Gut Flora-Targeted Photobiomodulation Therapy Improves Senile Dementia in an Aß-Induced Alzheimer’s Disease Animal Model

Authors: Qianqian Chen, Jinpeng Wu, Xiaoxi Dong, Huijuan Yin, Xiafei Shi, Siying Su, Bochen Che, Yingxin Li, Jichun Yang
Published in: Journal of Photochemistry and Photobiology B: Biology, Volume 216, March 2021, Article 112152
DOI: 10.1016/j.jphotobiol.2021.112152
Access Link: Elsevier

Key Findings & Conditions PBM May Benefit

This study investigates gut flora-targeted photobiomodulation therapy (gf-PBM) as a non-invasive approach for treating Alzheimer’s disease (AD) by modulating intestinal flora. PBM was applied to the abdomen of Aß-induced AD mice using 630 nm, 730 nm, and 850 nm light for 8 weeks at 100 J/cm².

The findings suggest that gf-PBM significantly improves:

• Cognitive function in AD mice, demonstrated by enhanced learning and memory retention.

• Amyloid plaque accumulation and tau phosphorylation in the hippocampus.

• Neuroinflammation, with reduced microglia activation.

• Gut microbiota composition, reversing AD-related increases in Helicobacter and uncultured Bacteroidales, and the decrease of Rikenella.

PBMT Effects on the Gut and Brain

PBM was applied only to the abdomen, targeting the gut microbiome to indirectly influence brain pathology. Key effects include:

• Reversing gut dysbiosis linked to AD.

• Enhancing mitochondrial function via cytochrome C oxidase activation.

• Reducing neuroinflammation, amyloid plaque formation, and tau protein hyperphosphorylation.

• Increasing hippocampal protein expression linked to hormone synthesis, metabolism, and immune response regulation.

Specific PBMT Protocols Mentioned

PBM was administered at the following parameters:

• Wavelengths: 630 nm, 730 nm, and 850 nm.

• Energy Density: 100 J/cm².

• Duration: 8 weeks of abdominal irradiation.

The study found that 630 nm and 730 nm wavelengths had the most significant effects on gut flora and AD-related pathology.

Other Conditions PBMT May Benefit

The study references PBM’s potential role in treating:

1. Neurodegenerative Disorders

• Alzheimer’s Disease (AD)

• Parkinson’s Disease (PD)

• Multiple Sclerosis (MS)

• Traumatic Brain Injury (TBI)

2. Inflammatory and Autoimmune Conditions

• Arthritis

• Muscle injuries

• Chronic pain conditions

3. Metabolic and Cardiovascular Diseases

• Diabetic foot disease

• Obesity and metabolic syndrome

4. Wound Healing and Tissue Repair

• Bone regeneration

• Oral mucositis

• Skin disorders

Conclusion

This study demonstrates that gut flora-targeted PBM (gf-PBM) at 630 nm, 730 nm, and 850 nm can reverse gut microbiota imbalances and reduce cognitive and neuropathological damage in Aß-induced AD mice. The results indicate that gf-PBM may serve as a promising non-invasive therapy for modulating the gut-brain axis in Alzheimer’s disease.

The study suggests mitochondrial respiratory chain complex enzymes as a potential key target of PBM. Future research will explore PBM’s long-term effects on the brain-gut axis and its application in other AD models.