Gut flora-targeted photobiomodulation therapy improves senile dementia in an Aß-induced Alzheimer’s disease animal model

Abstract

Background: Emerging evidence suggests that the gut microbiota plays an important role in the pathological progression of Alzheimer's disease (AD). Photobiomodulation (PBM) therapy is believed to have a positive regulatory effect on the imbalance of certain body functions, including in ammation, immunity, wound healing, nerve repair, and pain. Previous studies have found that the intestinal ora of patients with AD is in an unbalanced state. Therefore, we have proposed the use of gut ora-targeted PBM (gf-targeted PBM) as a method to improve AD in an Aß-induced AD mouse model. Methods: PBM was performed on the abdomen of the mice at the wavelengths of 630 nm, 730 nm, and 850 nm at 100 J/cm 2 for 8 weeks. Morris water maze test, immuno uorescence and proteomic of hippocampus, and intestinal ora detection of fecal were used to evaluate the treatment effects of gftargeted PBM on AD rats.Results: PBM at all three wavelengths (especially 630 nm and 730 nm) signi cantly improved learning retention as measured by the Morris water maze. In addition, we found reduced amyloidosis and tau phosphorylation in the hippocampus by immuno uorescence in AD mice. By using a quantitative proteomic analysis of the hippocampus, we found that gf-targeted PBM signi cantly altered the expression levels of 509 proteins (the same differentially expressed proteins in all three wavelengths of PBM), which involved the pathways of hormone synthesis, phagocytosis, and metabolism. The 16s rRNA gene sequencing of fecal contents showed that PBM signi cantly altered the diversity and abundance of intestinal ora. Speci cally, PBM treatment reversed the typical increase of Helicobacter and uncultured Bacteroidales and the decrease of Rikenella seen in AD mice.Conclusions: Our data indicate that gf-targeted PBM regulates the diversity of intestinal ora, which may improve damage caused by AD. Gf-targeted PBM has the potential to be a noninvasive micro ora regulation method for AD patients.

Aging effects on the diurnal patterns of gut microbial composition in male and female mice

“…The other genera such as Rikenella, Ruminococcaceae UCG-014, Alloprevotella, and Parasutterella, that showed changes in diurnal pattern of their abundance in the present study, have been also suggested to be involved in several diseases. Rikenella abundance decreased in the mouse gut of an Alzheimer’s disease (AD) model, and gut-flora targeted photobiomodulation therapy reversed the changes in gut microbiome with improved cognitive function and brain pathologies [ 35 ]. The authors suggest that interventions targeting gut flora can be a treatment modality for AD [ 35 ].…”

“…Rikenella abundance decreased in the mouse gut of an Alzheimer’s disease (AD) model, and gut-flora targeted photobiomodulation therapy reversed the changes in gut microbiome with improved cognitive function and brain pathologies [ 35 ]. The authors suggest that interventions targeting gut flora can be a treatment modality for AD [ 35 ]. Butyrate-producing Ruminococcaceae UCG-014 abundance also decreased in the mouse gut of a ulcerative colitis carcinogenesis model [ 36 ].…”

Microbiome Changes in Humans with Parkinson’s Disease after Photobiomodulation Therapy: A Retrospective Study

“…The observed changes to the gut microbiome of participants in this study, whose clinical signs and symptoms also improved with PBM, lend support to the important role of microbiome changes in PD. PBM has been shown to alter the microbiome in a mouse model, both in healthy mice [25] and in animal models of Alzheimer's disease [77,78] and osteoporosis [79]. In humans, one possibility is that the change in the microbiome with PBM could be a primary effect, either acting directly on the bacteria or as a result of the anti-inflammatory effect of PBM, counteracting inflammation in the gut [80] and, hence, reducing dysbiosis-induced gut leakage.…”

Therapeutic Potential of Photobiomodulation for Chronic Kidney Disease

“…Although the action mechanisms underlying the beneficial effect of PBM are not fully understood, the most widely accepted mechanism is that PBM improves mitochondrial function, leading to increased ATP production, inhibiting oxidative stress, and reducing inflammation [ 15 , 80 , 81 ]. Furthermore, recent studies have demonstrated that PBM can modulate the gut microbiota and may be a novel gut microbiota intervention in different animal disease models, including Alzheimer’s disease and osteoporosis [ 17 , 82 , 83 ] and, more recently, in patients with Parkinson’s disease [ 84 , 85 ].…”