The connection between the gut and the skin has attracted growing attention in research.
Many people today associate skin problems with diet or skincare, but the evidence has been fragmented.
A new large-scale research review now offers a more comprehensive picture of what is actually known.
What does the research show?
A review published in the journal Nutrition Reviews examined how probiotics, prebiotics, and synbiotics affect the skin.
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The researchers analyzed more than 500 studies involving both humans and animals.
The aim was not to issue recommendations, but to map where solid evidence exists and where research is lacking.
The most striking finding concerns atopic dermatitis, also known as eczema.
Here, a large proportion of studies show that probiotics in particular may have a positive effect, either by reducing symptoms or by lowering the risk of developing the condition.
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How solid is the evidence?
The review also reveals clear differences in research quality. Many studies involve small sample sizes and short study periods.
According to Nutrition Reviews, the vast majority of studies focus on children, while adults and older populations are far less studied.
For skin conditions such as acne and psoriasis, there are some positive findings, but the evidence is limited.
For other areas, such as skin cancer and pigment changes, very little is known.
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Cautious conclusion
Dermatologist Amy Huang, who was not involved in the study, told Medical News Today that imbalances in gut bacteria can worsen inflammatory skin diseases, and that the review provides a useful overview of the research.
There is solid evidence of an effect in eczema, but for most other skin conditions it is too early to draw firm conclusions.
The researchers therefore call for more standardized and long-term studies.
Sources: Medical News Today, and Nutrition Reviews.
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