The best overall gut test is the DD GI360, which you can order direct using that link or here on the shop. It just gives so much useful, practical information about your gut. I especially like the markers included to help find causes of food sensitivity. For other gut tests like SIBO, Leaky Gut, H Pylori etc, see the recommendations below. You can read more about gut testing and see my results videos here. And see the Gut Treatment Plan and Gut Results Guide, plus Stomach Acid Factsheet here. I've also added the Genova GI Effects and GI-MAP because people still ask for them - practitioners abroad especially like the GI MAP.

Essentially, the GI360 covers PCR and MALDI-TOF types of testing for bacteria, yeasts (including candida), parasites and some key gut viruses, but also uses microscopy and culture to confirm things. It gives you useful clinical information on inflammation levels, malabsorption, short chain fatty acids (important for food sensitivity, infections etc), leaky gut, blood presence and SIgA (the gut immunity and food ‘safety’ marker) and also gives you an idea of what natural and antibiotic remedies any ‘baddies’ found are most sensitive to – in your particular case.

You have the option of doing 1, 2 or 3 day collections – I always prefer at least 2, preferably 3, because parasites hide and you’ve more chance of finding them.

If you just need to test or check progress on the stool chemistry side (ie. not the infections side), you can do just the Stool Chemistries test. This will look for SIgA, butyrate levels, SCFA levels etc - particularly useful for finding the cause of food intolerances.

Candida

The main stool tests all include candida. I'm afraid BTS is not currently available.

SIBO (Small Intestine Bacterial Overgrowth)

The Genova SIBO breath test is a good choice here - this can be ordered direct or here on the shop. Please read the info on that link so that you do the test carefully and correctly. SIBO guru Alison Siebecker recommends lactulose mostly but there is a school of thought that it is best to do both. For info, the starches/sugars used in this type of SIBO test are likely to contain corn so will not likely be TGF safe. Use the Cyrex 22 instead. 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.

Leaky Gut

Nice and simple: use the Colab Intestinal Permeability Test, which includes loads of markers and is by far the best around. Note it needs centrifuging. Collection instructions here. Do bear in mind their shipping charges (to get the kit to you and have samples collected from you by courier and shipped abroad) can be quite high as they use Medical Express often to make sure the sample you send is as fresh and viable as possible, which is important with their complex type tests. I'll advise you of shipping costs before I place an order just to check if I think it is high.

If you need an alternative, this one from RG labs is also good.

Stomach/H pylori

The first thing is to try the lemon/cider vinegar/bicarb or betaine tests – see here. You also want to see if you have any Helicobacter pylori, the very common cause of gastric issues and more besides. You can add H pylori onto the stool tests if they are not included, or you can do it separately as the H Pylori Antigen stool test.

SIgA (Secretory IgA)

This is a measure for mucosal immunity - can you fight infections off or are you reacting to foods too much - both are caused by low SIgA? Or high SigA is a marker for inflammation. You can read more on my SIgA factsheet here. You can measure it in stool (inc in most gut tests) and saliva. Both will give an idea of mucosal immune strength, but they are quite localised. For respiratory, dental, upper tract conditions or candida in the mouth, salivary is good. For food intolerance or gut infections inc candida, use stool.

Testing Tips

Q: Why do you like the Doctors’ Data GI360 so much?

There are many gut tests. The reason I went for this one is that it is really comprehensive and uses PCR/DNA testing as well as MALDI-TOF analysis so you’re likely to find more ‘baddies’ if they’re there, plus a really useful raft of stool chemistry markers that allow me to see patterns causing eg. food sensitivity, or reasons for poor detoxification, why you can’t fight off infections well etc. 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?

The reason I recommend three 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 5 days before doing the test.

For candida, stop any form of anti-fungal (eg caprylic acid, oregano, garlic etc) at least a week before. You should stop taking all anti-fungal supplements at least a week before you take your sample (e.g. caprylic acid, garlic capsules, grapefruit seed extract, oregano oil). Two days before you take your sample avoid fungi-food eg. camembert, brie, stilton, kefir, kombucha and stop taking any probiotics for 5 days before the sample is taken. Natural probiotic yoghurt is fine.

For parasites, stop taking any anti-parasitics at least a week before.

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, collagen 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.