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FMT from elderly mice caused sig. more severe cognitive impairment in young mice. Severing vagus nerve significantly inhibited cognitive impairment.

junkcrap50

Senior Member
Messages
1,333
FMT from elderly people and aged mice caused significantly more severe cognitive impairment in transplanted young mice than those from young adults and mice. Severing the vagus nerve significantly inhibited the occurrence of cognitive impairment. Two bacteria species also singled out.

The extracellular vesicle of gut microbial Paenalcaligenes hominis is a risk factor for vagus nerve-mediated cognitive impairment
Microbiome volume 8, Article number: 107 (Jul 2020)
Abstract
Background
In a pilot study, we found that feces transplantation from elderly individuals to mice significantly caused cognitive impairment. Paenalcaligenes hominis and Escherichia coli are increasingly detected in the feces of elderly adults and aged mice. Therefore, we isolated Paenalcaligenes hominis and Escherichia coli from the feces of elderly individuals and aged mice and examined their effects on the occurrence of age-related degenerative cognitive impairment and colonic inflammation in mice.
Results
The transplantation of feces collected from elderly people and aged mice caused significantly more severe cognitive impairment in transplanted young mice than those from young adults and mice. Oral gavage of Paenalcaligenes hominis caused strong cognitive impairment and colitis in specific pathogen-free (SPF) and germ-free mice. Escherichia coli also induced cognitive impairment and colitis in SPF mice. Oral gavage of Paenalcaligenes hominis, its extracellular vesicles (EVs), and/or lipopolysaccharide caused cognitive impairment and colitis in mice. However, celiac vagotomy significantly inhibited the occurrence of cognitive impairment, but not colitis, in mice exposed to Paenalcaligenes hominis or its EVs, whereas its lipopolysaccharide or Escherichia coli had no such effects. Vagotomy also inhibited the infiltration of EVs into the hippocampus.
Conclusions
Paenalcaligenes hominis, particularly its EVs, can cause cognitive function-impaired disorders, such as Alzheimer’s disease, and its EVs may penetrate the brain through the blood as well as the vagus nerve.
 

junkcrap50

Senior Member
Messages
1,333
Very interesting that severing the vagus nerve stopped the cognitive impairment from the FMT / bad gut bacteria!

Looks to be very relevant to what Michael VanElzakker is studying and his Vagal Nerve Theory. Seems like it is easy for the vagus nerve to get infected and influence the brain / cognitive function.
 

ljimbo423

Senior Member
Messages
4,705
Location
United States, New Hampshire
Very interesting that severing the vagus nerve stopped the cognitive impairment from the FMT / bad gut bacteria!

Looks to be very relevant to what Michael VanElzakker is studying and his Vagal Nerve Theory. Seems like it is easy for the vagus nerve to get infected and influence the brain / cognitive function.

It is very interesting that severing the vagus nerve stopped the cognitive impairment!

This is quote from the paper-

"LPS" stands for Lipopolysaccharides. Which are powerful toxins that are part of gram negative bacteria in the gut.

Moreover, the excessive production of gastrointestinal bacterial byproducts such as LPS and kynurenine due to gut dysbiosis causes gastrointestinal and systemic inflammation, leading to inflammatory bowel disease and neuroinflammation [26,27,28].

https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-020-00881-2

There is a lot of research that has been done showing a very strong connection of gut dysbiosis to neuroinflammation. It looks like the vagus nerve can also have a big role in affecting the brain too, by causing cognitive impairment, as this study shows.
 

Hip

Senior Member
Messages
17,852
Very interesting that severing the vagus nerve stopped the cognitive impairment from the FMT / bad gut bacteria!

The mechanism by which an infection in the peripheries of the body has an effect on the brain is reasonably well understood. The vagus plays a fundamental role in this.

When the vagus detects infection and inflammation in any of the organs of the torso, it sends a signal to the brain, and that signal instructs the brain to ramp up its own internal immune response (ie, the signal triggers neuroinflammation). That neuroinflammation then leads to the sickness behavior symptoms, which includes fatigue and cognitive impairment.

I suspect this is how hepatitis virus infection of the liver causes ME/CFS-like fatigue and cognitive impairment: the vagus senses the chronic liver infection, and the signals this nerve sends to the brain induce neuroinflammation and sickness behavior.

The vagus is not the only route by which peripheral infections can affect the brain. There are 4 known routes, detailed in this post. But the vagus nerve is the main and most important route.



So how can we get our vagus nerve servered?

There are various types of vagotomy used for different reasons.

I would not like to be the first guinea pig to test to see if a vagotomy improves or cures ME/CFS.

Though if someone could develop a reversible vagotomy, such that your vagus nerve could be reconnected if the vagotomy offered no benefits, then maybe that would be interesting.