Biological complexity: gut biome may affect brain (Introduction)

by David Turell , Thursday, February 04, 2021, 14:34 (1388 days ago) @ David Turell

The research is suggestive:

https://www.nature.com/articles/d41586-021-00260-3?WT.ec_id=NATURE-20210204&utm_sou...

"Thousands of publications over the past decade have revealed that the trillions of bacteria in the gut could have profound effects on the brain, and might be tied to a whole host of disorders. Funders such as the US National Institutes of Health are investing millions of dollars in exploring the connection.

"But along with that explosion of interest has come hype. Some gut–brain researchers claim or imply causal relationships when many studies show only correlations, and shaky ones at that, says Maureen O’Malley, a philosopher at the University of Sydney in Australia who studies the field of microbiome research. “Have you found an actual cause, or have you found just another effect?”

"In recent years, however, the field has made significant strides, O’Malley says. Rather than talking about the microbiome as a whole, some research teams have begun drilling down to identify specific microbes, mapping out the complex and sometimes surprising pathways that connect them to the brain. “That is what allows causal attributions to be made,” she says. Studies in mice — and preliminary work in humans — suggest that microbes can trigger or alter the course of conditions such as Parkinson’s disease, autism spectrum disorder and more (see ‘Possible pathways to the brain’). Therapies aimed at tweaking the microbiome could help to prevent or treat these diseases, an idea that some researchers and companies are already testing in human clinical trials.

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"It’s not yet clear how that signal in the gut reaches the brain, but one likely conduit is the vagus nerve. The vagus connects the brainstem to many organs, including the colon, making it the longest of the twelve cranial nerves that carry signals between the brain and the rest of the body. “It’s really a highway,” Cryan says. And research in humans and animals suggests that it has a crucial role in ferrying at least some messages between the gut and the brain.

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"In each of these diseases, many mechanistic questions remain. Researchers in the field acknowledge that they have yet to flesh out the pathways from microbe to brain. And the trickiest step will be validating these animal findings in humans and moving into trials. “These are extraordinary claims, which should require extraordinary evidence,” says Mitchell."

Comment: This is early in discovery. When I was in practice many years ago H. pylori was found by two Australian pathologists related to duodenal ulcer. Their report was laughed at by American GI specialists. But the bug was easily treatable. I was one of many Docs who tried an antibiotic cure. Worked beautifully!!! This new research is pointing at a similar result. Bacteria started life and are still modifying more complex living forms. Bacteria
have been allowed to survive while 99% of all species disappeared because they were meant to continue to have these roles as God designed.