Autism Spectrum DisorderPASDNCT07345585
Probiotics for Autism Spectrum Disorders: a Randomized Controlled Trial (The PASD Study)
A study testing Lactobacillus rhamnosus GG in people with Autism Spectrum Disorder, run by Federico II University at 1 site in Italy.
Trial summary
Autism spectrum disorders (ASD) are a group of severe neurodevelopmental conditions characterized by impaired communication and social interaction, as well as repetitive/stereotyped behaviors deriving from a combination of genetic and environmental factors. Read more about this study
- Who is it for?
- Ages 4 to 12 years
- Conditions the study is for
- Autism Spectrum Disorder
- What is being tested?
- Lactobacillus rhamnosus GG
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 50 participants
- Where
- 1 siteItaly
- Study dates
- 1 Jan 2023to 30 Apr 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 12 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- children aged 4-12 years
- children of both sex
- children with a sure diagnosis of ASD and presence of FGIDs with a GSI ≥7 from at least 3 months.
Who cannot join
- children aged <4 or >12 years
- uncertain ASD and/or FGIDs diagnosis
- FGIDs duration lasting <3 months
- concomitant presence of other chronic conditions (adverse food reactions; genetic and metabolic disorders; malformations of GI, respiratory or urinary tract; neurologic diseases; immunodeficiencies; diabetes; cardiovascular diseases; autoimmune diseases; chronic infections; chronic respiratory, GI or urinary tract diseases; obesity; tumors; malnutrition).
- use of antibiotics and/or pre-/pro-/ synbiotics during the 6 months prior to enrolment
- participation into other clinical trials during the last 12 months.
Trial locations and contacts
1 site in 1 country.
Italy1 site
Department of Traslational Medical Science - University of Naples Federico II
Naples, Naples, 80131
About this study
Autism spectrum disorders (ASD) are a group of severe neurodevelopmental conditions characterized by impaired communication and social interaction, as well as repetitive/stereotyped behaviors deriving from a combination of genetic and environmental factors. The ASD diagnosis rates increased dramatically over the past number of decades. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) describes a worldwide prevalence of approximately 1%. The prevalence of ASD is 1 in 59 individuals in the US reported by the Centers for Disease Control and Prevention. According to the latest data from the Italian National Observatory for ASD, the actual prevalence in Italy is about 1/77 for children aged between 7 and 9 years, with a 4.4 times higher prevalence in male. The origin of ASD is still largely undefined. It has been hypothesized a possible role for the influence of early life alteration of gut microbiome (GM). We demonstrated an imbalance in Bacteroidetes and Firmicutes phyla with a decrease in Bacteroidetes/Firmicutes ratio in the GM of pediatric patients affected by ASD. Similar data have been observed by others. Data from ASD animal model confirm the presence of GM dysbiosis with significant correlation with behavioral, gastrointestinal and immunologic alterations. Altogether these data support the hypothesis that GM dysbiosis could be involved in the ASD pathogenesis. The ASD children present an increased prevalence of functional gastrointestinal disorders (FGIDs), mainly chronic constipation, functional diarrhea, and irritable bowel syndrome (IBS). A role for GM has been suggested also for these conditions. The presence of these disorders negatively influence the disease severity and the parental quality of life of ASD children. Starting from all these considerations GM is becoming a possible target of intervention for pediatric ASD. Probiotics are one of the most investigated strategy for a beneficial modulation of GM. Probiotics are commonly defined as live microorganisms which when ingested in adequate amounts confer a beneficial effect on the host. The most used probiotics in the pediatric age are Saccharomyces and Lactobacillus strains including Lactobacillus rhamnosus GG (LGG). Data report a beneficial influence elicited by LGG on GM structure and function. This probiotic resulted also effective in treating FGIDs patients. Preliminary evidence suggest the potential efficacy of probiotics for FGIDs treatment in ASD children. Altogether these evidence strongly support the hypothesis that LGG could exert a beneficial action in ASD children. The purpose of this study is to evaluate the therapeutic efficacy of LGG on FGIDs in ASD children.
- Conditions
- Autism Spectrum Disorder
- Being tested
- Lactobacillus rhamnosus GG, Placebo
- Medical subject headings
- Autism Spectrum Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lactobacillus rhamnosus GGOther
Lactobacillus rhamnosus GG
PlaceboOther
Placebo
| Study group | Role | What they receive |
|---|---|---|
| Probiotic | Experimental | Lactobacillus rhamnosus GG Receives: Other: Lactobacillus rhamnosus GG |
| Placebo | Placebo comparator | Placebo Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Functional gastrointestinal disorders (FGIDs) severity
Severity index of gastrointestinal symptoms (GI Severity Index, GSI) - Minimum Score: 0 (Indicates absence of gastrointestinal symptoms or optimal bowel regularity) Maximum Score: 17 (Represents the highest severity of symptoms reported in the questionnaire). The primary outcome was week-16 response, defined a priori as a reduction of more than 4 points in Gastrointestinal Severity Index (GSI) score.
Measured: At 16 weeks of treatment
Secondary outcomes (9)
Kinetics of Lactobacillus rhamnosus GG (LGG)
Using the GI Severity Index (GSI) - Minimum Score: 0 (Indicates absence of gastrointestinal symptoms or optimal bowel regularity) Maximum Score: 17 (Represents the highest severity of symptoms reported in the questionnaire)
Measured: At baseline and at 4 weeks, 8 weeks and 12 weeks of treatment
Duration of the LGG impact on FGIDs
Changes in the GSI - Minimum Score: 0 (Indicates absence of gastrointestinal symptoms or optimal bowel regularity) Maximum Score: 17 (Represents the highest severity of symptoms reported in the questionnaire)
Measured: At baseline and at 4 weeks and 12 weeks from the end of treatment
Gut Microbiome (GM) composition
Shotgun metagenomics analysis
Measured: At baseline and at 16 weeks of treatment
GM function: fecal short chain fatty acids (SCFAs) levels
Gas chromatograph(GC)-mass spectrometry (MS) analysis
Measured: At baseline and at 16 weeks of treatment
ASD children behavior
Aberrant Behavior Checklist (ABC) questionnaire - Minimum Score: 0 (Indicates the complete absence of aberrant or problematic behaviors in the assessed areas, e.g., aggression, social withdrawal, stereotypies, etc.) Maximum Score: 174 (Represents the highest severity and frequency of problematic behaviors reported in the test. All listed aberrant behaviors-such as self-injury, severe hyperactivity, complete social withdrawal, and repetitive speech-are present at maximum intensity.)
Measured: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Parental quality of life
EUROHIS QOL-8 questionnaire - Minimum Score: 8 (Indicates the lowest level of satisfaction and quality of life) Maximum Score: 40 (Indicates the highest level of satisfaction and quality of life)
Measured: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Body weight
Body weight will be evaluated in kilograms
Measured: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Height
Body weight will be evaluated in cm
Measured: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Infectious diseases
It will be assessed the number of infectious episodes, type of infectious diseases, need for drugs
Measured: At 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jan 2026
- Study start1 Jan 2023
- Primary completion30 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Autism Spectrum DisorderStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Federico II University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Roberto Berni Canani, MD, PhD, Federico II University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07345585
- Sponsor's protocol ID
- 38/2023
- Acronym
- PASD
- Status last verified
- Aug 2026
- First submitted
- 9 Dec 2025
- Last updated
- 31 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Probiotics for Autism Spectrum Disorders: a Randomized Controlled Trial (The PASD Study)
- ClinicalTrials.gov ID
- NCT07345585
- Acronym / sponsor ID
- PASD / 38/2023
- Conditions
- Autism Spectrum Disorder
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Federico II UniversityUniversity, hospital or other
- Study start
- 1 Jan 2023 (actual)
- Primary completion
- 30 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 15 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Autism spectrum disorders (ASD) are a group of severe neurodevelopmental conditions characterized by impaired communication and social interaction, as well as repetitive/stereotyped behaviors deriving from a combination of genetic and environmental factors. The ASD diagnosis rates increased dramatically over the past number of decades. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) describes a worldwide prevalence of approximately 1%. The prevalence of ASD is 1 in 59 individuals in the US reported by the Centers for Disease Control and Prevention. According to the latest data from the Italian National Observatory for ASD, the actual prevalence in Italy is about 1/77 for children aged between 7 and 9 years, with a 4.4 times higher prevalence in male. The origin of ASD is still largely undefined. It has been hypothesized a possible role for the influence of early life alteration of gut microbiome (GM). We demonstrated an imbalance in Bacteroidetes and Firmicutes phyla with a decrease in Bacteroidetes/Firmicutes ratio in the GM of pediatric patients affected by ASD. Similar data have been observed by others. Data from ASD animal model confirm the presence of GM dysbiosis with significant correlation with behavioral, gastrointestinal and immunologic alterations. Altogether these data support the hypothesis that GM dysbiosis could be involved in the ASD pathogenesis. The ASD children present an increased prevalence of functional gastrointestinal disorders (FGIDs), mainly chronic constipation, functional diarrhea, and irritable bowel syndrome (IBS). A role for GM has been suggested also for these conditions. The presence of these disorders negatively influence the disease severity and the parental quality of life of ASD children. Starting from all these considerations GM is becoming a possible target of intervention for pediatric ASD. Probiotics are one of the most investigated strategy for a beneficial modulation of GM. Probiotics are commonly defined as live microorganisms which when ingested in adequate amounts confer a beneficial effect on the host. The most used probiotics in the pediatric age are Saccharomyces and Lactobacillus strains including Lactobacillus rhamnosus GG (LGG). Data report a beneficial influence elicited by LGG on GM structure and function. This probiotic resulted also effective in treating FGIDs patients. Preliminary evidence suggest the potential efficacy of probiotics for FGIDs treatment in ASD children. Altogether these evidence strongly support the hypothesis that LGG could exert a beneficial action in ASD children. The purpose of this study is to evaluate the therapeutic efficacy of LGG on FGIDs in ASD children.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Probiotic | Experimental | Other: Lactobacillus rhamnosus GGLactobacillus rhamnosus GG |
| Placebo | Placebo comparator | Other: PlaceboPlacebo |
Who may qualify
- Ages
- 4 to 12 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- children aged 4-12 years
- children of both sex
- children with a sure diagnosis of ASD and presence of FGIDs with a GSI ≥7 from at least 3 months.
Key exclusion criteria (6 listed)
- children aged <4 or >12 years
- uncertain ASD and/or FGIDs diagnosis
- FGIDs duration lasting <3 months
- concomitant presence of other chronic conditions (adverse food reactions; genetic and metabolic disorders; malformations of GI, respiratory or urinary tract; neurologic diseases; immunodeficiencies; diabetes; cardiovascular diseases; autoimmune diseases; chronic infections; chronic respiratory, GI or urinary tract diseases; obesity; tumors; malnutrition).
- use of antibiotics and/or pre-/pro-/ synbiotics during the 6 months prior to enrolment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Lactobacillus rhamnosus GGLactobacillus rhamnosus GG | Other | Probiotic |
| PlaceboPlacebo | Other | Placebo |
Primary outcome
Functional gastrointestinal disorders (FGIDs) severity
Time frame: At 16 weeks of treatment
Severity index of gastrointestinal symptoms (GI Severity Index, GSI) - Minimum Score: 0 (Indicates absence of gastrointestinal symptoms or optimal bowel regularity) Maximum Score: 17 (Represents the highest severity of symptoms reported in the questionnaire). The primary outcome was week-16 response, defined a priori as a reduction of more than 4 points in Gastrointestinal Severity Index (GSI) score.
9 secondary outcomes
Kinetics of Lactobacillus rhamnosus GG (LGG)
Time frame: At baseline and at 4 weeks, 8 weeks and 12 weeks of treatment
Duration of the LGG impact on FGIDs
Time frame: At baseline and at 4 weeks and 12 weeks from the end of treatment
Gut Microbiome (GM) composition
Time frame: At baseline and at 16 weeks of treatment
GM function: fecal short chain fatty acids (SCFAs) levels
Time frame: At baseline and at 16 weeks of treatment
ASD children behavior
Time frame: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Parental quality of life
Time frame: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Body weight
Time frame: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Height
Time frame: At baseline, at 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Infectious diseases
Time frame: At 4 weeks, at 8 weeks, at 12 weeks and at 16 weeks of treatment, and at 4 weeks and 12 weeks from the end of treatment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lactobacillus rhamnosus GG in people with Autism Spectrum Disorder, run by Federico II University at 1 site in Italy.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 31 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Italy. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Functional gastrointestinal disorders (FGIDs) severity (time frame: At 16 weeks of treatment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2026.