Blood Type, Serotonin and CFS

A reader left a comment on my site this week and asked a few question.


I have had great success with your diet/probiotic information and I cannot thank you enough for sharing your story with the world.

I have something that took my health to the next level and I wanted to share it.
Note: This was before I found your blog and had made no other changes to my diet or lifestyle. I have had CFS for 7 years.

For depression, my doctor prescribed Sertraline, a serotonin reuptake inhibitor (SSRI). The first 3 weeks I had a terrible reaction but persevered and after about 12 weeks, I experienced a HUGE reduction in symptoms.

In regards to people with CFS having low E.coli, I have found links between E.coli and Serotonin.
1. “Escherichia coli Nissle 1917 [Mutaflor Probiotics] enhances bioavailability of serotonin in gut tissues through modulation of synthesis and clearance.”

Maybe low serotonin (low E.coli) resulted in exacerbated pain sensitivity and other symptoms? I believe Sertraline also lowered my stress levels which allowed my immune system to get back on its feet and heal my body.

I also wanted to throw in this little gem about blood type and intestinal microbiota composition, I thought it could be an important piece of information for the overall puzzle.
I was hoping your PubMed skills could interpret for us? I struggle to understand scientific papers and would love to understand more about this link to our health. My blood type is 0 positive.

Thank you again, Ken! Your work is so appreciated.”

Blood Types

Since blood type is connected to DNA, and your microbiome is connected with your DNA, I am not surprised. I suspect that in time we will find many conditions deemed to be inherited is not inherited by DNA proper, but inherited by microbiome. I include one of the diagrams from the article that you cited. I could not find any studies on fibromyalgia, CFS, IBS and blood types — it would be interesting to see a study on it!

For other microbiome dysfunction associated diseases,

  • “[Crohn’s disease] Patients with blood type AB had a better response to Infliximab [IFX] while those with blood type A appeared to have a risk of losing response to IFX.”[2016]
  • “Subjects with blood group “B” are at high risk while individuals with blood group “O” are at low peril of evolving type 2 diabetes.” [2016]
  • “The frequency of AB blood group was significantly higher in type-1 diabetics; and Ablood group was significantly higher in type-2 diabetics. Furthermore, Rh negativity were significantly more frequent in type-2 diabetics.” [2016]
  • ABO histo-blood group might modulate predisposition to Crohn’s disease and affect diseasebehavior.[2014]

Example of how strains varied according to blood type

Serotonin And Probiotics

Many probiotics help with serotonin, they tend to be the same ones that I suggest. “serotonin receptor modulators are used to treat IBS,”[2015]  I did a post on DNA and serotonin earlier this year that may interest some.

Not good:

  • “mice treated with either F. prausnitzii strain A2-165 and its culture supernatant (SN) exhibited significant decreases in intestinal permeability, tissue cytokines and serotonin levels.” [2015]