Dietary fiber in gut may help with skin allergies: Monash study

A Monash University study exploring the emerging gut-skin axis found that microbial fermentation of dietary fiber in the gut may protect against allergic skin disease. The research could potentially lead to new treatments to prevent or treat allergies.

Professor Ben Marsland from the Department of Immunology at the Central Clinical School, in collaboration with Swiss colleagues from the University Hospital Center of Lausanne (CHUV), has shown that the fermentation of fibers in the intestine by bacteria and the subsequent production of chain fatty acids (SCFA), in particular butyrate, protected against atopic dermatitis in mice.

The research was published on June 8, 2022 in Mucosal immunology.

While it is well established that the intestinal microbiota shapes the immune system, its influence on the skin is less explored.

“Previous work by our group, and others, has focused on the local health benefits of SCFAs in the gut as well as distal sites such as the lungs and cardiovascular system,” said Professor Marsland. . “We wondered if this could also extend to the skin, which is an area that hasn’t really been studied.

“People think diet can influence skin health, but there’s not a lot of science behind it.”

The researchers fed mice a diet high in fermentable fiber or gave them purified SCFAs. “This treatment was profoundly protective against allergic skin inflammation,” Professor Marsland said.

They tagged the butyrate with isotopes and tracked it through the body – it only took a few minutes to

reaching the skin where it enhanced keratinocyte metabolism, preparing them to mature and produce the key structural components necessary for a healthy skin barrier.

“The result was that the skin barrier was reinforced against allergens – we used house dust mite allergens – which would normally penetrate the skin barrier, activate the immune system and trigger an allergic reaction in these models,” a- he declared.

“It turns out that the immune system was secondary to this skin barrier function.”

Active enhancement of the skin barrier could have protective effects against environmental exposures that cause allergies and possibly even other skin diseases that are underpinned by a damaged or weak skin barrier. SCFAs could be given orally or directly to the skin as a cream, bypassing the gut, he said.

“The fact that short-chain fatty acids can be administered topically and are well tolerated opens up possibilities for the development of preventive strategies or disease-modifying interventions – which represents the most important translational potential of our research. “

One possibility to explore is whether it could help children who are at risk of developing skin allergies that turn into food allergies and asthma, the so-called ‘atopic march’.

Professor Marsland and members of his Melbourne-based team ran the project for five or six years with scientists at Lausanne University Hospital where he previously worked before being recruited by Monash. The main author was Aurélien Trompette, based in Switzerland.

Trompette, A., Pernot, J., Perdijk, O. et al. Gut-derived short-chain fatty acids modulate skin barrier integrity by promoting keratinocyte metabolism and differentiation. Mucosal Immunol (2022). doi.org/10.1038/s41385-022-00524-9

See also recent research by Professor Ben Marsland: www.monash.edu/news/articles/scientists-link-fibre-in-diet-to-flu-protection