The role of the oxytocinergic system in oral microbiome composition in children with autism: evidence from a randomized controlled trial of intranasal oxytocin.

Evenepoel M, Daniels N, Moerkerke M, Prinsen J, Steyaert J, Boets B, Joossens M, Alaerts K

Translational psychiatry24 Mar 2026

PMID41876480PMCIDPMC13040028DOI10.1038/s41398-026-03964-0PepBankPUB-41876480

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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: CC BY-NC-ND. Results still quote short attributed sentences.

Results from this study8

5 results from studies that gave the peptide. 5 results from people.

01HumanRandomized controlled trialMechanism
In autistic children, four weeks of intranasal oxytocin was associated with a significant increase in oral Centipeda abundance immediately after treatment.
In plain wordsIn children with autism, four weeks of oxytocin was linked to more Centipeda bacteria in the mouth right after treatment.
Peptide
Oxytocin
Outcome
IncreaseCentipeda abundance after oxytocin (T0-T1)
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Studied dose
Dose not stated · intranasal · four weeksAs given in this study (human).
Source sentences
Summary
In autistic children, four weeks of oxytocin administration was associated with significant increases in the abundances of Centipeda immediately post-treatment (T0-T1)
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
Report a problemFND-4187648004
02HumanRandomized controlled trialMechanism
In autistic children, four weeks of intranasal oxytocin was associated with a significant decrease in oral Moraxella abundance immediately after treatment.
In plain wordsIn children with autism, four weeks of oxytocin was linked to fewer Moraxella bacteria in the mouth right after treatment.
Peptide
Oxytocin
Outcome
DecreaseMoraxella abundance after oxytocin (T0-T1)
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Studied dose
Dose not stated · intranasal · four weeksAs given in this study (human).
Source sentences
Summary
In autistic children, four weeks of oxytocin administration was associated with significant increases in the abundances of Centipeda immediately post-treatment (T0-T1), alongside decreases in Moraxella (T0-T1)
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
Report a problemFND-4187648005
03HumanRandomized controlled trialMechanism
In autistic children, four weeks of intranasal oxytocin was followed by a significant reduction in oral Rothia abundance at the four-week follow-up.
In plain wordsIn children with autism, Rothia bacteria in the mouth fell by the four-week follow-up after oxytocin treatment.
Peptide
Oxytocin
Outcome
DecreaseRothia abundance at follow-up (T1-T2)
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Studied dose
Dose not stated · intranasal · four weeksAs given in this study (human).
Source sentences
Summary
In autistic children, four weeks of oxytocin administration was associated with significant increases in the abundances of Centipeda immediately post-treatment (T0-T1), alongside decreases in Moraxella (T0-T1), and subsequent reductions in Rothia observed at the four-week follow-up (T1-T2)
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
Report a problemFND-4187648006
04HumanRandomized controlled trialMechanism
In autistic children, a stronger oxytocin-induced downregulation of Moraxella correlated with greater increases in endogenous oxytocin levels.
In plain wordsIn children with autism, a bigger oxytocin-linked drop in Moraxella went with bigger rises in the body's own oxytocin.
Peptide
Oxytocin
Outcome
Not applicableMoraxella downregulation versus change in endogenous oxytocin
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Studied dose
Dose not stated · intranasal · four weeksAs given in this study (human).
Source sentences
Summary
a stronger oxytocin-induced downregulation of its abundance correlated with greater increases in endogenous oxytocin levels
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
Report a problemFND-4187648007
05HumanRandomized controlled trialMechanism
In autistic children, the oxytocin-induced Moraxella downregulation was accompanied by hypomethylation of the oxytocin receptor gene.
In plain wordsIn children with autism, the oxytocin-linked drop in Moraxella came with lower methylation of the oxytocin receptor gene.
Peptide
Oxytocin
Outcome
DecreaseOxytocin receptor gene methylation with Moraxella downregulation
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gene expression · Endocrine and hormones
Studied dose
Dose not stated · intranasal · four weeksAs given in this study (human).
Source sentences
Summary
accompanied by hypomethylation of the oxytocin receptor gene.
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
Report a problemFND-4187648008

Natural levels measured3

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

06HumanEndogenous levelObservational studyMechanism
In school-aged autistic and non-autistic children, lower endogenous salivary oxytocin levels were linked to greater oral microbial evenness and diversity at baseline.
In plain wordsIn children with and without autism, lower natural salivary oxytocin levels were linked to a more even and diverse oral microbiome.
Peptide
Oxytocin
Outcome
Not applicableOral microbial evenness and diversity versus endogenous salivary oxytocin
Study
n = 120
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Source sentences
Summary
At baseline, lower endogenous salivary oxytocin levels were linked to greater microbial evenness and diversity
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-4187648001
07HumanEndogenous levelObservational studyMechanism
In school-aged autistic and non-autistic children, twelve oral genera were significantly associated with endogenous salivary oxytocin levels at baseline.
In plain wordsIn children with and without autism, twelve oral bacterial genera were linked to the body's own oxytocin levels in saliva.
Peptide
Oxytocin
Outcome
Not applicableOral genera associated with endogenous salivary oxytocin
Study
n = 120
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Source sentences
Summary
with twelve genera showing significant associations with oxytocin levels.
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-4187648002
08HumanEndogenous levelObservational studyMechanism
In autistic children, lower baseline abundance of the genus Moraxella was associated with higher endogenous oxytocin levels.
In plain wordsIn children with autism, lower Moraxella bacteria at baseline were linked to higher natural oxytocin levels.
Peptide
Oxytocin
Outcome
Not applicableBaseline Moraxella abundance versus endogenous oxytocin
Study
n: not reported in source
Analysis
Exploratory
Outcome group
Gut microbiota · Infection
Source sentences
Summary
lower baseline abundance was associated with higher endogenous oxytocin levels
2 context sentences(design, population, supporting numbers)
Summary · context
This exploratory study examined for the first time how oral microbiome alterations link to oxytocinergic signalling in school-aged autistic (n = 80) and non-autistic children (n = 40).
Summary · context
Additionally, we investigated the effect of four-weeks of intranasal oxytocin administration in autistic children on oral microbiome compositions immediately post-treatment (T1) and at four-weeks follow-up (T2).
This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.
Report a problemFND-4187648003

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
11 Oct 2026, 00:50 UTC
Study results updated
Version 1
9 Oct 2026, 02:47 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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MeSH terms

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