Compared with a control group that also reduced calories but did not eat oats, those on the oat based plan saw a markedly greater improvement in their cholesterol levels. The reduction remained noticeable even six weeks later. Researchers also found that the diet changed the balance of bacteria in the gut. Substances produced by these microbes appear to play an important role in the health benefits linked to oats.

A Historic Diabetes Therapy Revisited

Oats have long been associated with metabolic health. In the early 20th century, German physician Carl von Noorden used oats to treat patients with diabetes, reporting strong results. “Today, effective medications are available to treat patients with diabetes,” explains Marie-Christine Simon, junior professor at the Institute of Nutritional and Food Science at the University of Bonn. “As a result, this method has been almost completely overlooked in recent decades.”

The volunteers in the new study did not have diabetes, but they did have metabolic syndrome, which raises the risk of developing the disease. This condition is defined by excess weight, high blood pressure, elevated blood sugar, and disorders of lipid metabolism. “We wanted to know how a special oat-based diet affects patients,” says Simon, who is also a member of the Transdisciplinary Research Areas “Life & Health” and “Sustainable Futures” at the University of Bonn.

300 Grams of Oatmeal Per Day

During the intensive phase, participants ate boiled oatmeal three times daily and could only add small amounts of fruit or vegetables. In total, 32 women and men completed the two day oat based intervention. Each person consumed 300 grams of oatmeal per day and cut their usual calorie intake roughly in half. The control group also reduced calories but did not consume oats.

Both groups experienced some benefits from eating fewer calories. However, the improvements were stronger among those who ate oats. “The level of particularly harmful LDL cholesterol fell by 10 percent for them — that is a substantial reduction, although not entirely comparable to the effect of modern medications,” stresses Simon. “They also lost two kilos in weight on average and their blood pressure fell slightly.”

Lowering LDL cholesterol is especially important for heart health. When LDL levels are too high, cholesterol can build up inside artery walls, forming plaques that narrow blood vessels. These plaques may rupture during physical strain, emotional stress, or spikes in blood pressure. A resulting blood clot can completely block blood flow or travel to the heart or brain, triggering a heart attack or stroke.

Gut Microbiome Changes May Explain the Effect

To understand why oats had this impact, researchers examined the gut microbiome. “We were able to identify that the consumption of oatmeal increased the number of certain bacteria in the gut,” says Linda Klümpen, the study’s lead author. Scientists increasingly recognize that gut bacteria are central to how the body processes food. These microbes generate metabolic byproducts that nourish intestinal cells and support their normal function.

Some of these bacterial products also enter the bloodstream, where they can influence other organs. “For instance, we were able to show that intestinal bacteria produce phenolic compounds by breaking down the oats,” says Klümpen. “It has already been shown in animal studies that one of them, ferulic acid, has a positive effect on the cholesterol metabolism. This also appears to be the case for some of the other bacterial metabolic products.”

At the same time, certain microbes help eliminate the amino acid histidine. Without this process, the body can convert histidine into a compound believed to promote insulin resistance, a hallmark of diabetes mellitus.

Short Intensive Plan Outperformed Longer Moderate Intake

The cholesterol lowering effects were still visible six weeks after the two day intervention. “A short-term oat-based diet at regular intervals could be a well-tolerated way to keep the cholesterol level within the normal range and prevent diabetes,” says Junior Professor Simon.

However, the benefits were strongest when oats were consumed in high amounts alongside calorie restriction. In a separate six week phase, participants ate 80 grams of oatmeal per day without additional dietary limits. That approach produced only modest changes. “As a next step, it can now be clarified whether an intensive oat-based diet repeated every six weeks actually has a permanently preventative effect,” Simon adds.

How the Randomized Controlled Trials Were Conducted

A total of 68 people took part in the research. In the two day oat based study, 17 participants in the oat group and 15 in the control group completed the trial. Two individuals in the control group withdrew for personal reasons. In the six week intervention, 17 participants in each group finished the study. The researchers determined the group size of 17 per arm based on earlier interventional data.

Both the short and longer interventions were randomized controlled trials. In these “RCTs,” participants are assigned at random to different groups. One group receives the intervention being tested, in this case oats, while the control group does not. Ideally, participants are “blind” and unaware of which group they are in, which reduces placebo effects.

In nutrition studies, full blinding is often difficult because people usually know what they are eating. That was true here. However, the laboratory teams analyzing blood and stool samples were unaware of which group the samples came from. The same applied to blood pressure and weight measurements, reducing the chance that expectations could influence the results.

Before any dietary changes, researchers collected blood and stool samples and measured blood pressure, weight, height, waist circumference, and body fat. Follow up assessments took place immediately after the two day oat phase and again at two, four, and six weeks. The same measurements and sample collections were repeated each time. The six week oatmeal group underwent identical testing procedures.

Blood samples were analyzed for LDL cholesterol levels and for dihydroferulic acid, a phenolic compound thought to be produced by beneficial gut bacteria. Stool samples were used to identify bacterial species by isolating 16S RNA, a molecule unique to bacteria that varies slightly between species, much like a fingerprint. Researchers also examined which metabolic byproducts were present.

The study received funding from the German Federal Ministry of Education and Research (BMBF), the German Diabetes Association (DDG), the German Research Foundation (DFG), the German Cereal Processing, Milling and Starch Industries’ Association (VGMS), and RASO Naturprodukte.

The research was conducted at Oregon Health & Science University and published in the journal Science Advances.

The Disease Behind “Brain on Fire”

Many people recognize this disorder from the bestselling memoir and the 2016 film “Brain on Fire.” Although widely publicized, the condition is rare, affecting roughly 1 in 1 million people each year, most often adults in their 20s and 30s.

The illness occurs when the immune system mistakenly attacks NMDA receptors in the brain. These receptors play an essential role in memory and thinking. The attack is driven in part by anti-NMDA receptor autoantibodies. Patients can experience dramatic personality changes, profound memory loss, seizures, and in severe cases, death.

Pinpointing the Antibody Binding Sites

In the new study, scientists identified specific locations on a subunit of the NMDA receptor where these harmful antibodies attach. Blocking these precise sites could potentially slow or even reverse the progression of the disease.

Lead author Junhoe Kim, Ph.D., a postdoctoral fellow at the OHSU Vollum Institute, analyzed anti-NMDA receptor autoantibodies taken from a specially engineered mouse model of the disease. He then compared those findings with detailed images of the same types of antibodies collected from people diagnosed with the disorder.

The binding locations observed in mice closely matched those seen in human patients.

“We have really solid evidence because the autoantibody binding sites that Junhoe identified overlap with those from people,” said senior author Eric Gouaux, Ph.D., senior scientist in the Vollum and an investigator with the Howard Hughes Medical Institute. “We’re focused now on this area as literally a hot spot for the interaction that underpins at least one component of the disease.”

Kim explained that earlier research had narrowed down the general region where antibodies might attach.

“From previous studies, people knew where the antibodies might bind,” he said. “But we collected the entire native autoimmune antibody panel from a mouse model with the disease, and we elucidated where specifically they bind onto the receptor.”

Near-Atomic Imaging Reveals a Critical Hot Spot

The team used advanced near-atomic imaging at the Pacific Northwest Cryo-EM Center on OHSU’s South Waterfront campus. The facility is one of three national centers dedicated to this state-of-the-art imaging technology. It is jointly operated by OHSU and the Pacific Northwest National Laboratory and supported by the National Institutes of Health.

Their analysis showed that nearly all of the antibodies concentrated on a single region of the receptor.

“Nearly all of the antibodies bound to a single domain of the receptor that happens to be the part of the receptor that’s simplest to target,” Gouaux said. “It’s a super exciting result, actually.”

Toward More Precise Treatments

According to co-author Gary Westbrook, M.D., a neurologist and senior scientist at the Vollum Institute, the discovery could help pharmaceutical companies design drugs that specifically block the damaging antibody interactions. Current treatments rely largely on immunosuppression, which does not work for everyone and can leave patients vulnerable to relapse.

“More specific approaches are definitely needed,” he said.

In addition to Kim, Gouaux, and Westbrook, the research team included Farzad Jalali-Yazdi, Ph.D., and Brian Jones, Ph.D., of OHSU.

The study was supported by the National Research Foundation of Korea, award RS202400334731; the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke, both part of the National Institutes of Health, under award numbers F32MH115595, R01NS117371 and R01NS038631; the Howard Hughes Medical Institute; and Jennifer and Bernard LaCroute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

All animal research at OHSU undergoes review and approval by the university’s Institutional Animal Care and Use Committee (IACUC). The IACUC ensures the welfare of animal subjects and the safety of research personnel. It also evaluates all proposed animal studies to confirm their scientific merit and justify the use of live animals.

Researchers from NASA Goddard Space Flight Center and Penn State recreated Mars like conditions in the laboratory to test that idea. They found that pieces of amino acids from E. coli bacteria, if trapped in Martian permafrost or ice caps, could survive more than 50 million years even under constant cosmic radiation. The findings, published in Astrobiology, suggest that missions searching for life on Mars should prioritize pure ice or ice rich permafrost instead of focusing mainly on rocks, clay, or soil.

“Fifty million years is far greater than the expected age for some current surface ice deposits on Mars, which are often less than two million years old, meaning any organic life present within the ice would be preserved,” said co author Christopher House, professor of geosciences, affiliate of the Huck Institutes of the Life Sciences and the Earth and Environment Systems Institute, and director of the Penn State Consortium for Planetary and Exoplanetary Science and Technology. “That means if there are bacteria near the surface of Mars, future missions can find it.”

Simulating Mars and Cosmic Radiation in the Lab

The study was led by Alexander Pavlov, a space scientist at NASA Goddard who completed a doctorate in geosciences at Penn State in 2001. The team sealed E. coli bacteria inside test tubes filled with pure water ice. Other samples were combined with water and materials commonly found in Martian sediment, including silicate based rocks and clay.

The frozen samples were placed in a gamma radiation chamber at Penn State’s Radiation Science and Engineering Center. The chamber was cooled to minus 60 degrees Fahrenheit to match temperatures in icy regions of Mars. The bacteria were then exposed to radiation equivalent to 20 million years of cosmic ray bombardment on the Martian surface. Afterward, the samples were vacuum sealed and shipped back to NASA Goddard under cold conditions for amino acid testing. Researchers then modeled an additional 30 years of radiation exposure, bringing the total to 50 million years.

Pure Ice Protects Organic Molecules

The results were striking. In pure water ice, more than 10 percent of the amino acids, which are the building blocks of proteins, survived the full 50 million year simulation. By contrast, samples mixed with Mars like sediment broke down 10 times faster and did not survive.

A 2022 study by the same team had shown that amino acids preserved in a mixture of 10% water ice and 90% Martian soil were destroyed more quickly than samples containing only sediment.

“Based on the 2022 study findings, it was thought that organic material in ice or water alone would be destroyed even more rapidly than the 10% water mixture,” Pavlov said. “So, it was surprising to find that the organic materials placed in water ice alone are destroyed at a much slower rate than the samples containing water and soil.”

Researchers think the faster breakdown in mixed samples may happen because a thin film forms where ice touches minerals. That layer could allow radiation to move more freely and damage amino acids.

“While in solid ice, harmful particles created by radiation get frozen in place and may not be able to reach organic compounds,” Pavlov said. “These results suggest that pure ice or ice-dominated regions are an ideal place to look for recent biological material on Mars.”

Implications for Europa and Enceladus

The team also tested organic material at temperatures similar to those on Europa, an icy moon of Jupiter, and Enceladus, an icy moon of Saturn. At those even colder temperatures, deterioration slowed down further.

Pavlov said the findings are encouraging for NASA’s Europa Clipper mission, which will study Europa’s ice shell and subsurface ocean. Europa is the fourth largest of Jupiter’s 95 moons. Europa Clipper launched in 2024 and is traveling 1.8 billion miles to reach Jupiter in 2030. The spacecraft will perform 49 close flybys to determine whether environments beneath the surface could support life.

Drilling Into Martian Ice

When it comes to Mars, accessing buried ice will require the right tools. The 2008 NASA Mars Phoenix mission was the first to dig down and photograph ice in the Martian equivalent of the Arctic Circle.

“There is a lot of ice on Mars, but most of it is just below the surface,” House said. “Future missions need a large enough drill or a powerful scoop to access it, similar to the design and capabilities of Phoenix.”

In addition to House and Pavlov, the research team included Zhidan Zhang, a retired lab technologist in the Penn State Department of Geosciences, along with Hannah McLain, Kendra Farnsworth, Daniel Glavin, Jamie Elsila, and Jason Dworkin of NASA Goddard.

The work was funded by NASA’s Planetary Science Division Internal Scientist Funding Program through the Fundamental Laboratory Research work package at Goddard Space Flight Center.