What is the recommended treatment approach for individuals with autism spectrum disorder (ASD) suspected of having a fungal gastrointestinal (GI) infection?

Treatment Approach for Fungal GI Infections in Autism Spectrum Disorder

There is insufficient evidence to support antifungal treatment for suspected fungal gastrointestinal infections in individuals with autism spectrum disorder, as no established clinical guidelines exist for this specific indication.

Diagnostic Considerations

• Suspected fungal GI infections in ASD patients should be confirmed through appropriate diagnostic testing before initiating any antifungal therapy, as there is no established causal relationship between fungal infections and ASD symptoms 1
• Research has shown altered gut microbiota in ASD patients, including potential increases in fungal species like Candida, but this does not necessarily indicate pathogenic infection requiring treatment 1
• The presence of GI symptoms in ASD patients should prompt investigation for conventional GI disorders before attributing symptoms to fungal overgrowth 2

Evidence Regarding Fungal Presence in ASD

• Some studies have observed that the relative abundance of fungal genus Candida was more than double in autistic subjects compared to neurotypical individuals, though with large variations between individuals 1
• Dysbiosis of the gut microbiome, including both bacterial and fungal components, has been associated with GI symptoms in ASD patients, but causality has not been established 2
• Current research does not fully support the hypothesis that Candida overgrowth is directly correlated with GI problems or contributes to autism behavioral symptoms 3

Treatment Options Based on Established Guidelines

• If invasive aspergillosis is confirmed (which would be extremely rare in ASD patients without severe immunocompromise), voriconazole would be the recommended first-line treatment according to IDSA guidelines 4
• For confirmed Candida infections, treatment should follow established guidelines for the specific type of infection, such as fluconazole for susceptible Candida species 4
• There are no established guidelines specifically for treating suspected fungal GI colonization in ASD patients 3, 2

Case Report Evidence

• A single case report described improvement in ASD symptoms after treatment with itraconazole in a child with suspected Aspergillus colonization, but this represents very low-quality evidence and cannot be generalized 5
• This case report lacks controls, blinding, or replication, making it insufficient to guide clinical practice 5

Alternative Approaches with Better Evidence

• Microbiota Transfer Therapy (MTT) has shown more promising results for improving both GI and ASD symptoms in a small open-label trial with 2-year follow-up 6
• Dietary interventions, probiotics, and other approaches to modulate the microbiome may help reduce GI problems in some ASD patients 2
• Studies on humans suggesting beneficial effects of sugar-free diet, probiotic supplementation, and microbiota-based treatments in ASD are limited but show more promise than antifungal treatments 3

Important Cautions

• Antifungal medications carry significant risks including hepatotoxicity, drug interactions, and potential for developing resistance 4, 7
• Azole antifungals like itraconazole require therapeutic drug monitoring to ensure appropriate dosing and minimize toxicity 4, 7
• Using antifungal medications without confirmed fungal infection is not supported by clinical evidence and may expose patients to unnecessary risks 3

Conclusion

• Current evidence does not support the routine use of antifungal medications for suspected fungal GI infections in individuals with ASD 3, 2
• Management should focus on established approaches for GI symptoms in ASD patients, including appropriate diagnostic workup and evidence-based interventions 2
• Further research with rigorous study designs is needed to elucidate any potential role of fungal organisms in ASD pathophysiology and symptomatology 3, 1