| Psoriasis is an immune-related inflammatory skin disease that affects more than 100 million people worldwide.It is of great significance to explore the risk factors of psoriasis and the possible prevention methods.In recent years,researchers have paid attention to the effects of diet and intestinal flora on various chronic non-communicable diseases,but there is still a lack of research on psoriasis.This study includes three independent and interrelated researches: the association between lifestyle behaviors with psoriasis;the association between diet or dietary patterns with psoriasis;and the characteristics of the intestinal flora of psoriasis and the relationship among diet,intestinal flora,and psoriasis.(1)Lifestyle behaviors and the risk of incident psoriasis.Objective: To evaluate the influence of lifestyle behaviors including diet on the risk of incident psoriasis separately and comprehensively;and to test whether there is an independent association between lifestyle behaviors and incident psoriasis.Methods: A prospective cohort study was established after submitting an application to the UK Biobank database to obtain relevant data.Multivariable cox proportional hazard regression models were used to examine the association between body mass index(BMI),smoking,physical activity,diet,and the healthy lifestyle score with incident psoriasis.And the population-attributable fraction(PAF)was also calculated.Results: After adjusting for age,sex,region,education,and socioeconomic status,the risk of incident psoriasis was significantly higher in the poor lifestyle group than in the ideal lifestyle group.And the healthy lifestyle score had a greater effect than each single lifestyle behavior.The lifestyle behaviors and the healthy lifestyle score was associated with the risk of incident psoriasis in each level of genetic risk.There was no significant interaction between lifestyle behaviors,or the healthy lifestyle score with genetic factors.The PAF of healthy lifestyle score was higher than genetic factors.Conclusions: BMI,smoking,physical activity,and diet are associated with the risk of incident psoriasis.Lifestyle behaviors are predictive of the risk of incident psoriasis independently of genetic risk.And the relative impact of lifestyle behaviors was greater than genetic risk.(2)Diet and the risk of psoriasis.Objective: To explore the association between dietary frequencies,and dietary patterns with the risk of psoriasis;and to compare the results of domestic and foreign populations.Methods: Firstly,a prospective cohort study was established after submitting an application to the UK Biobank database to obtain relevant data.Multivariable cox proportional hazard regression models were used to examine the association between dietary frequencies,and dietary patterns with the risk of incident psoriasis.Secondly,a case-control study among the Chinese population was established based on the medical platform of Xiangya Hospital,Central South University.The case group and control group were matched according to age and sex.Logistic regression model was established to analyze the relationship between the dietary frequency with psoriasis.Results: After adjusting for age,sex,BMI,total daily energy expenditure,smoking,race,region,education,and socioeconomic status,associations were observed between the frequencies of five diets(cereals,fish,fruits,alcohol,and tea)with the risk of incident psoriasis.A significant correlation was observed between increased Mediterranean diet score with reduced risk of incident psoriasis(HR=0.983,95%CI: 0.970～0.997,P=0.015).But there was no significant correlation between a low-calorie diet and the risk of incident psoriasis(HR=1.460,95%CI: 0.907～2.352,P=0.119).In the case-control study among the Chinese population,after adjusting for sex,age,and BMI,significant associations between dietary frequencies and psoriasis were observed in four kinds of diets(red meat,poultry,fish,and fresh vegetables).Conclusion: Higher frequencies of intake of cereals,fruits,fish,and tea were protective factors for incident psoriasis.There were two opposite effects of alcohol intake on the risk of incident psoriasis.Mediterranean dietary pattern is a protective factor for psoriasis.There was no significant association between a low-calorie diet with the risk of psoriasis.The association between the diet with psoriasis in the Chinese population is somewhat different from that in the European population.(3)The intestinal flora of psoriasis.Objective: To explore the characteristics of intestinal flora in patients with psoriasis;to explore the possible correlation between diet,intestinal flora,and psoriasis;and to preliminarily explore the intervention effects of possible intestinal flora markers of psoriasis.Methods: Firstly,a case-control study among the Chinese population was established based on the medical platform of Xiangya Hospital,Central South University.Metagenomic sequencing,data preprocessing and data analysis of fecal samples were performed on the platform of Advanced(Beijing)Clinical Medical Laboratory to obtain the characteristics of intestinal flora in patients with psoriasis.The mediation effect model of dietary frequency(X)→ relative abundance of intestinal flora(M)→psoriasis(Y)was established.Secondly,according to the results of the case-control study,a pathogenic bacteria specie and a beneficial bacteria specie were selected for the intervention experiments.Results: The β diversity and α diversity were significantly decreased in the psoriasis group.Prevotella copri and Parabacteroides merdae were significantly enriched in the psoriasis group.Anaerostipes hadrus,Blautia wexlerae,and other 6 species were significantly enriched in healthy controls.The results of dietary frequencies were basically consistent with those in Part II.The results of the mediation effect model showed that the mediating effects were mainly concentrated in species producing short-chain fatty acids.In the intervention study of intestinal flora,results showed that compared with the control group,the skin lesions of mice were heavier and the spleen index was higher in the group of Prevotella copri,while the skin lesions were lighter and spleen index was lower in the group of Anaerostipes hadrus.But the results were not statistically significant.Conclusions: The characteristics of intestinal flora in patients with psoriasis were significantly different from healthy controls.Intestinal flora mediated the association between the diet and psoriasis to some extent.The intervention of intestinal flora may alter the severity of skin lesions of psoriasis.In conclusion,this study analyzed the independent association between lifestyle behaviors such as diet with incident psoriasis,and focused on the analysis of the association between diet with the risk of psoriasis,and the characteristics of intestinal flora in patients with psoriasis.And this study also preliminarily explored the association between diet,intestinal flora,and psoriasis.This study intends to provide new epidemiological evidence for the prevention of the incident psoriasis,to provide new ideas for the adjuvant treatment of psoriasis through dietary intervention and intestinal flora intervention,and to make new suggestions for the prevention and adjuvant treatment of psoriasis. |
PDF Full Text Request