OBJECTIVETo study the effects of different perioperative treatments on the number and proportion of gut flora in SD rats.

METHODSForty-eight SD rats were randomized into 8 groups including the control group, antibiotics group, bowel preparation group, fasting group, antibiotic-bowel preparation group, antibiotics-bowel preparation-fasting group, bowel preparation-surgery-antibiotics-early postoperative feeding group (early feeding group), and bowel preparation-surgery-antibiotics-postoperative fasting group. The rats were sacrificed and stool specimens were collected from the cecum. Stools were diluted and transferred to selective medium. Bacteria counts were calculated after 48 hours of culture under constant temperature. The changes in gut flora between the different groups were compared in terms of E.coli, Bacteroides, Bifidobacterium, and Enterococcus.

RESULTSCompared with the control group, the total bacteria, Bacteroid, Enterococcus, Bifidobacterium were all significantly decreased(P<0.05), while the E.coli count and the bacillus/coccus ratio were significantly elevated(P<0.05). In the bowel preparation group, the total bacteria count, Bacteroid, Enterococcus, Bifidobacterium were all significantly decreased(P<0.05), while the E.coli count remained stable(P>0.05) and the bacillus/coccus ratio was significantly elevated(P<0.05). In the fasting group, the total bacteria count, Bacteroid, Enterococcus, Bifidobacterium were all significantly decreased(P<0.05), while the E.coli count remained stable(P>0.05) and the bacillus/coccus ratio was significantly elevated(P<0.05). Early postoperative feeding increased E.coli, Enterococcus, and total bacteria count(P<0.05), and lowered bacillus/coccus ratio(P<0.05) as compared to the fasting group.

CONCLUSIONSAntibiotics, bowel preparation, and fasting have influence on the gut flora of SD rats in count and bacillus/coccus ratio, leading to dysbiosis. Early postoperative feeding may improve dysbiosis.