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We evaluated the association between hippocampal atrophy and increase of the EEG markers alpha3/alpha2 relative power ratio in mild cognitive impairment (MCI) and Alzheimer's disease patients. Seventy-nine subjects with MCI and 11 patients with AD underwent EEG recording and MRI scan. The MCI group was subdivided in three subgroups according to growing hippocampal atrophy. The groups were characterized by alpha3/alpha2 relative power ratio. In AD patients group mapped hippocampal regions were computed and related with alpha3/alpha2 power ratio. Results show that the increase of alpha3/alpha2 power ratio is correlated with atrophy of hippocampus both in MCI and in Alzheimer's disease patients. This finding confirms the possible diagnostic role of EEG markers as diagnostic and prognostic factors in patient with prodromal and declared Alzheimer's disease.

We evaluated the relationship between brain rhythmicity and both the cerebrovascular damage (CVD) and amygdalohippocampal complex (AHC) atrophy, as revealed by scalp electroencephalography (EEG) in a cohort of subjects with mild cognitive impairment (MCI). All MCI subjects underwent EEG recording and magnetic resonance imaging. EEGs were recorded at rest. Relative power was separately computed for delta, theta, alpha1, alpha2, and alpha3 frequency bands. In the spectral band power the severity of CVD was associated with increased delta power and decreased alpha2 power. No association of vascular damage was observed with alpha3 power. Moreover, the theta/alpha1 ratio could be a reliable index for the estimation of the individual extent of CV damage. On the other side, the group with moderate hippocampal atrophy showed the highest increase of alpha2 and alpha3 power. Moreover, when the amygdalar and hippocampal volumes are separately considered, within amygdalohippocampal complex (AHC), the increase of theta/gamma ratio is best associated with amygdalar atrophy whereas alpha3/alpha2 ratio is best associated with hippocampal atrophy. CVD and AHC damages are associated with specific EEG markers. So far, these EEG markers could have a prospective value in differential diagnosis between vascular and degenerative MCI.

Objective. The increase of high alpha relative to low alpha power has been recently demonstrated as a reliable EEG marker of hippocampal atrophy conversion of patients with mild cognitive impairment (MCI) in Alzheimer's disease (AD). In the present study we test the reliability of this EEG index in subjects with AD. Methods. Correlation between EEG markers and volumetric differences in mapped hippocampal regions was estimated in AD patients. Results. Results show that the increase of alpha3/alpha2 power ratio is correlated with atrophy of mapped hippocampal regions in Alzheimer's disease. Conclusions. The findings confirm the possible diagnostic role of EEG markers.

Limosilactobacillus fermentum Lf2 (Lf2) is an autochthonous strain that produces high levels of exopolysaccharides (EPS). The objective of this work was to evaluate the probiotic potential of Lf2 and its relationship with these metabolites in a mouse model of TNBS (trinitrobenzene sulfonic acid)-induced chronic colitis. Mice were treated intrarectally with increasing doses of TNBS resuspended in 50% ethanol for 14 days. In parallel, they received different treatments by gavage (lactose 10% as the matrix): freeze-dried Lf2 (L); purified EPS (E); and lactose 10% (T). A healthy control group (H) was treated with 50% alcohol without TNBS (intrarectally) and 10% lactose (by gavage). In the small intestine, there was a significant increase in IgA levels for the group that received EPS and a decrease in IFN-γ for mice treated with the strain compared to the other groups. In the large intestine, IL-2 and IFN-γ presented the lowest levels in the groups treated with EPS and the strain. The concentrations of acetic and propionic acids in mice that received Lf2 were the highest, while the levels of butyric acid were comparable to the healthy control group. An increase in the abundance of SCFA-producing bacteria was observed for mice treated with EPS and the strain in comparison with the colitis control group. The enzyme activity of catalase was higher in all the treatments compared to the TNBS-induced colitis control mice. To summarize the results obtained, a principal component analysis (PCA) was performed, clearly grouping the treatments in different clusters according to the variables studied. This is one of the first studies to address the role of a potential probiotic strain in a chronic colitis mouse model, trying to elucidate the relationship between its properties and the EPS synthesized.

Elderly people are an important part of the global population who suffer from the natural processes of senescence, which lead to changes in the gut microbiota composition. These modifications have a great impact on their quality of life, bringing a general putrefactive and inflammatory status as a consequence. Some of the most frequent conditions related to this status are constipation, undernutrition, neurodegenerative diseases, susceptibility to opportunistic pathogens, and metabolic disbalance, among others. For these reasons, there is an increasing interest in improving their quality of life by non-invasive treatments such as the consumption of probiotics, prebiotics, and synbiotics. The aim of the present mini-review is to describe the benefits of these functional supplements/food according to the most recent clinical and pre-clinical studies published during the last decade. In addition, insights into several aspects we consider relevant to improve the quality of future studies are provided.