Investigating the relationship between nutrition, physical activity, gut microbiota, and adolescent idiopathic scoliosis: a cross-sectional comparative pilot study

Background: Adolescent idiopathic scoliosis (AIS) is defined as a three-dimensional spinal deformity of unknown cause that affects children between the ages of 10 and 18 years. Studies have shown that girls with AIS have different anthropometric features than their peers such as taller stature and lower body mass index. Dysfunctional energy metabolism could be involved in the discrepancies observed in AIS patients, and the gut microbiota is an important regulator of metabolic hormones. In this study, we aimed to compare gut microbiota composition, diversity and short-chain fatty acid (SCFA) between patients with AIS and healthy controls and to study their relation to metabolic hormones, anthropometry, and bone density, while taking diet and exercise into account. Methods: Nineteen age-matched pairs of AIS and control female participants were included in the study. A subset of 20 participants (9 AIS girls and 11 controls) provided fecal samples. Dietary intake and physical activity were assessed using questionnaires. Gut microbiota composition was investigated using 16S rRNA sequencing, while SCFA concentrations in feces were quantified using liquid chromatography-mass spectrometry. Results: AIS participants consumed less dietary fibers and engaged in less moderate-to-intense physical activity compared to controls. Fecal concentrations of the SCFA isobutyrate, valerate and isovalerate tended to be higher in AIS, though differences were not statistically significant. Gut microbiota α/β diversities were not statistically different between AIS participants and controls, although there were trends for differences within AIS participant α-diversity based on disease severity. Furthermore, there were several genera which trended towards being different between these populations, and our results suggest a switch in bacterial succinotypes. Additionally, correlations between fecal SCFA and adipokines or incretins were inversed in AIS participants as compared to controls. Conclusion: This pilot study suggests that gut microbiota and SCFA may be associated with AIS, but further research is needed to clarify their potential roles in disease development and progression.