Laura Bukavina, MD, highlights study of urinary microbiome profiling

In this video, Laura Bukavina, MD, MPH, highlights the background and key findings from the study, “Genome-scale metabolic reconstruction of urinary microbiome: Pathway for personalized medicine,” which was presented at the 2025 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium in San Francisco, California. Bukavina is an assistant professor of urologic oncology and the translational science lead in GU oncology at Cleveland Clinic in Ohio.

Video Transcript:

Could you describe the background/rationale for this study?

We have evolved our thinking about what microbiome does. Our initial look into microbiome, a lot of studies have been focused on characterization studies, which means looking at what's in the urine, what's in the tissue to see if there's any particular bacteria that potentially might be driving the cancer. In this case, it would be bladder cancer. And now I think we're evolving how we think about it, particularly in the always changing paradigm of non-muscle invasive bladder cancer. We are now thinking potentially along the path of what's called metabolomics, which is, how is the microbiome in the tissue, in the urine actually metabolizing the drugs that we're giving into the bladder?

People don't often think of BCG as bacteria, but it is. It's a huge microbiome, and it is essentially giving patients UTI to cure cancer. Along that route, we know that patients microbiome can interfere with BCG. It can also interfere with the drugs that we're giving to them, including chemotherapy, gemcitabine. This particular abstract is focused on gemcitabine. We know based on some pancreatic studies that bacteria can use gemcitabine as its own food to break it down into less active metabolites. Along that path, what we wanted to do is to see if we can compute, based on someone's urine sample, how much of the present bacteria in the urine can metabolize that gemcitabine. The long-term goal is to provide patients what is called precision microbiome testing, which allows them to potentially shift their microbiome to bacteria that's not metabolizing gemcitabine, hopefully, with a long-term goal of improving the outcomes in some of the chemotherapy setting.

What were the key findings?

This was almost like a feasibility [study]. We took patients from the RETAIN trial. So, if people remember the RETAIN trial was a bladder preservation protocol from Fox Chase, when I was still at Fox Chase. We took the urine from those patients, and we tested to see if we can predict their gemcitabine metabolism capability. We were able to predict it pretty accurately. The next step, this was a feasibility. Do we have the computational network down? Do we have the ability to take the whole genome sequencing, combine it with not only the minimal residual disease criteria, but also if we can extract the microbiome data and predict the bugs that can break down chemotherapy. We were successful in that. The next step is prospective collection of urine samples in patients who are undergoing gemcitabine or gemcitabine/docetaxel, and validating this in our own cohort of those patients and connecting it to their response data.

This transcript was AI generated and edited by human editors for clarity.