The Associations And Mechanisms Between Spicy Food Intake And Obesity In Han Obese Chinese Population In Cold Region Of Yunnan Plateau

Obesity prevention and treatment has become a serious public health issue in China.Numerous studies have shown that environmental factors are intimately related to obesity in metabolic diseases,and dietary habits are one of the most significant environmental factors affecting the risk of the development of obesity.In recent years,the correlation between spicy food intake and obesity has become a hot topic.However the relation of spicy food intake and risk of obesity is controversial,and there is no relevant report in the population in Cold Region of Yunnan Plateau.Hence,based on the established Southwest Natural Population Cohort（China Multi-Ethnic cohort,CMEC）,which is the first large-scale natural population cohort established in the high-altitude regions of Lijiang in Yunnan,Lhasa in Tibet,and Aba in Sichuan,we conducted a study to investigate the association between spicy food intake and obesity in the Han population of Yunnan plateau cold region and also explored its mechanism.Objective:Our study relies on the China Multi-Ethnic Cohort established by the National Key Research and Development Program "Precision Medicine".Taking the natural population of Han nationality in the cold area of Yunnan Plateau as the research object,we investigate the relation between spicy food intake and the risk of obesity in the Han nationality natural population in the cold region of the Yunnan Plateau.And the trend of Leptin,which is a key factor of obesity,and the important role of spicy food in the Han nationality obese population were also explored.Our study aims to provide a new target for the early prevention and treatment of obesity in Yunnan plateau region.Methods:1.Relies on the China Multi-Ethnic Cohort established by the National Key Research and Development Program "Precision Medicine",Our study selected subjects from Han Natural Chinese Population in Cold Region of Yunnan Plateau.Inquiries,dietary surveys,medical physical examinations,and laboratory index tests were carried out.With reference to the Chinese BMI evaluation standard,the obesity group and the control group were matched 1:1 by age ± 2 years,gender,and township.A total of 616 were included in study.Leptin、A-FABP and Visfatin were tested by ELISA.The correlation between spicy food intake and obesity key adipokines were investigated.2.The food frequency questionnaire（FFQ）was used to investigate the dietary and nutritional status of Han population in the cold plateau.The associations between spicy food intake and obesity in Han Chinese in the control group and the obese group were established.We also exmained the effect of spicy food intake on nutrition,lipid metabolism and obesity-related key factors and obesity to systematically and comprehensively reveal the assocition between spicy food intake and risk of obesity in the Han nationality natural population in the cold region of the Yunnan Plateau and the changing trend of Leptin,a key obesity factor.3.Based on the results of the population nutritional epidemiology survey,the obese rats model was established.Animals were divided into Control group,High-fat group,High Fat Diet-Low Capsaicin group,High Fat Diet-Medium Capsaicin group and High Fat Diet-High Capsaicin group to explore the effects and possible mechanisms.4.The body weight and food utilization rate of rats were measured every week.Blood samples,adipose tissue and fecal sampleswere collected at week 12.Serum Leptin levels were detected by ELISA,and animal experiments were used to verify the change trend of Leptin caused by the intake of spicy food.16s high-throughput sequencing was used to detect the intestinal flora in the feces of rats.The correlation between serum Leptin and intestinal flora was further analyzed by applying the association analysis between intestinal flora and clinical factors,and the preliminary exploration of the relationship between Leptin level and intestinal flora,To explore the role of leptin and intestinal flora in spicy food intake and obesity.Results1.The frequency of spicy food intake was higher,the initiation age of spicy food intake was younger,the years of intake were longer,and the degree of spicy food intake was milder in Han Natural Chinese Population in Cold Region of Yunnan Plateau;and the frequency of spicy food intake,the years of intake,and the burden of spicy food intake were higher in the obese population compared with the normal population（P<0.05）.2.Frequency of spicy food intake,years of spicy food intake,and the ratio of years of spicy food intake to age（i.e.,spicy food intake burden）were associated with increased risk of obesity among Han residents in Han Chinese Population in Cold Region of Yunnan Plateau（P<0.05）.3.Spicy food intake mainly increased energy and carbohydrates intake（P<0.05）,altered lipid metabolisms（high TC,high TG,high LDL and low HDL）and serum adipokines Leptin and A-FABP levels（P<0.05）by increasing staple food intake（P<0.05）in obese people.The serum Leptin levels were also higher（P<0.05）in obese individuals with different dose levels（low,medium and high）of different spicy food sources（chili sweet pepper,chili noodles,dried pointed red pepper,chili paste）than normal individuals.4.Capsaicin intervention did not significantly improve body weight and lipid metabolism in obese rats,but it promoted appetite and increased food utilization rate in obese rats（P<0.05）;and it is visible that capsaicin intervention was associated with increased changes in high TC,high TG,high LDL and low HDL lipid levels in obese rats,though without statistical significance.5.The animal model study found that the serum Leptin levels were higher in the obese rats than in the normal group（P<0.05）,which is consistent with the results of the population study.The serum Leptin levels in obese rats were showed an increasing trend with different doses of capsaicin intervention,but the difference was not statistically significant.6.The results of the animal intestinal flora study showed that HFD group were significantly changed compared with those in the control group（P<0.05）,and the abundance of butyric-producing bacteria Blautia,Clostridiaceae and Ruminococcus torques_group increased.What’s more beneficial bacteria Akkermansia Muciniphila（AKK）appeared;capsaicin intervention increased the multiplication of the intestinal harmful Clostridium_sensu_stricto₁,unclassified_fPeptostreptococcaceae,BurkholderiaCaballeronia-Paraburkholderia,Bacteroides,Romboutsia,etc.and reduce the production of beneficial bacteria Lactobacillus,Oscillibacter,norank_fDesulfovibrionaceae.As a result,the structure and diversity of intestinal flora are altered.The further analysis of the correlation between intestinal flora and clinical factors revealed that Leptin correlated with rat intestinal flora at any level of family and genus（P<0.05）;Leptin correlated with rat intestinal flora in the HFD group at any level of family and genus（P<0.05）;Leptin levels correlated with rat intestinal flora in the CAP intervention group at any level of phylum and genus（P<0.05）,capsaicin intervention may increase Leptin level and lead to intestinal microflora disorder,which plays a role in the occurrence and development of obesity.Conclusion1.Spicy food intake was related to a higher risk of obesity in Han Natural Chinese Population in Cold Region of Yunnan Plateau.2.Spicy food intake may influence the intake of staple food of obese people in cold plateau areas,promotes the increase of energy and carbohydrates intake,and then weaken the weight loss effect of Leptin,resulting in hyperleptinemia affecting the occurrence and development of obesity.3.The relationship between capsaicin and obesity was not observed in animal experiments,but capsaicin intervention may increase Leptin level and lead to intestinal microflora disorder,which plays a role in the occurrence and development of obesity.