Interplay between B vitamins, fiber, and Bacteroides abundance: a predictive model for anxiety and depression in amyotrophic lateral sclerosis.

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive and incurable neurodegenerative disease that not only affects motor function but is also associated with gastrointestinal and emotional disturbances. Recent research highlights the potential role of gut microbiota and diet in modulating these symptoms, suggesting a complex interaction between nutrition, intestinal health, and presence of anxiety and depression in ALS patients. This study aims to investigate the relationship between dietary intake, gut microbiota composition, and presence of anxiety and depression in patients with amyotrophic lateral sclerosis (ALS).

METHODOLOGY: A cross-sectional study conducted with a sample of 48 patients with bulbar-onset or spinal-onset ALS from different regions of Spain. Dietary intake was assessed through 24-h records and food frequency questionnaires, while anxiety and depression were evaluated using validated scales that formed a latent factor called emotional distress. Stool consistency was assessed following the Bristol Stool Scale and the abundance of bacterial microbiota was quantified.

RESULTS

Confirmatory factor analysis identified a nutritional factor composed of vitamins B1, B2, B9, C, and fiber, revealing a significant inverse association with anxiety and depression levels. The predictive model revealed both direct and indirect effects of this factor on presence of anxiety and depression, mediated by Bacteroides abundance and stool consistency.

CONCLUSION

This model explained 19% of the variance in psychological distress. Our findings suggest that a diet rich in B vitamins, C vitamin and fiber may help improve emotional well-being in patients with ALS, highlighting the importance of nutritional strategies, as well as the role of Bacteroides related to stool consistency in patients with ALS.