Currently, there is an increasing number of people with mild cognitive (MCI) impairment and dementia (D). In the present work we studied the role of tau protein, β-amyloid, LPS (lipopolysaccharide), and curli protein of elderly adults with MCI or D and the contribution of gut microbiota. Four groups were studied: young subjects, healthy adults older than 60 years (A), elderly adults with MCI (MCI), and elderly adults with dementia (D). A preclinical study was conducted in old male Wistar rats to evaluate the impact of gut microbiota on curli protein abundance in feces and brain. The results showed that with increasing age, tau protein, β-amyloid, and LPS significantly increased in serum during MCI and D, and this was associated with an increase in the abundance of E. coli that synthesize the amyloid protein curli, that may promote the aggregation of amyloid proteins. Rats showed a clear increase in the abundance of curli protein in the brain during aging. Thus, cognitive impairment and dementia are in part due to an alteration in the gut microbiota–brain axis via increase in curli protein and LPS leading to an increase in tau and β-amyloid protein.

People living in rural areas are prone to move to urban cities experiencing a dramatic change in the type of protein consumed. However, it is not know if those changes are associated with changes in the plasma amino acid concentration, especially the branched chain amino acids. Thus, the aim of the present study was to evaluate, in a rural Mexican population, the plasma amino acid profile after consumption of typical Mexican rural or urban diet. We evaluated the plasma amino acid concentrations of women from a rural population at 0, 30, 60, 90, 120, 180 and 240 min after ingestion of a typical Mexican rural or urban diet. Ingestion of a Mexican urban diet induced a higher increase in leucine, isoleucine, valine, phenylalanine, tyrosine and proline than ingestion of a Mexican rural diet in women from a Mexican rural population. Arginine, histidine, lysine, threonine, alanine, glycine and serine had the same area under the curve regardless of the experimental diet. Ingestion of a Mexican urban diet induced a higher increase in leucine, isoleucine, valine, phenylalanine, tyrosine and proline than ingestion of a Mexican rural diet in women from a Mexican rural area.

Excessive consumption of fat and carbohydrates, together with a decrease in traditional food intake, has been related to obesity and the development of metabolic alterations. Ramon seed is a traditional Mayan food used to obtain Ramon flour (RF) with high biological value in terms of protein, fiber, micronutrients, and bioactive compounds such as polyphenols. However, few studies have evaluated the beneficial effects of RF. Thus, we aimed to determine the metabolic effects of RF consumption on a high-fat-diet-induced obesity mouse model. We divided male BALB/c mice into four groups (n = 5 each group) and fed them for 90 days with the following diets: Control (C): control diet (AIN-93), C + RF: control diet adjusted with 25% RF, HFD: high-fat diet + 5% sugar in water, and HFD + RF: high-fat diet adjusted with 25% RF + 5% sugar in water. The RF prevented the increase in serum total cholesterol (TC) and alanine transaminase (ALT) that occurred in the C and HFD groups. Notably, RF together with HFD increased serum polyphenols and antioxidant activity, and it promoted a decrease in the adipocyte size in white adipose tissue, along with lower hepatic lipid accumulation than in the HFD group. In the liver, the HFD + RF group showed an increase in the expression of β-oxidation-related genes, and downregulation of the fatty acid synthase (Fas) gene compared with the HFD group. Moreover, the HFD + RF group had increased hepatic phosphorylation of AMP-activated protein kinase (AMPK), along with increased nuclear factor erythroid 2-related factor 2 (NRF2) and superoxide dismutase 2 (SOD2) protein expression compared with the HFD group. Thus, RF may be used as a nutritional strategy to decrease metabolic alterations during obesity.

Polycystic ovary syndrome (PCOS) is the main endocrine disorder in women of reproductive age worldwide. This condition is often associated with various metabolic alterations that contribute to the development of metabolic syndrome (MetS). Recent research suggests that branched-chain amino acid (BCAA) dysregulation is observed in PCOS. This study aims to investigate the relationship between dietary patterns, body composition, metabolic analytes, and serum amino acid levels in Mexican women with PCOS. Utilizing a cross-sectional design, we found that both study groups, PCOS (n = 24) and PCOS + MetS (n = 21), exhibited increased relative fat mass and dietary habits characterized by high simple sugar intake and low protein consumption, correlating with levels of relative fat mass and leptin. Notably, serum concentrations of BCAAs and glutamic acid were significantly elevated in the PCOS + MetS group. Our findings suggest that a metabolic approach may enhance the prediction and management of MetS in women with PCOS, highlighting the importance of dietary interventions in this population.