Neuroprotective effect of Vitamin K2 against gut dysbiosis associated cognitive decline

Vitamin K2/ Menaquinones produced predominantly by the gut microbiome improve bone health and prevent coronary calcification. The central nervous system has been linked with gut microbiota via the gut-brain axis and is strongly associated with psychiatric conditions. In the present study, we show the role of Vitamin K2 (MK-7) in gut dysbiosis-associated cognitive decline. Gut dysbiosis was induced in mice by administering Ampicillin (250 mg/kg twice a day orally) for 14 days and Vitamin K2 (0.05 mg/kg) for 21 days with or without antibiotic treatment and altered gene expression profile of intestinal microbes determined. This was followed by behavioural studies to determine cognitive changes. The behavioural observations are then correlated with proinflammatory, oxidative, and brain and intestinal histopathological changes in antibiotic-treated animals with or without vitamin K2 administration. With the use of antibiotics, Lactobacillus, Bifidobacterium, Firmicutes, and Clostridium's relative abundance reduced. When vitamin K2 was added to the medication, their levels were restored. Cognitive impairment was observed in behavioural trials in the antibiotic group, but this drop was restored in mice given both an antibiotic and vitamin K. Myeloperoxidase levels in the colon and brain increased due to gut dysbiosis, which vitamin K2 prevented. The acetylcholine esterase and oxidative stress markers brought on by antibiotics were also decreased by vitamin K2. Additionally, vitamin K2 guarded against alterations in intestine ultrastructure brought on by antibiotic use and preserved hippocampus neurons. So, it can be concluded that vitamin K2 improved cognitive skills, avoided hippocampus neuronal damage from antibiotics, and lowered intestine and brain inflammation and oxidative stress.