Studies related to microbiome were presented today at the American Society of Hematology (ASH) annual conference Dec. 7 to 10 in San Diego

Scientists and physicians with City of Hope^®, one of the largest and most advanced cancer research and treatment organizations in the U.S., whose Los Angeles comprehensive cancer center is ranked among the nation’s top 5 cancer centers by U.S. News & World Report, presented new research on high-fiber dietary interventions for patients at risk for graft-versus-host-disease (GVHD) and myeloma at a press briefing today at this year’s ASH conference, taking place Dec. 7 to 10 in San Diego.

Highlighting City of Hope’s leadership in treatment and research of blood cancers and related diseases, its experts will present or contribute to more than 104 sessions, including 35 oral sessions, 56 poster sessions, 13 scientific symposia, scientific workshops and educational programs.

“City of Hope continues to be at the forefront of innovative, leading-edge research on blood cancers,” said Marcel van den Brink, M.D., Ph.D., president of City of Hope Los Angeles and City of Hope National Medical Center, and Deana and Steve Campbell Chief Physician Executive Distinguished Chair. “City of Hope’s leadership in the microbiome spans from basic to clinical research and includes studies such as these focused on the crucial role a healthy gut microbiome can have in helping patients heal.”

In addition, City of Hope’s microbiome program is a leading-edge, multidisciplinary research program dedicated to expanding understanding of microbiome dynamics using high-efficiency, best-in-class standards and state-of-the-art science.

City of Hope microbiome research highlighted in ASH press briefings includes:

Reducing Risk of GVHD Through High-Fiber Diet

When patients undergo a bone marrow or stem cell transplant from a donor for blood cancer treatment, they run the risk of developing GVHD, the most common complication from the procedure. During GVHD, donated cells attack the patient’s own tissues and can cause a variety of symptoms ranging from mild to life-threatening.

A study (Abstract No. 259 Increased Fiber Intake Results in Better Overall Survival and Lower GI-aGVHD in Allo-HCT Recipients and Pre-Clinical Gvhd Models) led by Jenny Paredes, Ph.D., City of Hope staff scientist, suggests that consuming a high-fiber diet after transplantation could reduce the risk of developing GVHD by supporting a healthy gut microbiome. The microbiome is a collection of all microbes — bacteria, fungi and viruses — that are naturally found in a person’s body.

“We’ve known that dietary fiber plays a beneficial role regulating the immune system via the gut in healthy populations,” said Dr. Paredes. “Our work now shows this may be true for transplant patients, too, and that dietary restrictions postprocedure that might result in low fiber intake could be counterproductive.”

Patients with GVHD, who have similar symptoms to people with irritable bowel syndrome (IBS) and a depleted immune system, are often advised to refrain from eating raw vegetables and strawberries, blueberries and other fruits without a removable peel for about 40 days after transplantation. The low-fiber diet, which includes more cooked foods, can reduce a patient's exposure to harmful bacteria and reduce symptoms.

By analyzing the diets of 173 patients undergoing transplantation — from 10 days before the procedure until 30 days after — Dr. Paredes and a team of researchers found that a high-fiber diet was associated with a reduced risk of acute GVHD in the lower gastrointestinal tract and better overall survival. A low-fiber diet was linked with less diversity in the gut microbiome, which can make people vulnerable to infection.

The researchers also found that patients with higher fiber intake had higher levels of gut microbes that produce butyrate, a product of dietary fiber fermentation which has been shown in previous studies to protect against GVHD.

To further investigate the mechanisms involved in these effects, Dr. Paredes and her collaborators also did a preclinical companion study using mouse models of GVHD. After receiving a stem cell transplant, mice fed with a high-fiber diet of cellulose, which cannot be digested without the help of gut microbiota, had a reduced rate of death from GVHD and other markers of reduced GVHD risk, as well as higher microbial diversity and butyrate concentrations in the gut.

“While high-fiber diets may not be appropriate for everyone, this study shows the exciting potential for high fiber to play a role in reducing GVHD risk in transplant patients,” Dr. Paredes said. “We look forward to designing a nutritional intervention for clinics that can help diversify the gut microbiome through food choice and improve outcomes for people receiving bone marrow or stem cell transplants.”

The study, done in collaboration with investigators at Memorial Sloan Kettering Cancer Center, was supported by funding from the National Cancer Institute and private foundations.

Plant-Based Diet May Delay Disease Progression in Precancerous Plasma Cell Disorders

Diet and obesity are known to play a role in many diseases. But for people with monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM), two precursors to the blood cancer myeloma, poor diet quality low in plant foods and elevated body mass index, along with insulin resistance and inflammation, have been implicated in the progression of precursor plasma cell disorders to cancer.

To test whether a nutritional intervention consisting of a high-fiber, plant-based diet could impact these modifiable risk factors and delay the onset of cancer, a team of researchers enrolled 20 participants with MGUS or SMM and an elevated BMI in a pilot study (Abstract No. 671 A High-Fiber Dietary Intervention (NUTRIVENTION) in Precursor Plasma Cell Disorders Improves Biomarkers of Disease and May Delay Progression to Myeloma). Participants received a controlled diet for 12 weeks and health coaching for 24 weeks.

Urvi A. Shah, M.D., M.S., of Memorial Sloan Kettering Cancer Center, the trial’s principal investigator, will present the study at ASH.

“We saw an improvement for many risk factors, including weight loss, reduced insulin resistance, better microbiome profiles and decreased inflammation,” said Dr. van den Brink, the study’s senior author.

The intervention was also safe, feasible and improved quality of life for participants, two of whom were observed to have an improvement that slowed trajectory of long-term disease progression.

Additional studies by collaborators with the Laboratory of Microbiology at IRCCS Ospedale in San Raffaele, Milano, Italy, and done in SMM mouse models who were fed high-fiber diets or standard diets, found that the nutritional intervention delayed progression to myeloma. In fact, 44% of mice in the interventional arm did not progress to myeloma during the study period whereas all mice in the standard diet arm did progress.

“This is the first interventional clinical trial to show that plant-based, high-fiber diets can have a beneficial effect in delaying the progression of a blood cancer,” Dr. van den Brink said. “Our findings support further research into the role nutrition can play in changing the body’s immune response for patients with plasma cell disorders.”

The study, done in collaboration with Dr. Shah and other investigators, was supported by funding from the National Cancer Institute, Allen Foundation Inc., Paula and Rodger Riney Foundation, American Society of Hematology, Solomon Fund, AIRC Foundation for Cancer Research, and The Leukemia & Lymphoma Society.

About City of Hope

City of Hope's mission is to make hope a reality for all touched by cancer and diabetes. Founded in 1913, City of Hope has grown into one of the largest and most advanced cancer research and treatment organizations in the U.S., and one of the leading research centers for diabetes and other life-threatening illnesses. City of Hope research has been the basis for numerous breakthrough cancer medicines, as well as human synthetic insulin and monoclonal antibodies. With an independent, National Cancer Institute-designated comprehensive cancer center that is ranked top 5 in the nation for cancer care by U.S. News & World Report at its core, City of Hope’s uniquely integrated model spans cancer care, research and development, academics and training, and a broad philanthropy program that powers its work. City of Hope’s growing national system includes its Los Angeles campus, a network of clinical care locations across Southern California, a new cancer center in Orange County, California, and cancer treatment centers and outpatient facilities in the Atlanta, Chicago and Phoenix areas. City of Hope’s affiliated group of organizations includes Translational Genomics Research Institute and AccessHope™. For more information about City of Hope, follow us on Facebook, X, YouTube, Instagram and LinkedIn.

View source version on businesswire.com: https://www.businesswire.com/news/home/20241207141306/en/