Spending hundreds on a stool test promising 'personalized' answers? Before you click 'buy,' let's talk about what that expensive report actually tells you.
Your gut microbes play a very important role in the health of the whole body and the gut. If you want to be healthy and live long, it is vital that you take good care of your beneficial microbes. Gut dysbiosis, on the other hand, has been linked to most chronic illnesses, including IBS. Your gut microbes deserve to be noticed!
Home poop tests that measure microbial composition promise that by seeing what microbes there are in your poop, it can help you understand your gut better and give you precise and individualized recommendations to improve gut health.
We all want that silver bullet, but unfortunately, the current science behind these home tests simply doesn't support the marketing claims. Read on to find out the critical reasons why testing your gut microbiome today is premature, and possibly even harmful.
1. The tests are not accurate.
There are multiple different kinds of tests out there, some better than others, but they all have the same issue: they are not accurate. Here are various problems of multiple tests:(a) Some tests only measures bacteria (not fungi/viruses), (b) Functionality is often guessed from diversity, (c) Many microbes go undetected, (d) Contamination with human DNA complicates results.
Also, different tests give different results. Take all the different tests with the same sample and you’ll get different results. This can happen even with testing the same sample with the same test multiple times.
2. Challenges stemming from the microbiota itself
- Your gut microbiome fluctuates even WITHIN A DAY. The relative amounts of different microbes, species and strains are changing constantly. You microbes are different based on the season, your lifestyle, your diet and even the time of day. This means that a test taken in the morning shows a different result than a test taken in the evening. What conclusions can you really draw from this?
- We don’t have a standard with which to compare: science doesn’t know everything about the gut microbiome yet. Including what is ideal, or a healthy gut microbiota. Every person has their own individual microbial fingerprint and we know that diversity is good. But, even IBS doesn’t have an identified microbial signature yet, even though some trends can be detected. If a testing company has a scoring system, it’s not based on sound scientific evidence.
- Correlation does not mean causation: studies can show that in some illnesses, higher numbers of specific bacteria are present. However, this does not prove that those bacteria are what are causing the illness.
Your gut microbiota is highly complex and the truth is that microbiome test results are very difficult to truly interpret, even if they were accurate. This makes providing science-based recommendations based on test results virtually impossible.
Some companies provide dietary recommendations based on the results, however, but the scientific backing to prove them is thin. I contacted a company once to find out how they came up with their "foods to avoid and to eat" lists for different results and they couldn’t provide any real evidence for this.
And what’s worse, making big diet changes and restricting a lot of foods based on these tests can be harmful. They increase malnutrition risk, they increase stress and they can lead to disordered eating and food fears, all of which are damaging to gut health.
Ways to support gut microbe health (evidence-based)
- Lots of diet variety, especially plants
- Feed your gut microbes with fiber and prebiotics
- Fermented foods, potentially probiotics
- Avoid low-quality foods, like certain ultraprocessed foods
- Proper sleep
- Exercise
- Stress reduction
The gut microbiota is hugely important in IBS and in health in general, but testing your poop to see what bacteria it has is not the answer. Rather focus on the foundational lifestyle and diet habits that we know help your gut. It might not be exciting, but it is powerful.
If you need help building these solid lifestyle and diet foundations, join my group program in January 2026! Together we will take 15 gut health steps in 15 days that are designed to take only 15 minutes per day to get through. It’s a low threshold program with no fluff and only evidence-based practices to soothe your digestion. Go here to sign up!
PS. The program has also a version in Finnish, here’s the sign-up page.
References:
Matsuo Y, Komiya S, Yasumizu Y, Yasuoka Y, Mizushima K, Takagi T, Kryukov K, Fukuda A, Morimoto Y, Naito Y, Okada H, Bono H, Nakagawa S, Hirota K. Full-length 16S rRNA gene amplicon analysis of human gut microbiota using MinION™ nanopore sequencing confers species-level resolution. BMC Microbiol. 2021 Jan 26;21(1):35. doi: 10.1186/s12866-021-02094-5. PMID: 33499799; PMCID: PMC7836573.
Wensel CR, Pluznick JL, Salzberg SL, Sears CL. Next-generation sequencing: insights to advance clinical investigations of the microbiome. J Clin Invest. 2022 Apr 1;132(7):e154944. doi: 10.1172/JCI154944. PMID: 35362479; PMCID: PMC8970668.
Heiman ML, Greenway FL. A healthy gastrointestinal microbiome is dependent on dietary diversity. Mol Metab. 2016 Mar 5;5(5):317-320. doi: 10.1016/j.molmet.2016.02.005. PMID: 27110483; PMCID: PMC4837298.
So D, Whelan K, Rossi M, Morrison M, Holtmann G, Kelly JT, Shanahan ER, Staudacher HM, Campbell KL. Dietary fiber intervention on gut microbiota composition in healthy adults: a systematic review and meta-analysis. Am J Clin Nutr. 2018 Jun 1;107(6):965-983. doi: 10.1093/ajcn/nqy041. PMID: 29757343.
Leeuwendaal NK, Stanton C, O'Toole PW, Beresford TP. Fermented Foods, Health and the Gut Microbiome. Nutrients. 2022 Apr 6;14(7):1527. doi: 10.3390/nu14071527. PMID: 35406140; PMCID: PMC9003261.
Pérez-Prieto I, Plaza-Florido A, Ubago-Guisado E, Ortega FB, Altmäe S. Physical activity, sedentary behavior and microbiome: A systematic review and meta-analysis. J Sci Med Sport. 2024 Nov;27(11):793-804. doi: 10.1016/j.jsams.2024.07.003. Epub 2024 Jul 9. PMID: 39048485; PMCID: PMC12510671.
Hantsoo L, Zemel BS. Stress gets into the belly: Early life stress and the gut microbiome. Behav Brain Res. 2021 Sep 24;414:113474. doi: 10.1016/j.bbr.2021.113474. Epub 2021 Jul 16. PMID: 34280457; PMCID: PMC8380711.
Morwani-Mangnani J, Giannos P, Belzer C, Beekman M, Eline Slagboom P, Prokopidis K. Gut microbiome changes due to sleep disruption in older and younger individuals: a case for sarcopenia? Sleep. 2022 Dec 12;45(12):zsac239. doi: 10.1093/sleep/zsac239. PMID: 36183306; PMCID: PMC9742900.
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</script>If you thought the answer is “the low FODMAP diet”, you wouldn’t be the only one. Sadly, it’s not as simple as you might expect.
As a dietitian, I’ve taken care of a lot of different kinds of people with all kinds of health problems. Everyone is an individual and diet must always be individualized, but it seems that IBS is much more difficult to generalize than other health problems.
For example, if you have diabetes, you should always pay attention to everything that affects your blood sugar levels. Most often this means counting all the carbohydrates you eat, and sometimes also taking protein and fat into account. For cardiovascular disease, fat quality is something that everyone with high cholesterol needs to consider.
When it comes to IBS, there is no “one-size-fits-all” diet that works for everyone. For one, there are four different IBS types and the advice you give to someone with diarrhea is not the same if the problem is constipation instead.
While the low FODMAP diet is the most “popular” diet for IBS, in my expert opinion, the low FODMAP diet is overused and is NOT a good idea for many, if not most, people. You can read why in my two blog posts “Is the low FODMAP diet the best diet for IBS?” and “Should you try the low FODMAP diet for IBS?”. I know most other dietitians love the low FODMAP diet, but I can’t overlook all the problems that come with this diet. Yes, FODMAPs are small fibers that are easily fermented by your gut microbes and cause relatively more gas, but this happens in everyone, not just in people with IBS. The reason why you are more sensitive to them is because of visceral hypersensitivity, which is caused by IBS (this sensitivity is something I want to improve, rather than just remove foods as a bandaid solution).
So, if it’s not the low FODMAP diet, then what is the right diet for IBS?
It certainly is a highly individualized one. Here are the first five diet and food related questions you should ask yourself regardless of your IBS symptoms:
- How often do I eat?
- How big are my meals?
- How quickly do I eat?
- Do I chew my food until it’s apple sauce consistency?
- What’s my frame of mind when I eat?
I find that regular eating times, and not eating too often or too seldom, lay a foundation for a gut healthy diet. This way you are less likely to overeat or keep taxing your digestion with new food all the time. Eating too quickly results in food that is poorly chewed and a belly full of air, both of which cause bloating and indigestion. Chewing properly begins the digestive process right away and makes food more digestible. Eating when stressed, worried or angry triggers a stress response, i.e. the body’s fight-or-flight mode, which is terrible for digestion. The fight-or-flight mode is the opposite from the rest-and-digest mode. To harness the digestion-promoting rest-and-digest mode, make sure to eat when you feel calm, find a calm environment, and sit down.
Some clients of mine have found that this is all they need to keep their symptoms at bay! So, while they seem simple, these points are truly foundational and have an enormous effect on how well you digest and absorb your food.
What else for IBS?
Once the foundation is well in place, it’s important to find out if your diet is in balance, especially thinking of your individual symptoms. Balance means getting all the nutrients your body needs to be well while including food items that support easing your symptoms, and it also means that your microbiota gets all the food they need. Your gut microbes keep you well if you nourish them properly. Well-fed beneficial bacteria then send positive signals to the brain through the gut-brain axis, with health promoting effects.
A balanced diet is an optimal mix of protein, fat, and carbohydrates (including fiber), as well as vitamins, minerals and antioxidants. A plate method is a nice way of visualizing a balanced diet (see image above), but this also is a generalization that is not appropriate for everyone. It also doesn’t address fat in the diet.
What’s more, sometimes it’s not your diet that is the problem – there are situations when it doesn’t matter what you eat and your symptoms are difficult anyway. This is because IBS is caused by a problem in the way in which your gut and your brain talk to each other, and food is not exactly what causes this disruption. I talk about the gut-brain axis in a blogpost here, a great read!
Are your eating habits helping you ease IBS symptoms? Is your diet in balance?
If you are not sure, get in touch with me. During a 30-minute free gut health review I will give you the tools to build a diet that will keep your gut, and the rest of your body happy, but not only that. We’ll address your gut-brain axis also, for best results. Book your free call here.
Love,
Anna-Kaisa
PS. Don’t wait to get individualized advice for FREE! Book your call now.
PPS. Did you download my free Ebook “5 Easy Ways to Beat the Bloat” yet? These five ways are simple, yet effective in easing bloating that you can put to use right away.