The effects of probiotics on the oral cavity-gut-brain correlation: A study on autism spectrum disorder

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K17199
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57080:Social dentistry-related
• Research Institution: Hiroshima University
• Principal Investigator: Oda Yuki 広島大学, 病院(歯), 専門研究員 (40641949)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: Autistic spectrum / oral flora / intestinal flora / ゲノム解析 / 16S rRNA gene analysis

Outline of Final Research Achievements

In the first year, due to COVID-19, the number of patients with ASD visiting the hospital dropped sharply, making it difficult to determine the subjects. The study broadly targeted people with intellectual disabilities, and first examined whether there were differences in the oral flora of healthy people and those with intellectual disabilities. It was found that the diversity of the oral flora of people with intellectual disabilities was significantly lower than that of healthy people. The above results were presented at the Japanese Society of Disability Dentistry and the International Society of Disability Dentistry, and then compiled as an English paper. From the following year onwards, saliva, dental plaque, and stool were collected from 16 people with ASD and their siblings living together, and genome analysis was performed. It was found that the ASD group had significantly higher diversity in saliva and dental plaque than healthy people, but there was no difference in stool.

Free Research Field

障害者歯科学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果より、自閉スペクトラム症者の細菌叢を健常者と比較した結果、唾液と歯垢では自閉症者で多様性が有意に高かった。一方で、かねてより報告されていた便においては多様性に違いがみられなかった。かねてより、精神疾患の精神症状と腸内細菌叢に何らかの関連がある可能性が指摘されているが、本研究よりASD群と健常群の口腔内細菌叢の違いは、腸内細菌叢における違いよりも顕著であった。このことから、口腔・腸・脳相関が存在する可能性が示唆された。