Figure 3 ABO blood group related differences in the microbiota diversity. The Shannon Diversity index calculations

of the PCR-DGGE profiles obtained with a) universal eubacterial (UNIV) primers, b) Eubacterium rectale – Clostridium coccoides (EREC) primers and c) Clostridium leptum (CLEPT) primers. Columns are averaged ± SD values of the corresponding ABO blood groups. Statistically significant differences BASED on ANOVA tests between ABO blood groups are marked with diagonal bars and with the corresponding p-value. The association we found between the ABO blood groups, especially the presence of the group B antigen, is strengthened by comparable results having been obtained using two broad-spectrum profiling 4SC-202 methods. The semi-quantitative PCR-DGGE method identified Geneticin purchase specific associations within the major intestinal bacterial groups, and the qualitative %G + C profiling supported these CP673451 findings and demonstrated that the microbial differences associated with the blood groups are large enough to affect the relative quantities of the major bacterial groups, thus impacting the overall microbial profile. We speculate that the statistically

significant differences in these important bacterial groups may indeed have in vivo relevance. Besides adhesion sites, mucus provides endogenous substrates for bacteria in the intestine, especially in the colon, where the easily degradable carbohydrates have already been consumed [13, 18, 19]. Our present finding on the association of the blood group and the group B antigen with the composition of intestinal microbiota may partly help to explain the recent discovery of the three enterotypes of human intestinal microbiota [2]. Interestingly, an early study supports our result on the importance of the blood group B antigen: in 1976, Hoskins & Boulding published their findings showing that blood group B subjects had more B-antigen degrading glycosidases producing microbes in their faeces compared with other subjects [9]. To further explore the ABO blood group and ABO blood group antigen related associations Parvulin in the

intestinal microbiota, we continued microbiota profiling by targeting selected, less dominant bacterial groups colonising the intestine. Large individual variation in the diversity of the Bacteroides population was observed by BFRA DGGE. No ABO blood group related differences in the diversity or clustering of the Bacteroides population was observed (Figure4) even though Bacteroides spp. is known to be capable of utilising a variety of host-derived glycans, including blood group glycans [14]. We nevertheless observed certain ABO blood group associated differences in the detection frequency of some of the band positions in the BFRA DGGE (Figure 3), suggesting the existence of species or strain level differences in the Bacteroides population between the ABO blood groups.