Probiotic for ME/CFS –
I felt worse, more ill

My personal experience of taking a probiotic and feeling worse

I took a probiotic for ME/CFS (Myalgic Encephalomyelitis Chronic Fatigue Syndrome).
My aim was to help my gut achieve the right level of friendly bacteria.

The instructions said to take it for a minimum of 20 days.
After a few days I got more ill.

I am writing this article to give you, the visitor, information I did not have.
Also as a request for further information on probiotics and ME/CFS (Myalgic Encephalomyelitis Chronic Fatigue Syndrome).

Probiotic for ME/CFS – I felt worse. Why?

Or click here to CHOOSE FROM
RANGE OF personalizable cards and gifts.

The healing-themed gifts are designed by myself, Katherine, the author of
this website

Proceeds go towards the cost of the website. Thank you. Enjoy!

Early on I hadn’t identified the probiotic as the cause of my becoming more ill.

Once I associated the aggravated symptoms with the probiotic, I thought ‘maybe it is a healing crisis and is doing me some good’, so I persisted.

I took the brand Probio7.
This brand was recommended by an acupuncturist, and by a friend who tried it. They had amazingly positive results.
The daughter of the acupuncturist was a pharmacist in Germany and had recommended it.

Sign up to receive the free book
and to keep in touch

Enter Your E-mail Address
Enter Your First Name (optional)

Don't worry — your e-mail address is totally secure.
I promise to use it only to send you Healing CFS/ME.

I went on to become incredibly ill on the probiotic.

I had very low energy production, such that I couldn’t walk around the house. It felt truly dangerous to do so.

I became reliant on someone’s help for food preparation. If I hadn’t had that help, I think I would have continued to get more and more ill, as I would have been forced to push through my limits.
Eight weeks later and I haven’t yet returned to my previous level of health. I am getting there.

I have now been through my diary for the previous year when I had also taken the probiotic for a while.
It turns out, I had become very ill when I took the same probiotic before!

My questions about taking the probiotic for ME/CFS are as follows:

1. Is the fact that I got so ill on the probiotic a clue as to why I have ME/CFS in in the first place?

2. After about 18 days on it, I was starting to feel better. I ran out.
Would I have continued to get better if I had continued to take it?

3. Should I buy some more and take it less often?
Should I try another brand of probiotic?
Or is my reaction a sign I should avoid probiotics altogether?

I have since had a free consultation with the company who provided the probiotic.
The nutritionist was lovely and just said to stop straight away. Ho hum.

Below I share the answers I received in a forum.
I hope these will be useful to you. If you have your own comments, you can share them in the forum on this website.
Please share your experience with probiotics, positive or negative.

Thank you.

The ingredients of the Probio7 probiotic I took.

  • Chicory Inulin Fibre (Fructo-Oligosaccharide),
  • Soy Fibre, Hydroxy Propyl Methyl Cellulose (Vegetable Cellulose Capsule Shell),
  • Bulking Agent (Maltodextrin),
  • Bacteria Complex*,
  • Anti-caking Agents (Magnesium Stearate & Silica), Colour (Calcium Carbonate).
  • *Bacteria Complex contains:
  • Lactobacillus acidophilus,
  • Lactobacillus casei,
  • Lactobacillus bulgaricus Streptococcus thermophilus, Bifidobacterium bifidum,
  • Bifidobacterium longum & Lactococcus lactis.
  • Allergen Information: Contains Soy


Lactobacillus is a genus of bacteria. This group contains a large number of different types of bacteria that produce lactic acid.

Bacteria per capsule vary up to 10 mill per capsule.

Additional informations on probiotics and MECFS

Research in 2016 suggested the balance of good bacteria versus bad bacteria in the gut of people living with CFS/ME could move the body away from obtaining energy from glucose to obtaining energy instead from fats and proteins.

The research also identifies that amino acid levels in patients with CFS/ME differ from those in the control group.
Someone more knowledgeable than me would be needed to explain the connection!

Click to read more about this research.

I wonder if I got so ill because my body was exaggerating this tendency to obtain energy from fats and proteins.

Answer to ‘As someone with ME/CFS, why did I get worse, feel more ill when taking a probiotic?

SIBO small intestine bacteria overgrowth, Sugar content


Have you been tested for SIBO?

Katherine T Owen:

No. I have looked it up. It says that if you test for it you then need antibiotics. I wouldn't know how to go about getting them. Do you have any advice? Also, I have a recommended website for a test, but would appreciate your recommendation as well if you have one. Thank you.

EDH:  I’m not sure the best lab to get tested, but you don’t necessarily need antibiotics... there’s special diets and herbal remedies that also work. If you’re able to see a functional practitioner at all, that would definitely be easier than doing it yourself.
SIBO test is basically a breath test.

MJ: I would advise that a course of anti biotics should be the last course of attack, after doing nutritional therapy.
I've found this UK SIBO Support Group very helpful and knowledgeable.

JH: Add to the many comments above to say that fructo oligosaccharide are sugar molecules - it's not beyond doubt that this can feed bad bacteria in the gut. Same goes for maltodextrin. If it is known that fermenting gut or sibo is not an issue then this product could be ok - otherwise caution.....

MJ: I had a terrible relapse last summer due to a course of probiotics. It turns out I have sibo and the bacteria in the gut just sort of rebelled against it.

Katherine T Owen. Maybe that's it, MJ. I was quietly hoping that maybe I have done myself some good.
Have you resolved the SIBO. Any advice would be gratefully received.

MJ: No, it can take a long time. I'm working with a nutritional therapist at the optimum health clinic.
It can take up to 2 years to populate the gut with friendly bacteria. I'm currently eating about 8-10 portions of veg a day and eating a fair amount of resistive carbs to feed the gut

If you have ME/CFS, take a probiotic in small doses, build up slowly

HR and others:

Start very slow & low not every day. Took me a couple of months to build up to full dose

A healing crisis


It is possible that a die off of the bad ones is making you ill

Which probiotic is best for someone with ME/CFS myalgic encephalomyelitis/chronic fatigue syndrome? Recommendations

Katherine: Additional recommendation of Probiotics for those with ME/CFS AND histamine response are below.
They are:
Mutaflor which is also recommended by Dr Myhill and by others in this thread with SIBO.
The only place I can see to buy it in the UK at present is from Breakspears.
Optibac for women

Lactobacillus Rhamnosus

EM: I take the one reccommended for people with MECFS.
It’s called  S Boulardii. I take the one from Swanson, Ultimate.

66 billion probiotic was great too.

I also take Restore.

HR: megaspore biotic

CH: Megaspore probiotic is recommended by Alison Vickery.
Seeking Health Probiota Histaminx is ok too.

DP: I did best on CanDefence from Amazon.

Possible Histamine Reaction to probiotic

CH: Some probiotics increase histamine which can lead to problems. Choosing bacteria that lessen histamine might help.

SR: I recently read about lactobacillous rhamnosus GG, which doesn't contain histamine. There's a lot of information about it online as there's been quite a bit of research. So far, it's all positive. I've just started using it, so can't really relate much from personal experience.

CO: Many probiotics & Kefir, too, for that matter are high in histamine which can be a real problem for those of us with HI, histamine Intolerance or MCAS, mast cell activation syndrome. I have both of these conditions alongside my ME.

I take Optibac for women & lactobacillus rhamnosus, neither of which make my HI or MCAS worse. I take 2 different one to maximise the different strains in my microbiome. I recommend that you try lactobacillus rhamnosus first. 

LG: I also felt awful on probiotics, I tried several types, and also went down the non histamine variety root, but they all made me feel rough.
For me, my body tells me when it does and doesn't want things, it's struggling enough and is of course in a sensitive state, so I try to listen to it 

GC: If you're worried about histamine then I'd use Mutaflor. You can also make your own yogurt with this to keep costs down. It is a recommended probiotic from Dr Myhill.
I couldn't do the yoghurt, 8 weeks of Mutaflor capsules worked for me.

 Katherine T Owen. Thank you. I did make my own kefir for quite a long time but not mutaflor. I got a culture passed on to me. It's one of those things I have done without seeing any particular positive change, but I kept on going. It certainly didn't make me dramatically worse though.

MJ: This list of Histamine friendly probiotics is from the uk sibo admin

Histamine friendly probiotics

bifidobacterium longum

bifidobacterium infantis

(aka B.longum subsp. infantis)

bifidobacterium lactis

bifidobacterium breve

Lactobacillus plantarum

lactobacillus gasseri

lactobacillus salivarius

lactobacillus rhamnosus

lactobacillus sporogenes

soil-based organisms

Saccharomyces Boulardii

Additional note. Histamine Intolerance (HI) is a subtype of MCAS.
MCAS is more than just histamine. Other mediators can be inappropriately expressed by mast cells.

Moulds/Mold and yeast

VC: I can’t take them either. I think it’s possibly those who react badly to moulds who can’t tolerate them.
You can still help yourself a bit by eating prebiotic foods.

SY: I’m allergic to yeast. Also I gut tested to see which bacteria was overgrown and which I was short of. Probiotics will be very targeted and possibly only one strain at a time

Dairy and strep in probiotic

Katherine T Owen: NB, I can tolerate some milk so. It makes me phlegmy, but nothing as dramatic as this. For me, dairy intolerance is unlikely to be the reason why probiotics made me more ill.

CC: Strep in there. Could have activated some latent strep

AN: These all look very dairy based. I have been growing my own coconut milk yoghurt culture which has been much friendlier on the stomach. Have mutaflor suspension to start growing next week.

CH: Have you read Ken Lassesen’s blog? He recommends to avoid lactic acid’s strains like lactobacillus etc. with ME. (If I remember correctly) Bulgaricus also makes me very bad.

NT: Mutaflor and s boulardii are the only ones I could ever take. It could be a D-lactate issue? I think that's the conclusion I came to, or.immune activation, I can't take them either as they cause infection like symptoms

For more information on probiotics for someone living with ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome), follow this link to Dr Myhill's website.

Other articles related to Probiotic for ME/CFS made me worse

  • Move to read a visitor's experience with probiotics. Probiotics made her worse too, but she found something that helped.
  • There is a link below labelled CFS vitamins. Click on this if you are interested in reading about more natural healing supplements that may help as potential treatments for symptoms of ME/CFS.
  • There is also a diet I recommend for ongoing liver detox.
    The liver produces some of the nutrients we need, so it’s important to keep the liver functioning well.

Receive daily inspiration...
by putting your favorite (favourite) healing quote on
a mug, cushion, postcard, coaster, T shirt etc.
You will find my zazzle gift store at
Use one of my designs or start from a blank.

Thank you from me, Katherine, author of

© Katherine T Owen. All articles on this website are copyrighted. I am delighted if you choose to click above to share this page on social media, but please do not copy, print or otherwise use without my permission. Thank you.

Disclaimer: I am not a medical practitioner. The articles on this website are not to be taken as medical advice. Please consult a medical practitioner as necessary.

Disclosure: On some pages, there are affiliate links, for example to Amazon. If you click and then buy within a certain time period, I will receive a small commission which goes towards the running of this healing website. Abundant thanks :-)