Alzheimer's --Gut Microbiome Connection
What's New Monday: Can gut microbes affect Alzheimer's?
Alzheimer’s and dementia are becoming so prevalent in society I venture to bet that nearly everyone reading this has had a loved one succumb to these diseases. We know there is a relationship between gut health and brain health known as the gut-brain axis. Maybe there’s something more going on. Let’s look into this latest research by Grabrucker et al.
Faecal microbiota transplantation (FMT) studies using mouse models of Alzheimer’s disease have implicated the gut microbiota in pathological features of Alzheimer’s disease
Rats were inoculated with human fecal implants for this study. The feces were from non-Alzheimer’s patients and those with Alzheimer’s.
Rats underwent a battery of behavioural tests conducted in the following order: Open Field, Elevated Plus Maze, Modified Spontaneous Location Recognition Test, Novel Object Recognition, Novel Location Recognition, Morris Water Maze and Forced Swim Test.
Multiple parameters were tested, including immunological, Rat hippocampal and caecal metabolomics, cell culture and serum, and cytokines.
Notably, we detected specific differences in the abundance of the genera Desulfovibrio in human Alzheimer’s colonized rats compared to control colonized rats, which reflects our findings in Alzheimer’s patients. …However, human Alzheimer’s disease colonized rats displayed a significant increase in faecal water content (Fig. 2D) and intake (Supplementary Fig. 3E) along with a reduction in colon length (Fig. 2G), suggesting specific effects of the human Alzheimer’s gut microbiota on colonic function.
The implants with Alzheimer’s fecal matter did exhibit a decrease in neurogenesis, meaning there was a lowered survival rate of new neurons.
In this study, we demonstrate that the transplantation of human gut microbiota from Alzheimer’s patients is sufficient to produce core cognitive symptoms of Alzheimer’s disease coupled with an impairment in AHN, in healthy young adult rats. Moreover, application of human Alzheimer’s disease serum provoked an impairment in AHN in human cells in vitro, supporting AHN as a converging cellular process regulating systemic circulatory and gut-mediated factors in Alzheimer’s disease.
It is amazing how the fecal matter from one person with a disease is so potent that it can cause similar symptoms in a healthy subject. It demonstrates the power of microbes and their metabolites.
As usual, the article is cited below for you to read.
Stefanie Grabrucker, Moira Marizzoni, Edina Silajdžić, Nicola Lopizzo, Elisa Mombelli, Sarah Nicolas, Sebastian Dohm-Hansen, Catia Scassellati, Davide Vito Moretti, Melissa Rosa, Karina Hoffmann, John F Cryan, Olivia F O’Leary, Jane A English, Aonghus Lavelle, Cora O’Neill, Sandrine Thuret, Annamaria Cattaneo, Yvonne M Nolan, Microbiota from Alzheimer’s patients induce deficits in cognition and hippocampal neurogenesis, Brain, 2023;, awad303, https://doi.org/10.1093/brain/awad303
Found here: https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awad303/7308687?login=false