Abstract: Objective To discuss the condition of small intestinal bacterial overgrowth (SIBO) in patients
with primary liver cancer and the roles of intestinal flora and toll-like receptor 4 (TLR4) in the occurrence
and development of primary liver cancer. Methods Total of 51 patients with primary liver cancer in Qingdao
Municipal Hospital Affiliated to Qingdao University from July 2013 to July 2015 and 20 healthy controls
were selected. Among the 51 patients with primary liver cancer, 38 cases were male and 13 cases were female,
the average age was (55.71 ± 8.99) years old. The glucose hydrogen breath test (GHBT) was used to detect
the condition of SIBO and the immunohistochemical method was used to detect the expression of TLR4 in
liver tissue of all subjects. Results Of 51 patients with patients with primary liver cancer, 37 (72.6%) were
GHBT positive and 14 (27.4%) were GHBT negative, while in the control group, none was GHBT positive.
The difference in the incidence of SIBO between liver cancer patients and control group was statistically
significant (χ 2 = 30.3, P = 0.000). The expressions of TLR4 were different in all liver cancer tissues, and in
normal liver tissue it had only a small amount of expression. In patients with liver cancer, the expression
level of TLR4 in GHBT positive patients was higher than that of GHBT negative (χ 2 = 5.088, P = 0.024).
Conclusion Patients with primary liver cancer are prone to SIBO, and the intestinal flora may promote the
occurrence of liver cancer through the expression of TLR4.