Research advances from the National Institutes of Health (NIH) Intramural Research Program (IRP) often make headlines. Read the news releases that describe our most recent findings:
BETHESDA, Md. (AP) — Sam Srisatta, a 20-year-old Florida college student, spent a month living inside a government hospital here last fall, playing video games and allowing scientists to document every morsel of food that went into his mouth.
From big bowls of salad to platters of meatballs and spaghetti sauce, Srisatta noshed his way through a nutrition study aimed at understanding the health effects of ultraprocessed foods, the controversial fare that now accounts for more than 70% of the U.S. food supply. He allowed The Associated Press to tag along for a day.
“Today my lunch was chicken nuggets, some chips, some ketchup,” said Srisatta, one of three dozen participants paid $5,000 each to devote 28 days of their lives to science. “It was pretty fulfilling.”
Examining exactly what made those nuggets so satisfying is the goal of the widely anticipated research led by National Institutes of Health nutrition researcher Kevin Hall.
“What we hope to do is figure out what those mechanisms are so that we can better understand that process,” Hall said.
Scientists at the National Institutes of Health (NIH) have leveraged artificial intelligence to transform a device designed to see tissues in the back of the eye into one sharp enough to make out individual cells. The technique provides imaging resolution that rivals the most advanced devices available and is cheaper, faster, and doesn’t require specialized equipment or expertise. The strategy has implications for early detection of disease and for the monitoring of treatment response by making what was once invisible now visible.
“AI potentially puts next-generation imaging in the hands of standard eye clinics. It’s like adding a high-resolution lens to a basic camera.” said Johnny Tam, Ph.D., investigator at NIH’s National Eye Institute and senior author of the study report, which published in Communications Medicine.
Imaging devices, known as ophthalmoscopes, are widely used to examine the light-sensing retina in the back of the eye. A scanning laser ophthalmoscope is standard in eye clinics, but its resolution can only make out structures at the tissue level — things such as lesions, blood vessels, and the optic nerve head. Next-generation ophthalmoscopes enabled with adaptive optics — a technology that compensates for light distortion—can make out cellular features, providing greater diagnostic information. However, adaptive optics-enabled imaging is still in the experimental phase.
Comparison of the same patch of retina labeled with indocyanine green and visualized 3 different ways. A) Scanning laser ophthalmoscopy. B) AI-enhanced scanning laser ophthalmoscopy. C) Adaptive optics scanning laser ophthalmoscopy. Arrows highlight the same cell seen in different modalities.
Researchers uncover the cellular and molecular basis for sensing heat and inflammatory pain
Researchers at the National Institutes of Health (NIH) have discovered clues as to how our bodies turn sensations such as heat and touch into signals sent to the brain — and how these signals can be altered by inflammation to drive pain. The research focuses on the nerve cells in the skin that help us detect the location, intensity, and emotional quality of touch, known as somatosensory neurons. By combining advanced imaging techniques with detailed molecular analysis, the researchers explored how heat and touch activate different types of receptor cells in mice.
“To develop better treatments for pain, it’s critical that we deepen our understanding of the biology behind how sensory signals are received, transmitted, and ultimately perceived by the brain,” said Alex Chesler, Ph.D., co-author of the study and senior investigator at NIH. “Over the past few years, we developed a platform for watching sensation in action, revealing new details about the cells and molecules required and, in this study, how inflammation triggers pain.”
The research revealed how different types of cells were 'called into action' depending on whether the stimulus was innocuous, such as gentle warmth or touch, or noxious, meaning a stimulus strong enough to potentially cause damage to normal tissue. For example, heat and gentle touch were transmitted by entirely different types of cells. When the stimulus was more intense, the nerve cells began to overlap in their roles for transmitting the sensations of heat and pressure, providing an explanation for how cells detect and distinguish between innocuous and noxious stimuli.
NIH studies in animals show reserpine protects retinal-neurons necessary for vision, especially in females
New studies in rats suggest the drug reserpine, approved in 1955 for high blood pressure, might treat the blinding disease retinitis pigmentosa. No therapy exists for this rare inherited disease, which starts affecting vision from childhood. A report on the studies, conducted at the National Institutes of Health (NIH), published today in eLife.
“The discovery of reserpine’s effectiveness may greatly speed therapeutics for retinitis pigmentosa and many other inherited retinal dystrophies, which can be caused by one of more than a thousand possible mutations affecting more than 100 genes. Reserpine’s neuroprotective effect is independent of any specific underlying gene mutation,” said the study’s lead investigator, Anand Swaroop, Ph.D., senior investigator at NIH’s National Eye Institute.
Inherited retinal dystrophies cause degeneration of the retina, the light-sensing tissue at the back of the eye. Vision loss can be present at birth or develop later in early adulthood. Disease progression varies depending on the gene involved. Some genetic defects may be inherited as dominant, where a mutation in just one of the two copies of the gene (one each from the mother and father) is sufficient to cause vision loss. Other genetic defects are recessive, where both copies of a gene must carry a mutation to cause vision loss. Gene therapies to correct inherited retinal dystrophies are promising, but take a long time to develop, are gene specific, and are often quite expensive.
The preservation of rod photoreceptor structure is shown in these representative images involving female rats. Rod photoreceptors are immunostained with REEP6 (green). Rod photoreceptor inner segments are shorter in the control-treated rats (left) compared with those treated with reserpine (right).
NIH findings could lead to more efficient monitoring of twin pregnancies.
Twins—smaller at birth, on average, than singletons—start out smaller in pregnancy than was previously known, according to a study by researchers at the National Institutes of Health (NIH). The ultrasound study revealed that twins have less fat tissue and less muscle mass than singletons beginning at 15 weeks of pregnancy. If results are confirmed by additional research, the findings could provide information to guide physicians in monitoring and managing twin pregnancies.
Researchers analyzed data from previous ultrasound studies of fetal development in the uterus. Included in the analysis were 3D ultrasound scans of 2,604 singleton pregnancies and 315 twins. All twin pairs had individual placentas. Twin pairs who shared a placenta were not included in the analysis.r
Beginning at 15 weeks, thigh volumes were significantly smaller for twins than singletons. Twins had smaller fat and lean thigh volumes than singletons. They also had a lower thigh fat to lean ratio than singletons, having proportionately 2.7 to 4.2 percent less fat from 15 to 37 weeks. Previous studies of twin growth in the womb involved 2D ultrasound scans and had documented decreased twin growth relative to singletons only in the early third trimester (28 to 40 weeks).
NIH trial shows new form of TIL therapy effective against colon, rectum, pancreas, and bile duct tumors
A new form of tumor infiltrating lymphocyte (TIL) therapy, a form of personalized cancer immunotherapy, dramatically improved the treatment’s effectiveness in patients with metastatic gastrointestinal cancers, according to results of a clinical trial led by researchers at the National Institutes of Health (NIH). The findings, published April 1, 2025 in Nature Medicine, offer hope that this therapy could be used to treat a variety of solid tumors, which has so far eluded researchers developing cell-based therapies.
This form of therapy involves identifying and selecting immune cells (TILs) that are found in the tumor that specifically recognize and attack a patient’s tumor cells. Next, scientists grow those TILs into large quantities in the laboratory before they are finally administered to the patient.
Patients in the clinical trial, who had a variety of gastrointestinal tumors, also received the immune checkpoint inhibitor pembrolizumab (Keytruda) to help further boost their immune response. The result was nearly 24 percent of patients treated with selected TILs plus pembrolizumab had a substantial reduction in the size of their tumors, compared with 7.7 percent of patients who received selected TILs without pembrolizumab. Patients treated with TILs that had not been selected for anti-tumor activity had no tumor shrinkage.
“We're seeing the first extension of cellular therapy with TILs into the common solid cancers,” said Steven A. Rosenberg, M.D., Ph.D., the study’s lead investigator at NIH’s National Cancer Institute. “We see a little crack in the solid wall of cancer by using cell-based immunotherapy for the common solid cancers, and we think we have ways to open that crack even further.”
Image of an MRI scan showing shrinkage of multiple liver metastases from a patient with rectal cancer
Jayanta “Jay” Bhattacharya, M.D., Ph.D., took office today as the 18th Director of the National Institutes of Health (NIH). President Trump nominated Dr. Bhattacharya for the position on Nov. 26, 2024, and the U.S. Senate confirmed him on March 25, 2025.
As Director, Dr. Bhattacharya will oversee the nation’s medical research agency. Dr. Bhattacharya will play an instrumental role in shaping the agency’s activities and outlook and ensuring they align with the President’s Make America Healthy Again Commission.
"Under Dr. Bhattacharya’s leadership, NIH will restore its commitment to gold-standard science,” said HHS Secretary Robert F. Kennedy, Jr. “I’m excited to work with Dr. Bhattacharya to ensure NIH research aligns with our Administration’s priorities — especially tackling the chronic disease epidemic and helping to Make America Healthy Again.”
“Chronic diseases such as cancer, heart disease, diabetes and obesity continue to cause poor health outcomes in every community across the United States. Novel biomedical discoveries that enhance health and lengthen life are more vital than ever to our country’s future,” said Dr. Bhattacharya. “As NIH Director, I will build on the agency’s long and illustrious history of supporting breakthroughs in biology and medicine by fostering gold-standard research and innovation to address the chronic disease crisis.”
NIH study finds number of steps taken daily may be more important for cancer risk than the intensity of activity
In a prospective cohort study of more than 85,000 adults in the United Kingdom, researchers at the National Institutes of Health (NIH) and University of Oxford found that individuals who engaged in light- and moderate-to-vigorous-intensity daily physical activity had a lower risk of cancer than individuals who were more sedentary. The findings, published March 26, 2025, in British Journal of Sports Medicine, are among the first to evaluate the cancer risk reduction associated with light intensity activities such as doing errands and performing household chores.
Previous studies have shown an inverse association between physical activity and cancer risk, but most of these studies relied on self-reported questionnaires, which may not accurately capture the intensity of different activities. Earlier studies that used objective measures were focused on higher-intensity physical activity. In the new study, led by researchers from NIH’s National Cancer Institute, participants in the UK Biobank study (median age of 63) wore wrist accelerometers that tracked total daily activity, activity intensity, and daily step count over a period of one week. The researchers then looked at the relationship between the daily averages and incidence of 13 cancer types, including breast and colorectal cancer, previously associated with physical activity.
After a mean follow-up of 5.8 years, 2,633 participants had been diagnosed with one of the 13 cancer types. Individuals with the highest total amount of daily physical activity had a 26 percent lower risk of developing cancer than individuals who had the lowest amount of daily physical activity. The researchers also explored the impact of replacing daily sedentary time with light- and moderate-to-vigorous-intensity physical activity and found that this shift was associated with a reduced risk of cancer. The associations between physical activity and cancer risk remained even after researchers adjusted for demographic factors, lifestyle factors, body mass index (BMI), and other health conditions.
Treatment shows potential to slow the progression of human degenerative eye diseases, including retinitis pigmentosa
Researchers at the National Institutes of Health (NIH) have developed eye drops that extend vision in animal models of a group of inherited diseases that lead to progressive vision loss in humans, known as retinitis pigmentosa. The eye drops contain a small fragment derived from a protein made by the body and found in the eye, known as pigment epithelium-derived factor (PEDF). PEDF helps preserve cells in the eye’s retina. A report on the study is published in Communications Medicine.
“While not a cure, this study shows that PEDF-based eye drops can slow progression of a variety of degenerative retinal diseases in animals, including various types of retinitis pigmentosa and dry age-related macular degeneration (AMD),” said Patricia Becerra, Ph.D., chief of NIH’s Section on Protein Structure and Function at the National Eye Institute and senior author of the study. “Given these results, we’re excited to begin trials of these eye drops in people.”
Model of PEDF protein alongside the smaller, modified versions of it used in the IRP study.
Researchers at the National Institutes of Health (NIH) have determined that dermatitis resulting from topical steroid withdrawal (TSW) is distinct from eczema and is caused by an excess of an essential chemical compound in the body. Scientists from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) identified treatments that could be studied in clinical trials for the condition based on their potential to lower levels of the chemical compound — called nicotinamide adenine dinucleotide (NAD+), a form of vitamin B3. The findings were published today in the Journal of Investigative Dermatology.
Dermatitis is characterized by inflammation, itching, or burning sensations on the skin, and can result from various conditions including TSW and eczema. Eczema, also known as atopic dermatitis, is a common cause of dermatitis and affects 10 to 30% of children and 2 to 10% of adults each year in the United States. Topical steroids — specifically glucocorticoids or topical corticosteroids — have long been used as a first-line treatment for dermatitis caused by eczema because the drugs are safe, effective, easy to apply, and considered well-tolerated.
Some people experience dermatitis after using topical steroids for prolonged periods of time and then stopping — a condition called TSW. Diagnosing and treating this condition is difficult because TSW is not well understood. Symptoms include skin redness, burning sensations, skin heat (thermal dysregulation), itching and peeling, which can even occur on parts of the body where topical steroids were not applied. As TSW and eczema have similar symptoms, it has been difficult to distinguish the two disorders.
Hand and wrist of a participant in the pilot study before (left) and after (right) treatment of topical steroid withdrawal symptoms with berberine, a mitochondrial complex I-blocking drug.
NIH study reveals key players underlying disease onset and repair
Using an animal model of multiple sclerosis (MS), researchers at the National Institutes of Health (NIH) have created a four-dimensional brain map that reveals how lesions similar to those seen in human MS form. These findings, published in Science, provide a window into the early disease state and could help identify potential targets for MS treatments and brain tissue repair.
The researchers, led by postdoctoral fellow Jing-Ping Lin, Ph.D., and senior investigator Daniel S. Reich, M.D., Ph.D., both at NIH’s National Institute of Neurological Disorders and Stroke (NINDS), combined repeated MRI imaging with brain-tissue analysis, including gene expression, to track the onset and development of MS-like lesions. They uncovered a new MRI signature that can help detect brain regions at risk for damage weeks before any visible lesions occur. They also identified “microenvironments” within affected brain tissue based on observed patterns of neural function, inflammation, immune and support cell responses, gene expression, and levels of damage and repair.
“Identifying the early events that occur after inflammation and teasing apart which are reparative versus which are damaging, can potentially help us identify MS disease activity sooner and develop treatments to slow or stop its progression,” said Dr. Reich.
