Researchers discover new bacterium that causes gut immunodeficiency

[Wishful]

https://www.sciencedaily.com/releases/2024/09/240926144904.htm

"In this new study, researchers found that T. immunophila'spresence in the gut increases susceptibility to pathogens and delays repair of the gut's protective barrier. T. immunophila'sname is an homage to a pioneer in immunology. SIgA was discovered by Dr. Thomas Tomasi, who published his findings in a foundational paper in Science in 1963.

"Drs. Stappenbeck and Lu's rigorous and elegant study provides a key insight and an exciting potential mechanism for why some people have low or absent levels of SIgA in their gut, yet retain normal levels of SIgA in their bloodstream,""

 

[BrightCandle]

Not something either of my biomesights has picked up.

 

[Lolinda]

T. immunophilia is a mouse gut bacterium and this study is in mice.
But bugs degrading IgA (ordinary IgA and not sIgA in the gut) have already been found in humans:
https://en.wikipedia.org/wiki/Immunoglobulin_A
Neisseria species including Neisseria gonorrhoeae (which causes gonorrhea),[21] Streptococcus pneumoniae,[22] and Haemophilus influenzae type B[23] all release a protease that destroys IgA. Additionally, Blastocystis species have been shown to have several subtypes that generate cysteine and aspartic protease enzymes which degrade human IgA.[24]
In conclusion, it looks very likely to me that human bad bugs will be found that are capable of degrading sIgA.

The simple solution one could think would be to take a probiotic or prebiotic known to increase sIgA. There are tons of research papers on Google Scholar reporting positive results. But unfortunately, sIgA is not some "general utility substance" but it is just like with IgM and IgG: it is custom made for a specific antigen:
https://en.wikipedia.org/wiki/Immunoglobulin_A
Production of sIgA against specific antigens depends on sampling of M cells and underlying dendritic cells, T cell activation, and B cell class switching in GALT, mesenteric lymph nodes, and isolated lymphoid follicles in the small intestine.[18]

This then raises questions:
1. so if we would increase sIgA using some probiotic or prebiotic, do we cause harm by forcing the body to increase sIgA production for these beneficial bacteria (sIgA is used to coat beneficial bacteria which helps their adhesion) while possibly diverting resources away from sIgA production against harmful bugs (it marks them for clearance for example by the complement system)?
2. Even if we succeeded to raise sIgA production against harmful bugs, wouldn't that simply feed them after they made some of this sIgA dysfunctional using their proteases?

3. The practically most important question: scanning through a lot of papers on Google Scholar, I noticed a peculiarity: it doesn't seem like anyone succeeded to raise sIgA for more than 2 or max 4 weeks. Do you know any research that succeeded for a longer term?

 

[Wishful]

An even simpler solution would be to target the offending bacterial strain, perhaps via a phagocyte. Maybe people lacking T. immunophila have such a phagocyte.

 

[Lolinda]

Hi Wishful and everybody else reading this thread, I am personally very interested in sIgA, because in my dozen of sIgA measurements in stool that I had, it was often low: from 280 to 370 mg/L (normal range: 510-2040). How about you? Did you try to increase it? And what I am very interested in: if you succeeded, did you earn any concrete improvements in any symptoms or did you get worse? (if it is something too personal to discuss in a public thread, let's do PM)

 

[Wishful]

I haven't had any sigA measurements done. I also don't have any noticeable symptoms of leaky gut, so I expect mine is normal. I just posted the link because I thought it might be helpful for someone who does have intestinal barrier problems.

I recently noticed a paper about identifying microbiome strains linked to specific diseases. That area of research is still in its early stages, but it does show promise of diagnostic and treatment techniques in the future. Give a stool sample, and the AI sends you a prescription for specific probiotics (and phagocytes?) and supporting diet.