Eczema Points to the Gut

By Jane Litsey, ND

Atopic dermatitis, also known as eczema, is a chronic inflammatory skin condition that can cause dry, itchy, red and irritated skin.  It affects 15-30% of children and 2-10% of adults (1). Although the disease presents topically, the pathology begins with imbalances in the gut —- a connection now known as the gut-skin-axis.

Inflammation and imbalances in the digestive tract have been found in patients with eczema.  Research points to three areas of gut-skin connection.

  1. Intestinal permeability, also known as ‘leaky gut’
  2. A decrease in short chain fatty acids (SCFAs)
  3. Dysbiosis – an imbalance in the community of bacteria in the small intestine or colon

Intestinal Permeability / Leaky Gut

Leaky gut syndrome is a theory that intestinal lining of the gut can become more permeable to toxic agents and trigger an inflammatory response in the body.  In a healthy gut, our gut lining, or semi-permeable mucous membrane is designed to absorb water and nutrients from food into our blood stream.  It also acts as a protective barrier shielding your body from toxins, pathogenic bacteria and infectious agents.

The theory of leaky gut, or intestinal permeability, suggests that poor diet, lack of fiber, chronic stress, repeated use of NSAIDS and antibiotics, and gastrointestinal infections can all wear down the protective mucus layer in the gut lining, leaving intestinal cells vulnerable to damage.  Over time, after chronic assault, the intestinal lining can weaken allowing bacteria, toxins, and poorly digested food to be absorbed into the blood stream and deposit in tissues throughout the body – including the skin.  These foreign substances can stimulate the immune system resulting in damage to the integrity of the skin. (4)

Intestinal permeability also sets the stage for food sensitivities, gastrointestinal diseases, skin conditions and autoimmune diseases to emerge.  An important species of bacteria often missing or low in patients with eczema is called Akkermansia, a organism known to stimulate the production of mucus (5).

Low Short Chain Fatty Acids

Our daily diet has a direct impact on the microbiome in our intestine. The dietary fiber we consume in the form of plants (veggies, fruits, grains, nuts and seeds) provides food for bacteria. In turn, the bacteria produce something called short chain fatty acids, SCFAs.  SCFAs are actually a preferred food source for the cells of the colon.

The function of SCFAs extends beyond the gut. They are also powerfully anti-inflammatory and help maintain the integrity of the skin barrier (6) . Before the onset of eczema, studies have shown a decline in SCFAs, setting the stage for disease (4). The average American consumes 12-15 grams of fiber in their daily intake of food, whereas healthy intestinal communities often require at least 30-35 grams of fiber daily to achieve healthy SCFA levels (7).

Another important species of bacteria absent or low in patients with eczema is Faecalibacterium prausnitzii, a well known producer of the SCFA butyrate. (4)  In addition to improving skin integrity, SCFA like butyrate have been shown to prevent overgrowth of Staph aureus on the skin.

Dysbiosis – Imbalanced Gut Bacteria

Fecal studies of patients with eczema found lower amounts of commensal or beneficial bacteria in the colon. They specifically found decreased amounts of Bifidobacterium, Bacteroides, Akkermansia and Faecalibacterium prausnitzii. (5)  In addition, they found overgrowth of the bacteria called Enterobacter and Staphylococcus aureus and overgrowth of candida albicans, a type of fungus (5).

Research showing the connection between the skin and gut helps explain why topical steroids often ignore the root of the problem and can require higher doses over time to keep the disease in check.  Addressing imbalances in the microbiome, increasing fiber intake to support SCFAs, and repairing a leaky gut are all potential treatment strategies with patients with eczema.