P101: GUT MICROBIOTA IMPACT ON ANGOLAN CHILDREN WITH SICKLE CELL DISEASE

Abstract

Background: Sickle cell disease (SCD) is one of the most prevalent genetic diseases, affecting between 20 and 25 million people worldwide. In the Sub-Saharan Africa, where it is more prevalent, it contributes to 50–80% of under-5 mortality. Clinical manifestations of SCD are very heterogeneous and the intestinal microbiome appears to be crucial in the modulation of inflammation, cell adhesion and induction of aged neutrophils, which are the main interveners of recurrent vaso-occlusive crisis. Enterocyte injury, increased permeability, altered microbial composition, and bacterial overgrowth have all been documented as microbial and pathophysiologic changes in the gut microbiome of SCD patients in recent research studies. Microbiota analysis in SCD populations will be essential to demonstrate the importance of specific bacteria and their function in this disease and provide new insights for attenuating symptoms and new drug targets. Aims: Given this, our aim is to sequence by NGS bacterial 16S RNA gene in order to characterize the gut microbiome of SCD children and healthy siblings, as a control. A written informed consent was presented and explained to all the guardian participants prior to the data collection. A total of 72 stool samples were obtained from children between 3–14 years old. Results: Our preliminary results showed that the SCD and control samples exhibit some notable differences in microbiota relative abundance, at different levels of classification. Children with the disease have a higher number of the phylum Actinobacteria (p=0.013) with a mean of sequences of 5.47% (± 3.49), while the siblings have a mean of 3.25% (± 2.98). As for the genus level, only Clostridium cluster XI bacteria was more prevalent in the SCD children, whereas the siblings had higher numbers of Blautia, Aestuariispira, Campylobacter, Helicobacter, Polaribacter and Anaerorhabdus. Conclusion: There is still much to learn before fully relying on the therapeutic approaches for gut modulation, which is why more research in this field is crucial to making this a reality. This works as been supported by FCT/Aga Khan (project n°330842553) and FCT/MCTES (UIDB/05608/2020 and UIDP/05608/2020) –H&TRC.