Medical Bulletin 27/February/2026

Here are the top medical news for today:

Two Days of Oatmeal May Lower Bad Cholesterol by 10%, Study Finds

Eating mostly oatmeal for just two days may significantly lower “bad” LDL cholesterol and trigger beneficial changes in gut bacteria, according to a randomized clinical trial from the University of Bonn published in Nature Communications. The study involved people with metabolic syndrome, a cluster of risk factors that includes excess body weight, high blood pressure, elevated blood sugar, and abnormal cholesterol levels.

During the 48-hour intervention, participants consumed 300 grams of oatmeal per day-served as three meals-while reducing their overall calorie intake by about half. They were allowed only small portions of fruit and vegetables. A control group also followed a calorie-restricted diet but did not consume oats. In total, 32 individuals completed the short-term oat-based phase.

Although both groups experienced some benefits from eating fewer calories, the improvements were more pronounced in the oat group. LDL cholesterol levels dropped by approximately 10%, a substantial reduction linked to lower cardiovascular risk. Participants in the oat group also lost an average of two kilograms and experienced slight reductions in blood pressure. Notably, the cholesterol-lowering effect remained measurable six weeks after the two-day intervention.

Further analysis suggested that changes in the gut microbiome may explain part of the benefit. Oat consumption increased specific bacteria that produce phenolic compounds such as ferulic acid, which has been associated with improved cholesterol metabolism. Researchers also observed microbial shifts related to histidine metabolism, potentially influencing insulin sensitivity.

In a separate six-week phase where participants consumed 80 grams of oats daily without calorie restriction, only modest improvements were seen. The findings suggest that short, intensive oat-based interventions may offer a practical strategy to improve heart and metabolic health.

REFERENCE: Linda Klümpen, Aakash Mantri, Maren Philipps, Waldemar Seel, Laura Schlautmann, Mohamed H. Yaghmour, Verena Wiemann, Birgit Stoffel-Wagner, Martin Coenen, Leonie Weinhold, Jan Hasenauer, Thomas Fließwasser, Sven Burgdorf, Christoph Thiele, Peter Stehle, Marie-Christine Simon. Cholesterol-lowering effects of oats induced by microbially produced phenolic metabolites in metabolic syndrome: a randomized controlled trial. Nature Communications, 2026; 17 (1) DOI: 10.1038/s41467-026-68303-9

Ketogenic Diet May Reduce Epileptic Seizures by Changing Brain Signals: Study

A ketogenic diet-rich in fat and extremely low in carbohydrates-has been used for decades to help control seizures in people with epilepsy, especially children whose condition does not respond to medication. Yet the precise biological mechanisms behind its benefits have remained unclear. Now, researchers at Washington University School of Medicine in St. Louis have identified specific changes in brain cells that may explain how the diet suppresses seizures. Their findings were published in Cell Reports.

In many patients, as much as 90% of daily calories must come from fat for the diet to be effective, and even minor lapses can reduce its seizure-controlling benefits. The diet forces the body to switch from using glucose as its primary energy source to producing ketones in the liver. These ketones then serve as fuel for neurons in the brain.

To understand how this metabolic shift affects brain function, the researchers studied mice fed a strict ketogenic diet and analyzed changes in the hippocampus, a region commonly involved in seizure activity. They discovered hundreds of alterations in gene expression, many linked to synapses—the communication points between neurons.

Further experiments showed that excitatory signals, which stimulate neighboring brain cells, were significantly reduced, while inhibitory signals that calm neural activity were increased. This rebalancing dampened overall communication within neural circuits, creating a quieter brain environment less susceptible to seizure-triggering hyperactivity.

These findings suggest that replicating the diet’s molecular and cellular effects through targeted therapies could provide new, less restrictive treatment options for epilepsy patients.

REFERENCE: Stunault, Marion I. et al.; Ketogenic diet dampens excitatory neurotransmission by shrinking synaptic vesicle pools; Cell Reports, Volume 45, Issue 2, 116945; DOI: 10.1016/j.celrep.2026.116945

Chronic Cola Consumption Reduces Key Immune Cells, Animal Study Shows

In a study published in Frontiers in Nutrition, researchers examined the long-term effects of replacing drinking water entirely with sugar-sweetened or sugar-free cola in rats. Over eight weeks, 24 Sprague-Dawley rats were divided into three groups: water, sugary cola, and diet cola. Each group consumed its assigned beverage as the sole fluid source while maintaining a standard diet.

Despite concerns about daily soda intake, the rats showed no significant differences in body weight, body mass index, blood glucose, or lipid profiles after eight weeks. On the surface, they appeared metabolically stable. However, deeper analysis revealed notable physiological changes.

Both cola groups had significantly lower white blood cell counts, indicating leukopenia and possible immune alterations. The sugar-sweetened cola group showed a reduced thymus index and enlarged spleen, suggesting immune organ stress. Meanwhile, the diet cola group exhibited elevated liver enzymes—ALT and AST—pointing to potential liver strain.

Renal markers also differed. The sugar-sweetened cola group had increased blood urea nitrogen levels, indicating kidney burden, though creatinine remained unchanged. Both cola groups demonstrated reduced serum total protein, suggesting broader systemic effects.

Gut microbiota analysis using 16S rRNA sequencing revealed marked dysbiosis in both cola groups. Microbial diversity indices were significantly higher, particularly in the sugar-sweetened group. At the phylum level, Firmicutes declined while Bacteroidota increased, lowering the Firmicutes/Bacteroidota ratio. Beneficial genera such as Lactobacillus were reduced, especially with sugary cola.

Correlation analyses linked certain microbial shifts with immune and renal markers, though causation was not established. The findings suggest that replacing water with cola—whether sugary or diet—may disrupt immune balance, organ function, and gut microbiota, even without obvious metabolic changes.

REFERENCE: Gao H, Li W, Wang X, Ren Y, Li X, & Liu C. (2026). Gut dysbiosis and immune dysfunction induced by chronic cola replacement of water in rats: not just a sugar problem. Frontiers in Nutrition, 12. DOI: 10.3389/fnut.2025.1707842, https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2025.1707842/full