Stephen Hawking was a renowned physicist and author, who was known for advancing the understanding of the origin and nature of the universe.

However, he faced an incredibly debilitating condition called amyotrophic lateral sclerosis (ALS) which rendered him unable to move or speak. Despite this, he continued to work and communicate through a special computer interface, until his death in 2018.

ALS is a neurodegenerative disease that affects the nerve cells responsible for muscle control.

As the disease progresses, these cells deteriorate and eventually die, leading to paralysis of the muscles throughout the body, including those that control speech, breathing and swallowing. Unfortunately, there is currently no cure for ALS, and treatment is focused on managing symptoms to improve the quality of life for people living with the disease.

The Gut-Brain Axis and ALS

One emerging area of ALS research is the gut-brain axis, which refers to the communication pathway between the gut microbiome – the collection of microorganisms that live in our digestive system – and the brain.

The gut microbiome is critical for maintaining the health of our digestive and immune system, and has also been linked to a variety of health conditions, including anxiety, depression and autism. Recent studies have also shown that the gut microbiome may play a role in the development and progression of ALS.

In a study published in 2021 in the journal Neurobiology of Disease, researchers found that mice with ALS had alterations in their gut microbiome composition compared to healthy mice.

In particular, they found a decrease in the abundance of a type of gut bacteria called Akkermansia muciniphila, which is known for its anti-inflammatory properties and has been associated with improved outcomes in other neurodegenerative diseases such as Parkinson’s and Alzheimer’s.

The researchers then tested whether supplementing the mice with this bacteria could improve their symptoms.

They found that mice that received Akkermansia muciniphila had improved muscle strength and coordination compared to those that did not receive the bacteria. Additionally, they found that the bacteria helped to reduce the levels of inflammation and oxidative stress in the mice, which are two key drivers of ALS progression.

How Bacteria Can Help

The study on mice with ALS is just one example of the potential for bacteria and other microorganisms to help alleviate symptoms of neurodegenerative diseases.

Currently, there are several ongoing clinical trials examining the effects of fecal microbiota transplantation (FMT) – the transfer of fecal matter from a healthy donor to a patient – in people with ALS.

FMT has been shown to be effective in treating conditions such as Clostridioides difficile (C. diff) infections, which are caused by an overgrowth of harmful bacteria in the gut.

However, FMT is still considered an experimental treatment for ALS, and more research is needed to determine its safety and efficacy.

In addition to FMT, researchers are also exploring other ways to modify the gut microbiome in people with neurodegenerative diseases.

This includes the use of probiotics – live bacteria that are believed to have beneficial effects on health – and prebiotics – substances that promote the growth of beneficial bacteria in the gut.

Nutrition and the Microbiome

Another important aspect of the gut-brain axis is the role of nutrition in shaping the composition of the microbiome.

Recent studies have shown that certain types of diets can have a profound impact on the diversity and abundance of gut bacteria, which can influence health outcomes.

In a study published in 2021 in the journal Nature Communications, researchers found that a high fiber diet was associated with an increased abundance of gut bacteria that produce short-chain fatty acids (SCFAs), which are important for maintaining the health of the intestinal tract. Additionally, they found that the fiber-rich diet was associated with a decrease in the abundance of harmful gut bacteria, which are associated with inflammation and other health problems.

The role of nutrition in shaping the gut microbiome has important implications for people with ALS, who often have difficulty swallowing and may require a feeding tube for nutrition.

In a study published in 2020 in the journal PLoS One, researchers found that people with ALS who received a high-protein, high-fiber diet through a feeding tube had improvements in their microbiome composition compared to those who received a standard formula diet. Specifically, they found an increase in the abundance of bacteria that produce SCFAs, which has been associated with improved outcomes in other neurodegenerative diseases.

The Future of Microbiome Research in ALS

The gut-brain axis and the role of the microbiome in ALS is a rapidly evolving area of research, with new studies being published on a regular basis.

While there is still much to be understood about the mechanisms underlying the relationship between the gut microbiome and ALS, the research thus far has been promising.

As scientists continue to unravel the complex relationship between the gut microbiome and neurodegenerative diseases, it is becoming increasingly clear that there may be ways to modify the microbiome to improve symptoms and quality of life for people living with ALS. Whether through the use of probiotics, FMT, or dietary interventions, the potential for bacteria to play a role in alleviating ALS is an exciting avenue of research.