Investigating the role of Lactobacillus Crispatus in healthy skin and psoriasis

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Psoriasis is a life-long condition that causes unsightly red, flaky patches of skin. It is also linked with other problems including obesity and depression. Although some treatments exist for psoriasis, many patients do not have adequate control with currently available creams and ointments. More severe psoriasis is treated with tablets and injections that act on the immune system, but these are associated with considerable side effects and require long term monitoring with many blood tests and clinic visits. New genetic techniques have shown a diverse collection of 'harmless' bacteria that reside on the surface of human skin. A large study of patients with psoriasis and healthy volunteers have shown that there is are differences in the types and numbers of bacteria between the two groups. Lactobacillus Crispatus is a type of bacteria found on the skin that is more common in healthy skin than psoriasis.The meaning of this finding is not yet clear. However there is evidence that rather than acting as 'innocent bystanders', these bacteria may have an important role in altering the immune system response in the skin. Previous research has shown that overactivity of the immune system is important in promoting psoriasis. The presence of Lactobacillus Crispatus in healthy skin but not psoriasis suggests it may be important in preventing overactivity of the immune system. The exact way that the bacteria do this is not known, but previous studies have shown the importance of certain immune signaling pathways in preventing excess skin inflammation. Our study looks to answer if Lactobacillus Crispatus activates this particular pathway in the skin to prevent inflammation.There are three main parts to our study:1) Test how skin samples (biopsies) from healthy volunteers and psoriasis patients are affected by Lactobacillus Crispatus by mixing them with the bacterium in test tubes2) Test how skin cells from healthy volunteers and psoriasis patients are affected by Lactobacillus Crispatus by mixing them with the bacterium in test tubes3) Test the effects of Lactobacillus Crispatus on psoriasis severity by applying extracts of the bacterium to a model of psoriasisTo answer this I will take skin biopsies from healthy volunteers and psoriasis patients and mix them with extracts of Lactobacillus Crispatus. We also separate skin cells (keratinocytes) from biopsies and treat these with extracts of the bacterium. We then remove DNA from the cells and biopsies to measure the levels of genes and chemical messengers linked to psoriasis.To further understand the effects that bacteria have on live systems, we will use well established models of human psoriasis. We treat the inflamed area with extracts of the bacterium to see if this improves the appearance and severity of psoriasis and also asses the effect on genes and messengers. Learning more about the role of these bacteria in psoriasis may help us identify if we can use them medically (for example in the form of creams or ointments) to treat psoriasis in the future.