Psychobiotics in pediatric autism spectrum disorder: A systematic review of efficacy, mechanisms, and clinical translation

Table 5 Mechanistic effects of psychobiotics in autism spectrum disorder

Ref.	Psychobiotic intervention	Microbiome changes	Metabolic/neurochemical changes	Immune/inflammatory effects	Proposed clinical impact
Santocchi et al[30]	Multi-strain probiotic (Lactobacillus, Bifidobacterium, Streptococcus)	Increased abundance of beneficial gut bacteria; improved microbial diversity	Modulation of SCFA production	Reduction in gut inflammation and improved intestinal barrier function	Improvement in gastrointestinal symptoms and potential behavioral benefits in subgroups
Liu et al[24] (PS128)	Lactobacillus plantarum PS128	Increased Lactobacillus colonization	Modulation of neurotransmitter-related metabolites, including serotonin and dopamine pathways	Possible modulation of neuroinflammatory signaling	Improvements in hyperactivity, anxiety, and behavioral regulation
Shaaban et al[28]	Multi-strain probiotic (Lactobacillus, Bifidobacterium)	Increased beneficial bacterial taxa and a reduction in potentially pathogenic microbes	Normalization of microbial metabolic products	Decreased systemic inflammatory markers	Reduced ASD symptom severity and improved gastrointestinal function
Narula Khanna et al[25]	Multi-strain probiotic formulation	Increased Bifidobacterium and Lactobacillus species	Increased production of SCFAs is associated with gut barrier integrity	Reduced pro-inflammatory cytokine activity	Improvement in social responsiveness, stereotypic behavior, and gastrointestinal symptoms
Other pilot studies	Various probiotic combinations	Improved microbial diversity and reduction of dysbiosis	Altered microbial metabolite profiles affecting gut-brain signaling	Modulation of immune responses and gut permeability	Potential improvements in both behavioral and gastrointestinal outcomes

ASD: Autism spectrum disorder; SCFAs: Short chain fatty acids.