Probiotics show benefits for atopic dermatitis, but research gaps remain for other skin conditions

A study published in Nutrition Reviews in November 2025 found evidence linking oral probiotics and synbiotics to improvements in atopic dermatitis (AD) symptoms. However, research for other skin conditions such as acne, psoriasis and skin aging remains more limited and is still emerging.

Skin health changes throughout life, with different conditions affecting people at different stages, from AD in childhood to acne in adolescence and skin aging later in life. Globally, skin diseases represent a major health burden and can contribute to chronic symptoms such as itching, pain, sleep disruption and emotional distress that interfere with daily life.

Internal factors such as genetics and external influences including sun exposure, pollution, smoking and nutrition play important roles in skin health. In past studies, researchers have increasingly focused on the gut–skin axis, which describes how the gut microbiome could influence skin function and disease.

Oral probiotics, prebiotics and synbiotics can shape the gut microbiome and may help improve skin health, slow skin aging or manage certain skin conditions, the study shared. While evidence is strongest for AD, research across other areas of dermatology remains unclear.

To better understand the full research landscape, investigators from the Department of Nutritional Services in the School of Life Course and Population Sciences at King’s College London in the UK conducted the review to examine existing evidence, identify gaps and help guide future research and product development.

Six major databases of peer-reviewed and non-peer-reviewed studies published from March 2024 through June 2024 were reviewed, including clinical trial registries, preprint servers, essays and recent conference abstracts. Studies involving humans or animal models were included if oral probiotics, prebiotics or synbiotics were used and outcomes related to skin health or skin disease were reported.

After screening more than 17,000 reports, the authors included 523 publications representing 516 unique studies. Most of the results came from primary research. Research activity increased significantly after 2006, with more than 40 studies published in both 2022 and 2023, and about 80% of studies focused on oral probiotics.

Most studies were conducted in Europe and Asia, with fewer carried out in the U.S. and other regions. Infants and children were the most commonly studied populations, particularly for skin disease prevention and management, while adults were more often studied for skin health and aging outcomes as well. In addition, AD accounted for more than half of all outcomes evaluated in primarily systematic reviews.

The data also showed that probiotics were the most frequently studied intervention, though reporting on strains, dosing and gut viability was inconsistent. Evidence for prebiotics and synbiotics was more limited but growing. Across reviews, most meta-analyses showed a positive effect of probiotics on preventing or managing AD, while evidence for other skin conditions such as psoriasis, acne and skin aging remained sparse and less conclusive.

Based on the study’s format and findings, its main strength is that it brings together a large and rapidly growing body of research on oral probiotics, prebiotics and synbiotics and their relationship to skin health and disease. By reviewing more than 500 sources across different study types, age groups and skin conditions, the authors highlight where evidence is strongest, especially for AD, and where important gaps remain.

The study also has its limitations. Many studies didn’t clearly report probiotic strains, doses, participant diets or demographic details such as ethnicity and skin type. Most of the evidence came from Europe and Asia, with much less research from other regions. In addition, because this was a scoping review, the quality of individual studies was not assessed.

To address these gaps, the authors urge for better-designed randomized trials, more consistent reporting and more inclusive study populations. They also recommend umbrella reviews for AD and additional evidence synthesis to help guide future clinical recommendations.