The Cognitive benefits of nitrate in patients with alcohol use disorder: unraveling the oral microbiome ectopic colonization pathwayOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers tested whether dietary nitrate could improve cognition in people with alcohol use disorder (AUD). AUD is linked to cognitive decline and gut dysbiosis, but nitrate's therapeutic potential had not been established in patients.
How was it studied?
In a randomized, double-blind, placebo-controlled pilot trial (NCT05963659), 70 AUD patients drank nitrate-rich beetroot juice or placebo for 14 days. Spatial memory was measured with the Cambridge Neuropsychological Test Battery, and oral and gut microbiota were profiled by 16S rRNA sequencing before and after. Germ-free mice were then colonized with patients' pre- and post-intervention saliva to test causality.
What did they find?
Delayed Matching to Sample scores improved significantly more with nitrate than placebo, a mean difference of 9.784 (95% CI 1.85 to 17.72, P = 0.016). Nitrate shifted oral microbiota more than gut microbiota, and germ-free mice given pre-intervention saliva developed elevated Klebsiella throughout the gut. In mice, nitrate reduced systemic inflammation, strengthened intestinal barrier integrity, and improved cognitive performance.
Why it matters
The findings implicate ectopic oral bacteria, notably Klebsiella, in alcohol-related cognitive impairment via oral-to-gut colonization. Dietary nitrate may offer a microbiota-targeted strategy to support cognition in AUD.