Wednesday, November 11, 2009

The Long-Term Effects of Antibiotics on Health and Immunity

Garlic is the famous natural antibiotic.
Garlic is the famous natural antibiotic. (Photo by stijn)

This is the third and last installment in a series of posts on immune function and gastrointestinal health. Given that the swine flu is still making rounds around the world, learning more about how beneficial bacteria can ward off viral infections has been very useful at least for me.

So far, we've seen that foods and supplements containing probiotics can reduce the occurrence and severity of the common cold. Probiotics also have other benefits, such as protection from cancer and increased resistance to cancer. We've also seen that another way to increase beneficial bacteria in the gut are prebiotics, which are a form of fiber found in foods such as Jerusalem artichoke and chicory root. The combinations of prebiotics and probiotics are known as synbiotics and may be superior to either one alone.

Antibiotics and resistant bacterial strains

The one group of biotics that's left to tackle is antibiotics. Most people have probably gotten a prescription of antibiotics at least once in their life. Most people are probably also aware that antibiotics are prescribed way too frequently these days by many doctors, even for health issues that antibiotics can't relieve. As antibiotics only work against bacterial infections, not viruses, taking them for flu symptoms is useless.

The commonly known problem is that as the use of antibiotics becomes more and more widespread, the bacteria become more and more resistant. This is especially common when people quit their antibiotics prescription halfway through because they "feel fine"; some of the surviving bacteria then mutate into more resistant strains and spread into other people.

In a way, there is an evolutionary war going on between medicine and bacteria, and while antibiotics are a fantastic discovery and have many applications, their overuse is a serious problem. That's why taking antibiotics "just in case" is not a great idea long-term.

Other health problems from antibiotics

If the well-being of the rest of humanity doesn't bother you all that much, there are also other, less known reasons to stay away from antibiotics unless you actually need them. Let's look at some of the evidence showing the harmful effects of antibiotics.

Most of the negatives stem from the positive fact that antibiotics are so effective. The problem is that antibiotics are not as specific as we'd like: while they do destroy harmful bacteria, they also destroy beneficial bacteria. That's why it's never recommended to take probiotics at the same time with antibiotics, because the probiotics are just rendered useless.

Since one of the functions of intestinal bacteria is to aid in food digestion, it's no surprise that antibiotics can cause digestive problems. Diarrhea occurs in about 25% of patients receiving antibiotics (link). Probiotics, on the other hand, can counter some of this effect. At least Lactobacillus GG and Saccharomyces boulardii appear to be effective. As mentioned before, leave about 3 hours between taking antibiotics and probiotics to avoid killing the beneficial bacteria right away.

The effect of antibiotics may be especially pronounced in babies, whose bacterial colonies have not yet matured. In one study, rats who were given an antibiotic for 10-17 days saw a near complete eradication of Lactobacillus in the intestine along with a drastic reduction in other bacteria (link). This would obviously have a negative effect on immunity in general.

Another group to whom antibiotics may pose a real danger are the critically ill. One study showed that not only did the microflorarl biodiversity of patients in the intensive care unit significantly decrease with antibiotics, but there were also more organ failures and deaths in patients given antibiotics (link).

Antibiotics also seem to have a negative effect on phytoestrogens. The levels of the lignan enterolactone, a type of phytoestrogen, were significantly lower in men and women who had taken oral antibiotics up to 16 months before measurement (link). The reduction was associated with the number of treatments and time from last treatment. Although not life-threatening, this reduction should be of some concern to those who are taking for example flax lignans for hair growth or other health benefits.

Long-term impairment of immunity from antibiotics

If the above reasons didn't put you off antibiotics for good, here comes the worst part: the previously unknown long-term effects of antibiotics.

Until recently, the effect of antibiotics was thought to be temporary. As long as you took your prebiotics at least 3 hours after your antibiotics, you'd be fine. Any long-term changes in intestinal microflora were considered to last only a few months, after which everything would return to normal.

Unfortunately, some new studies have begun to show that this is not necessarily the case. A study funded by the Finnish Academy found that the earlier estimates were too conservative, and that the effects of antibiotics on intestinal bacteria were visible even after a year (link). Surprisingly, they also discovered that using one type of antibiotic (such as penicillin or tetracycline) increases the resistance of bacteria to other types of antibiotics as well. The old idea of switching to a different antibiotic to avoid resistance doesn't seem so good after all.

A study from last year confirms these findings. Using a novel method of observing the human gut microbiota, the authors found that antibiotic treatment "influenced the abundance of about a third of the bacterial taxa in the gut, decreasing the taxonomic richness, diversity, and evenness of the community" (link). While the conditions partly returned to normal after four weeks, several bacterial taxa failed to recover even after six months.


While antibiotics certainly have their uses, taking them when unnecessary can be harmful in many ways. Here's a summary of the negatives:

  • Increased resistance to antibiotics
  • Diarrhea and digestive problems
  • Reduction in beneficial phytoestrogens
  • Impaired immunity, especially in children and the critically ill
  • Long-term changes in gut microflora

Since antibiotics, by definition, are substances or compounds that kill or inhibit the growth of bacteria, it's good to keep two things in mind. First, antibiotics destroy not only bad bacteria but also good ones. Second, antibiotics are only effective against bacteria, not viruses. So before getting antibiotics for an infection, make sure it really is a bacterial and not a viral infection (the common cold, for example, is a viral infection).

For more information on health and immunity, see these posts:

Prebiotics, Synbiotics and the Immune System
The 7 Types of Aging Damage That End up Killing You
Intermittent Fasting Reduces Mitochondrial Damage and Lymphoma Incidence in Aged Mice
Swine Flu and Avoiding the Cytokine Storm: What to Eat and What Not to Eat?

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39 kommenttia:

valy November 25, 2009 at 2:42 PM  

Hi there!
I like the info from your site.
I was reading this topic a few days ago and i was wondering if the antibiotics found in garlic have the same effect on intestinal microbial flora as synthethic antibiotics have.
Do you have some info on this?
Thank you.

JLL November 30, 2009 at 10:35 AM  


Yes, I would think that they do. See for example this page. Note, though, that it's the allicin in garlic that seems to have the most potent effect -- and since allicin is produced by crushing the garlic (and letting it sit for about a minute) and destroyed by heat, you can partly if not completely avoid the antibiotic of garlic by using it in cooking instead of eating it raw.

The opposite is also true; if you're taking garlic to prevent an infection, crush it, wait for a while, and then eat it raw.

paul2978 December 13, 2009 at 1:10 AM  

have you heard of colloidal silver I found this very interesting as silver is a antibiotic :)

Anonymous June 16, 2010 at 10:19 PM  

overuse of antibiotics causes an overgrowth of yeast in the intestines which causes countless other problems in individuals

Anonymous March 16, 2011 at 9:17 PM  

Wow! I have been searching for hours, Ihave finally found this site and it has been very very helpful! I was diagnosed with a heart murmur as a child, at that point, early 1970's my doctor put me on a daily dose of pennicillin for many years,he said to "prevent" any illness from going to my heart? I don't know, sounded good at the time I guess. As an adult, I have experienced alot of digestive problems and Iam now beginning to believe it comes from the anitbiotic use. Anyone else with this problem??

Unknown April 21, 2011 at 4:45 PM  

Long term antibiotic use can cause so many issues because it depletes your good bacteria and leaves room for the bad bacteria to grow. That attacks the digestive tract along with the Yeast. Pro biotic and acidophiles treatments can turn it around but it takes time. also add some pro biotic foods to your diet and at fiber one your digestive tract settles down. I suffered from this from post surgery which was called clostridium diffice colitis

Anonymous May 8, 2011 at 11:08 AM  

Very interesting article. I'm on 500 mgs of amoxicillin daily as I've no spleen. It appears a common treatment to boost the immune system. Im on it nearly 6 years and will be for life I'm told. Would this dosage, longterm, cause I'll effects. I definitely have had yeast infections and feel gas in my stomach at times which is uncomfortable.

JLL May 8, 2011 at 8:19 PM  


I can imagine prolonged use of amoxicillin (or any other antibiotic for that matter) can cause the kind of symptoms you describe -- however, I'm not sure getting off it would be any better, as I'm no expert on that matter.


Anonymous July 4, 2011 at 1:47 PM  

Well said! I have been suffering for about 2 or 3 years now with digestive problems. I have had a colonscopy and gastroscopy and no problems were found. I must make mention though that about 2 or 3 years ago I had 5 sets of antibiotics (mostly ciproflaxin) over a period of 8 months for either influenza or a sore throat. After a while I realised I shouldn't have taken the antibiotics (which my doctor prescribed) and so I stopped taking them and decided to fight the flu and sore throats on my own which worked out well. Unfortunately I discovered my ignorance too late and now I just hope someday my GI tract will stabilise itself.

purushotam September 22, 2011 at 6:16 AM  

hi, i was very much interested and keen interest to know about the antibiotic, my mother is suffering from leg cellulitis and she was admitted for 20 days in hospital and she came to home with less dangerous, again after a month now she got again leg cellulitis, doctor preferred to elevate her leg and stay bed rest. i want to now will it turns to some other things. plz refer me

Anonymous October 26, 2011 at 6:47 AM  

what a joke. In this article it states that it is NEVER recomended to take probiotics at the same time as antibiotics. It is actually almost ALWAYS recomended to take them. so I'm guessing that most of the facts in here should be questioned or at the very least double checked.

JLL October 26, 2011 at 4:06 PM  


You're more than welcome to double check them and inform me if/when you find any mistakes. I'm glad that some readers take the time and effort to point out corrections.

As for taking probiotics with antibiotics, I've never heard anyone recommend taking them *together*. That just makes no sense, if the probiotics get destroyed by the antibiotics. As I said, however, it *is* often recommended to take probiotics during an antibiotics treatment -- just as long as there is a gap between taking the antibiotics and the probiotics.


Ron Lavine, D.C. January 3, 2012 at 3:44 AM  

Interesting article. I've created a link to it from an article on my blog about probiotics from soil bacteria.

By the way, do you have an opinion about probiotics from soil vs. probiotics from dairy products (the main type of probiotic people seem to consume)?

Anonymous January 3, 2012 at 7:01 PM  

I am currently fighting a prostate infection.I have already taken 4 rounds of antibiotics over a 5 month period. Is there another way to fight this infection?

JLL January 4, 2012 at 2:28 PM  


I haven't read any studies comparing the two; all of the studies that I've read that showed benefits used probiotics from dairy. But who knows.


Sorry, but I don't know.


NoodleUnit January 12, 2012 at 7:17 PM  


Found this very interesting. I was prescribed heavy duty antibiotics for a period of about 6 months due to an infection deep in some damaged muscle. It took at long to persuade them to just slice me open and clean it out that way. I even had a double dose of metronidazole and coamoxiclav at one point, which saw me in the emergency room.

I've suffered serious damage to my insides and it seems to have triggered off latent celiac disease. I now can't tolerate gluten, dairy or soya and even a small amount triggers a huge immune reaction. Not an allergic one, but I very rapidly get neuro symptoms and arthritic symptoms after ingestion.

I've also recently started to get additional problems with bloating and possible gallbladder issues. Before the antibiotics, i was perfectly healthy. I'm now very wary of the things. And certainly wouldn't want to be on them for more than a couple of weeks.

My question is, is there any research or info on how to restore your gut after such a long exposure to antibiotics?

JLL January 13, 2012 at 10:58 AM  


I would look into probiotics. There was a health blog with a lot of information on gut health, but I can't seem to find it right now. I'll put up a link in the comment section if I find it.


Anonymous March 14, 2012 at 8:24 PM  

I've just finished a treatment of stacked antibiotics (low dosage)along with a angio tensin receptor blocker.
I started with Clindamycin then added Minocycline then added Arithromycin with an Olmetec receptor blocker.
I have been on this treatment for three years to combat Lyme Disease.
It has made things better for me as I dealt heavily with Migrating Chronic Joint Pain.
I feel as though I may be dealing with low testosterone but all the quizzes I take say ...possibly.
Is this the time to ingest a lot of probiotics and synbiotics?
Do I need to look at things like prostate cancer because of the long term treatment.
I am 50 in relatively good shape but lacking good muscle tone and dealing with increased body fat in my 'spare tire' area and breasts.
Does this bring up any warning signs in your mind.
Thx for the time.

Anonymous April 2, 2012 at 1:08 PM  

Hi. I've had 4 mastitis infections over the past 10 weeks after the birth of my son and have been on 6 rounds of different antibiotics bc it won't stop coming back. Do u know if this will hurt me long term or the baby from taking do much in just a short amount of time? My dr never recommended taking a probiotic. I didn't even know that existed until I read about it on my own the other day. I plan to start taking then ASAP. I have yet to have a yeast infection as well. Not that I'm hoping for one but I've heard usually that's what happens. My baby has not had thrush either. I would like to like ur thoughts on this. Ty

Quatro April 10, 2012 at 6:35 AM  

I was prescribed as an infant for boils on the head and then child for chronic ear infections until 12 years of age continuous antibiotics. I have suffered for the last thirty years (now 50) with extreme reflux, have had constipation that sends me to the floor in pain years back - before I realised what it was. Many years of yeast infections - which I have combatted apart from my toe nails and now long term psoriasis which has been at all extremities. Bringing it all together I believe the intake of antibiotics as I child prevented the development of my digestive organs. I take the best probiotics I can, and now do not take any of the extreme high dose reflux medication I was prescribed, as it is not good for my other organs and was causing general poor health. I suffer with autoimmune deficiency obviously with ankylosing sponylitis thrown in. So most of my night I sleep sitting up. I am not sure of the answer however I am pretty convinced I have the cause down to pat. The best result seems eat little at night, take probiotic an hour before eating, limit alcohol at night. I can suffer with reflux at any time of the day and not just related to the type of food as I get it even when I do not have food. So I think the damage done as a child is permanent and I have spent a fortune on natural products to rectify and naturapaths the improvement seems to be just in the simple things as I mentioned.

Anonymous May 21, 2012 at 10:04 PM  

I have been on antibiotics for 4 months now and suddenly i started feeling pains in my whole body especially my legs, could it b as a result of d antibiotics use, somebody help.

Anonymous May 29, 2012 at 6:58 PM  

Oh my gosh...antibiotics are poison! Stop taking them! They are NOT cure-alls. There is so much information on the internet, even from well respected medical institutions and experts. Go do your browser searches and you will be glued to your seat because of all the information that can help you understand, but take into consideration all the information. In just the last two days I've found enough shocking and unbelievable bad news about anti-biotics that it makes my heart skip a beat!
Remember...on all prescription drugs there are fact-sheets attached that state for user to "discontinue use of any medication if side effects are experienced" so what are you waiting for?! stop the medication! We are being used as human genny-pigs for the pharmaceutical industry and it is high time we all wake up and realize it. Do your homework...there are herbal alternatives that have no side affects...I know because I've used them and they work. Even the doctors/dentist etc that prescribe them are shocked to find out I didn't use prescription but instead natural altenatives to heal and prevent.

Anonymous May 29, 2012 at 9:24 PM  

stop taking antibiotics that are prescribed and find natural herbal alternatives. all prescription drugs are tested on humans because that's the only real way to find out it safe or not. Think of it this way...if you are fatigued it's not because you have a prozac need to take vitamins that you are lacking to restore what is not in the foods you currently are shoveling down in between your busy-ness and hectic lifestyle. set priorities and learn to cook and eat healthy non-processed foods. We are all going to die and that is 100% certain but you can still feel great while you are alive if you make smarter choices.

D June 28, 2012 at 5:16 PM  

im 40yrs old male and i have suffered eczema for the past 20 years, on and off,when i was a teen, there was a time, i had sorethoat every other week bec of the teeth retainers i has(bad bad choice) it was a breeding ground for bacteria) until i had tonsilectomy, i was frequently on antibiotics, i think with all those years ( 1-2 years)of too much antibiotic,the digestive system was affected, autoimmune disroder like eczema just came out,i had experienced extreme stomach pain where im down on the floor and could almost faint. i share with u people, to start with rich fiber foods,i eat oatmeal everyday to lower my LDL.and now im going to take this probiotic.i read somewhere that something with pineapple is good for the intestines that helps restores the natural bacteria.
Antibiotic cause-digestive problems which will later cause kidney problems then liver, so everything starts with the digestive system, keep it healthy.thats the way i see it.

Anonymous July 13, 2012 at 1:56 AM  

I've been getting sick like crazy the past 6 months, and several times I've resorted to using antibiotics. Cures me at the time, but then I get sick again.

Now it seems like what may have happened is that my overuse of antibiotics destroyed my immune system...

How do you get probiotics again?

Unknown August 29, 2012 at 5:14 PM  

My 11 yr old son was diagnosed w/Job's Syndrome in April 2011. It is a rare genetic condition that affects his immune system. He has been prescribed a regular daily dose of Bactrim to minimize the chance of pneumonia. His immunologist recommends that he take antibiotics indefinitely. What are the long term effects on his reproductive system? Will it have any effects on his normal growth & development? His doctor's never seem to want to give me a straight answer on the long term effects :-\

Anonymous September 16, 2012 at 11:23 AM  

Thanks for a very informative article. I am suffering due to taking a lot of anti biotics, hence surfing the net for answers and ideas. I work as a hypnotherapist so although I am a therapist and very much into health and well being this is quite new to me. I think a lot of us get candidaa due to taking anti biotics. In my case I get extremely mentally and physically tired, feel like it is an effort to stand up and move around or do anything at all. You are welcome to contact me and post on my own site at and thanks again.

Anonymous October 18, 2012 at 6:21 PM  

is too much antibiotic prevents me from getting pregnant,im 27 and is infected with encephalitis b

adipex-p October 26, 2012 at 5:18 PM  

So just express, your energetic reasoning, your words value a great deal and are extremely convincing!

Anonymous March 19, 2013 at 9:08 AM  

I've been on amoxicillin. 500 mg for maybe 2 years or more.2 1/2 years ago had bad knee pain for no reason. Now my other leg is hurting badly have to go to using a crutch.

Denis January 8, 2015 at 11:44 PM  

Very interesting reading, I was diagnosed with Rheumatic fever as a child and was prescribed antibiotics (penicillin) for 13 years. I avoided heart disease and had a normal sporting life. However I am now 52 and have always had digestive and arthritis issues. I am wondering if this could be the cause.
Thank you.

defining male extra here January 19, 2015 at 5:19 AM  

Testosterone is known as the male hormone and everything that it connotes – “That man has an excess of testosterone – for good reasons. Declining testosterone levels usually cause significant physical and mental changes in a man, thus, the cause for concern.

Penyebab Demam March 13, 2015 at 5:18 PM  

Proper-factorial completo y todo eso. Es generalmente más fácil y más rápido, sin embargo, para mirar a uno a la vez. Si podemos identificar los que son malos en el aislamiento, podemos eliminarlos del resto del experimento.

Anonymous July 7, 2015 at 9:24 AM  

Yes you can't take antibiotics and probiotics togetjer it will decrease the effect of antibiotics.. At least wait 1 hour after antibiotics thenbtake probiotics

Unknown July 9, 2015 at 9:47 PM  

I've been taken antibiotics for 2 weeks and now have the problem with erection. May be it is not caused by antibiotics.

Quintin Coetzee December 23, 2015 at 11:00 PM  

Hi there. I was on a course of Doxycycline for 2 weeks and immediately started bloating, belching, and having abdominal tightness, whenever I eat or drink anything. It lasts 24 hours a day. It is now 3 months after the course ended, and I still have bloating problems. I have been for celiac tests and an endoscopy, and all results were fine. My gut definitely doesn't feel fine, however.

Could it be an imbalance in intestinal flora? Will it go away over time (if so, how long could it take)? Should I take a probiotic like VSL#3 and/or use something like Iberogast?

Unknown February 9, 2016 at 7:47 AM  

HI I have an infected wisdom tooth and my dentist has had me on keflex for the past 3 months till I can get an oral surgeon to cut it out. Is it ok to be on keflex this long. I have to take 500 mg 4 times a day and brush every time. It just seems like it would destroy my immune system.

Helpful probiotic america review February 18, 2016 at 5:11 AM  

The human body is complex and amazing. The manner in which so many systems and organs work together to maintain health is inspiring and researchers are still struggling to understand all of the specifics.

Did you know, however, that the human body gets a little bit of assistance to do its job?

Various kinds of microorganisms coexist with us peacefully. Some of these microorganisms help the human body do its job. A number of beneficial strains can be found in the gut.

They improve digestion and help us fight pathogens. As a result, these beneficial bacteria play an important role in the immune response.

cara menghilangkan jerawat June 9, 2016 at 8:46 AM  

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