Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the degeneration of motor neurons, leading to progressive muscle weakness and functional decline. This study is designed as a randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of an oral preparation of C. cicadae in patients with sporadic ALS and elevated plasma sphingolipid (SL) levels. Efficacy will be assessed primarily by changes in the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score and plasma SL levels.Participants who meet the eligibility criteria and provide written informed consent will be randomly assigned in a 1:1 ratio to either the C. cicadae treatment group or the placebo group. The treatment group will receive oral C. cicadae at a dose of 0.1 g/kg/day (dry weight), administered in three divided doses per day. The placebo group will receive a matched placebo with a similar appearance and odor, administered according to the same schedule. A total of approximately 84 participants will be enrolled. The intervention period will be 6 months, and participants will be followed for a total of 9 months.

Inclusion Criteria:

• Patients with ALS diagnosed according to the revised El Escorial criteria.
• Significantly elevated plasma levels of key SL molecules (e.g., Cer(d18:0/24:0), Cer(d18:1/22:0), and other relevant molecules), meeting the predefined cut-off values for metabolic stratification.
• Time from disease onset to enrollment ≤24 months
• For participants receiving riluzole and/or edaravone, the dose must have been stable for at least 30 days prior to enrollment.
• Male or non-pregnant, non-lactating female patients, aged > 18 and ≤ 80 years old.
• Voluntarily participate in clinical trials, sign informed consent, and be able to understand and abide by research procedures.

Exclusion Criteria:

• Presence of peripheral neuropathy or motor neuron injury attributable to other clearly defined etiologies and sufficient to interfere with disease classification in this study, including but not limited to vitamin deficiency, toxic neuropathy, drug- or chemotherapy-related neuropathy, alcoholic neuropathy, paraneoplastic syndrome, autoimmune neuropathy, and infection-related neuropathy;
• Severe hepatic or renal dysfunction that may affect the safety evaluation of the investigational product or the interpretation of metabolomics results;
• Severe cardiopulmonary dysfunction, active infection, active malignancy, or other major systemic diseases that, in the opinion of the investigator, may significantly affect prognosis assessment or completion of follow-up;
• Women who are pregnant or breastfeeding, or who plan to become pregnant during the study period;
• Participation in another interventional clinical trial within 30 days prior to enrollment, or being within the washout period of another investigational product;
• Inability to comply with clinical assessments, sample collection, or follow-up procedures;
• Persistent high dependence on noninvasive ventilation (>16 hours/day), or advanced respiratory failure as judged by the investigator, such that the participant is unable to complete oral intervention and efficacy evaluation;
• Severe dysphagia, gastrointestinal dysfunction, or other conditions rendering the participant unable to tolerate oral administration;
• Known allergy to C. cicadae preparations, fungal products, or any of their excipients;
• Concomitant diseases or conditions that may substantially affect motor function assessment and thereby interfere with evaluation of the primary endpoint;
• Any other condition that, in the opinion of the investigator, makes the participant unsuitable for study participation.