Is it possible that there is a connection between an individual’s gut microbiota and the ability to fight off gastrointestinal (GI) cancer? Findings from a preliminary research study performed by researchers in South Korea suggest that a link between the two may exist and that fecal microbiota transplants (FMTs) may enhance the efficacy of immunotherapies for GI cancer patients.
The proof-of-concept clinical trial, conducted at the Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea, analyzed how an FMT could help 13 patients with metastatic solid tumors that were resistant to the anti-PD-1 antibody drug known as nivolumab (Opdivo). Anti-PD-1 drugs are immunotherapies that help treat cancer by improving an individual’s immune response against cancer cells.
Four of the trial participants had gastric cancer, five had esophageal cancer, and the remaining four had hepatocellular carcinoma. The patients were given a colonoscopy to implant the FMTs. The recipients also received antibiotics to reduce the response of their existing microbiotas.
The FMT donors also had gastric cancer, esophageal cancer, or hepatocellular carcinoma. Prior to donating their fecal matter, the donors experienced complete or partial response to the anti-PD-1 drugs nivolumab or pembrolizumab (Keytruda) for at least six months after receiving initial treatments.
“This research highlights the complex interplay between beneficial and detrimental bacteria within the gut microbiota in determining treatment outcomes,” co-senior study author Hansoo Park, MD, PhD, Assistant Professor, Biomedical Science and Engineering, Gwangju Institute of Science and Technology, told The ASCO Post. “While the connection between gut microbiota and immune response to cancer therapy has been a growing area of interest, our study provides concrete evidence and new avenues for improving treatment outcomes in a broader range of cancers,” he added. Further studies may confirm the need for microbiome testing by clinical laboratories to guide clinicians treating patients with colon cancers. (Photo copyright: Gwangju Institute of Science and Technology.)
Surprising Results
Fecal material for an FMT procedure combines donated fecal matter with a sterile saline solution which is then filtered to produce a liquid solution. That solution is then administered to the recipient via colonoscopy, upper GI endoscopy, enema, or an oral capsule. The solution may also be frozen for later use.
Upon analyzing the recipients, the scientists found that six of the patients (46.2%) who had experienced resistance to immunotherapies for their cancers, benefitted from the FMTs.
“Both donors were long-lasting, good responders to anti-PD-1 inhibitors, but because we did not yet know the causative bacteria responsible for the [FMT] response, we could not predict whether the treatment would be effective,” she added.
The researchers also determined that the presence of a bacterial strain known as Prevotella merdae helped to improve the effectiveness of the FMTs, while two strains of bacteria—Lactobacillus salivarius and Bacteroides plebeius (aka, Phocaeicola plebeius)—had a detrimental impact on the transplants.
Challenges to Widespread Adoption of FMTs
The researchers acknowledge there are challenges in widespread acceptance and use of FMTs in treating cancers but remain optimistic about the possibilities.
“Developing efficient and cost-effective methods for production and distribution is necessary for widespread adoption,” Sook Ryun Park told The ASCO Post. “Addressing these challenges through comprehensive research and careful planning will be essential for integrating FMT into the standard of care for cancer treatment.”
More research and clinical trials are needed before this use of FMTs can be utilized in clinical settings. However, the study does demonstrate that the potential benefits of FMTs may improve outcomes in patients with certain cancers. As this happens, microbiologists may gain a new role in analyzing the microbiomes of patients with gastrointestinal cancers.
“By examining the complex interactions within the microbiome, we hope to identify optimal microbial communities that can be used to enhance cancer treatment outcomes,” Hansoo Park told The ASCO Post. “This comprehensive approach will help us understand how the microbial ecosystem as a whole contributes to therapeutic success.”
GI pathologists will be interested in how the Endoculus device uses tank-like treads to traverse the gastrointestinal tract, where it can capture images and perform biopsies
Gastroenterologists (GI) may soon gain a useful new tool for use in gathering both biopsies and diagnostic information when examining the gastrointestinal tract. Ongoing development of a new robotic device promises both capabilities using technology that will be of interest to GI pathologists and clinical laboratory scientists.
The minute robotic device uses tank-like treads to traverse the colon. While there, it can capture live images and perform biopsies under the control of a gastroenterologist. The researchers believe the robotic technology will benefit GIs performing the colonoscopies as well as the pathologists called upon to analyze biopsies.
“Currently, endoscopy consists of a gastroenterologist using a semi-rigid, long rope-like device and endoscope to propel through your colon manually,” Gregory Formosa, PhD (above) a member of the AMTL team that developed Endoculus, said in a YouTube video describing the device. “We think that a robotic capsule endoscope can replace conventional endoscopes by making them faster, safer, and more robust than a human operator can do currently with traditional techniques,” he added. (Photo copyright: University of Colorado.)
AMTL researcher Gregory Formosa, PhD, said the team’s goal is to “have a capsule-sized robot that can actively traverse [a patient’s] entire gastrointestinal tract and send out diagnostics in real time, as well as autonomously navigate itself to localize problematic areas within [the] intestinal tract.”
Formosa noted that colorectal cancer is “the third-most fatal and diagnosed cancer in the United States.” But if caught at an early stage, these cancers are “95% treatable,” he added. “So, if we can get people screened early, we definitely can reduce the fatality rate of colorectal cancers significantly.”
Currently about the size of a C battery, Endoculus (above) is a “fully packed medical device, complete with a camera, an air pump for inflating the colon, a water pump for cleaning, and a tool port for holding biopsy snares,” states a University of Colorado news story, titled, “A Robot May One Day Perform Your Colonoscopy.” (Photo copyright: University of Colorado.)
How Endoculus Works
One key to the device are the four treads, which are designed for traction on digestive tissue.
“You have to forget about everything you know from a locomotion standpoint because driving around inside the body is very different than driving around in a car,” said Rentschler in the University of Colorado news story. “The environment is highly deformable. It’s very slick. There are sharp peaks that you have to go over.”
The university news story noted the current availability of ingestible “pill cams” that can take photos as they travel through the digestive system. But once swallowed, their movements cannot be controlled.
“For our robots to be able to reach those regions that [can be] reached with a pill-cam—but also be able to stop and look around—that could be a big paradigm shift in the way we view these procedures,” said Micah Prendergast, PhD, an AMTL research team member.
Could Biopsies Be Diagnosed In Situ with Endoculus?
The researchers currently view Endoculus as a potentially better way to perform conventional biopsies. But could it lead to bigger advancements?
“Researchers continue to develop devices to help various specialist physicians—in this case GIs—do more when treating patients,” said Dark Daily Publisher and Editor-in-Chief Robert Michel. “This device fits that description. It is designed to improve the ability of GIs to evaluate the colon. Not only does this device do that, but it can also collect a biopsy at sites of interest. In this way, it is a device that can be a benefit to pathologists who will analyze the biopsy.
“With improvements in digital cameras and associated AI-powered analytical tools, the day might not be far off when a device like this can use the camera and artificial intelligence to diagnose the tissue of interest in situ,” he added. “This might create the opportunity for pathologists to be present in the exam room during the procedure, or even viewing the images remotely.
“Not only would that eliminate the need to collect a tissue specimen that must then be sent to a pathology lab, but it would create a new opportunity for pathologists to add value to patient care while shortening the time to diagnosis for the tissue of interest during these procedures,” Michel noted.
