Can probiotics benefit children with autism spectrum disorders?

Table 1 Evidence supporting a role for probiotics in treating gastrointestinal symptoms in autism spectrum disorders

Clinical symptoms	Ref.
Children with ASD have an abnormal fecal microbiota	[28,35,48,51,54,98-100]
GI symptoms common in ASD are similar to those in IBS	[11,12]
IBS also is associated with an abnormal fecal microbiota	[61,62,101]
Meta-analysis shows IBS symptoms are improved by probiotic treatment. (Preliminary evidence suggests potential benefits in ASD in children and rodents models.)	[65,72,102-104]
Mild inflammation in the GI tact may be seen in children with ASD. (There is evidence to support or refute this contention: abnormal duodenal and ileal biopsies and high plasma S100A9 but normal fecal calprotectin and lactoferrin levels)	[19,22-26,31,37]
Probiotics reduce gut inflammation (Shown in animal models and in human diseases)	[70,105-108]
Systemic inflammation can be also seen in children with ASD	[18,109-111]
Immune modulation of children with ASD may reduce clinical symptoms	[41,112]

ASD: Autism spectrum disorders; GI: Gastrointestinal; IBS: Irritable bowel syndrome.