Please click on the test links given below to see more detail, collection instructions, sample reports etc...
There are lots of different types of gut test and it generally depends on what you want to know. Here is a simple (ha!) overview with my key recommendations. Click on each test link to go to the lab sites for details, collection instructions and sample reports.
In general, most gut tests will look for absorption, inflammation and immunology markers. The difference comes in how we look for any bacterial, yeast, parasitic and viral pathogens present and your choice of test really comes down to what you most want to know.
There are now two main ways to test the microbiome - the gut environment - for pathogens. You can do the usual culture, microscope and mass spectrometry way of looking at what's in the gut, such as the DD CSAP3 and CDSA2 tests below, or you can use molecular DNA/PCR testing, such as the GI-MAP and GI Effects below; a new way of picking up stuff you can't find in the samples. There is mass controversy about which is best in the industry, of course, and it really depends who you are listening to at any given time! Here is my take on it - and I will update this as necessary, of course. I have listed both types because I get asked for both.
In short, in my view: if you want a general gut screen, do a DD CSAP3. If you want specifically to look for baddies in the gut, do a GI-MAP. Check what each test includes as they vary. In an ideal world, most experts think you should do both types if you want to find the most stuff. Sorry, don't shoot me ;)
The DD CSAP3 is the best 'traditional' test in my view. There are lots of reasons for this and I have studied the different tests long and hard. In the end, I think this one gives you the most useful and effective testing for the money. It covers bacteria, yeasts, inflammation, parasites (3 days, which is important as they hide!), malabsorption, short chain fatty acids, leaky gut, blood presence and SIgA. You can do the same test without parasites if needed as the DD CSA (Comprehensive Stool Analysis). You can also add several things onto this test and/or do the elements separately. See here for a list of Doctors' Data gut tests. I can confirm prices if you need something. The DD test samples are returned to a UK lab for onward shipping.
Incidentally, sometimes you only need to go back and check if a bacteria found in the CSA/CSAP3 has gone and you don't need a full re-test. In this case, use the DD Bacteriology Culture Test.
There are two main other alternatives to this kind of comprehensive testing: Genova's CDSA2P, which I have listed for you - along with a version with added stool zonulin for leaky gut. Some people prefer the CDSA historically as it's been around a long time. Again, you can add stuff on, or do elements separately. See here for a list of Genova's stool tests.
Molecular DNA/PCR Testing
Here, you have a choice of two tests. Diagnostic Solutions' new GI-MAP (Microbial Assay Plus) measures opportunistic organisms (including H pylori and its phenotypes, which is an add-on with the other tests usually and a very useful one to look at), normal flora, yeasts, parasites, viral pathogens, worms and antibiotic resistance genes as well as absorption markers (Elastase), inflammation (lactoferrin) and immunology (SIgA). It also includes occult blood and an anti-gliadin test. You can see a sample report and collection instructions here. Note that zonulin (a leaky gut marker) at the bottom of the sample report is an add-on, but I have listed a separate discounted GI-MAP with stool Zonulin for you to make life easier if you need that. To get the antibiotic resistant genes - for no extra cost - just tick the box on the requisition form in your kit.
And, if you want to read much more deeply about microbiome testing using PCR and see the whole list of pathogens included, see Diagnostic Solutions' white paper here. You don't get a lot of interp help or a pretty report on this one but they have written the huge white paper above which certainly will help you. This is returned to the UK lab for onward shipping.
You can also do PCR testing using the Genova GI Effects Comprehensive test and I've listed with and without zonulin. This measures similar, fewer pathogens as well as markers for absorption (elastase, fecal fat), inflammation (calprotectin, EPX etc) and immunology (SIgA). I like the fact it includes the SCFAs including the butyrate level as I see that a lot as a main cause of leaky gut (this is also in the DD CSAP tests which is one reason I like it). If you read the GI Effects Interpretation Guide, it shows how each bacteria is linked to illness. It can be very useful to make connections, of course, if a bacteria comes up which matches your symptoms - at least you have more of an idea what's causing it! I do like their instant interpretation on the report and the Interpretive guide is very useful. Again, returned to the UK lab for onward shipping.
Overall: I would say that the GI Effects test is very useful if you are looking for a good general PCR/DNA test to check if any pathogens are causing illness and need a general screen of your gut with some info on what, in-vitro, is likely to kill any baddies found. The report is much better; it's easy to see what's been found and the implications of the findings so many people prefer it. The GI-MAP comes into its own if your main need is to check as many pathogens as possible; it simply includes a lot more for less money, especially the H Pylori and the different types, the viruses, which antibiotics you may have a resistant gene for and a standard anti-gliadin gluten test (although I will never take a negative here as enough!). Check the sample reports and read up to establish which test covers what you most want to know.
Candida. Candida and yeasts are generally covered in the comprehensive tests above. But, if your test comes up negative and you still suspect it OR you simply want a candida test done OR you want to double-check if a positive finding is a significant one, I would look for a SAPS positive candida. Everyone has a level of candida in their gut. The question is whether it has changed to the mycelial form, which is when it becomes pathogenic (ie needs treating). There is only one lab who looks for that, and they also include a moulds check too - BTS Candida SAPs Stool Test. Very useful.
SIgA. This is a measure of mucosal immunity (ie in the gut, sinuses, vaginal areas etc). Put simply, if your SIgA (secretory IgA) level is too low, you will find it very difficult to fight off 'baddies' like yeasts and bacteria. You then need to work to raise your levels first. If your SIgA is high, it suggests an acute problem somewhere - usually inflammation, infection or a sensitivity to something (eg. a food intolerance). SIgA is measured in the stool tests but you can do it separately too. Do BTS SIgA Stool test if you suspect a gut problem, or Genova' SIgA Saliva Test if you have problems elsewhere. See the Bowel Factsheet above for a link to an article I've written on SIgA generally.
For SIBO, I use the Aero Diagnostics SIBO Breath test mainly because that's all they do and I really like their report, which is one of the clearest I've found. This breath test can be done using glucose or lactulose and both are good with different experts recommending either or both. Alison Siebecker, the SIBO guru, tends to recommend lactulose so I will order that unless you ask specifically for glucose in comments on your order. You can see collection instructions including a video and the patient preparation instructions here. This test is returned to the UK lab for onward shipping.
For info, the ingredients of the lactulose substrate is: 10 g lactulose (and less than 1.6 g galactose, less than 1.2 g lactose, and 1.2 g of other sugars). Also contains FD&C Yellow No. 6, purified water, USP and wild cherry flavoring. A minimal quantity of sodium hydroxide, NF is used to adjust pH when necessary. (not dairy free) And the glucose: DEXTROSE, HYDROUS, POWDER, USP. Synonyms: Corn sugar; Dextrosol; Glucose, monohydrate (not grain free)
There is also a new type of SIBO test from good-old Cyrex now - Cyrex 22. This is very different to the breath test in that it is looking for antibodies to bacterial cytotoxins released in SIBO rather than the gases we produce. It also looks for evidence to see if the cytotoxins have caused a leaky gut. You can see more info on this sheet here.
In terms of leaky gut, a lot of the time you can assume it is present because of the case and just treat. However, I have found sometimes it can help you find what is causing the leaky gut specifically. For example, if an LPS marker comes up on the results for Cyrex Number 2, it is far more likely to be a bacterial infection problem than it is food sensitivity. Can help with the detective work. More on the Cyrex 2 test here, and please note the sample needs centrifuging! I also find it useful as a progress marker, but sometimes prefer the cheaper Biolab PEG test for that. If fewer larger molecules are getting through, then you are getting less leaky. Nice and simple. You might find this blog post useful: Should You Test For A Leaky Gut?
Helicobacter Pylori is a useful addition to the comprehensive tests above and I have listed a DD CSAP3 with H Pylori for you to make life easier (and slightly cheaper, always good!) and it is included in the GI-MAP for a molecular check. Or, it can be done via Doctors' Data H Pylori stool test or Genova's H Pylori Breath Test. Both are effective. H pylori is the most common gut infection and very linked to acidity (eg. GERD, acid reflux), chronic stomach pain and ulcer problems. See also the new GastroPanel below for a more comprehensive test if your issues are stomach rather than bowel based.
For pancreatic function, that's included in the above gut tests but you can also do just pancreas elastase separately in a stool test too. Here is an info sheet from Genova but they no longer do it apart from in the CDSA, so I do the same with BTS - cheaper too :)
Clostridia is tested for in the gut screens above. However, the lab will look for and report on the presence of any clostridia found, but you need to do further tests then to see what strain of clostridia it is as there are loads. If your symptoms fit, do further testing with the Comprehensive Clostridium test. This is a stool culture but they will also do a DNA check if any C. Diff is found as this helps determine if it is a pathogenic type.
Note that you can also use functional testing for gut problems, see Metabolic & Functional Tests, which helps identify whether there are any clues to what's going on in the body - are there any markers suggesting gut issues?
Most of the issues so far have concentrated on the intestine; the small and large bowels, but what about the stomach? I have now managed to get a GastroPanel which is being reliably used as a kind of pre-gastroscopy, if you like. GastroPanel® is a blood test, which provides information on the status of your stomach mucosa, possible helicobacter pylori infection or lack of acid in your stomach, also known as achlorhydria or hypochlorydia. The test can also estimate the risk of developing vitamin-B12 or micronutrient deficiency. It measures four antibody markers to pepsinogens, gastrin and Helicobacter pylori and the test comes with a report on what the specific mix of results on your report means. You can read much more about it here, see a sample report here and a different one here and also review a pretty technical interpretation guide here if you are that way inclined. The test needs to be centrifuged and a stabiliser added, then frozen and sent off to the UK lab for onward shipping. You can see collection instructions here and you fill in a form to say if you are on anti-acid meds etc so the results can take that into account.
Testing Hints & Tips:
Q: Why do you like the Doctors' Data CSAP so much?
There are many gut tests. For a comprehensive one, I have chosen to list this one but I can organise stool tests from any of the labs including the CDSA from Genova and the GI Effects from Metametrix. People used to like the GI Effects one because it used DNA technology for parasites but it no longer does and, in fact, I never believed it was as effective since detection levels have to be quite high and the lab has to actually have a DNA probe of that specific parasite to use. In future, it may well be good, but not yet in my opinion. If you wish to have one of these, though, or indeed a different one, just email and I will organise it for you.
The reason I went for this one is that it is just as comprehensive and uses MALDI-TOF analysis which has been shown to identify and classify more bacteria, yeast and fungi than automated analysis, which most labs use, and DNA testing combined. Plus it looks for actual fibres of veg and protein in the stool and includes a carbohydrate malabsorption check as well as fat. It also has lysozyme, a good inflammation marker the others don't have (they all have inflammation markers but this is an extra in the Doctor's Data version). It also includes occult blood (an important bowel cancer test) and a consistency check, which the others don't. Bonus: it's cheaper both to buy and to return to the lab.
Q: Why do you do a 3 day version? Can I do 1 or 2 days?
I have chosen to offer the 3 day version, although I can do 1 or 2 days if you prefer. The reason I have gone for 3 is that parasites hide and it is best to have a 3 day sample to give yourself the best chance of finding them. One tip: if you wish to make sure parasites are found, some practitioners suggest you 'purge' your bowel eg. using Vitamin C, magnesium or something from your health shop/pharmacist (not salt or castor oil) on the 3rd day so you get a 'clear-out' if you like. Then use that for your third day sample. Yum!
Q: Sadly, I don't go to the loo that often. What if it takes me several days to get the three samples?
I asked the lab this for someone who was taking 9-10 days to get the three samples, which is about the limit really I would say. They advised: The samples need to be with us within 4 days of the LAST day – the chemistry tube (frozen) and the parasites (preservative) keep them viable. The culture tube on the last day is the most time sensitive.
Q: Any advice on stopping supplements etc?
For gut tests, my standard advice is to do the following unless you are monitoring yourself on them - please be led by your health professional and the specific instructions in your test kit/on the lab sites; these are my general tips:
Please make sure you stop taking any probiotics (bacteria eg. acidophilus) at least 3 days before doing the test.
For candida, stop any form of anti-fungal (eg caprylic acid, oregano, garlic etc) at least a week before.
For parasites, stop taking any anti-parasitics at least a week before and it is best to do a 3 day sample so we have the best chance of finding anything; they hide!
For the pancreatic function test, this will be affected by any pancreas meds and pancreatic enzyme products, including glandulars.
The SIgA and leaky gut tests will be affected by any supplements designed to assist them eg beta glucans, glutamine, saccharomyces boulardii etc, so stop these a few days before unless you are monitoring yourself on them.
Immune-suppressant medication may affect the inflammatory markers, specifically Calprotectin and Eosinophil-Protein X, though the labs cannot predict exactly how these medications may impact the test results. They say: "We never recommend patients discontinue medically prescribed medications in order to do testing. With regards to medicines in general, we cannot know for certain how long a specific dosage will impact test results. Patients on regular medications can continue during testing to see how they are impacting. However if the medication is temporary they may choose to wait until the medication course has been completed." Wise words.
Q: What's the difference with the Genova CDSA and DD CSA?
They are both excellent tests. I think the DD one is probably better for finding baddies because they use MALDI-TOF techniques. The CDSA is probably better for analysing bile flow if that is a concern and I like the clear report and analysis you get with this test. Horses for courses. You can't really go wrong with either test. Just compare the two to make sure you are covering what you want to test.
Q: Do I have to return my samples to the US for Doctor's Data etc?
No, although many of these tests are actually run in US or European labs, all Doctor's Data, Breathtrackers, Genova, BTS and Cyrex samples are returned to the UK lab for onward drop-shipping, which saves a lot of time and money!