Investigating brain–gut microbiota dynamics and inflammatory processes in an autistic-like rat model using MRI biomarkers during childhood and adolescence
Lalitha Palanivelu,
You-Yin Chen,
Chih-Ju Chang,
Yao-Wen Liang,
Hsin-Yi Tseng,
Ssu-Ju Li,
Ching-Wen Chang,
Yu-Chun Lo
Affiliations
Lalitha Palanivelu
International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, 7F., No. 250, Wuxing St., Xinyi Dist., Taipei city 110, Taiwan
You-Yin Chen
Department of Biomedical Engineering, National Yang Ming Chiao Tung University, No.155, Sec.2, Linong St., Taipei 11221, Taiwan; Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University. 12F., Education and Research Building, Shuang-Ho Campus, No. 301, Yuantong Rd., New Taipei City 23564, Taiwan
Chih-Ju Chang
Department of Neurosurgery, Cathay General Hospital, No. 280, Sec. 4, Renai Rd., Taipei 10629, Taiwan; School of Medicine, Fu Jen Catholic University, No.510, Zhongzheng Rd., New Taipei City 242062, Taiwan
Yao-Wen Liang
Department of Biomedical Engineering, National Yang Ming Chiao Tung University, No.155, Sec.2, Linong St., Taipei 11221, Taiwan
Hsin-Yi Tseng
Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, 12F., Education and Research Building, Shuang-Ho Campus, No. 301, Yuantong Rd., New Taipei City 23564, Taiwan
Ssu-Ju Li
Department of Biomedical Engineering, National Yang Ming Chiao Tung University, No.155, Sec.2, Linong St., Taipei 11221, Taiwan
Ching-Wen Chang
Department of Biomedical Engineering, National Yang Ming Chiao Tung University, No.155, Sec.2, Linong St., Taipei 11221, Taiwan
Yu-Chun Lo
Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University. 12F., Education and Research Building, Shuang-Ho Campus, No. 301, Yuantong Rd., New Taipei City 23564, Taiwan; Correspondence author. Yu-Chun Lo, Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University. 12F., Education and Research Building, Shuang-Ho Campus, No. 301, Yuantong Rd., New Taipei City 23564, Taiwan.
Autism spectrum disorder (ASD) is characterized by social interaction deficits and repetitive behaviors. Recent research has linked that gut dysbiosis may contribute to ASD-like behaviors. However, the exact developmental time point at which gut microbiota alterations affect brain function and behavior in patients with ASD remains unclear. We hypothesized that ASD-related brain microstructural changes and gut dysbiosis induce metabolic dysregulation and proinflammatory responses, which collectively contribute to the social behavioral deficits observed in early childhood. We used an autistic-like rat model that was generated via prenatal valproic acid exposure. We analyzed brain microstructural changes using diffusion tensor imaging (DTI) and examined microbiota, blood, and fecal samples for inflammation biomarkers. The ASD model rats exhibited significant brain microstructural changes in the anterior cingulate cortex, hippocampus, striatum, and thalamus; reduced microbiota diversity (Prevotellaceae and Peptostreptococcaceae); and altered metabolic signatures. The shift in microbiota diversity and density observed at postnatal day (PND) 35, which is a critical developmental period, underscored the importance of early ASD interventions. We identified a unique metabolic signature in the ASD model, with elevated formate and reduced acetate and butyrate levels, indicating a dysregulation in short-chain fatty acid (SCFA) metabolism. Furthermore, increased astrocytic and microglial activation and elevated proinflammatory cytokines—interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α)—were observed, indicating immune dysregulation. This study provided insights into the complex interplay between the brain and the gut, and indicated DTI metrics as potential imaging-based biomarkers in ASD, thus emphasizing the need for early childhood interventions.
