Objective:To evaluate the effect of early enteral nutrition supplemented with synbiotics on the levels of C reactive protein (CRP) and Procalcitonin(PCT)level of patients with severe brain injury.The clinical outcomes were also observed.Methods:Forty-seven patients with identified severe brain injury were randomized into study group (n =24) and control group (n =23).All patients received enteral nutrition via nasogastric tube within 24 to 48 h following admission.Patients in the study group were also given synbiotics.Fasting blood samples were collected for detecting the levels of CRP,PCT on day 1,4,7 and 15,respectively.The incidence of lung infection,the length of ICU stay,the cost,the GCS score,the APACHE Ⅱ score,and the mortality in 30 days after administration were collected and compared between 2 groups.Results:Patients in the study group had a lower level of PCT than control group on day 7 and 15 (P ＜0.05,P ＜0.05),and a lower level of CRP on day 15 (P ＜0.01)was also found in the study group.The incidence of lung infection of the study group was also significantly lower than the control group (P ＜ 0.05).A reduced length of hospital stay and a lower cost were found in the study group (P ＜0.05).The GCS scores in the study group was higher on day 15 when compared with that in the control group (P ＜ 0.05).However,There was no significant change in APACHE Ⅱ score and mortality in 30 days(P ＞ 0.05).Conclusion:Nutrition supplemented with synbiotics leads to a lower rate of infection,a shorter length of ICU stay,a reduced the cost,and a better outcome in patients with severe brain injury.