Role of Porphyromonas gingivalis infection in the development of autism

Introduction:

Emerging evidence suggests that oral pathogens may contribute to systemic inflammation and neurodevelopmental disorders. Porphyromonas gingivalis, a keystone pathogen in periodontitis, has been implicated in chronic inflammatory pathways that may influence brain development. This study aims to map the existing evidence on the potential relationship between P. gingivalis infection and the development of autism spectrum disorder (ASD).

Methods:

A bibliographic search was conducted following Joanna Briggs Institute guidelines. Electronic databases (PubMed, Scopus, Web of Science and ScienceDirect) were systematically searched using predefined PCC-based strategies. Studies were included if they examined P. gingivalis infection or periodontal disease in relation to ASD or neurodevelopmental outcomes. Both human and mechanistic (animal and in vitro) studies were considered. Data extraction focused on study characteristics, exposure measures, and reported associations.

Results:

The search identified a limited but growing body of literature exploring links between oral microbiota and neurodevelopment. While direct evidence specifically connecting P. gingivalis to ASD remains scarce, several studies suggest plausible indirect pathways. These include systemic dissemination of bacterial components, induction of pro-inflammatory cytokines, and potential disruption of the blood-brain barrier. Experimental studies indicate that P. gingivalis may influence neuroinflammation and synaptic function, which are relevant to ASD pathophysiology. However, heterogeneity in study design and outcomes limits definitive conclusions.

Conclusions:

Current evidence suggests a biologically plausible but not yet established association between P. gingivalis infection and ASD development. Further interdisciplinary research, particularly longitudinal human studies, is needed to clarify causality and underlying mechanisms.