Nikhil Prasad Fact checked by:Thailand Medical News Team Jun 06, 2026 1 hour, 26 minutes ago
Medical News: Age-related macular degeneration (AMD), one of the leading causes of blindness among older adults, may be closely linked to changes in the gut microbiome, according to a new pilot study that sheds light on the emerging “gut-retina axis.” Researchers found that individuals suffering from AMD had significantly lower levels of beneficial gut bacteria and a much less diverse intestinal microbiome compared to healthy individuals, raising new questions about whether gut health could influence eye disease progression.
New research suggests that disruptions in beneficial gut bacteria may be closely linked to age-related macular
degeneration and vision loss
Scientists Explore the Gut-Eye Connection
AMD is a chronic disease that damages the macula, the central part of the retina responsible for sharp vision. It affects nearly 200 million people worldwide and is expected to become even more common as populations age. While genetics, inflammation, oxidative stress, and lifestyle factors have long been known to contribute to AMD, researchers are increasingly investigating whether microbes living in the intestines may also play a role.
The study was conducted by researchers from the Doctoral School, Department of Ophthalmology, Biochemistry Discipline, Center for Complex Network Science, Department of Microbiology, and the Multidisciplinary Research Center on Antimicrobial Resistance (MULTI-REZ) at the “Victor Babes” University of Medicine and Pharmacy in Timisoara, Romania.
Using advanced long-read whole-genome sequencing technology, the team analyzed stool samples from 19 AMD patients and 16 healthy controls to identify differences in their gut microbial communities.
Major Loss of Beneficial Gut Bacteria
One of the most striking findings was a dramatic reduction in microbial diversity among AMD patients. Researchers observed significantly lower richness, Shannon diversity, and Simpson diversity scores, all indicators of a healthy and balanced microbiome.
A healthy gut normally contains a wide variety of bacteria that work together to support digestion, immune regulation, and protection against harmful microbes. In AMD patients, this diversity was substantially reduced, suggesting that the microbial ecosystem had become less stable and more vulnerable to imbalance.
Several beneficial bacterial species were found at much lower levels in AMD patients. These included Faecalibacterium prausnitzii, Parabacteroides distasonis, Bacteroides ovatus, and Christensenella minuta. Many of these microbes are known producers of short-chain fatty acids, especially butyrate, compounds that help maintain intestinal barrier integrity and reduce inflammation throughout the body.
Signs of a More Inflammatory Gut Environment
The researchers also discovered an increase in certain bacteria often associated with dysbiosis, or microbial imbalance. Among the most notable was Staphylococcus aureus, which was significantly enriched in AMD patients.
According to the study, the loss of beneficial microbes combined with the rise of potentially harmful spe
cies may contribute to chronic low-grade inflammation. This could allow bacterial products and inflammatory molecules to enter the bloodstream more easily, potentially influencing retinal tissues and accelerating damage within the eye.
This
Medical News report highlights that the findings support growing evidence that disturbances in gut bacteria may affect distant organs through immune and metabolic pathways. Scientists believe microbial metabolites may influence retinal cells, blood vessel health, oxidative stress levels, and inflammatory responses that are already known to play important roles in AMD development.
AMD Patients Showed Greater Microbial Instability
Beyond simple changes in bacterial abundance, AMD patients displayed significantly greater variation in their microbiomes compared to healthy individuals. The microbial communities were more heterogeneous, meaning patients tended to have highly individualized and unstable gut bacterial profiles.
Researchers noted that the differences between AMD patients and controls were driven primarily by shifts in the abundance of existing bacterial species rather than the complete disappearance of certain microbes and replacement by others.
This finding suggests that AMD may be associated with a gradual imbalance in microbial populations rather than a unique disease-specific bacterial signature.
Wet and Dry AMD Show Similar Patterns
The study also compared patients with wet AMD and dry AMD, the two major forms of the disease. Surprisingly, researchers found no significant differences in overall microbial diversity or community structure between these subtypes.
Although a few bacterial species appeared more common in one subtype than the other, the sample size was too small to draw firm conclusions. The researchers stressed that larger studies will be needed to determine whether subtype-specific microbial patterns truly exist.
Conclusions
The findings provide further evidence that gut microbiome disturbances may be linked to age-related macular degeneration. AMD patients consistently showed lower microbial diversity, depletion of beneficial anti-inflammatory bacteria, increased abundance of potentially harmful microbes, and greater instability within their gut ecosystems. These changes may contribute to systemic inflammatory and metabolic processes that influence retinal health and disease progression. However, the researchers emphasize that the study was small and observational, meaning it cannot prove that gut bacteria directly cause AMD. Future research involving larger populations, long-term monitoring, dietary assessments, immune profiling, metabolomics, and functional microbiome analyses will be essential to determine whether modifying the gut microbiome through diet, probiotics, prebiotics, or other interventions could help prevent or slow the progression of this sight-threatening disease.
The study findings were published in the peer reviewed journal: Biomedicines.
https://www.mdpi.com/2227-9059/14/6/1290
For the latest on age-related macular degeneration (AMD), news, keep on logging to Thailand
Medical News.
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