What if your lung cancer doctor could get a huge amount of information about your health, how you might respond to different treatments, and possibly even be able to tell you the best diet for your specific needs, all based on a simple test that involves no needles, no surgery, no special preparation, just a small sample… of your stool. That’s the potential of studying the gut microbiome. Find out why some of LCFA’s Young Investigators are so excited about including the gut microbiome in the fight against lung cancer.

Getting over the ick factor: Talking about poop

Our bodies are teeming with microorganisms. Only 10% of the 100 trillion cells in us are human – the rest are microbes. Most of these microorganisms are found in the gastrointestinal tract with the highest concentrations found in our large intestine or gut.

“So the microbiome is the collection of organisms that live on you and in you. So you have about 10 trillion human cells on your body and roughly the same number of microbes, either bacteria, viruses, fungi, and other things. They live all over, but mostly in your gut in terms of concentration. And they’ve got something like a hundredfold more genes than you do for being able to degrade different carbohydrates, make different molecules. And we’re just starting to understand how they affect many different things, including cancer.” says Dr. Daniel Spakowicz.

The immune effect of the microbiome on lung cancer may be due to specific compositions of both lung and gut microbiomes. Three of LCFA’s Young Investigator grant recipients are continuing this study of gut microbiome and lung cancer, Dr. Jarushka Naidoo, Dr. Daniel Spakowicz, and Dr. Zoltan Lohinai.

Gut microbiome and immunotherapy

The composition of bacteria in the gut may also have a strong influence on how well advanced lung cancer patients respond to immunotherapy. Finding a positive correlation will allow doctors to use the gut microbiome as a biomarker to predict how well future patients may respond to treatment. It also raises the possibility of modifying the patient’s gut bacteria before therapy with the expectation of improved effectiveness of immunotherapy.

“We know that certain cells that line the gut are very important for modifying or changing our immune response. And now that we have new treatments that harness our immune response to fight cancers such as lung cancer treatments called immunotherapy, it becomes very important to understand why some immune responses are the way they are in certain patients. And can we make those immune responses stronger for some patients or change the immune responses so that perhaps patients who develop the side effects of these immune related treatments don’t happen as severely or as often.” – Dr. Jarushka Naidoo

The 3rd Revolution: Gut microbiomes in lung cancer treatment

According to Dr. Jarushka Naidoo there have been two revolutions in lung cancer: the genomic revolution and the immunotherapy revolution.

The genomic revolution happened about 10 to 15 years ago with the discovery of several genomic biomarkers. This discovery then led to several targeted therapies and understanding that lung cancer is not all created equal. And that some patients may have cancers that do well with special targeted pill therapies that may shrink those cancers.

And then from there came the immunotherapy revolution, where the understanding came that maybe different lung cancers might respond to immunotherapy – using the body’s immune system to fight cancer.

“I think, and I hope, that our projects are the start of the microbial revolution. That we will understand that our microbiome is somehow intrinsically related to perhaps how lung cancer develops, why lung cancer grows, and how long cancer is treated. And we may be able to understand how to harness that microbial intervention to help patients and pave the way for the future.” – Dr. Jarushka Naidoo

Understanding The Effects of Medications on the Gut Microbiome

It often takes months or even years, to get the correct diagnosis of lung cancer. And for many people, the diagnosis happens only after medications for various respiratory ailments didn’t work. These medications seem to affect the microbiome, such as antibiotics or steroids. So it’s frequently treated with antibiotics that might alter the long-term outcomes of immunotherapy according to Dr. Lohinai.

“So physicians should think, right, days, or weeks or months ahead of the treatment, even we don’t know what treatment the patient will get by immunotherapy, but we have to see what medications we administer months before the treatment. I think it’s recommended, there is no evidence, but there is a lot of data that would say that the treatment with antibiotics and steroids should be as the lowest dose. And should be lowered to the minimum to increase the outcomes of some patients because these medications can alter the outcomes of immunotherapy.” – Dr. Zoltan Lohinai

The Future is Gut Microbiomes, Icky As it May Be

Discovering whether a patient’s gut health plays a role in determining the benefits – or, conversely, the harm – of immunotherapy treatment. Until now, there has been scant research connecting gut health with both cancer diagnoses and treatment protocols.

The LCFA Young Investigator Grants are designed to help researchers look at lung cancer in new and creative ways, always with an eye toward finding better treatments that help people live longer and healthier lives.

“The microbiome is certainly a very influential factor in those who get cancer, those who respond or don’t respond to immunotherapy or chemotherapy…. And we don’t really know the mechanism, but we’re getting a whole lot better and a whole lot closer to understanding that mechanism. And it really could give us some novel insights, novel therapy targets, novel ways of improving outcomes.” – Dr. David Carbone

Familiarizing the practicing clinician with the experimental methods used to generate the information that will likely impact the field of lung cancer, helping to understand gut microbiome in lung cancer treatment.

As Dr. Daniel Spakowicz says, “in general, collecting somebody’s poop before they start a treatment is not a commonly done practice right now, and it tends to be sort of icky to some people. And that’s the essence of what we want to change.”