Intra- and Inter-individual Variation in Population of Lactobacillus and Bifidobacterium in Faeces of Some Healthy Individuals

Abstract

Aims: To evaluate the variation of Lactobacillus and Bifidobacterium population within and between healthy individuals. Methodology: Five healthy participants were recruited, and advised not to consume yoghurt, antibiotics, alcohol and steroid during the study. Three (3) fecal samples from each participant obtained at one week interval (total of 15 samples a week) for three weeks were examined for each subject bacteria. The samples were collected in sterile specimen jars and immediately taken to the laboratory for analysis. MRS and BIM-25, a selective medium were used for the enumeration of Lactobacillus sp and Bifidobacteria respectively using plate count method. Target bacteria were confirmed by PCR technique and biochemical tests. Results: All isolates picked from their respective selective media were confirmed to be lactobacillus and bifidobacteria. The confirmation was carried out using both biochemical tests and PCR. The results of the statistical analysis of the data obtained using SPSS version 16 showed that intra-individual variation of the population of Lactobacillus and Bifidobacteria was significantly lower than inter-individual variation at P <0.05. Conclusion: This study establishes the fact that the composition level of Lactobacillus and Bifidobacterium varies within and between healthy human gut at different points in time.