Investigate The Effects Of HDMTX On Intestinal Flora Of Children With ALL

Objective: To investigate the effects of HDMTX therapy on intestinal flora ofchildren with ALL and the feasibility of fluorescent quantitative 16SrRNA/DNA-targeted PCR in quantitative study of bacterium.Methods: (1)Extract the bacterial DNA in stool among 36 healthy children and 36children with ALL in pre- and post- HDMTX therapy, detect and compare OD₂₆₀ ofbacteria between the two groups.(2)16SrRNA/DNA PCR were applied in compare thebacterial content of Bacillus bifidus and Escherichia coli in stool among controlgroup and group with ALL in pre- and post- HDMTX therapy.Results: (1) Bacterial OD₂₆₀ of stool is respectively: control3479.3±870.5ng/ulpre-therapy group 2436.3±768.6 ng/ul, on 3th day of post-therapy1496.5±577.1 ng/ul, on 7th day1966.6±598.3 ng/ul;There is significant differencebetween bacterial OD₂₆₀ of healthy group and ALL group in pre- and post-therapy (p＜0.01);(2) The logarithm of Bacillus bifidus of stool is respectively: control 9.49±0.41, pre-therapy group7.24±0.33, on 3th day of post-therapy6.00±0.27, on 7thday6.59±0.33; and Escherichia coli is respectively:control 7.52±0.43, pre-therapygroup 6.62±0.42, on 3th day of post-therapy5.964±0.42,on 7th day7.02±0.41;The number of Bacillus bifidus and Escherichia coli in stool among healthy group,pre-therapy group and post-therapy group are significantly different (p＜0.01),especially on 3th day, which begin to rise on 7th day;Conclusions: (1) HDMTX therapy has great effects on intestinal bacterial flora ofBacillus bifidus and Escherichia coli in children with ALL, the bacterial contentsharply decreased post-therapy;(2) Sum of bacteria and Probiotics significantlydecreased in ALL group than healthy group,which maybe correlate to use chems andantibiotic long term; (3) 16SrRNA-targeted PCR technique is practicable in study ofquantitative analyses of intestinal bacterial flora.