Effect of Dietary Fiber Intake on the Prognosis of Amyotrophic Lateral Sclerosis

Abstract Objectives The gut microbiota has been suggested to associate with the pathophysiology of amyotrophic lateral sclerosis (ALS), and thus prebiotic effect of fiber could play an important role on pathophysiology of ALS. The present study aimed to investigate the effect of dietary fiber intake on the disease progression rate (∆FS) and survival time among Korean ALS patients. Methods A total of 272 Korean sporadic ALS patients diagnosed according to the revised EI Escorial criteria were recruited during 2011–2019, and were followed until the occurrence of events or the end of September 2020. The events were defined as percutaneous endoscopic gastrostomy, tracheostomy, or death. Intake of dietary fibers was calculated based on 24-hour dietary recall, and divided into five major fiber-rich foods: vegetables, fruits, grains, legumes, and nuts/seeds. Results There were higher proportion of participants with lower than the mean value of ∆FS (0.75) in the highest tertile of total fiber and vegetable fiber intake than those in the lowest tertile. Kaplan–Meier analysis showed that participants in the highest tertile for vegetable fiber intake had longer survival. Cox regression analysis showed that intake of vegetable fiber was negatively associated with risk for events after adjustment. Notably, vegetable fiber intake was negatively correlated with pro-inflammatory cytokine such as interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1 in the cerebrospinal fluid. Conclusions In conclusion, this study showed that vegetable fiber intake was negatively associated to the ∆FS and shorter survival time, suggesting that vegetable fiber intake could influence the prognosis of ALS. Further clinical trials are needed to confirm whether supplementation of dietary fiber improves the prognosis in ALS. Funding Sources This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT).