Medical Bulletin 3/June/2025

Here are the top medical news for the day:

Study Unveils Obesity’s Impact on Mental Health

A new study presented at NUTRITION 2025, the flagship annual meeting of the American Society for Nutrition, reveals a compelling link between obesity and anxiety, potentially driven by changes in the brain and gut microbiome. The research, conducted in mice, suggests that diet-induced obesity may trigger anxiety-like behavior through altered brain signaling and gut health, shedding light on how physical health may influence mental well-being.

While previous studies have hinted at a relationship, it remains unclear whether obesity causes anxiety or if both conditions are shaped by shared societal or environmental influences. “Our findings suggest that obesity can lead to anxiety-like behavior, possibly due to changes in both brain function and gut health,” said Desiree Wanders, PhD, associate professor and chair of nutrition at Georgia State University, who led the study.

To investigate this connection, researchers designed a controlled experiment using 32 male mice. From 6 to 21 weeks of age—comparable to adolescence into early adulthood in humans—half the mice were fed a low-fat diet while the others received a high-fat diet. By the study’s end, the high-fat group exhibited significantly more body fat and weight gain. Behavioral tests showed that these obese mice demonstrated more anxiety-like behaviors, such as freezing in response to perceived threats.

Further analysis revealed changes in signaling patterns in the hypothalamus, a brain region involved in metabolism, as well as distinct differences in gut microbial composition between the two groups. These findings reinforce the growing body of evidence that the gut-brain axis plays a crucial role in behavior and cognitive function.

“These findings could have important implications for both public health and personal decisions,” said Wanders, emphasizing the role of diet in mental health. However, she also noted that genetics, lifestyle, and environment must be considered to fully understand these complex interactions. Future research will examine the effects across genders, age groups, and whether interventions like weight loss can reverse the observed changes.

Reference: https://nutrition.org/meeting/

How Plastic Particles in Food Affect Liver Function: Study Finds

New research presented at NUTRITION 2025, the annual meeting of the American Society for Nutrition held May 31–June 3 in Orlando, highlights potential health concerns related to microscopic plastic particles in food and beverages. The study, conducted in mice, found that ingestion of polystyrene nanoplastics may disrupt glucose metabolism and cause liver injury—raising concerns about possible health effects in humans.

As plastics break down over time, they form microplastics (less than 5 mm) and nanoplastics (less than 100 nanometers). These particles often enter the food chain, ending up in seafood and packaged foods. Research suggests people may consume between 40,000 and 50,000 plastic particles each year, with some estimates reaching as high as 10 million.

To simulate real-world exposure, the researchers administered a daily oral dose of polystyrene nanoparticles to 12-week-old male mice on a standard rodent diet. The dose—60 milligrams per kilogram of body weight—was chosen based on human exposure estimates and prior animal studies showing biological effects. Polystyrene is a common plastic found in food packaging.

“We can’t control for all the plastics the mice are exposed to,” said Amy Parkhurst, a doctoral candidate in the lab of Fawaz George Haj, PhD, at the University of California, Davis. “However, our study design allowed us to see dose-correlated changes since the nanoplastics-dosed group would have a higher exposure.”

The mice exposed to polystyrene showed systemic glucose intolerance and elevated levels of alanine aminotransferase, a marker for liver damage. Increased gut permeability and higher endotoxin levels were also observed—factors that contribute to liver dysfunction.

The team is now exploring how nanoplastics accumulate in different organs and plan to use advanced imaging techniques to map their metabolic impact.

Reference: https://nutrition.org/meeting/

New Nasal Deformity Classification System May Enhance Standardization in Cleft Lip and Palate Assessment

A new classification tool for assessing nasal deformities in infants with cleft lip and/or palate (CLP) demonstrates high accuracy and reliability, according to a study published in The Journal of Craniofacial Surgery. The system is designed to improve diagnosis, treatment planning, and outcomes for infants with cleft lip and/or palate -related nasal abnormalities.

Cleft lip and/or palate is one of the most common birth defects, and many infants with cleft lip and/or palate also present with nasal deformities. However, these nasal issues are often overlooked in standard classification systems.

The study involved the development and evaluation of a standardized classification system based on visible nasal features such as nostril shape, nasal tip projection, and septum symmetry. The tool uses patient photographs and separates cases into unilateral and bilateral cleft categories. Clinicians rate each feature on a scale from mild to severe.

To test its effectiveness, the classification guide was sent to an international panel of plastic surgeons and orthodontists with various levels of experience in treating cleft lip and/or palate. Participants reviewed a randomized set of infant photographs and assessed the severity of nasal deformities using the proposed criteria. The consistency of their ratings was measured using the intraclass correlation coefficient (ICC).

Results showed "excellent" agreement among panelists, with ICC values of 0.816 for unilateral and 0.743 for bilateral clefts. These results affirm the tool's strong reliability and clinical usefulness.

The authors conclude that the system could play a key role in future treatment planning and outcome tracking.Medical Bulletin 2/June/2025

Reference: Mejia, Martha DDS; Bernal, Isabel DO; Cordero, Juan P. BS; Bercu, Caleb BS; Policherla, Rohan MD; Steinberg, Jordan P. MD, PhD. A Proposed Nasal Deformity Classification System for Infants With Cleft Lip and Palate. The Journal of Craniofacial Surgery ():10.1097/SCS.0000000000011151, May 27, 2025. | DOI: 10.1097/SCS.0000000000011151