Return to David's theory of theodicy; good and bad bugs (Evolution)

by David Turell , Wednesday, March 27, 2024, 22:00 (239 days ago) @ dhw

Many more good than bad, as usual:

https://www.the-scientist.com/clostridia-to-the-rescue-71741?utm_campaign=TS_News%20Ale...

"Food allergies arise partly because of reduced gut barrier integrity, giving food molecules access to the circulatory system where they contact the immune system. The gut microbiome promotes intestinal health in part by helping to maintain the barrier function of this tissue. Clostridia bacteria promote the gut barrier and reduce food sensitization and allergy. Cathryn Nagler, a mucosal immunologist at University of Chicago, and her team previously found that this class of bacteria were more abundant in nonallergic individuals than those with food allergies.

"The production of interleukin (IL)-22 from host cells promotes gut barrier integrity, and bacterial products such as metabolites and flagellin induce host IL-22. In an article published in Cell Reports, Nagler’s team demonstrated that Clostridia-produced flagella and indole, a tryptophan metabolite, also promote barrier integrity.

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"One week after weaning, the team isolated the animals’ intestinal tissues and treated them with flagella from commensal Clostridia or pathogenic Salmonella. “Commensal flagellins and pathogen flagellins are structurally and functionally distinct,” Nagler explained.

"Both flagella treatments led to the production of barrier protective IL-22 from intestines. “It's really fascinating that [the] same protein but different amino acids elicit different responses,” said Pamela Chang, an immunologist at Cornell University who was not involved in the study.

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"According to Nagler, this study reveals how Clostridia bacteria protect the gut barrier and prevent food allergies. “You can imagine that if someone has a dysbiotic microbiome, and they don't have enough or any Clostridia that have these specific molecules, then they might be more likely to develop food allergy,” Chang said.

"Nagler believes that these results have broad implications for understanding gut microbe-host health. “Maintaining an effective barrier protective response is fundamental to the whole family of noncommunicable chronic diseases that are rising in parallel with food allergy,” she said."

Comment: there are good and bad bugs. The good ones support and maintain many bodily functions and ae in far greater number than the bad. Which means it is perfectly reasonable to tolerate some bad. In this case usually bad Clostridia and Salmonella work well for us!