A grant of nearly $500,000 has been awarded to a UNSW Sydney scientist to investigate how the relationship between gut and brain health is impacted by chemotherapy, in young adults with cancer.

Dr Caitlin Cowan, a microbiome-gut-brain relationship expert, returned to the university last year as an NHMRC research fellow and a Superstar of STEM, and will now be exploring an important, under-studied question in cancer science.

“Essentially, we’re trying to understand cognitive impacts of chemotherapy, known as “chemobrain”, in young people, which are pretty understudied, despite the fact that cognitive issues can be more problematic during that stage of life,” says Dr Cowan.

In particular, Dr Cowan will be investigating whether the gut-brain axis has any role to play in this. “We know that the bugs that live in our guts (our microbiome) can influence the success of certain chemo drugs, and there’s evidence in animal models that the microbiome also influences side effects of the drugs, including chemobrain,” says Dr Cowan. “But we’re planning a study that will answer this question more definitively, using samples from young people undergoing chemo.”

The impact of “chemobrain”

Cancer survivors have to deal with a range of side effects during, and for a long time after, cancer treatment and some of the most harmful and long-lasting side effects are those affecting the brain.

These side effects include cognitive changes (including memory loss, difficulty paying attention and learning difficulties) and psychological changes (for example low mood and anxiety).

Understanding this impact is especially important for adolescents and young adults (AYAs) because their brains are still developing, making them potentially more vulnerable to brain-related side effects.

“If you’re a teenager you still have lots of study for school, university, and learning at work to do, not to mention all the other changes you’re likely going through,” says Dr Cowan. “So if you’re suffering from brain fog, each of those steps will be harder and probably hold you back from reaching your full potential.”

Currently, there are very limited neuropsychology or clinical psychology services available via the NSW public health system, which makes it difficult for AYAs to access help for this issue and means that the extent of the problem is not well understood. Further, little is known about what causes brain-related side-effects.

“Our research will address this problem, helping us to account for why some AYAs are more vulnerable. This information will help tailor services and support to ensure that our limited clinical resources are used most effectively,” says Dr Cowan. 

A diagram explaining how chemotherapy can cause cognitive changes. Photo provided to UNSW

What will the research be looking at?

Dr Cowan aims to better understand how cancer treatment affects the brain of young patients. The team tackling this research will test brain function and psychological wellbeing in patients and healthy AYAs using questionnaires and standardised tests of attention, learning and memory.

“We will then analyse blood and stool samples to identify markers related to symptoms. We will also use these samples in laboratory models to better understand whether gut bacteria can cause the symptoms,” says Dr Cowan.  

“Finally, we will ask young people about their experiences so that we can eventually develop useful treatments to reduce the impact of cancer therapy on the brain.”