Medical Bulletin 31/October/2025

Parkinson’s disease has been linked to oxidative stress and inflammation damaging brain neurons, and diet could be a significant modifiable factor. Prior studies focusing on individual foods or predefined diets like Mediterranean or DASH have yielded inconsistent results. This study used data-driven analysis to identify dietary patterns specific to the Italian population that may better reveal associations with PD risk.

Researchers conducted a retrospective case-control study with 680 PD patients and 612 matched controls recruited from six Italian neurology centers. Dietary intake was assessed using a 77-item Food Frequency Questionnaire reflecting typical Italian foods consumed before PD symptoms. Non-dietary factors—such as pesticide exposure, smoking, coffee consumption, and family history—were also collected. Principal Component Analysis and Exploratory Factor Analysis identified seven distinct dietary patterns. Logistic regression models adjusted for demographic and environmental factors tested associations between these patterns and PD risk.

The analysis showed that higher consumption of sweets (OR 1.20), red meat (OR 1.15), and cured meats (OR 1.32) was significantly associated with greater odds of PD. Conversely, fruit intake lowered PD odds (OR 0.84), with citrus fruits driving this protective effect. Non-dietary factors such as pesticide exposure and family history exerted even stronger risk influences, while coffee and smoking were protective. Physical activity’s protective effects were confounded by correlated unhealthy dietary habits. These results point to practical dietary adjustments—reducing sweets and processed meats while increasing fruit—that may complement other known PD risk reduction strategies.

Lead researchers highlighted the need for prospective and diverse-population studies to confirm causality and generalize findings, but the study offers actionable insights for PD prevention through diet modification.

REFERENCE: Gigante, A. F., Vitucci, B., Velucci, V., Pellicciari, R., Modugno, N., Pietracupa, S., De Bartolo, M. I., Costanzo, M., Terravecchia, C., Mascia, M. M., Muroni, A., Ercoli, T., Solla, P., Magrinelli, F., Conte, A., Fabbrini, G., Nicoletti, A., Tinazzi, M., Berardelli, A., Defazio, G., & Belvisi, D. (2025). The impact of diet on Parkinson’s disease risk: A data-driven analysis in a large Italian case-control population. Journal of Parkinson’s Disease. DOI: 10.1177/1877718X251388058

Scientists discover hidden antibiotic 100 times stronger against superbugs

Chemists from the University of Warwick and Monash University have discovered a potent new antibiotic that targets drug-resistant bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE). Published recently in the Journal of the American Chemical Society, this compound, called pre-methylenomycin C lactone, was found "hiding in plain sight" as an intermediate during the natural biosynthesis of the older antibiotic methylenomycin A.

Antimicrobial resistance (AMR) poses a critical global health threat, with millions of deaths annually due to antibiotic-resistant infections. However, the development of new antibiotics has slowed, partly because discovery is challenging and financially unrewarding. This team’s breakthrough offers renewed hope by identifying a previously overlooked chemical intermediate with extraordinary antibacterial activity—over 100 times more potent against Gram-positive bacteria than methylenomycin A.

The researchers deleted biosynthetic genes in Streptomyces coelicolor, a well-studied soil bacterium known for producing methylenomycin A, to isolate and characterize two new intermediate compounds. These intermediates were then tested for antimicrobial activity against various drug-resistant pathogens, including the bacteria responsible for MRSA and VRE. The compound's potency and resistance profile were examined through laboratory assays, particularly assessing the likelihood of resistance development.

Pre-methylenomycin C lactone demonstrated exceptional efficacy, showing a 100-fold increase in activity against Gram-positive bacteria compared to methylenomycin A. Notably, no resistance emerged in Enterococcus faecium after prolonged exposure, a significant advantage over current last-resort antibiotics like vancomycin. The researchers speculate that S. coelicolor originally evolved to produce the more potent pre-methylenomycin C lactone but shifted toward producing the weaker methylenomycin A over time. The team also developed a scalable synthetic route to produce pre-methylenomycin C lactone and analogues for further study.

Lead researcher Professor Greg Challis noted this discovery signals a new approach to antibiotic development—exploring biosynthetic intermediates to find powerful, resistance-resilient drugs. This breakthrough could help save millions of lives worldwide threatened by antimicrobial resistance.

REFERENCE: Christophe Corre, Gideon A. Idowu, Lijiang Song, Melanie E. Whitehead, Lona M. Alkhalaf, Gregory L. Challis. Discovery of Late Intermediates in Methylenomycin Biosynthesis Active against Drug-Resistant Gram-Positive Bacterial Pathogens. Journal of the American Chemical Society, 2025; DOI: 10.1021/jacs.5c12501

Gut microbes may convert fiber into extra calories, study suggests

Scientists at Arizona State University have discovered that certain microbes in the human gut, known as methanogens, influence how efficiently individuals extract calories from high-fiber foods. Published in The ISME Journal, their research highlights that people whose gut microbiomes produce more methane absorb more energy from fiber-rich diets, suggesting a novel biomarker for personalized nutrition.

The gut microbiome, the community of microorganisms living in the digestive tract, breaks down food components the body cannot digest alone. One key function is fermenting dietary fiber into short-chain fatty acids (SCFAs), an important energy source. Methanogens consume hydrogen produced during this fermentation, releasing methane gas as a byproduct and maintaining chemical balance. This microbial activity appears to enhance energy absorption.

In collaboration with the AdventHealth Translational Research Institute, researchers enrolled participants who followed two controlled diets of equal macronutrient content but differing in fiber: a processed, low-fiber diet and a whole-food, high-fiber diet. Each participant spent six days inside a whole-room calorimeter—a sealed chamber that continuously measured metabolic rates and methane emissions via breath and other routes—allowing precise tracking of energy use and microbial methane production. Blood and stool samples were collected to assess metabolism, microbial activity, and SCFA levels.

Results showed that participants generally absorbed fewer calories from the high-fiber diet than from the processed diet. However, individuals with higher methane production absorbed significantly more calories from fiber, linked to elevated SCFAs in the gut. Methane production may thus serve as an indicator of efficient fiber fermentation and calorie extraction.

Lead author Blake Dirks noted that these findings emphasize how the gut microbiome shapes individual metabolic responses to diet, underscoring the potential for personalized nutrition interventions to optimize health outcomes based on microbial composition.

REFERENCE: Blake Dirks, Taylor L Davis, Elvis A Carnero, Karen D Corbin, Steven R Smith, Bruce E Rittmann, Rosa Krajmalnik-Brown. Methanogenesis associated with altered microbial production of short-chain fatty acids and human-host metabolizable energy. The ISME Journal, 2025; 19 (1) DOI: 10.1093/ismejo/wraf103