Medical Bulletin 26/May/2026

Here are the top medical news for today:

New Research Highlights Gut Health Benefits Linked to Yoga and Meditation Practices

Your gut may be listening to your mind more closely than scientists once believed. A growing body of research now suggests that yoga and meditation could influence the trillions of bacteria living inside the digestive system — microbes increasingly linked to immunity, metabolism, mood, and even brain health.

A recent systematic review published in the International Journal of Yoga examined clinical evidence on how yoga and meditation affect the human gut microbiome. Researchers analyzed studies involving 440 healthy adults between ages 24 and 55 from China and the United States. While only four studies met strict scientific criteria, the findings consistently pointed in the same direction: mind-body practices appeared to promote healthier gut bacteria profiles.

The gut microbiome is made up of vast communities of microorganisms that help digest food, produce vitamins, regulate inflammation, and communicate with the brain through the gut-brain axis. When this microbial balance is disrupted — a condition known as dysbiosis — it has been linked to digestive disorders, obesity, depression, anxiety, and heart disease.

Researchers found that people practicing yoga or long-term meditation showed higher levels of beneficial bacteria. These microbes are associated with lower inflammation, better digestion, and improved mental health markers.

The yoga intervention study included breathing exercises, meditation, physical activity, and a vegan diet over 68 days. Other studies examined experienced meditators who practiced daily for 30 minutes to two hours. Scientists also observed favorable shifts in gut-related metabolites, including increases in short-chain fatty acids, compounds known to support intestinal and immune health.

Researchers believe stress reduction may be one key reason. Chronic stress can alter gut bacteria through hormonal and immune pathways, while meditation and yoga may help stabilize those signals.

Still, experts caution that the science remains early. Most participants also followed vegetarian or vegan diets, making it difficult to separate the effects of meditation from nutrition alone. Researchers say larger randomized controlled trials are needed.

REFERENCE: Math, Renukaradhya K.; Javaregowda, Palaksha Kanive; Patil, Satish G. Effect of Yoga and Meditation on Human Gut Microbiota: A Systematic Review. International Journal of Yoga. 19(1): 41-53. DOI: 10.4103/ijoy.ijoy_15_25, https://journals.lww.com/ijoy/fulltext/2026/01000/effect_of_yoga_and_meditation_on_human_gut.6.aspx

Blood Carotenoid Levels May Accurately Reflect Fruit and Vegetable Consumption Patterns: Study

What if doctors could tell how healthy your diet is just by testing your blood, urine, or even your skin? Scientists are getting closer to that reality with a growing field of research focused on “dietary biomarkers” — measurable chemicals in the body that may reveal how many fruits and vegetables a person actually eats.

A new review published in Nutrition Bulletin examined the most promising biomarkers currently being studied to objectively measure fruit and vegetable intake.

Traditional methods such as food diaries, 24-hour recalls, and food frequency questionnaires rely heavily on memory and honesty. That can make it difficult for researchers to accurately connect diet with long-term health outcomes like heart disease, obesity, diabetes, and cancer.

Scientists are now investigating biological markers that change in response to fruit and vegetable consumption. Among the strongest candidates are vitamin C, carotenoids, folate, flavonoids, hippuric acid, and potassium.

Blood carotenoids currently appear to be the most reliable biomarker overall. These natural plant pigments are found in colorful produce such as carrots, spinach, tomatoes, and peppers. Since the human body cannot make carotenoids on its own, higher blood levels generally reflect higher fruit and vegetable intake.

Researchers are also exploring skin carotenoid scans as a faster, noninvasive alternative to blood testing. Meanwhile, serum vitamin C may help measure recent fruit and vegetable consumption, especially in people who do not regularly take supplements.

Urinary flavonoids and hippuric acid also show promise because they reflect compounds naturally abundant in plant foods. However, these markers can also be influenced by tea, coffee, wine, chocolate, and spices, making interpretation more complicated.

The review highlights that no single biomarker is perfect. Factors like age, medications, smoking, alcohol use, supplements, genetics, and underlying health conditions can all influence results.

REFERENCE: Madore MP. 2026. A Narrative Review of Candidate Biomarkers of Total Fruit and Vegetable Intake. Nutrition Bulletin. https://onlinelibrary.wiley.com/doi/10.1111/nbu.70054

Scientists Discover Unexpected Reason Bananas May Not Belong in Smoothies

Your morning smoothie may not be as healthy as you think — especially if you’re blending bananas with berries. New research from the University of California, Davis suggests that one of the world’s most popular smoothie ingredients could dramatically reduce your body’s ability to absorb beneficial plant compounds called flavanols.

Flavanols are natural compounds linked to heart and brain health. They are abundant in foods such as blueberries, blackberries, apples, grapes, cocoa, and tea. But according to a study published in Food & Function, combining these foods with bananas may sharply cut how much of those compounds your body actually absorbs.

The reason comes down to an enzyme called polyphenol oxidase, or PPO. This is the same enzyme responsible for the browning seen when bananas or apples are sliced and exposed to air. Bananas contain especially high PPO activity, while berries contain relatively low levels.

Researchers tested how different smoothies affected flavanol absorption in healthy volunteers. Participants consumed a banana smoothie, a mixed berry smoothie, and a flavanol capsule used as a control. Blood and urine tests later revealed a striking result: people who drank the banana smoothie had 84% lower flavanol levels compared with the control group. Meanwhile, the berry smoothie preserved flavanol absorption almost as effectively as the capsule.

Scientists say the enzyme appears to break down flavanols before the body can absorb them. Even when flavanols and banana were consumed separately but at the same time, absorption still dropped significantly.

The findings do not mean bananas are unhealthy. Bananas remain rich in potassium, fiber, and important nutrients. The study simply suggests that if your goal is to maximize flavanol intake from berries, grapes, apples, or cocoa, bananas may not be the best smoothie partner.

Instead, researchers recommend combining flavanol-rich fruits with low-PPO ingredients such as mango, pineapple, oranges, or yogurt.

REFERENCE: Javier I. Ottaviani, Jodi L. Ensunsa, Reedmond Y. Fong, Jennifer Kimball, Valentina Medici, Gunter G. C. Kuhnle, Alan Crozier, Hagen Schroeter, Catherine Kwik-Uribe. Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies: a controlled, single blinded, cross-over study. Food, 2023; 14 (18): 8217 DOI: 10.1039/D3FO01599H