Associations of the Gut Microbiota Composition and Fecal Short-chain Fatty Acids with Leukocyte Telomere Length in Children Aged 6-9 Years Old in Guangzhou, China: A Cross-sectional Study

Background Telomere length serves as a marker of cellular senescence and appears to plateau between the age of 4 years and young adulthood after when gut microbiota is supposed to be established. However, scarce data is known about the correlation between gut microbiota composition and telomere length in pediatric population. Objectives We aimed to investigate whether the gut microbiota and the concentrations of short-chain fatty acids (SCFAs) in feces are associated with leukocyte telomere length in children. Methods Four hundred and one children aged 6-9 years from Guangzhou were enrolled in this cross-sectional study. Quantitative polymerase chain reaction was used to determine relative telomere length in peripheral blood leukocytes. The gut microbiota was characterized by 16S ribosomal RNA amplicon sequencing and the fecal concentrations of total SCFAs and SCFA subtypes were determined using high-performance liquid chromatography. The multivariate methods with unbiased variable selection algorithm (MUVR) and partial least square models were used to selected predictable operational taxonomic units (OTUs). Further correlation analyses were performed based on multiple linear regression models with adjustment for covariates and false discovery rate. Results By using MUVR, 35 all relevant and minimal-optimal OTUs were finally selected. Multiple linear regression analysis showed that the abundance of several OTUs, including OTU334 (belonging to the genus Family_XIII_AD3001_group), OTU726 (belonging to the species Lachnoclostridium_phocaeense), OTU1441 (belonging to the genus [Ruminococcus]_torques_group), OTU2553 (belonging to the genus Lachnospiraceae_UCG-010) and OTU3375 (belonging to the family Lachnospiraceae) was negatively associated with leukocyte telomere length (beta = -0.187 to -0.142; P-FDR = 0.009-0.035). However, neither SCFA subtype nor total SCFA content in feces exhibited significant associations with telomere length (beta = -0.032 to 0.048; P-FDR = 0.915-0.968). Conclusions The gut microbiota, but not fecal SCFA concentration, was significantly associated with telomere length in this pediatric population.