Diet Could Reduce Alzheimer Disease-Linked Gut Fungi
Previous evidence has linked specific gut bacteria (microbiome) with mild cognitive impairment (MCI) and suggested that following a (MMKD) could improve markers for Alzheimer Disease (AD) in these patients. In a new study, the researchers sought to evaluate whether fungi present within the gut (mycobiome) could have similar effects in this population.
They conducted a single-center, randomized, double-blind, crossover pilot study involving 17 participants, 11 of whom had been diagnosed with MCI and were at risk for AD. The other 6 participants were cognitively normal.
Both groups of participants were randomly assigned to follow either the (MMKD) or an American Heart Association Diet (AHAD). Participants were to follow their randomly assigned diet for 6 weeks, before resuming their pre-study diet for another 6 weeks, after which they began following the second dietary intervention for 6 weeks.
The participants provided stool samples from the beginning of the study, after diet 1, and after diet 2, and also underwent a lumbar puncture at the beginning and following the completion of each diet.
The researchers found that MCI patients had significantly higher proportions of fungal families Sclerotiniaceae, Phaffomyceteceae, Trichocomaceae, Cystofilobasidiaceae, Togniniaceae and genera Botrytis, Kazachstania, Phaeoacremonium and Cladosporium, and lower levels of Meyerozyma. Further, specific fungi were shown to be associated with markers of AD and gut bacteria in these patients.
MMKD influenced fungal diversity in patients with MCI, increasing Agaricus and Mrakia while decreasing Saccharomyces and Claviceps.
Of these results, the researchers noted that “the findings corroborate the notion of considering gut mycobiome as a unique factor that can affect cognitive health/AD by interacting with gut bacteria and diet and facilitate better understanding of the AD and related microbiome, using unique diet or microbiome modulators.”
Nagpal R, Neth BJ, Wang S, et al. Gut mycobiome and its interaction with diet, gut bacteria and Alzheimer’s disease markers in subjects with mild cognitive impairment: a pilot study. EBioMedicine. Published online September 1, 2020. doi:10.1016/j.ebiom.2020.102950