The mechanisms responsible for cardiovascular and neurodegenerative diseases have been the focus of
experimental and clinical studies for decades. The relationship between the gut microbiota and the organs and
system tissues represents the research field that has generated the highest number of publications. Homeostasis of
the gut microbiota is important to the host because it promotes maturation of the autoimmune system, harmonic
integrative functions of the brain, and the normal function of organs related to cardiovascular and metabolic systems.
On the other hand, when a gut microbiota dysbiosis occurs, the target organs become vulnerable to the
onset or aggravation of complex chronic conditions, such as cardiovascular (e.g., arterial hypertension) and neurodegenerative
(e.g., dementia) diseases. In the present brief review, we discuss the main mechanisms involved in
those disturbances and the promising beneficial effects that have been revealed using functional food (nutraceuticals),
such as the traditional probiotic Kefir. Here, we highlight the current scientific advances, concerns, and
limitations about the use of this nutraceutical. The focus of our discussion is the endothelial dysfunction that
accompanies hypertension and the neurovascular dysfunction that characterizes ageing-related dementia in patients
suffering from Alzheimer's disease.