RESUMEN
There is a variety of gut microbiota in human body, which is closely associated with the health and disease. Normal gut microbiota can produce colonization resistance to pathogens. Antibiotics can affect the composition of gut microbiota and change the intestinal microenvironment, resulting in intestinal microecological disorders, which in turn cause intestinal pathogenic infections and other diseases. In this paper, the concept of intestinal microecology, the mechanism of intestinal colonization resistance, the effect of antibiotics on intestinal microecology, and the treatment methods were reviewed, aiming to provide the information for the rational use of antibiotics and the development of more effective treatment methods to maintain the stability of intestinal microecology.
RESUMEN
Background & objectives: Despite advancements in molecular-based methods, the composition of the human ileal microbiota and the effects of synbiotics/probiotics on its microbes remain poorly understood. The aim of this study was to determine the composition of the mucus microbiota in the human ileum and to assess the effects of oral administration of synbiotics on the microbiota. Methods: As part of a clinical trial for synbiotics treatment and surgical infection, ileal mucus was sampled when resection of the ileocecal portion was required. The microbiota composition was examined using 16S rRNA-targeted real-time-quantitative polymerase chain reaction. Results: A total of 33 samples from the synbiotics group and 39 from the control group were analyzed. Total numbers of bacteria in the ileum were 108.5 cells/g in the synbiotics group and 108.4 cells/g in the control group, in which obligate anaerobes were dominant over facultative anaerobes. The level of Enterobacteriaceae was significantly lower in the synbiotics group than in the control group. The administered probiotics species Lactobacillus casei strain Shirota and Bifidobacterium breve strain Yakult were detected in 42 and 76 per cent of the synbiotics group, respectively. No significant correlations were observed between tumour stage/size and the various microbes present, except for a negative correlation between tumour size and Bifidobacterium. Interpretation & conclusions: The present analysis of a substantial number of samples from surgically resected intestines showed an abundance of obligate anaerobes as a characteristic feature of the ileal mucus microbiota. Our results also indicated that the synbiotics intervention induced a prominent reduction in Enterobacteriaceae in the ileal microbiota.
RESUMEN
Objective To investigate the effects of peri-operative enteral nutrition (EN) and antibiotics on intestinal flora balance in patients with esophageal carcinoma.Methods Sixty patients were randomly divided into six groups:Group B,treated with antibiotics for 3 days and supported with EN before and after operation; Group C,treated with antibiotics for 3 days and supported with parenteral nutrition (PN) before operation and EN after operation ; Group D,treated with antibiotics for 3 days and supported with PN before and after operation ; Group E,treated with antibiotics for 7 days and supported with EN before and after operation; Group F,treated with antibiotics for 7 days and supported with PN before operation and EN after operation ; and Group G,treated with antibiotics for 7 days and supported with PN before and after operation.The first stool after surgery was obtained and tested for Bacteroides,Bifidobacterium,Lactobacillus,Escherichia coli,and Enterococcus.Ten healthy adults were enrolled as the blank control group.The numbers of the flora and ratio of Bifidobacteria to Enterococci (B/E) were compared.Complications such as incision infections,lung infections,and anastomotic fistula were recorded.Results The numbers of Bifidobacterium [(10.59 ± 0.39) vs.(10.88 ± 0.10) lg10n/ml,P =0.186),Lactobacillus [(8.59±0.31) vs.(8.72 ±0.22) lg10n/ml,P=0.534],Escherichia coli [(8.43 ±0.50) vs.(8.67 ±0.24) lg10n/ml,P=0.266],Enterococcus [(7.40 ±0.61) vs.(7.78 ±0.16) lg10n/ml,P =0.111],and B/E value [(1.2589 ± 0.0644) vs.(1.2560 ± 0.0330),P =0.825] in the Group B were not significantly different from the blank control group.The numbers of Bacteroids [(11.08 ± 0.48),P =0.139 ; (9.23 ± 0.42),P =0.000; (10.80±0.26),P=0.004; (10.24±0.45),P=0.000; (8.05±0.53),P=0.000vs.(11.36±0.48) lg10n/ml],Bifidobacterium [(10.19 ±0.49),P=0.062; (9.00 ±0.52),P=0.000; (9.31 ±0.45),P=0.000; (8.47±0.56),P=0.000; (6.99 ±0.56),P =0.000 vs.(10.59±0.39) lg10n/ml],Lactobacillus [(7.99 ± 0.58),P =0.006 ; (6.84 ± 0.47),P =0.000 ; (7.72 ± 0.35),P =0.000 ; (6.93 ±0.43),P =0.000; (5.93 ±0.76),P=0.000 vs.(8.59 ±0.31) lg10n/ml],Escherichia coli [(8.19 ±0.43),P=0.258; (7.93±0.60),P=0.020; (7.47±0.43),P=0.000; (6.90±0.42),P=0.000; (6.58±0.57),P =0.000 vs.(8.43 ± 0.50) lg10n/ml],and Enterococcus [(6.90 ± 0.54),P =0.037 ; (5.89 ± 0.68),P =0.000; (6.20±0.52),P=0.000; (5.91 ±0.39),P=0.000; (5.14±0.58),P=0.000 vs.(7.40±0.61) lg10n/ml] of groups C,D,E,F,and G decreased compared with those of the Group B.The values of B/Ein the D and G groups decreased significantly when compared to the blank control group (1.1433 ±0.1350,P =0.025 ; 1.0706 ± 0.1413,P =0.000 vs.1.2560 ± 0.0330).The incidences of pulmonary infections (x2 =3.647,P =0.601) and anastomotic leak (x2 =5.000,P =0.416) among all groups were not significantly different.Conclusions EN applied 3 days before surgery and after surgery is beneficial for maintaining the balance of intestinal flora.Long-term administration of antibiotics may cause dysbacteriosis and even increase complications.