Although the global benefits of gastrostomy have been proven in amyotrophic lateral sclerosis (ALS), the impact on biological parameters has not been explored yet. The aim of this preliminary work was to evaluate the modification of biological parameters in patients with ALS undergoing gastrostomy. We retrospectively collected clinical and biological data from 44 patients having undergone gastrostomy at three time points (T0, T1 and T2: before, at the time of and after gastrostomy). We examined the relationship between the biological parameters and disease progression. Variations of the concentrations of total cholesterol significantly differed before (T1-T0) vs those after gastrostomy (T2-T1; P=0.0044). The variations of total cholesterol and low-density lipoprotein cholesterol concentrations after gastrostomy were negatively associated with survival (P=0.0002). This study showed for the first time that patients with ALS fed quite exclusively by gastrostomy had decreased blood cholesterol after gastrostomy. We suggest that a restoration of normal lipid metabolism should be planned in patients with ALS.