RESULTS: We compared the anal microbiota composition of adult survivors of childhood ALL (N = 73) with healthy control subjects (N = 61). We identified an altered community with reduced microbial diversity in cancer survivors, who also exhibit signs of immune dysregulation including increased T cell activation and chronic inflammation. The bacterial community among cancer survivors was enriched for Actinobacteria (e.g. genus Corynebacterium) and depleted of Faecalibacterium, correlating with plasma concentrations of IL-6 and CRP and HLA-DR+CD4+ and HLA-DR+CD8+ T cells, which are established markers of inflammation and immune activation.
CONCLUSIONS: We demonstrated a relationship between microbial dysbiosis and immune dysregulation in adult ALL survivors. These observations suggest that interventions that could restore microbial diversity may ameliorate chronic inflammation and, consequently, development of late effects of childhood cancer survivors.
METHODOLOGY: We conducted a longitudinal observational study in gut microbiota profile in a group of paediatric patients diagnosed with ALL using 16 s ribosomal RNA sequencing and compared these patients' microbiota pattern with age and ethnicity-matched healthy children. Temporal changes of gut microbiota in these patients with ALL were also examined at different time-points in relation to chemotherapy.
RESULTS: Prior to commencement of chemotherapy, gut microbiota in children with ALL had larger inter-individual variability compared to healthy controls and was enriched with bacteria belonging to Bacteroidetes phylum and Bacteroides genus. The relative abundance of Bacteroides decreased upon commencement of chemotherapy. Restitution of gut microbiota composition to resemble that of healthy controls occurred after cessation of chemotherapy. However, the microbiota composition (beta diversity) remained distinctive and a few bacteria were different in abundance among the patients with ALL compared to controls despite completion of chemotherapy and presumed restoration of normal health.
CONCLUSION: Our findings in this pilot study is the first to suggest that gut microbiota profile in children with ALL remains marginally different from healthy controls even after cessation of chemotherapy. These persistent microbiota changes may have a role in the long-term wellbeing in childhood cancer survivors but the impact of these changes in subsequent health perturbations in these survivors remain unexplored.
METHODS: Purposive sampling was used to select the 73 caregivers of children with ALL who participated in this cross-sectional study. The Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) were used to measure psychological distress.
RESULT: There was a low prevalence (11%) of post-traumatic stress disorder (PTSD) among the participants. Although all the criteria for PTSD were not met, a few post-traumatic symptoms remained, suggesting that PTSS was likely present. Most of the participants reported minimal symptoms of depression (79.5%) and anxiety (65.8%). Anxiety, depression, and ethnicity predicted the PTSS scores (R2 = .77, p =.000). Subsequently, depression predicted the PTSS scores (R2 = 0.42, p =0.000). Participants of 'Other' or 'Indigenous' ethnicity had lower PTSS scores and higher anxiety scores (R2 = 0.75, p =0.000) than participants of Malay ethnicity.
CONCLUSION: The caregivers of children with ALL experience post-traumatic stress symptoms (PTSS), depression, and anxiety. These variables co-exist and may have different trajectories in different ethnic groups. Therefore, healthcare providers should take ethnicity and psychological distress into consideration when providing paediatric oncology treatment and care.