Balance of nature: viral biome calms mice (Introduction)

by David Turell , Thursday, May 09, 2024, 19:16 (11 days ago) @ David Turell

An amazing result:

https://www.the-scientist.com/viruses-keep-mice-from-stressing-out-71832?utm_campaign=T...

"In a recent paper, published in Nature Microbiology, researchers demonstrated that stress alters the gut virome, which in turn, affects behavior in mice. Understanding these interactions could help researchers better identify targets in dysregulated microbiomes of patients experiencing chronic stress to modulate their symptoms.

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“'We always think of viruses as something we want to get rid of and are negative,” said John Cryan, a stress neurobiologist at the University College Cork and coauthor of the study. “What this paper does is… turn that whole aspect on its head and say, ‘what if they’re good viruses?’” (my bold)

"To test their hypothesis, Cryan and his team first assessed the effect of stress on the bacterial and viral populations in mouse guts by intermittently housing one mouse with an aggressive mouse in an overcrowded cage over the course of three weeks. Using metagenomic or 16S ribosomal sequencing, the team analyzed the virome and bacteriome, respectively.

"Stress altered the bacterial microbiome composition to a greater degree than the virome, but it did not change the species diversity in either the bacteriome or virome. However, the experimental housing modified the population density of 12 distinct viruses.

"Corticosterone, a steroid hormone, regulates stress and immune responses, so the researchers assessed levels of this hormone as well as inflammatory cytokines produced from cells in the spleen.8 They showed that the adverse housing conditions increased circulating corticosterone and interleukin-6 production from splenocytes after stimulation with the antagonist concanavalin A (ConA).

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"When the researchers assessed the mice for social, anxiety-like, and stress-coping behavior, they observed that stressed animals that didn’t receive a virome transplant exhibited increased stress and anxiety behaviors. Meanwhile, mice that received the intervention during the stress experiment behaved comparably to normal mice that did not undergo the environmental stressor. “It was really remarkable that we could normalize it,” Cryan said. The viral transplantation also reversed the effect of stress on the animals’ production of inflammatory cytokines with and without ConA stimulation.

"Finally, the researchers studied the role of the virome during stress by measuring gene expression using RNA sequencing in the hippocampus and amygdala, two brain regions that respond to stress. They showed that stress altered the expression of genes related to fear and stress responses, immune processes, viral activities like replication, and neurotransmitter levels. Transplanting mice with their virome returned the expression of these genes to normal levels.

“'What this paper has done is added another level of complexity by introducing the fact that the viruses just don't sit there and handle the bacteria,” Collins said. “The virome control of the microbiota has consequences for behavior.'”

Comment: like bacteria, viruses play a helpful role in living organisms. Note the bold. we need to recognize the good they do and realize the bad events are a necessary byproduct of the actions of free-acting organisms. This is a real answer to dhw's theodical complaints about God. Obviously, God created viruses and bacteria to play helpful roles in life, which this study clearly shows. The problem is these organisms are running on their own controls and are free to get us trouble. An all-knowing God has produced what He had to produce to fill specific needs. We need to stop fearing viruses and bacteria. They are here for our good.