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Chronic skin conditions such as psoriasis are becoming more common place. The cyclical nature of this condition can feel especially traumatic for sufferers.
This article looks at potential causes of psoriasis, and the way in which probiotics can help as part of a management protocol:
Psoriasis is an autoimmune condition whereby the immune system mistakenly attacks healthy skin cells causing them to multiply too rapidly. A healthy turnover of skin allows old cells to shed before new skin cells are produced.
When skin cells multiply too rapidly, new cells push up old cells to the outmost layer of the skin. This causes the primary symptom of psoriasis - areas of thick, dry skin covered with silvery scales, known as plaques. These plaques can be sore and itchy as well as unsightly. Psoriasis typically affects the elbows, knees, scalp, nails and trunk of the body, but plaques can appear anywhere on the body.
In some people, the effects of psoriasis are not restricted to the skin. Chronic inflammation present in a specific type of psoriasis, known as psoriatic arthritis, affect the joints, causing swelling, stiffness and pain. It is thought that up to 1 in 4 people with psoriasis also go on to develop psoriatic arthritis1.
The autoimmune nature of psoriasis causes systemic inflammation which speeds up skin cell growth and the tell-tale signs of plaques. It is thought that the combination of environmental factors and genetics play a role in the initiation and subsequent development of psoriasis. Unfortunately, some people are simply more predisposed to developing psoriasis and outer autoimmune conditions than others. Another skin condition, lichen sclerosis, which typically shows up as white, itchy patches on the genitals and other areas of the body, is also thought to be an autoimmune reaction. Recent research indicates some possible links between lichen sclerosis and psoriasis, particularly for women12.
There is also a growing body of evidence suggesting that an imbalance of bacteria in the gut, known as dysbiosis, is a causative factor in psoriasis and other inflammatory diseases. A 2015 study showed that people with psoriasis tend to have less diversity in their gut microbiome than healthy individuals2.
Interestingly, a small-scale study a few years later reported conflicting findings in terms of gut microbiome diversity in psoriasis sufferers. The researchers in this instance found individuals with psoriasis to have increased diversity in the gut microbiome and a reduced stability of the skin’s microbiome when compared with healthy individuals3.
For some people, their first occurrence of psoriasis can happen during a particularly stressful period. We know that during high periods of stress levels of the stress hormone, cortisol, increase. The increased cortisol in turn promotes an inflammatory response throughout the whole body which can result in a worsening of psoriasis symptoms. For psoriasis sufferers any significant worsening of symptoms can lead to more stress, resulting in a vicious cycle that make psoriasis plaques more prolonged and sorer.
An imbalanced gut microbiome plays a role in the development of psoriasis in many instances. As mentioned above, dysbiosis is associated more often with psoriasis sufferers than healthy individuals.
Another way that dysfunction in the gut can be related to psoriasis is through intestinal permeability (also known as leaky gut). An altered intestinal barrier, when the lining of the gut is damaged allowing bacteria and undigested food particles to pass through, tends to manifest as systemic inflammation and higher incidence of disease, including psoriasis.
Studies have yet to confirm whether intestinal permeability causes the pathogenesis of psoriasis or is a result of the condition. A small study in 2018 confirmed a relationship between dysfunction of the intestinal barrier, and imbalanced gut microbiome, immune system dysfunction and in psoriasis4, but further research is needed to establish the exact mechanisms.
Additionally, studies on mice suggest that early exposure to sex hormones and certain types of gut bacteria may have strong effects on the development of autoimmune conditions, of which psoriasis is one type. One study in particular investigated transferring gut microbes from adult male mice to young female mice. This resulted in increased testosterone and reduced autoantibody production in the female mice, which reduced their risk of type 1 diabetes10. The research team concluded that the introduction of certain gut microbes, potentially from probiotic supplements, early in life may reduce the risk of autoimmune conditions in children. Further studies in humans could prove to be ground breaking.
In many cases an outbreak of psoriasis is triggered by a bacterial infection, typically streptococcus (strep throat). The infection can set off an immune system reaction that causes a specific type of psoriasis called guttate psoriasis, characterised by small, raised papules on the chest, arms or legs. Guttate psoriasis is the second most common type of psoriasis, often starting in childhood or as a young adult5.
Research has shown that the microbes in our skin, known as our skin microbiota, play a role in the development of chronic psoriasis. In addition to streptococcus, other types of pathogenic bacteria including Corynebacterium, Propionibacterium, and staphylococcus, have been identified as bacterial genera indicated in the development of psoriasis6.
At present there is limited research on probiotic strains specifically for psoriasis. However, it is known that probiotics help to maintain a good balance of healthy gut bacteria which can have a positive impact on controlling chronic inflammation, which as explained earlier is a factor in the development of psoriasis.
Here, we explain which probiotic strains may be beneficial to take for psoriasis.
The probiotic strain, Bifidobacterium infantis 35624, has been investigated for people with psoriasis. A 2013 study looked at the effects of supplementation of Bifidobacterium infantis 35624 on a small number of people with psoriasis. Researchers concluded that taking the oral probiotic over an 8 week period reduced the biomarkers for inflammation8. You may like to read about further research behind the strain Bifidobacterium infantis 35624 on our Probiotics Database: Bifidobacterium infantis 35624.
Additionally, a 2018 study looked at the effects of probiotics on skin conditions in mice, with the aim of establishing how the gut microbiome affects other areas of the body. The researchers found that certain strains, including Lactobacillus salivarius LA307 and Lactobacillus rhamnosus LA305, reduced chronic skin inflammation and improved outcomes for both atopic dermatitis and psoriasis9.
Other probiotic strains that have been researched in relation to dysbiosis and gut health included the extensively researched probiotic strain Lactobacillus acidophilus NCFM®. Lactobacillus acidophilus NCFM® has been shown in many trials to improve regularity and prevent gut dysbiosis, which in turn improves the health of the skin11. As mentioned earlier, individuals with skin conditions including psoriasis, acne and eczema all exhibit gut dysbiosis to some degree.
You can find out more about the probiotic strain Lactobacillus acidophilus NCFM® on our Probiotic Database.
As mentioned earlier, psoriasis often has an element of gut inflammation and intestinal permeability, or leaky gut. Saccharomyces boulardii, a yeast with probiotic properties, can help to restore the strength and function of intestinal cells, so may be a helpful supplement for psoriasis sufferers.
You may like to read more about research behind Saccharomyces boulardii on our Probiotics Database: Saccharomyces boulardii.
The link between gut health and skin health is becoming increasingly well-studied and documented, however we would welcome more specific research into probiotic strains for psoriasis.
Psoriasis is a chronic condition, and many people suffer for long periods of time before seeking help. Therefore, it is usually best to take probiotic supplements long term to give them the best chance of taking effect. Probiotics do not provide a quick fix because they get to the root cause of why psoriasis may be occurring.
The length of time psoriasis symptoms takes to show improvement when supplementing with probiotics varies. One study reported significant clinical improvement in severe pustular psoriasis within two weeks, and almost complete remission after four weeks7. The participants in the study had previously been unresponsive to several other treatments before commencing Lactobacillus sporogenes supplementation 3 times per day.
Health professionals may also be interested in reading other related articles on our Probiotics Professionals: