Mo1818 Effect of Aging on the Fecal Microbiome in Healthy Donors for Fecal Microbiota Transplant

Abstract

Background: Fecal microbiota transplant (FMT) is fast emerging as a promising therapy for recurrent clostridium difficile colitis in patients not responding to antibiotic therapy. However all patients for FMT need a fecal sample from a healthy donor. However the effect of age on the fecal microbiome of the healthy donor and its clinical efficacy, has not been examined previously. Aim: To examine fecal samples of healthy human subjects of various ages, volunteering to donate their samples for FMT by genomic analysis and clinical outcom. Methods: All healthy subjects who were rigorously screened for infectious disease and selected as donors for FMT were included in the study. Fecal samples were processed and analyzed using 16S rRNA gene amplicon sequencing. Microbiota compositions were studied using standard 16S rRNA analysis tools (CloVR-16S). Differences in bacterial phylum abundance and diversity (Shannon index) of the donor fecal microbiota were analyzed using three different cutoff for age of 50 years, 60 years and 70 years. Effect of fecal microbiota from donors of different age groups on efficacy of FMT in patients with RCDI was monitored in the GI clinic. Results: Fecal microbiota of 30 healthy donors was analyzed. The mean age of the donors was 50±15.3 years and ranged between 20 years to 82 years. Of these 30 donors, 18 (60%) were males and 26 (87%) were related to the recipients. The Shannon index did demonstrate significant increase in the fecal microbiome diversity in 70+ year old donors, as demonstrated in Figure 1. Althoughmicrobiome dissimilarity between the younger donors groups was relatively larger than the older donors groups on weighted UniFrac metric analysis, the association was not statistically significant. At phylum level, while the relative abundance of Firmicutes was higher in older groups (p<0.05), Actinobacteria was higher in younger groups (p<0.05). At family and genus level, the relative abundance of bifidobactericeae members were higher in younger group of donors than older group (p<0.05). However, despite these genomic differences in the fecal microbiota with ageing, all of our patients recovered completely from the recurrent clostridium difficile infection. Conclusion: This data suggests that there is a trend towards increase in relative abundance of Firmicutes with ageing. Furthermore the younger subjects were more dissimilar by measuring phylogenetic distances than the older donors. These observations indicate that human fecal microbiome evolves with ageing process and associated factors.