Pay attention to the slogan of Alzheimer's disease.

People often think that when you get old, it is a matter of course to forget more. As we all know, the precious memories of a small number of elderly people have not become "old", but have been stolen by a "thief" who is good at hiding. The thief is Alzheimer's Harmo's disease (AD 200), and it has a well-known nickname "Alzheimer's Harmo's disease".

Alzheimer's Harmo's disease (AD) is a degenerative disease of the central nervous system, which always occurs inadvertently and gives people a pleasant surprise. It likes to "haunt" the elderly over 65 years old, gradually devouring their memories, causing mental and behavioral abnormalities, decreased living ability and other problems; Moreover, the older you get, the higher the probability of encountering it. According to statistics, the incidence rate of elderly people over 65 years old in Europe and America is 5%, and the incidence rate over 85 years old is as high as 30%.

According to the World Report on Alzheimer's Harmo's Disease 20 18 published by the International Association for Alzheimer's Harmo's Disease, in 20 18, there were 50 million people suffering from dementia in the world, which is expected to reach 82 million in 2030 and 65,438+52 million in 2050. The report also mentioned that in the world, one person suffers from Alzheimer's disease every three seconds.

Alzheimer's disease can be said to be a "brain killer", which will damage neurons and synapses in the brain and specific subcortical areas, and then lead to obvious brain atrophy. Therefore, compared with normal people, some sulcus gyrus in temporal lobe, parietal lobe and cingulate gyrus of patients with Alzheimer's disease will disappear.

At the same time, the hippocampus responsible for learning and memory will also shrink extremely, which will not only lead to imperceptible memory damage, make it difficult for patients to remember new things, but also increase the risk of emotional illness and dementia. Not only that, the ventricles will also expand, leading to more hydrocephalus. ...

However, the medical community has not yet found the root cause of the above changes in the brain. However, some people think that the deposition of Aβ is the initial event leading to Alzheimer's disease, which in turn leads to the formation of neurofibrillary tangles of highly spiral hyperphosphorylated Tau protein. The deposition of these two abnormal proteins eventually leads to synaptic deletion and neuronal apoptosis.

According to the hypothesis of β -amyloid protein (Aβ), there is a transmembrane protein-pre-amyloid protein (APP) on the cell membrane of neurons, which is very important for the growth, survival and post-traumatic repair of neurons. aβ is a small fragment. Although Aβ is also produced in the normal brain, it will be decomposed and cleared soon. However, the production and elimination of Aβ in the brain of patients with Alzheimer's disease are out of balance. When APP is decomposed into small molecular fragments by some enzymes, the decomposed Aβ will accumulate and deposit outside neurons, which will have toxic effects on brain nerves.

Tau protein hypothesis points out that each neuron has an intracellular supporting system composed of microtubules, which is called cytoskeleton. These microtubules act as orbits, guiding nutrients and other molecules to move back and forth between cell bodies and axons. Tau protein can stabilize microtubules after phosphorylation, but in patients with Alzheimer's disease, Tau protein is mutated and hyperphosphorylated, leading to microtubules disintegration. The released Tau protein will aggregate, produce nerve fiber clumps and disintegrate the transport system of neurons. The denatured Tau protein will make the transposon run abnormally, leading to neuron death.

According to the above two hypotheses, the research shows that the disorder of intestinal flora will affect the deposition of amyloid β protein (Aβ) and the hyperphosphorylation of Tau protein through the brain-gut axis, and then affect the occurrence and development of Alzheimer's disease.

Intestinal-brain axis is a two-way communication system between intestinal microorganisms and brain, which is composed of many factors such as immunity, metabolism, neuroendocrine and vagus nerve. Intestinal flora can act on the central nervous system through the gut-brain axis, thus affecting the metabolism and behavior of the whole body.

Under normal circumstances, the intestinal flora will develop with the development of the human body and remain relatively stable until adulthood. In old age, there will be problems such as the gradual decline of diversity and stability, which will lead to the disorder of intestinal flora. However, the disorder of intestinal flora will affect the absorption of related nutrients, damage the human immune mechanism and trigger an inflammatory reaction, which will lead to a series of health problems.

On the one hand, if the intestinal flora is disordered, the structure of gastrointestinal mucosa and blood-brain barrier may change, and the permeability will increase, so that some harmful substances can reach the brain more easily, thus causing Alzheimer's disease. In addition, although Aβ can be eliminated by the liver, the disorder of intestinal flora will affect the intestinal barrier. Energy homeostasis and other ways lead to liver dysfunction, which in turn affects the process of liver clearance of Aβ.

On the other hand, normal intestinal flora can destroy antioxidant stress and inhibit excessive phosphorylation of Tau protein by producing antioxidant substances or enhancing the activities of superoxide dismutase, glutathione and other substances, while disorder of intestinal flora will lose this protective effect. Intestinal flora can also interfere with insulin signaling pathway by inducing inflammation and promoting lipogenesis, thus activating glycogen synthase kinase -3β and promoting hyperphosphorylation of Tau protein. Not only that, lipopolysaccharide secreted by bacteria will also enter the blood, promote the occurrence of systemic inflammation, and then accelerate the hyperphosphorylation of Tau protein.

Although researchers have found that there is a correlation between intestinal flora and Alzheimer's disease, according to the current medical means, patients' pain can only be alleviated by relevant means, but it cannot be completely cured. For Alzheimer's disease, prevention in advance is the best way, which can be achieved by keeping good eating habits, using more brains, making people feel happy and insisting on physical exercise.

Develop good eating habits and achieve "three orientations, three highs, three lows and two trainings". "Three determinations" means timing, quantification and quality assurance, "three highs" means high protein, high unsaturated fatty acids and high vitamins, "three lows" means low fat, low calorie and low salt, and "two abstinence" means quitting smoking and drinking. At the same time, we should also ensure adequate sleep in our work and rest. Because lack of sleep will cause the accumulation of amyloid β-protein.

Often using your brain to do interesting things can exercise the reaction speed of brain cells (such as playing Sudoku and video games); Hobbies can activate brain cells; Thinking about new things can stimulate brain activity, which is an effective measure to delay brain aging.

Communicating with others through group activities can not only maintain good interpersonal relationships and maintain a happy mood, but also rely on beneficial external stimuli to delay the decline of brain function.

Insisting on physical exercise can release bad emotions, keep the brain functioning normally and delay the aging of brain nerve cells.

reference data

1, World Alzheimer's Day | Care for the elderly, please pay attention to Alzheimer's disease.

2. Wikipedia: Alzheimer's disease

3. The relationship between Alzheimer's disease and intestinal flora.

4. The fight against Alzheimer's Harmo's disease is a protracted war.

5, popular science | Be careful! Alzheimer's disease is more than just a bad memory.

6. Research progress on the correlation between intestinal flora and Alzheimer's disease.

7. The role of intestinal flora in the pathogenesis of Alzheimer's disease.

8. Everyone's health: How to prevent Alzheimer's disease when people get old?

Mengen Biology: Rebuilding a Green Future with Microorganisms