Alternation Of Murine Enteric Bacteria In Intestinal Inflammation Induced By Tichina Spiralis Infection

Trichinella spiralis is a kind of zoonotic parasites and widely spread in theworldwide. It can cause the Trichinosis which affects the health of human and animalsby eating undercooked pork and the meat of other animals containing with Trichinellaspiralis larvae. Course of the disease is mainly divided into three period includingintestinal, muscular period and recovery period. In the intestinal, some patientspresent gastrointestinal symptoms including abdominal pain, diarrhea and vomitingwhich harm to human health seriously.With recent technological developments in life science, a number of studiesdemonstraded that gut microbiota is an important organ which is closely related tohuman and animal’s health. The relationship between the gut microbiota and the hostis the key link to human and animal’s health and disease. The intestinal microflora inmammals is mainly comprised of bacteria, the number of living bacteria in normalhuman intestinal is up to1014, which is10times more than the number of the bodycells. The intestinal microflora, which significantly impacts on the human and animalhealth and growth, not only involved in the digestion, nutrient absorption, metabolismand immune regulation, but also protects from the infections of pathogenic andpotential pathogenic bacteria. Intestinal flora can be divided into probiotics,conditional pathogenic bacteria and pathogenic bacteria. The balance of bacteria ingut benefits host health, but once the balance destroyed, it will result a variety ofdiseases, such as diabetes, intestinal inflammation, cardiovascular diseases and evencancers.There is a huge amount of literature on the interaction between the Trichinellaspiralis and host or intestinal microflora and host were documened, but few on therelationship between the intestinal inflammatory and intestinal microflora in miceinfected with Trichinella spiralis. In this study, we applied Trichinella spiralis infected mouse model and DSS induced colitis model to explore the relationshipbetween symbiotic microorganisms and intestinal inflammation in mice infectedTrichinella spiralis. The alteration of intestinal flora during the course of intestinalinflammation after infection was investigaed by the Real-time PCR depend on16S r-DNA, histological and immunological technology. Feces and intestinal tissues wereobtained from BALB/c mice infected or uninfected with Trichinella spiralis ISS534atday7,14and28post infection (PI). The inflammation was seen in small intestine atday7, and became worse at day14, and reduced at day28PI. The16S rDNAexpression level of Bifidobacterium was significant decreased at day7and day14(p<0.05) PI,and Lactobacillus was significant decreased at day14(p<0.05) PI. Onthe contrary, the16S rRNA level of Clostridium and Enterococcus was significantincreased at the same time points. Compared with the control group, the16s RNAlevel of these bacteria at day14was significant higher than that at day7, and thendecreased to the normal level at day28PI. The16S rDNA expression level of RectalEubacterium and Faecalibacterium prausntzi had no significant in this research.Meanwhile, the16S rDNA expression of Bacteroides and Desulfurization arc spp wasvariety among the different mice. Cytokine (IL-10, TNF-a, IL-12and IL-17)productions in duodenum and jejunum fragment cultures were measured by ELISA.Compared to controls, IL-10and TNF-a production in duodenum and jejunum ofinfected mice was significant increased at day7(p<0.05) and day14(p<0.01), whilerestored in the day28. However, the IL-12and IL-17secretion in either duodenum orjejunum of infected mice was significant decreased at day7(p<0.05) and day14(p<0.01), while restored at day28. Compared to the mice infected with Trichinellaspiralis, severe damage in the colon tissue of the uninfected mice administrated with2.5%DSS, which presented the shedding and necrosis of epithelial cells and erosion,in contrast, significant attenuated DSS-induced colitis was seen the mice infected withTrichinella spiralis for28days.The results showed that after the infection of Trichinella spiralis, the changes of16s RNA expression of Bifidobacterium, Lactobacillus, Clostridium and Enterococcus in mice intestine is related to the alteration of intestinal inflammation. In the earlyperiod of infection with initial inflammation, intestinal flora balance was detoured, thenumber of probiotics bacteria significantly were reduced while the opportunisticpathogenic bacteria or pathogenic bacteria were increased, IL-10cytokine in intestinewhich mediated the immune suppression and TNF-a was significant increased, inorder to suppress the inflammation. At late time point of post infection with therecovery from inflammation, the number of probiotics bacteria significantly wereincreased while the opportunistic pathogenic bacteria or pathogenic bacteria weredecreased, the production of TNF-a and IL-10in intestine dropped to normal level.Compared to the control group, the attenuated DSS-induced colitis in mice infectedwith Trichinella spiralis confirmed that Trichinella spiralis mediated intestinal mucosainmmune suppression. This experiment is providing the experimental tools andstrategies for studying on the link among the parasitic infection, intestinal microfloraand intestinal inflammation. It helps to better understand that the symbiotic bacteria,probiotics and intestinal parasites involve in intestinal mucosa immune and theirpotential role in suppression of intestinal inflammation for further develop the newmicro ecological productions and treatment of autoimmune disease and inflammatorydiseases.