Antibiotic treatment slows the development of Alzheimer's symptoms
A new study by US researchers has shown that long-term antibiotic treatment can slow the development of Alzheimer's symptoms.
In Germany alone, around 1.2 million people suffer from dementia, the majority of them from Alzheimer's. There are around 47 million dementia patients worldwide. Although the disease has not yet been curable, it can be delayed with medication in the early stages. And only recently have researchers reported that light and sound therapy can also slow Alzheimer's. A new study has now shown that long-term antibiotic treatment can slow the development of the disease.
Antibiotic treatment can slow the growth of amyloid plaques
According to a report on the Medical News Today portal, scientific studies have shown that antibiotic treatment affects the intestinal bacteria in mice to such an extent that it slows the growth and development of Alzheimer's, but only in males.
The study conducted at the University of Chicago showed how long-term use of antibiotics can reduce inflammation and slow the growth of amyloid plaques in male mice.
Amyloid plaques are a characteristic that is specific for Alzheimer's disease. They disrupt the function of the brain cells and lead to the symptoms of Alzheimer's disease.
The results of the researchers were published in the journal "Journal of Experimental Medicine".
Gut bacteria affect various diseases
The research team already knew that the community of bacteria living in the gastrointestinal tract - the intestinal microbiome - can affect a wide range of diseases.
"Recent evidence suggests that gut bacteria can play an important role in various neurological disorders, including autism spectrum disorders, multiple sclerosis, Parkinson's, and Alzheimer's," said Sangram S. Sisodia, director of the Center for Molecular Neurobiology at the University of Chicago.
Alzheimer's disease is characterized by the formation of amyloid plaques and the activation of immune cells in the brain known as microglia.
These cells can help clear amyloid plaques, but their activation can also make the disease worse by causing neuroinflammation (inflammation in the brain).
Alzheimer's patients have changes in the gut microbiome, and Sisodia and colleagues have previously reported that gut bacteria can affect the development of these symptoms in rodents.
Long-term antibiotic treatment limited the formation of amyloid plaques and reduced microglia activation in male but not female mice.
"Although our published studies on the role of the gut microbiome in the formation of amyloid plaques were convincing, they were limited to a single strain of mouse," said Sisodia.
No effect on female mice
In the new study, the scientists therefore investigated the effect of antibiotics on another mouse model.
Long-term treatment with an antibiotic cocktail again reduced the formation of amyloid plaques in male mice, but had no effect on female animals.
Antibiotic treatment also appeared to alter the activation of microglia in male mice.
To prove that these improvements in Alzheimer's symptoms were caused by changes in the gut microbiome, the researchers transplanted feces from untreated mice to animals treated with antibiotics.
This procedure restored the gut microbiome and caused an increase in amyloid plaque formation and microglial cell activation.
But why do changes in the gut microbiome only affect male mice? Sisodia and colleagues discovered that long-term antibiotic treatment changed the gut bacteria in male and female mice in different ways.
The changes in the microbiome of female mice caused her immune system to increase the production of several pro-inflammatory factors that could affect the activation of microglia.
"Our study shows that antibiotic-mediated intestinal microbiome disorders have selective, gender-specific influences on the formation of amyloid plaques and microglial activity in the brain," said Sisodia.
"We now want to investigate whether these results are due to changes in a certain type of bacteria." (Ad)