Hypothesis: Currently any other study to our knowledge has studied the relationship between
gut microbiota and dementia symptoms in our country. Although there are few recent studies
that have explored relations between microbiota and dementia, they were conducted in Japan or
USA. Taken into account the important factor of diet and lifestyle in microbiota composition
and the differences between these countries (Japan and USA) and Mediterranean diet and
lifestyle, it was the need of a relational study in our context. The hypothesis is that
although it will be different microbiota between healthy and demented subjects, the
microbiota composition of healthy subjects in Mediterranean context could significant differ
from the above-mentioned studies.
In the few studies already conducted, the patients included were diagnosticated of AD or it
were included patients from all type of dementias. Even though AD is the most common type of
dementia, there are more types of dementias that should be considered differentially as the
features are significantly different. Given the diversity through the symptoms across
dementias, a characterization of the gut microbiota of different types of dementia will be
described, specifically, AD, LBDs: LBD and PDD separately, and FTD-behavioral variant.
Furthermore, MCI subjects will be also studied in order to explore the microbiota changes
before the onset of dementia (taking into account the high percentage of MCI that progress to
dementia). These studies could reveal a risk factor compositional microbiota to develop
dementia. The hypothesis is that microbiota will differ through different dementias and could
be related to the feature symptoms of each one, being MCI subjects between healthy and
dementia patients, in terms of microbiota composition.
As pointed out in the introduction, preclinical research shows that probiotics may improve
cognitive performances in animal models with impaired cognition. However, data about the
effects of probiotics on cognitive performance or psychopathological symptoms in humans are
scarce and controversial. This lack of agreement could due to the differences in the
population studied (young adults, elderly, healthy and clinic population, neurologic and
psychiatric patients), the measures (different mood scales and different cognitive
assessments), the probiotic compositions and the duration of treatment (from 3 weeks to 12
weeks). Considering the lack of knowledge about the probiotics potential treating dementia
symptoms, dementia AD patients will be treated with a probiotic compound (a probiotic mixture
already successful in improving cognitive impairment in AD patients, but only assessed by a
cognitive screening and with no analysis of microbiota). The study will be conducted in an
elderly group affected from AD, with a broad type of neuropsychological, neuropsychiatric and
functional measures, and microbiota characterization at 12 and 24 weeks of treatment. An
improvement of dementia symptoms due to probiotic consumption is expected, not only
neuropsychological but also at a neuropsychiatric and functional level and these changes will
be related to the changes of microbiota composition.
General objective: The main objective of DEM-BIOTA is to confirm the relationship between
microbiota and dementia in our model of diet and lifestyle, improving the knowledge of the
relationship between microbiota and dementias. This means to explore the possible differences
between dementias in relation to microbiota in our context (Mediterranean diet and style of
life) and characterize them in relation to neurocognitive and neuropsychiatric symptoms as
well as patient functionality (dependency level). Moreover, the capacity of a probiotic
compound in reverting or improving neurocognitive and neuropsychiatric symptoms and patient
functionality will be studied.
This objective will be achieved through a multidisciplinary study considering microbiota
composition and deep study of the dementia symptoms taking into account the personal
characteristics of each patient. The final issue is to draw a relational map about the
microbiota composition and dementia symptoms and the identification of the microbiota strains
that are a risk factor of produce a deficit in metabolites. The project proposes to finally
study how can a probiotic mixture improve AD symptoms, and study in deep the microbiota
composition changes along with the changes (or not) of dementia symptoms.
This main objective will be carried out by combining our previous knowledge, partly of the
collaboration with European Union partners, with data provided by literature on international
studies on human population.
The aim match with the activities addressed in 1st Challenge identified in the Spanish
Strategy for R+D+I Targeted to Societal Challenges "Health, Geographical change and
Well-being": 1.1.2. Understanding disease; 1.2.1. Development of effective prevention and
detection programs and improvement of disease propensity assessment.
1.3. SPECIFIC OBJECTIVES
- Protocol revision and preparation. Revision of the all tests and scales, writing down
all the protocols, alignment the study protocols with the hospitals' procedures,
timetables, sample collection protocols, etc.
- Study the microbiota composition (from stool samples of the patients) of AD patients
in our context (Mediterranean lifestyle).
Describe the microbiota composition from AD patients in relation with their healthy
controls.
To what extent does it differ from their controls and from the AD patient's composition
of other countries?
- Study microbiota composition differences (from stool samples of the patients) between
some of the most known dementias: AD, PDD, LBD, FTD-behavioral variant
Describe and compare microbiota composition between some of the most known dementias:
AD, PDD, LBD, FTD-behavioral variant.
Describe and compare microbiota composition between MCI patients and AD patients.
Describe and compare microbiota composition between MCI patients and PDD, LBD,
FTD-behavioral variant patients.
Are there any relations between the microbiota composition of all experimental groups
with neuropsychological, neuropsychiatric and functional characteristics present in
these dementias and in these patients? All these relations could be modulated by life
stressors and diet (adherence to Mediterranean diet)?
- Study the effects of a probiotic compound in AD patients. In relation to AD symptoms:
neuropsychological, neuropsychiatric and functional In relation to microbiota
composition (analyzed from the stool samples of the patients) Until what extend and how
the microbiota composition explains the AD symptoms? Can this probiotic compound improve
the symptoms and is in general a good treatment/complement to the nowadays treatment?
- Dissemination and formation. Dissemination of results at scientific (open access
journals, congresses and other national and international meetings) and social level
disclosure (newspapers, research group web, webs of the hospitals and Alzheimer
association, conferences to general public, radio, television, etc.), as well as
formation to patients, professionals and general public.
