said, is a repository for beneficial bacteria, providing support for bacterial growth and facilitating the re-population of the gut with good bacteria in the event that the intestinal tract is “purged” following exposure to a pathogen.

The Beneficial Appendix Theory

This theory stems from the few known facts about the appendix and the growing body of knowledge surrounding the role of beneficial bacteria to gut health. It goes something like this:

1. “Biofilms” of beneficial bacteria form outside of cells in the intestine, where they have a symbiotic relationship with the mucus lining intestinal walls. These colonies of bacteria are essential for having a healthy gut and immune system.

2. The appendix contains a particular kind of lymph tissue (the lymphatic system carries the white blood cells that help fight infections, among other things).

3. This kind of lymph tissue is known to promote and encourage the growth of beneficial bacteria biofilms in the gut.

4. The appendix is isolated from the rest of the gut in such a way that it is protected from the fecal stream that carries pathogens out of the gut.

5. Therefore, the appendix is well-suited to be a “safe house” for beneficial bacteria, “providing support for bacterial growth and potentially facilitating re-inoculation of the colon in the event that the contents of the intestinal tract are purged following exposure to a pathogen.”


William Parker, co-author of the 2007 study and professor of surgery at Duke University, said:

“At this point, this is a deduction based on a lot of information that we’ve had for many years and some key pieces of information that have only been uncovered recently by our lab and others. It does make sense.

But an experiment to prove this theory would be very expensive. And in any case, why would you want to spend money to find out something that is not likely to help cure a disease?”

In other words, this is a solid working theory, but few would be willing to test it.

The Appendix is NOT Unique

We used to think that the appendix was unique to primate anatomy, a withering (and now useless) vestige leftover after apes shifted to eating fruit. But current research belies that. More than 50 species of mammals have an appendix.

In a new study this year, Dr. Parker and other researchers at Duke University Medical Center published a study that:

compiled information on the diets of 361 living mammals, including 50 species now considered to have an appendix, and plotted the data on a mammalian evolutionary tree. They found that the 50 species are scattered so widely across the tree that the structure must have evolved independently at least 32 times, and perhaps as many as 38 times.

Furthermore, their findings throw a wrench in Darwin’s evolutionary hypothesis — suggesting that the appendix didn’t evolve because of shift in diet. Instead, their study shows the appendix is adaptive, but not because of any known dietary or social shift. It also heavily suggests that the appendix has an actual, viable, biological use, giving weight to their theory that the appendix is a safe house for beneficial bacteria.

Other evolutionary biologists agree.

Randolph Nesse, an evolutionary biologist at the University of Michigan, Ann Arbor, is impressed by the new study. “I salute the authors for creating an extraordinary database,” he says. “The conclusion that the appendix has appeared 32 times is amazing. I do find their argument for the positive correlation of appendix and cecum sizes to be a convincing refutation of Darwin’s hypothesis.”

What does this mean for you?

Well, not much. If you suffer from appendicitis, the only recommended medical treatment is still an appendectomy.

It, does, however suggest that your appendix may not have to work so hard at repopulating your gut with beneficial bacteria if you do a decent job of that yourself. It also suggests that taking care of your gut lining will further aid your appendix in functioning efficiently.

In practical terms that looks like:

  • Eating naturally-fermented, probiotic-rich foods. — This means you eat living sauerkraut instead of the pasteurized sauerkraut found on store shelves, drink probiotic beverages like raw milk, kefir, fermented lemonade, or kombucha.
  • Taking therapeutic grade probiotics if you have any known digestive, mood, or neurological disorders. — I recommend these brands, although there are many other quality sources for probiotics.
  • Eliminating foods that irritate the gut lining if you have any known digestive, mood, or neurological disorders. — These include grains and some dairy. There are many well-known gut-healing protocols that will allow you to heal your gut through diet, including the Gut & Psychology Syndrome Diet and the Body Ecology Diet.


While this isn’t earth-shattering news, you’ve got to admit it’s pretty nifty! And, it adds even more weight to the growing consensus that taking good care of your gut is essential for having a healthy, happy, long life.

What are your thoughts on the newly held usefulness of your appendix?

(photo: istockphoto)


  1. says

    Love this! Once again, it’s clear that nothing in our bodies is there by chance and that God did indeed know what He was doing when He created us! I’m currently struggling with gallbladder issues, despite my whole foods diet, cutting out gluten and processed foods and sugar. Everyone tells me “just have it out; you won’t regret it!”. No thank you. I’m determined to keep my gallbladder in my body, where it belongs. The medical community makes it so easy to have an organ removed, that everyone believes that is the only way. Like removing a tumor or a parasite. It’s part of our body, not a foreign invader! I’ll keep my appendix too, thank you very much. 😉

      • Lindsey says

        Thanks for the link! I have done a couple of gallbladder cleanses, where I have passed stones. I do eat a lot of coconut oil. It is my primary fat source with butter being a close second. I actually haven’t found a specific trigger for my pain. It’s been very strange. I just wish I could find an article about the gallbladder that doesn’t advocate a low fat diet! Anyway, love this post!

        • Cheryl P says

          Lindsey, check out the herb: “chanca piedra”, also known/sold as “stone breaker”. Here’s one article I found on it, and I know there are several versions sold from dry tea, to tinctures to powders to supplements. I know when I read about this, I could have kicked myself for having my gallbladder out 10 yrs ago (after 2 yrs of attacks). But I didn’t know any better back then. Good for you wanting to keep it in your body! :)

      • Christy says

        Hi! I have had a healthy vegan/vegetarian diet for the past 13 years, yet I still ended up having my appendix removed 6 weeks after my son was born in 2010… It’s obviously not what I ever wanted, but my options at that point were have it removed within 24 hours or leave the hospital and allow it rupture, spreading the infection throughout my body. By the time you know there is an issue (with the appendix anyway), it’s too late to make any dietary changes. I had been eating healthier than ever for 9 months while pregnant and it still happened to me. Just sayin’ 😉

        • says

          There are people who’ve reversed appendicitis with anti-inflammatory diets and activated charcoal and saved their appendix from being removed.

          I’m not implying that you made the wrong choice, just trying to let readers know that there *may* be other options.

          Also, I don’t consider a vegan/vegetarian diet to be “healthy” by nature. (They certainly *can* be under specific parameters.)

          The point here is that a probiotic-rich diet helps aid the gut (and by extension, the appendix). Probiotics means real, living, lacto-fermented foods. (Read this for more on what I mean by that.)

        • says

          Since I had my appendix out too (at age 9), I feel qualified to comment. Numerous things could have been done and could still be done when the appendix becomes infected. A castor oil pack and internal herbs such as pau de arco, for example. A naturopathically trained local massage to bring circulation. Cayenne fomentations. These are similar care approaches to washing and protecting a wound from infection.

          Aftercare to heal the tissue. Aftercare to prevent future occurence. Awareness to notice incipient formation of infection.

          There IS acute care and also the longer “dietary changes” care present in natural healing. When I had appendicitis I was basically made to wait more than 15 hours WHILE NOTHING WAS DONE, (this after calling doctors office) which was and still is the fashion of the day. allopathic Medical care only offers surgery, and yes, when YOU DO NOTHING , the infection could turn dangerous in time.

          So I certainly understand being backed into a corner, as I and many others were. Of course I am glad to have been able to at least had the medical care that saved my life due to the ignorance all around me.

          But for the general sake of the discussion, it must be said that this infection, like so many others, can be treated with natural means successfully.

          And yes once I got (much) older I finally, gradually learned I have to take care with awareness of my digestive system forevermore- we all do really, but even more now that this organ is gone.

      • amy says

        It really isn’t a major surgery in most cases. The majority of the time people are forced to have the appendix removed because it is a critical, life and death situation. There is no diet or lifestyle change that is going to help you when you bowel contents are spilling into your abdomen. It’s painful, I have been through it, as have my father and grandfather. Only I was pregnant at the time. I am thankful it is gone and was instructed by the surgeon to begin a probiotic regimen for life. Cheers!

      • Lori says

        Prior to my appendectomy, I had been drinking homemade kefir, juicing, and trying to eat as healthy as I could because my body was telling me there was something wrong. I had continuous bloating etc. None of that helped my appendix get better. Maybe it was because I was pregnant but I ended up having it taken out because it was inflamed and about to burst. It could have been detrimental for my baby and I. Some situations require such a decision. I had heard that if an appendix bursts it can kill you. I wasn’t about to risk my baby’s life in making such a decision.

    • Sharyn says

      All good, but if it comes time that your appendix needs to come out, it comes out or you die. Plain and simple…IT decides when it ‘s coming out. I know several people who waited too long, and did come VERY close to dying and in the hospital for WEEKS with several surgeries during those weeks, because of the infection that leaked into their bodies from waiting too long. Just sayin…

    • Cheryl P says

      Lindsey, check out the herb: “chanca piedra”, also known/sold as “stone breaker”. Here’s one article I found on it, and I know there are several versions sold from dry tea, to tinctures to powders to supplements. I know when I read about this, I could have kicked myself for having my gallbladder out 10 yrs ago (after 2 yrs of attacks). But I didn’t know any better back then. Good for you wanting to keep it in your body! :)

  2. carolyn says

    as a young child i decided that i was going into the ground with all my parts. i’m one of a few of my generation (i’m 60) to still have appendix and tonsils

  3. Julie says

    Fascinating!!! Thanks for posting. I think the Lord knew what he was doing when he designed us the way he did.

  4. Cherie says

    Thanks for sharing that. I too always felt God gave it to us for a reason, we just hadn’t figured it out yet!

  5. Roy Smalley says

    Incredibly interesting, and complements advice I read in another article recently that suggests 3/4 of your immune system is located in the gut and gives ideas on how to fix gut issues –

    Our six-year-old daughter is actually undergoing a surgical procedure next week where they’re using her appendix to create a sort of artificial urinary tract. With her appendix being essentially gone, we’ll have to be especially active in maintaining her gut flora balance and health.

  6. grh says

    King David said in the scriptures:

    “I shall laud you because in a fear-inspiring way I am wonderfully made. Your works are wonderful, As my soul is very well aware“.

    Enough said.

  7. Amy says

    My thoughts are that the appendix is a specific, intentional creation of an Almighty God who is wise beyond anything we can imagine or comprehend.

  8. Cat says

    Well… since I just had my appendix removed 2 days ago, I’m feeling disappointed that my little appendix didn’t make it to keep the good bacteria in check. However, I am so relieved that I read the whole article because – given the article that it was included with in the email I received, “Sneak Peeks Into How Busy People Prepare Real Food in Less Time” – I was afraid that people were turning an appendix into some kind of snack food.

    • says

      LOL. Oh my, Cat! Your imagination runs a bit on the scary side. Although, I guess it’s not so far fetched given that many new moms eat their placentas.

  9. Terry Ryan says

    Makes sense. So, what to do if you no longer have an appendix.
    I’m sure the appendix wasn’t placed in the human body randomly.

    • says

      I agree.

      I think if you no longer have an appendix, then you simply need to be super-vigilant about taking care of your gut with probiotics (including food!).

  10. Lindsey says

    I had my appendix out in 2007 after getting a flu shot. The surgeon told me that the appendix was part of the newborn immune system and was useless as an adult. My reaction to the flu shot was an inflammatory response. Seems only natural that my poor appendix was trying to do it’s job.

    Now I have bowel issues and my side hurts when the weather changes (weird, right?). Drinking kefir or kombucha with every meal really seems to help.

  11. says

    Kristin, my son just had an appendectomy, after four years at Stanford, had just graduated and started an internship. This should be the time of his life, right? There’s no doubt college is an assault on your health system, even when you are an athlete and attempt to eat healthy as he did, there is alcohol, late nights, stress, illness, sports injury, all dumping toxins in your system. You are no longer at home where your mother takes good care of you and gives you fresh green juice to drink every morning. You skip breakfast, for years, to get a few minutes extra sleep, burn the midnight oil, fraternize a little too much, and at the end of the road, graduation, your system is toxic. This happened to him. Now the appendix is gone. I’ve let him know he now must be more careful, but I will share this blog post as well. Thanks! PS: Lost mine when I was 28.

  12. Kim Hamilton says

    God put every part of our body there for a reason. I have always believed that & wondered why they said it was useless. I have my appendix, yet got a serious, almost life threatening infection in my intestines A couple of years ago. As amassage therapist Im learning how important lymphatic drainage is. I totally see how this could be. I have since made a big change in lifestyle & diet. Hoping 2 keep my parts & prevent return of infection.

  13. Rachel says

    Good info, Kristen!
    I had what was probably appendicitis last year (according to the urgent care center I went to), and antibiotics helped save my appendix! I just wanted to let your readers know surgery isn’t the only answer. Antibiotics took care of the immediate pain, and then I worked hard to support digestion and lower bowel health over the next few months.
    I unfortunately had to take antibiotics again recently, and I think the hard work I did earlier really paid off. I’ve had no troubles from the antibiotics since then. (Whew!)

  14. says

    I wish my mom had known about these things when I was growing up. Though she did an admirable job of steering us towards conventionally healthy foods – whole grains, no sugar cereals, no sodas, low fat, etc. But I still ended up losing both my appendix and my gallbladder and have digestive issues now as an adult. I can’t be certain that my issues were caused by those -ectomies, or if they should be considered symptoms as well. In any case, despite my conventionally healthy diet growing up, I’ve still struggled as an adult and wish more moms of the 80s and 90s had known about traditional food diets.

    • Doug says

      So much for whole grains and a low-fat diet. Sorry Amy, but that is not necessarily a healthy diet for many people.

  15. Emily says

    I would be curious to see a follow up study of people who have had appendectomies, comparing their bowel health to that of people who still have their appendix, ie, are they more prone to IBS etc. While it wouldn’t prove one way or another, due to so many people having a crappy diet and that possibly being the cause of them losing their appendix in the first place, it could potential show an interesting trend that would support this idea.

    • Gini says

      My mom had to have her gall bladder out when she was a teen, back in the 1950s. When she came out of surgery, the doctor said, “Oh, by the way, we also went ahead and got rid of your appendix, so now you’ll never have to worry about that again. Isn’t that great?” (…How’s that for hubris?) Anyway, after the age of 50, she began having the most horrible intestinal issues; pretty much IBD symptoms. I’m trying to get her to at least try the GAPs diet, and she’s taking probiotics, although probably not the best kind. It’s really heartbreaking to see a woman in her mid-70s have to deal with this! I don’t know for a fact that her gut problems are caused by the removal of her (perfectly healthy) appendix, but still, it makes us wonder.

  16. jeanie glass says

    I’ve heard about a correlation between people who’ve lost their appendix & hypothyroidism. I’m one of them…I’ve talked with other people who have the connection also…I’d like to learn about this.

  17. amanda says

    I totally believe this! I never had stomach issues (pain/bloating) until after my appendectomy! And it took me several months to find a dr to tell me to start talking probiotics. The surgeon should have done that! So frustrating!!!

  18. Doug says

    Have you researched the notion that the appendix grows back in 25% of those who’ve had it removed?
    Just following up.

  19. Tom says

    I recently had my appendix out. And after reading this article I am wondering what I should do. I know I should take probiotics which I do (bio kult) and eat more fermented foods but how much should I be eating. I drink raw milk and eat raw cheese on ocassion and drink kombucha daily. Is that enough or should I look for more ways to add fermented food to my diet?

  20. Barbara Hester says

    I grew increasingly ill over a 3 year period and not one doctor could figure out why until my appendix burst. About 12 years after that I was diagnosed with IBS and about 13 years after that I’m now allergic to almost everything and was diagnosed with Humoral Immunodeficiency. I somehow think it may be all connected, I feel almost normal when I’m eating unprocessed foods, organic and add probiotic containing foods to my diet.

  21. Mary TItus says

    For me, this is very significant news. My ex husband had a fistula, that connected his gut to his bladder. It was surgically removed, along with a portion of his gut to treat diverticulitis. I began speculating that these events were all symptomatic of the same ailment. I also believe that there is one issue that is being totally ignored by him and his medical team and that is leaky gut, B12 deficiency and low if no intrinsic factor.

  22. Faith says

    I was wondering if you could answer a question concerning the appendix? There is so much debate that it is hard to find anything other than “how to recognize an appendicitis”. I recently went toxin free, mainly due to food allergies, and my body is still adjusting and occasionally goes through detox (tired, anxious, need small, high protein meals often,frequent bowel movements, etc.) With that, I *usually* get a pain in the lower right abdomen, mostly when I need to use the bathroom or when I need food, sometimes randomly. The appendix plays a role in detoxifying and re-booting a damaged digestive system, right? Does it make sense for that to happen?

  23. Nancy Rojo says

    In the late 1960’s, I had ovarian cysts removed and “OH, WHILE WERE WERE AT IT…WE REMOVED YOUR APPENDIX…THANK US VERY MUCH”. In my late 50’s I was diagnosed with Rhuematoid disease. OK…I have changed my diet over the last 10 years to compensate for the affects of this disease and life is pretty good. Doctors don’t have the time to analyze each individual system…they doctor by the numbers. I take charge of my own health now and do what is best for me, not what doctors think what is best for me. After all…they are just practicing and I am the one occupying my body.

  24. says

    I have found in 25 years of Clinical practice that people who have lost their appendix are often Celiac patients. It’s my theory that gluten inflammation affects the appendix in some way, and it gets infected and can burst open. Perhaps it bursts to release beneficial bgs into a sick colon!

  25. Meshele Coleman Tomplait via Facebook says

    Nothing in the human body is “useless”. Once upon a time, the greatest minds in medical science told us that our spleen (produces red blood cells) and gallbladder (vital filtering system) were useless too.

  26. Sara says

    This is pretty cool. Very different from the “it was useful when we ate more vegetation” hypothesis that [I’m fairly certain] isn’t directly supported by animals that do eat a lot of vegetation. I am reading the book “Why We Get Sick,” by Nesse and Williams right now (I noticed you cited Nesse). Have you read it? It’s an interesting read.

  27. Mary Light via Facebook says

    Your appendix, tonsils and gall bladder are quite useful to someone – for buying a summer house, a boat, or taking a safari to Africa. That little joke aside, there is now a new (medical) theory being promoted that we have a microbiomass which is established at birth. There are problems with this theory , from a brief listen to the interview (Terry Gross NPR) in that too much blame is put on early life, as if food choices later have nothing much to do with it. But it shows growth in medical thinking, which is terribly hampered by cartels , medical school curriculums, and the industry interests. Worth a hear:

  28. Regina Marie Petersen via Facebook says

    I loved this article…I actually think that Anna Marie Kuck might be interested in reading it. It also caused me to look into some of the “related” links and read about recovering from an antibiotic. Thanks for sharing.

  29. Caf says

    While this is great and all, I don’t know if it could have saved my appendix. I was sixteen and it was a very rare case (my appendix was behind my intestines, I didn’t feel the normal, excruciating pain most people feel) and my appendix had been burst for two weeks by the time they removed it. I was septic, had tubes coming out of every orifice to suck out infection and it nearly killed me. It’s been 6 years now and I still suffer from a compromised immune system, getting colds, stomach bugs, ect., every time they come anywhere near me and usually developing an infection because for some reason my body just doesn’t seem to be able to fight off anything. I have to figure my appendix has to have something to do with it, since it started after that. I’m on probiotics and the healthiest I’ve ever been was when I was on a strict gluten free diet where I consumed mostly fruits and vegetables. I did find this article very interesting, but in some cases, I don’t believe the appendix can be saved, and maybe it shouldn’t.

  30. Mary Light via Facebook says

    Good old “researchers”. The function of the appendix has been known for eons! “Researchers” just figured this out a few years ago? I don’t think so. It also lubricates content coming in from the ileocecal valve, an important digestive juncture, thus providing important ease of passage. It is an organ of the IMMUNE SYSTEM, catagorically. “Researchers” remove the spleen, tonsils, (tonsils , which protect from the POLIO VIRUS- funny how polio rose with the fashional removal of tonsils….) gall bladder, etc- I wonder when the “research” is forthcoming, awaited with bated breath, for these organs, the functions of all of which are clearly described in old and current anatomy books. These organs were removed because it was profitable and lazy to do so. Period.

  31. Frasier says

    Your “recommended brands” of probiotics just links to Vitacost’s full selection of 421 products… not very helpful.

  32. Allison says

    I am so relieved to find this article. My husband had his appendix removed 4 years ago and has had non-stop health issues that nobody could solve. This makes total sense. His gut is a mess. He was so healthy before, and now he is in constant pain and suffers from all kinds of intestinal distress. Now that I finally understand the function of his appendix, it makes perfect sense as to why he is feeling this way. This is an answer to my prayers and perhaps now he can finally get the help he needs. Obviously, we need to now focus on getting that good bacteria back in his gut. We already have made a host of changes such as switching to coconut oil, but fermented food sounds like it would really help him. Thank you so much for this post!

  33. Callie Sabens via Facebook says

    For several years after I had mine removed I would periodically have awful spells of nausea that were relieved after I ate yogurt.

  34. says

    Thank you, I believe the scientific community does want to back track on the “useless appendix” verbiage because it is a major contributor of evolution. “See how we evolved we don’t need our appendix anymore.” Good article!

  35. Kendra Brown via Facebook says

    I know sometimes people have no choice, I completely get that. But why anyone would believe that an organ is useless baffles me. Obviously it’s there for a reason, even if we’ve yet to fully understand it.

  36. Mari Morgan via Facebook says

    Mine burst in the doctor’s hand – they delayed surgery for two days saying I had food poisoning! They started the IV antibiotics while I was still in the OR. 5 days in the hospital really sucks when you’re ten.

  37. says

    I started reading about 6 years ago how important the appendix really is, and I suspected as much for sometime before that. In December of 2000, I endured a ruptured appendix during the time I was pregnant with my one and only child. I was 7+ months along when I began to experience pain in my lower right quadrant. The midwife I was seeing at the time said it was “round ligament pain” and sent me home on bedrest and recommended a maternity belt. The pain only became worse as time went on. Eventually I ended up in the ER, spent the weekend there with no answers, bleeding, and then was sent home.

    The following day I continued to have more pain and eventually went into labor in the wee hours of the morning. I arrived at the ER and was examined by the nurse who told me I was 9 centimeters dilated. My son was born about 25 minutes later. I remained in the hospital with a distended abdomen and still no answers. Three days after delivering my son I was taken into exploratory surgery and low and behold … my appendix had been ruptured for at least several days. I spent an additional week and a half in the hospital.

    The day I was to be discharged, the nurse told me I should be careful as many pregnant women develop gallstones. During my initial hospitalization I was given an ultrasound and told I had gallstones, but nothing was ever said or done about it until the nurse just happened to mention it again right before I was going home. The night I came home I had my first “gallbladder attack.” I had 8 more of these before I was talked into having my gallbladder removed. If I knew then what I know now, I would have cleaned up my diet and started eating traditional foods. I may have very well been able to save my organs from being harvested, I believe.

    I am now sans an appendix and gallbladder, and much wiser.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>