In common medical practice, bacteria ranges tend to be very random. Often it becomes values above or below average plus/minus 1.96 Standard Deviations. Bacteria are abnormal (i.e. are not a normal or bell curve distribution).
My training is in statistics and operations research. This post and other posts are intended to ask “why not do things this way” and to inspire lifting the bar in approaching the microbiome.
From some 7,500 samples I computed statistical ranges for 2,470 different bacteria with a threshold of Chi2 > 6.6 (around p < 0.01). The higher the odds, the more significant. The ranges apply only is the bacteria was detected in the sample. The page is available here.
Some Highlights
- Lactobacillus is unhealthy if below the 68%ile
- Bifidobacterium is unhealthy if below the 16%ile
- Akkermansia muciniphila is unhealthy if below the 36%ile
Some bacteria appear to have no ranges, for example: Bacteroides, Firmicutes
Example of one bacteria with multiple ranges
- Blautia producta
- Below 19%ile Unhealthy
- 20 -26%ile Healthy
- 27 -38%ile Unhealthy
- Over 38%ile no statistically significant impact
- Bifidobacterium bifidum
- Below 25%ile Unhealthy
- 26 -28%ile Healthy
- 32 -42%ile Unhealthy
- Other values – no statistically significant impact
- Bifidobacterium dentium
- Below 50%ile Unhealthy
- 51 -64%ile Healthy
- 65 -73%ile Unhealthy
- Other values – no statistically significant impact
- Rickettsiales
- 0 – 100% is unhealthy!
Summary
So far, most of the numbers appear to follow common sense (see Highlights above). Bacteria with multiple ranges is more of a challenge to understand and exposes a concept close to a “Yin/Yang” of the microbiome.
A more interesting one is: Lysobacterales. The low odds ratios for healthy hints that we may wish to discard those values resulting in < 60 as unhealthy.
Adding to Microbiome Prescription
I am planning to add it as a bacteria selection method using a higher Chi2 value then used for the demo table. Stay tune.
I will be using P < 0.001 to safely identify the bacteria of concern.