In a new study, researchers at the University of Cork in Ireland transplanted intestinal microbes from young mice into old mice in the form of feces, which can reverse the aging brain clock. This shows that microorganisms in the intestine can reverse the deterioration of brain and cognitive function related to aging. This breakthrough research has opened up a potential new treatment method, that is, intervention measures based on intestinal microorganisms to delay brain aging and related cognitive problems. The related research results were published online in NatureAging journal on August 9th, 20021year, and the title of the paper was MicrobiottafromyongmicAccess Selective Age-related dbehavioralfidecities. The correspondent of this paper is Professor John. Kerian, deputy director of research and innovation at Cork University, said. The first author of this paper is Dr. MarcusBoehme and Dr. KatherineE from Cryan Laboratory. Guzta and Dr. Thomas Bastiansen.
People are increasingly aware of the importance of intestinal microorganisms in all aspects of physiology and medicine. Bacteria in our intestines affect everything from our daily mood to our overall health. During our lifetime, the intestinal microflora will also change. However, although some studies show that young blood can rejuvenate old mice, the influence of intestinal microflora on age-related decline is still unclear.
In order to test whether young intestinal microflora can reverse the signs of aging, the author extracted fecal samples from young mice aged 3 to 4 months and transplanted them into mice aged 20 months. They used a feeding tube to feed the old mice with fecal mud twice a week for 8 weeks. As a control, the aged rats were fed with the feces of other aged rats, and the young rats were fed with the feces of the young rats.
The first thing these authors noticed was that the intestinal microflora of old mice receiving the intestinal microflora of young mice began to resemble that of young mice. For example, enterococcus, a common intestinal microorganism, becomes more abundant in the intestines of old mice, just like in young mice.
The brain has also changed. The hippocampus of old mice-a brain region related to learning and memory-has become more similar to that of young mice in physics and chemistry. Older rats who receive the feces of young rats can also learn to solve the maze problem faster and better remember the layout of the maze in subsequent attempts. However, these effects were not observed in elderly mice that received feces from other elderly mice. Cryan said, "It's almost like we can press the back button of the aging process."
However, although transplanting intestinal microorganisms from young mice into old mice can rejuvenate many aspects of brain and immune function of old mice, these old mice have not changed significantly in some aspects. For example, these elderly mice remain unchanged in many types of intestinal bacteria, and they have not become more socially interactive, which is surprising because the influence of intestinal microflora on social interaction has been observed in other studies.
However, some scientists in this field have raised some questions. For example, AryaBiragyn, a molecular biologist at the National Institute on Aging, said he hoped Cryan and his team would conduct more experiments to show that the intestinal microflora of old mice had indeed changed. He believes that because the Cryan team checked the differences in intestinal microbiota shortly after fecal transplantation, there is no way to know whether the new microorganisms really entered the intestines of animal recipients or just passed by.
SeanGibbons, a researcher of intestinal microbiology at the American Institute of Systems Biology, also pointed out that the field of mouse feces transplantation is still a complex field. He said that although some studies have found that fecal transplantation seems to be beneficial, for example, young infertile mice receiving fecal transplantation from elderly mice have increased hippocampal nerves and increased intestinal growth. However, at least one study found that transplanting feces from old rats into young rats can increase the levels of pro-inflammatory cytokines and oxidative stress, which may be the result of the increase of pro-inflammatory cytokines and oxidative stress, leading to the decrease of cognitive ability of the latter.
Professor Cryan said, "We and other research teams have previously found that intestinal microflora plays a key role in aging and aging process. This new study is expected to lead to changes in this field, because we have determined that intestinal microflora can be used to reverse age-related brain degeneration. We also observed evidence of improving learning ability and cognitive function. Although this progress is very exciting, it is still in the early stage and more research work is needed to understand how these findings are transformed in humans. "
This new study further proves the importance of intestinal microflora in many aspects of health, especially in the brain/intestinal axis, and brain function can be positively affected. It is possible to regulate intestinal flora as a therapeutic target affecting brain health in the future.
Since this research is entirely based on rodents, Cryan himself is cautious about turning the research object to humans too early. Nevertheless, he believes that this research still brings hope. "The advantage of your gut microbiota over your genome is that you can change it."
References:
MarcusBoehmeetal. Age-related behavioral defects of microorganisms. NatureAging，202 1，doi: 10. 1038/s 43587-02 1-00093-9。
RochellysDiazHeijtzetal。 youngmicrobiotarejuvenatestehaingbrain . nature aging，202 1，doi: 10. 1038/s 43587-02 1-00 100-z。
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