Molecular analysis of bacterial populations in the ileum of broiler chickens and comparison with bacteria in the cecum

Abstract

Bacterial populations in the ileum of broiler chickens were analyzed by molecular analysis of 16S rRNA genes and compared to those in the cecum. Bacteria found in the ileal mucosa were mainly Gram-positive with low G+C content. There were 15 molecular species among 51 cloned sequences. More than 70% of the cloned sequences were related to lactobacilli and Enterococcus cecorum. Two sequences had 95% or less homology to existing database sequences. Terminal restriction fragment length polymorphism (T-RFLP) analysis revealed differences among bacterial populations present in the mucosa and lumen of the ileum. Comparative studies by T-RFLP and sequence analyses of 16S rRNA genes indicated a less diverse bacterial population in the ileum (mucosa and lumen) than in the cecum. Lactobacilli, E. cecorum, and butyrate-producing bacteria related (including both identified and unidentified species) sequences were the three major groups detected in ilea and ceca. Although butyrate-producing bacteria may have good potential in the development of novel probiotics for poultry, verifying the presence of the bacteria in the chicken gut is required to warrant further investigation.

Effects of Two Probiotic Lactobacillus Strains on Jejunal and Cecal Microbiota of Broiler Chicken under Acute Heat Stress Condition as Revealed by Molecular Analysis of 16S rRNA Genes

“…In addition, it has been demonstrated that T-RFLP analysis is useful for assessment of the diversity of the human fecal microbiota and rapid comparison of the community structure among individuals (13,32). T-RFLP analysis revealed differences among bacterial populations present in mucosa and lumen of the chicken ileum and cecum (8,9).…”

Detection of Clostridium sp. and its Relation to Different Ages and Gastrointestinal Segments as Measured by Molecular Analysis of 16S rRNA Genes

“…It is known that the gut microflora cans significantly be influenced by the diets and other factors, such as the hosts and environment. Therefore, the data presented in this study should be considered to be case-specific (Gong et al, 2002). The present study has also revealed the heterogeneity of Clostridium sp.…”

“…The function of the ileum (the lower end of the small intestine) is mainly nutrient absorption, while the cecum is the site where extensive bacterial fermentation occurs, resulting in further nutrient absorption and detoxification of substances that are harmful to the host (Csordas, 1995). Since these segments function differently and provide different environments, it is expected that different types of bacteria would colonize them and distinct microflora would develop (Gong et al, 2002). In this study, some differences of the Clostridium sp.…”

Antimicrobials, Gut Microbiota and Immunity in Chickens

“…Given that the mucosa-associated microbiota has been known to play a role in pathogen control and immune modulation (Gong et al, 2002), future studies should be targeting on analyzing the mucosa-associated bacteria in relation to the responses to dietary antimicrobials. observed.…”

“…Gong et al (2002) analyzed microbiota community on the mucosa and digesta of the ileum by T-RFLP with restriction enzymes such as AluI, HhaI, and MspI and found the heterogeneous bacterial population in the mucosa and digesta in the ileum.…”