P874 ulcerative colitis patients and the patients’ relative enterobacteria Bush comparative investigation

Abstract

Background: The gut microbiota has been recognised as a relevant fingerprint to predict the development of inflammatory bowel disease (IBD) like ulcerative colitis (UC). Accordingly, inter-individual variation in the gut microbial community may reflect inter-individual variation in the risk of developing IBD or other diseases. Furthermore, the next-generation sequencing (NGS) has been validated for determining bacterial species in faecal samples. Method(s): Eighty-two UC patients together with 61 healthy relatives as controls were included for investigations of gut microbiota in faecal samples. Twenty-five patients had active UC (group I) and 57 had quiescent UC; 29 with mild inflammation in the large intestine (group II), and 28 without inflammation (group III). The patients' relatives were consanguineous (group IV, n = 33), and non-consanguineous (group V, n = 28). Faecal bacteria between groups I to V were compared by the t-test. The discriminant analysis in all five groups was done for Species. We calculated the discriminant score (Ds) in each case. Next, we tried to analyse the quantity and the diversity of the bacteria which had significant difference. Result(s): We obtained 1011 varieties of bacteria as Phyla, Class, Order, Family, Genera and Species. 648 bacteria that were not considered important were excluded. The t-statistic was done on 363 bacteria between groups I to V. Significant difference was calculated in 18 Species, 10 Genera, and 4 Families. The Discriminant analysis was done on these 18 Species from all groups. The Ds value showed an increasing tendency in this order: group I < group II < group III < group IV < group V. This is indicating a relation between this score and UC activity. In bacteria having significant difference, especially Bacteroides Genus was numerous clearly, and higher in group I. But the diversity of Bacteroides Genus was higher in Group V. And in group I, the amount of Bacteroides fragilis was increased, but the diversity of Bacteroides Genus was decreased. On the other hand, in Group V, the amount of Bacteroides fragilis was decreased extremely, but the diversity of Bacteroides Genus was increased. The balance between Bacteroides fragilis and the diversity of Bacteroides can be key point in UC activity. And Clostridiales Family XI. Incertae Sedis was also increased in active UC clearly. Conclusion(s): We compared 363 bacteria between active UC patient to control, significant difference was calculated in 18 Species, 10 Genera, and 4 Families. So many bacteria may be related to UC activity. Additionally, Ds might be a clinically relevant biomarker of disease activity in UC. Moreover we could obtain a lot of interesting results the quantity and the diversity of the bacteria, especially Bacteroides.