The skin is often viewed as something separate from the rest of the body, but research increasingly shows that skin health is closely connected to internal systems — particularly the gut microbiome.

The gut microbiome refers to the trillions of microorganisms that live within the digestive tract. These microbes interact with the immune system, influence inflammation and help regulate many biological processes throughout the body.

Scientists now describe the relationship between the digestive system and the skin as the gut–skin axis. This connection helps explain why gut health is increasingly being explored in relation to inflammatory skin conditions such as eczema, acne and psoriasis.

Founder Insight

Hanna Sillitoe first became interested in the role of the gut microbiome while naturally treating her psoriasis. During this time she began exploring research into how gut bacteria influence inflammation, digestion and immune responses.

This experience sparked a long-standing interest in the relationship between gut health and skin wellbeing, and the growing scientific understanding of the gut–skin axis.

What Is the Gut–Skin Axis?

The gut–skin axis describes the biological connection between the gut microbiome and the skin.

Although the digestive system and skin may appear unrelated, they are linked through several key systems in the body, including:

• the immune system
• inflammatory signalling
• metabolic pathways
• the nervous system

Because the gut microbiome interacts closely with these systems, changes in microbiome balance may influence processes that affect skin health.

Researchers now recognise that the gut microbiome plays an important role in maintaining immune balance and regulating inflammation — both of which are important factors in many skin conditions.

How the Gut Microbiome Influences Skin Health

Immune System Regulation

Around 70% of the body’s immune cells are located within the digestive system. The gut microbiome interacts closely with these immune cells and helps regulate immune responses.

When the microbiome is balanced and diverse, it can help support immune regulation. Changes in microbiome composition may influence immune signalling and inflammatory pathways throughout the body.

Inflammation and Skin Health

Inflammation plays a key role in many skin conditions. Conditions such as acne, eczema and psoriasis all involve inflammatory processes within the skin.

The gut microbiome helps regulate inflammatory responses by producing compounds that interact with immune cells and help maintain balance within the gut environment.

Because these immune signals can circulate throughout the body, researchers are exploring how microbiome balance may influence inflammatory skin conditions.

The Gut Barrier

The intestinal lining acts as a protective barrier between the digestive system and the bloodstream.

A healthy gut barrier helps prevent unwanted substances from entering circulation while allowing nutrients to be absorbed.

Gut bacteria help maintain the integrity of this barrier by producing beneficial compounds known as short-chain fatty acids, which support the cells lining the digestive tract.

Researchers are studying how gut barrier function may influence systemic inflammation and skin health.

The Gut–Brain–Skin Axis

The digestive system and nervous system communicate through a network known as the gut–brain axis.

Gut microbes produce compounds that interact with the nervous system and influence signalling between the gut and the brain.

Stress is known to affect both digestive health and skin conditions, and scientists are exploring how the microbiome may influence these interactions through the gut–brain–skin axis.

What Research Shows

Interest in the gut–skin connection has grown significantly in recent years.

Research findings include:

• Microbiome differences in inflammatory skin conditions – Studies have found differences in gut microbiome composition in people with conditions such as psoriasis, eczema and acne.

• Immune system interactions – The gut microbiome plays an important role in regulating immune responses that influence inflammatory pathways.

• Microbial metabolites and skin health – Gut bacteria produce compounds such as short-chain fatty acids that support immune balance and gut barrier function.

• Gut–brain–skin signalling – Researchers are exploring how microbiome interactions with the nervous system may influence inflammatory skin conditions.

Although research continues to develop, these findings highlight the growing interest in the gut–skin axis as an important area of study in skin health.

Sources

Bowe WP & Logan AC. Acne vulgaris, probiotics and the gut–brain–skin axis. Gut Pathogens, 2011.

Salem I et al. The gut microbiome as a major regulator of the gut–skin axis. Frontiers in Microbiology, 2018.

Schommer NN & Gallo RL. Structure and function of the human skin microbiome. Trends in Microbiology, 2013.

Koh A et al. From dietary fibre to host physiology: short-chain fatty acids as key bacterial metabolites. Cell, 2016.

Supporting the Gut Microbiome

Supporting a healthy and diverse microbiome may help maintain balance within the systems that influence skin health.

Eat a diverse range of plant foods

A diet rich in vegetables, fruits, legumes and whole grains provides fibre that nourishes beneficial gut bacteria.

Increase fibre intake

Fibre feeds gut microbes and allows them to produce beneficial compounds that support gut health.

Include fermented foods

Fermented foods such as kimchi, kefir and sauerkraut contain naturally occurring microorganisms that may help support microbiome diversity.

Maintain healthy lifestyle habits

Sleep, stress management and physical activity can influence microbiome balance and immune regulation.

Consider probiotic support

Some people choose to support their microbiome with probiotics — live microorganisms designed to help maintain microbial balance within the digestive system.

Common Questions About the Gut–Skin Axis

Can gut health affect skin conditions?

Researchers are increasingly studying how the gut microbiome may influence inflammatory pathways, immune signalling and metabolic processes that affect skin health.

What is the gut–brain–skin axis?

The gut–brain–skin axis describes the communication network linking the digestive system, nervous system and skin.

Can probiotics improve skin health?

Some studies have explored whether probiotics may influence immune regulation and microbiome balance. Research in this area is ongoing.

Conclusion

The gut–skin axis highlights the complex relationship between the digestive system and skin health. The trillions of microbes living in the gut interact with immune cells, influence inflammation and help regulate many biological processes throughout the body.

Although research continues to evolve, scientists increasingly recognise that the gut microbiome plays an important role in maintaining balance within systems that influence skin health.

Supporting a healthy and diverse microbiome through diet, lifestyle habits and microbiome support may therefore contribute to overall wellbeing and skin balance.

Some people choose to support their microbiome with probiotics — live cultures designed to help maintain a healthy balance of gut bacteria. Learn more about our Multi-Strain Biotic and how it supports gut health.