# Amyotrophic Lateral Sclerosis: The State of the Art on Treatments and the Therapeutic Role of the Intestinal Microbiome in Human Studies

## TL;DR

This review examines the potential of fecal microbiota transplantation as a treatment for ALS, comparing results from three studies with mixed outcomes.

## Contribution

The paper provides a comparative analysis of existing human studies on FMT for ALS, highlighting methodological differences and their implications.

## Key findings

- Two studies observed halted ALS progression and improved health after FMT.
- One large study found no significant effect of FMT, possibly due to prior antibiotic use.
- Ongoing research is needed to clarify FMT's therapeutic effectiveness for ALS.

## Abstract

Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disorder; to date, there is no long-term effective treatment. Recently, a relationship has been discovered between the human intestinal microbiome and the pathogenesis of ALS, on which basis faecal microbiota transplantation (FMT) has been proposed as a potential treatment for ALS. In this review, we compare three existing case studies examining the effect of FMT on the course of ALS, highlighting differences in methodology and results. In two of the studies, a halt in the progression of ALS symptoms was observed following FMT, accompanied by improvement in patient health. However, in the third and largest study, no significant effect of FMT was observed. The possible explanation for this discrepancy may be the intentional depletion of intestinal microorganisms using antibiotics prior to FMT in the third study. Future studies and/or completion of the ongoing clinical studies will help clarify the therapeutic effectiveness of FMT in ALS patients.