Related Experiment Videos
Postnatal microbial colonization programs the hypothalamic-pituitary-adrenal system for stress response in mice
Nobuyuki Sudo1, Yoichi Chida, Yuji Aiba
1Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. sudo@hcam.med.kyushu-u.ac.jp
The Journal of Physiology
|May 11, 2004
Summary
Early-life microbial colonization is crucial for developing the stress response system. Germfree mice show exaggerated stress reactions, which can be corrected by specific beneficial bacteria like Bifidobacterium infantis.
Area of Science:
- Neuroscience
- Microbiology
- Endocrinology
Background:
- The gut microbiota plays a role in host physiology.
- The impact of early microbial colonization on brain plasticity and stress response is not well understood.
Purpose of the Study:
- To investigate how postnatal microbial colonization influences the development of the hypothalamic-pituitary-adrenal (HPA) axis and its response to stress.
Main Methods:
- Comparison of stress response in germfree (GF), specific pathogen free (SPF), and gnotobiotic mice.
- Assessment of plasma ACTH and corticosterone levels post-stress.
- Evaluation of brain-derived neurotrophic factor (BDNF) expression.
- Reconstitution experiments with Bifidobacterium infantis, Escherichia coli, and SPF feces at different developmental stages.
Main Results:
- GF mice exhibited a significantly higher HPA stress response compared to SPF mice.
- Reduced BDNF expression was observed in GF mice.
- Reconstitution with Bifidobacterium infantis normalized the HPA response in GF mice.
- Exposure to specific bacteria like E. coli altered the stress response.
- Early-stage microbial colonization was critical for proper HPA axis development and regulation.
Conclusions:
- Postnatal microbial colonization is essential for the normal development of the HPA stress response system.
- The timing of microbial exposure is critical for establishing neural regulation of stress.
- Commensal microbiota can modulate the development of brain plasticity and endocrine stress responses.