The microbiome – the “intestinal flora”
The microbiome is booming. The wondrous world of bacteria in the human intestine is currently not only occupying experts (in specialist publications, the number of literature citations on the subject doubles every two years1)), but is also found in the public media and on social networks. We have only known about the bacteria that live inside us since the mid-17th century2), but our knowledge remained fairly limited for a long time until the 20th century, when we developed new methods to study the so-called intestinal microbiome (the “gut flora”) in more detail. In recent years, we have begun to understand that the microbiome and our health are linked. Bacteria (and fungi) in the intestine are important for digestion and the immune system. Nevertheless, research is still in its infancy and we still know relatively little about these specific connections. However, this does not stop resourceful business people from earning good money with so-called microbiome tests. This is despite the fact that these products, which are marketed as “Florastatus” or “Gut Health Check”, are far from delivering what they promise. Instead of providing answers, these tests only raise more questions, as my self-experiment has shown.
What is a Florastatus?
The idea behind this is to look at the composition of the intestinal microbiome. Put simply, the question should be answered: What types of bacteria are present in the gut and are they good or bad? Equipped with this knowledge, the aim is then to “rebalance” the microbiome, for example through a special diet or by administering probiotics.
And this is how a Flora test works: You take a stool sample at home and then send it in a special container to a laboratory as quickly as possible. A few days later you can view the “findings report” online.
I have done such tests before and have also written about them. I would just like to briefly summarize the criticism at the time:
- Only the genera of the bacteria are determined, not the species. There are more than 40 species of Lactobacillus alone in the intestine3), but the findings report only refers to“Lactobacillus species” in general terms. This is not so tragic in principle, but there are important differences in other genera, such as E. coli. There can be harmless and (very rarely) dangerous species. But they would not be recognized. When asked about this criticism, the test manufacturer wrote to me: “Our method only shows the quantitative measurement of the specified groups – further differentiation is not technically possible for us. If, for example, the E. coli bacterial count increases, we cannot make any statement about the involvement of potentially pathogenic germs.”
- The bacterial mix in the stool does not indicate which bacteria are located where in the intestine, nor in which section larger accumulations of them can be found. But that is exactly what would be important for a serious diagnosis.
- It is not known how many bacteria of which type are “normal” and at what quantities one can speak of problems. There is no scientific literature on this. And yet arbitrary limit values are used to speak of too much or too little in the findings report. According to the manufacturer: “The reference values come from internal studies and are reviewed annually”.
- The result is usually discussed in Facebook groups and evaluated by laypeople. These provide nutritional tips and medical recommendations. The manufacturer says: “In our findings, we point out the need for competent interpretation by a doctor or therapist.” Okay, but what if the competent doctor doesn’t know that such tests exist (why should he know about tests that don’t work?) or if he even knows that these tests are useless and tells the patient this? Well, then the offended patient goes online and seeks advice in Facebook groups.
I received a lot of letters after the blog at the time. There were all sorts of things, from letters of thanks for finally clearing things up, to the wildest insults that I had no idea and that these tests would improve lives. I took this criticism seriously and observed several Facebook groups in the following months. This is because “diagnosing” and discussing test results in these groups increased rather than decreased.
Diagnoses in Facebook groups
What I experienced on Facebook was frightening. I can’t really go into it all here, but I was inspired to write my own blog. There was all sorts of nutritional advice based on Flora tests. For example, precise information on why you should eat which carbohydrates and which proteins because too many E. choli have been detected. Long lists of dietary supplements, alkaline waters, healing clays and special superfoods to rebalance the gut were also exchanged. I was particularly annoyed by the example of a lady who fed her 7-year-old daughter a strict diet for a year because of such a test. She has now repeated the test, but it is again very poor. Of course, she got all kinds of advice online. A small excerpt: Her child was diagnosed with leaky gut syndrome, she was told to give the child food supplements and“Perocur“. Of course, she should continue to put her daughter on a strict diet.
Intestinal checks in the self-check
Let’s assume that all my previous criticisms are wrong and these tests actually work. In this case, my self-test should give the same result for two stool samples taken on the same day. My critics probably agree with that too. Because if the results were different, why should I go through all the fuss with diet, probiotics, alkaline water etc.?
Two intestinal tests in one day
No sooner said than done. I do the first test at 8:00 in the morning and a second one seven hours later – yes, I am blessed with two bowel movements a day. I send off both tests and wait for the results. A few days later it arrives.
According to the report, my stool in the morning showed too many E. choli, too many Enterococcus species and too few Lactobacillus species. There were a few pages of text that even as a nutritional biologist I didn’t understand or couldn’t follow. The report is chaotic and you don’t understand whether this is meant in general or refers to yourself. It’s no wonder that ordinary people look for help on the Internet. But a graphic makes it clear that I must have problems. Putrefactive flora too high, histamine formers too high, acidifying flora too low, fungi okay and pH value too high. I get scared. Something seems to be wrong in my gut.
The test from 15:00 (on the same day!), on the other hand, is fine. Only Enterococcus is still too numerous. The graphic that illustrates all this is green. My fear disappears again. My gut seems to be healthy.
| 8:00 | 15:00 | |
|---|---|---|
| pH value stool | 7,5 | 7,5 |
| E. choli | 7*10^8 | 1*10^6 |
| Enterococcus spec. | 8*10^8 | 1*10^9 |
| Lactobacillus spec. | 1*10^5 | 5*10^5 |
| Flora index | 5: putrefactive flora, histamine too high, acid flora | 2 – everything ok |
Legend – red: too high, yellow: too low, green: OK
What does that mean?
Dear critics and Florastatus gurus: This means that the intestinal microbiome, i.e. the “intestinal flora”, cannot be determined by such tests. If I get different results within seven hours these tests simply cannot provide any information. They are too imprecise. The manufacturer says: “Slight fluctuations are always possible when testing organic material. When comparing both results, the statements remain similar: high pH value, low lactobacilli, high enterococci. Only E. coli is subject to greater fluctuation.” Is the manufacturer right? No, he is not. Yes, the pH value is high both times. However, Lactobacillus is within the normal range defined by the manufacturer in the second test (difference 400,000 colony-forming units – this is the unit in which the measurement is made). The enterococci even differ by 200 million units in the two tests. That’s quite a lot.
The bottom line
What comes out of such a test depends on when you take the test. If you don’t have time today and think: “Oh, I’ll do it tomorrow”, you’ll have a significantly different result tomorrow. Imagine a serious medical test for cancer, malaria or HIV.
Yes, the intestinal flora is important for our health. Yes, the intestinal flora has an influence on us. Yes, you can influence the intestinal flora a little through nutritional intervention. Yes, there are microbiome analyses that are useful – but these are very rarely needed, cost a lot of money and are carried out by a doctor. But home tests that analyze the intestinal flora do not provide any useful information. Not even rudimentarily. And certainly not when you post and discuss them in Facebook groups.
By the way, I did a third test. 10 days later, without changing my diet, without any probiotics or other measures. The pH value was normal and I suddenly had too few E. cholis.
| 8:00 | 15:00 | 8:00, but 10 days later | |
|---|---|---|---|
| pH value stool | 7,5 | 7,5 | 6,5 |
| E. choli | 7*10^8 | 1*10^6 | 1*10^4 |
| Enterococcus spec. | 8*10^8 | 1*10^9 | 8*10^8 |
| Lactobacillus spec. | 1*10^5 | 5*10^5 | 6*10^6 |
| Flora index | 5: putrefactive flora, histamine too high, acid flora | 2 – everything ok | 3 – everything ok |
Legend – red: too high, yellow: too low, green: OK
Sources
(1) Salzberger, B., Lehnert, H. & Mössner, J. Internist (2017) 58: 427. https://doi.org/10.1007/s00108-017-0230-3
(2) Steinhagen, P.R. & Baumgart, D.C. Internist (2017) 58: 429. https://doi.org/10.1007/s00108-017-0224-1
(3) Hof H, Dörries R. Medical Microbiology [Internet]. 5th ed. Georg Thieme Verlag; 2014. Available from: https://books.google.at/books?id=MtFmAwAAQBAJ&dq=wie+many+lactobacillus+species+are+there&source=gbs_navlinks_s
