Γ—

Gut Viruses Found to Improve Cognition in Humans

These viruses infect bacteria, not people.

Share







Gut bacteriaGut bacteria

A study published in Cell Host & Microbe has found that members of the Cuadovirales viral order positively affect cognition in multiple species, including humans.

To do this, we need your support. Your charitable contribution tranforms into rejuvenation research, news, shows, and more. Will you help?

Viruses in the human body, but not human viruses

Cuadovirales is an order of bacteriophages, which infect bacteria rather than animal cells. Previous research has noted that 80% of bacterial genomes contain viral DNA, which is linked to the diversity of gut bacteria, and therefore a healthy gut microbiome [1].

It has been previously discovered that viral abundance changes with age. Specifically, within the Cuadovirales order, Microviridae goes up and Siphoviridae goes down [2]. This change also occurs in mice fed a high-fat diet [3].

The taxonomy of these viruses is not fully eludicated, and, in fact, has been recently changed; because this change was done after the researchers finished their work, the researchers’ investigation into Siphoviridae now includes two other taxonomic familes as well; however, approximately 90% of the viruses in these three families are still Siphoridae. The researchers refer to members of these three families as “specific Cuadovirales“.

As the gut-brain axis is known to have effects on cognition, the researchers of this study sought to determine the extent of these viruses’ effects, and what they found was substantial.

Effects on bacterial metabolism

Viral infection, as expected, changes how the infected bacteria work. Surprisingly, the researchers found a strong negative association between specific Cuadovirales and multiple aspects of folate metabolism, including DNA repair mechanisms and the use of vitamins B2 and B6 in the folate cycle. However, the researchers also found that many of the bacterial pathways associated with folate metabolism were increased instead.

The researchers point to one specific bacterial gene upregulated by Siphoviridae: thyX, a gene that is known as TYMS in humans and is instrumental in neuroplasticity, neurological development, and memory retention [4]. Specific Cuadovirales also affected bacterial genes associated with multiple other aspects of central nervous system biochemistry, and they were shown to largely infect lactic acid-related bacteria, which are associated with dairy products [5].

Human cognition effects

Using multiple diagnostic tests and a careful examination of gut bacteria, the researchers investigated a discovery cohort of 114 people. Controlling for confounding factors such as age and BMI, the researchers found that specific Cuadovirales were associated with improved performance on the trail-making task B, a measurement of cognitive ability, in women, while Microviridae were associated with decreased performance in both sexes. On the other hand, specific Cuadovirales were associated with the backward digit span test, another measure of cognitive performance, in men but not women.

The researchers then examined a larger validation cohort of 942 people. The results in this cohort were even more pronounced in men; specific Cuadovirales were associated with improved short-term and long-term memory, executive function, and speed of information processing.

Animal results

The researchers also explored the effects of specific Cuadovirales in mice and fruit flies. Transplanting bacteria infected with these viruses into mice improved their scores on the novel object recognition test and increased gene expression associated with cognition; as expected, Microviridae were shown to negatively affect these genes.

In flies, the researchers chose to test specifically Lactococcal 936-type viruses, giving a control group whey without any viruses. Flies given live viruses were found to score better on learning and memory, which, in flies, is represented by an aversive taste test.

Conclusion

This study is extremely detailed with multiple layers of results, and it involves a great many individual viruses, bacteria, proteins, and genes. While some of the contradictory results are not fully elucidated, and the sex-based differences are not explained, this study offers very good insight into these topics, and it provides interesting potential for future development.

This study could be foundational for managing our fecal bacteria, even to the point of genetic manipulation, in order to keep our gut microbiomes functioning as they should to provide our brains with what they need.

We would like to ask you a small favor. We are a non-profit foundation, and unlike some other organizations, we have no shareholders and no products to sell you. We are committed to responsible journalism, free from commercial or political influence, that allows you to make informed decisions about your future health.

All our news and educational content is free for everyone to read, but it does mean that we rely on the help of people like you. Every contribution, no matter if it’s big or small, supports independent journalism and sustains our future. You can support us by making a donation or in other ways at no cost to you.

Restoring Heart Regeneration With a Metabolic Switch

In a recent article in Nature, researchers have restored cardiac regeneration to adult mice by disabling fatty acid oxidation, discovering...

Human Clinical Trials of NMN for Safety and Effectiveness

In a recent paper, researchers reviewed the literature for human clinical trials that address NMN's safety and anti-aging effects [1]....

Lifespan News – Elon Musk and the Living Forever Curse

On this episode of Lifespan News, Ryan O'Shea ruminates on Elon Musk's statement on living forever being a curse rather...

ARDD 2023: The Mother of All Longevity Conferences

Once a year, Copenhagen becomes a Mecca for the longevity community. Hundreds of people flock to the picturesque Danish capital...

Literature

[1] Keen, E. C., & Dantas, G. (2018). Close encounters of three kinds: bacteriophages, commensal bacteria, and host immunity. Trends in microbiology, 26(11), 943-954.

[2] Gregory, A. C., Zablocki, O., Zayed, A. A., Howell, A., Bolduc, B., & Sullivan, M. B. (2020). The gut virome database reveals age-dependent patterns of virome diversity in the human gut. Cell host & microbe, 28(5), 724-740.

[3] Schulfer, A., Santiago-Rodriguez, T. M., Ly, M., Borin, J. M., Chopyk, J., Blaser, M. J., & Pride, D. T. (2020). Fecal viral community responses to high-fat diet in mice. Msphere, 5(1), e00833-19.

[4] Heyward, F. D., & Sweatt, J. D. (2015). DNA methylation in memory formation: emerging insights. The Neuroscientist, 21(5), 475-489.

[5] Mahony, J., & Van Sinderen, D. (2014). Current taxonomy of phages infecting lactic acid bacteria. Frontiers in microbiology, 5, 7.

CategoryNews
About the author
Josh Conway

Josh Conway

Josh is a professional editor and is responsible for editing our articles before they become available to the public as well as moderating our Discord server. He is also a programmer, long-time supporter of anti-aging medicine, and avid player of the strange game called β€œreal life.” Living in the center of the northern prairie, Josh enjoys long bike rides before the blizzards hit.
No Comments
Write a comment:

*

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.