Dietary Fiber Modulates the Release of Gut Bacterial Products Preventing Cognitive Decline in an Alzheimer's Mouse Model.

Fiber intake is associated with a lower risk for Alzheimer´s disease (AD) in older adults. Intake of plant-based diets rich in soluble fiber promotes the production of short-chain fatty acids (SCFAs: butyrate, acetate, propionate) by gut bacteria. Butyrate administration has antiinflammatory actions, but propionate promotes neuroinflammation. In AD patients, gut microbiota dysbiosis is a common feature even in the prodromal stages of the disease. It is unclear whether the neuroprotective effects of fiber intake rely on gut microbiota modifications and specific actions of SCFAs in brain cells. Here, we show that restoration of the gut microbiota dysbiosis through the intake of soluble fiber resulted in lower propionate and higher butyrate production, reduced astrocyte activation and improved cognitive function in 6-month-old male APP/PS1 mice. The neuroprotective effects were lost in antibiotic-treated mice. Moreover, propionate promoted higher glycolysis and mitochondrial respiration in astrocytes, while butyrate induced a more quiescent metabolism. Therefore, fiber intake neuroprotective action depends on the modulation of butyrate/propionate production by gut bacteria. Our data further support and provide a mechanism to explain the beneficial effects of dietary interventions rich in soluble fiber to prevent dementia and AD. Fiber intake restored the concentration of propionate and butyrate by modulating the composition of gut microbiota in male transgenic (Tg) mice with Alzheimer´s disease. Gut dysbiosis was associated with intestinal damage and high propionate levels in control diet fed-Tg mice. Fiber-rich diet restored intestinal integrity and promoted the abundance of butyrate-producing bacteria. Butyrate concentration was associated with better cognitive performance in fiber-fed Tg mice. A fiber-rich diet may prevent the development of a dysbiotic microbiome and the related cognitive dysfunction in people at risk of developing Alzheimer´s disease.

Malian Thick Porridges (tô) of Pearl Millet Are Made Thinner in Urban Than Rural Areas and Decrease Satiety.

BACKGROUND: Changes in preparation, preference, and consumption of traditional staple foods between rural and urban areas in sub-Saharan Africa may be associated with the nutrition transition. OBJECTIVE: Millet porridge thickness and postprandial hunger were investigated in Mali with the aim of understanding consumer preference and satiety properties. METHODS: Rural and urban residents from 3 regions (N = 60) were surveyed regarding their porridge consumption frequency and thickness preference. Influence of millet porridge thickness on satiety was investigated. Ten participants consumed 4 porridges of different thicknesses (3 of millet and 1 thin porridge of rice) and rated their subjective hunger on 4 different days. RESULTS: Thicker porridges were consumed more frequently in rural areas than in urban (P < .05). For the satiety study, thicker porridges induced higher satiety than thinner ones at 2 and 4 hours postconsumption (P < .05; Visual Analog Scale rating). A greater amount of flour, but not volume, was consumed for the thicker porridges (P < .05). CONCLUSIONS: Urban participants preferred and consumed porridges that are less satiating, potentially contributing to higher food consumption related to the nutrition transition in Africa.

Descriptive sensory analysis of instant porridge from stored wholegrain and decorticated pearl millet flour cooked, stabilized and improved by using a low-cost extruder.

Pearl millet flour, particularly wholegrain flour, is highly susceptible to development of rancid aromas and flavors during storage. Grain decortication and extrusion cooking using a friction-heated single-screw extruder were investigated as potential flour stabilization processes. Raw and extruded wholegrain and decorticated grain pearl millet flours were stored at ambient (25°C) and elevated (40°C) temperatures for 6 months. A trained descriptive sensory panel developed a lexicon of 44 attributes to profile the aroma, flavor, and texture of porridges prepared from the flours. Grain decortication alone did not show an effect on the aroma and flavor profile of porridge. Extrusion cooking of both wholegrain and decorticated flours increased cereal-like aromas (branny, canned sweetcorn, sweet, and wheaty) and flavor (starchy), as well as stiffness and cohesiveness of the porridges. The porridges from the extruded pearl millet flours stored for up to 6 months at ambient and elevated temperatures did not show any indications of rancidity. In contrast, rancidity-associated aromas (chemical, painty, and soapy) and flavor (chemical) increased in porridges from the raw flours stored for 4 weeks and longer. These results indicate that grain decortication did not sufficiently reduce fat content to prevent oxidation, while extrusion cooking stabilized the pearl millet flours. In addition, intensified "cereal-like" aromas and flavors were probably due to Maillard reactions occurring during extrusion cooking. Resulting aroma compounds could have been immobilized in the extruded matrix and not released during flour storage. The application of extrusion cooking with a simple friction-heated single-screw extruder is a viable process for both precooking and extending the shelf life of pearl millet flours. PRACTICAL APPLICATION: This study demonstrates the potential of extrusion cooking to precook wholegrain pearl millet while preventing fat rancidity in wholegrain pearl millet flour, thereby improving the sensory quality and stability of pearl millet food products. The extensive sensory characterization of pearl millet porridge-type foods can serve as a guidance tool for development, improvement, and quality control of pearl millet foods. Furthermore, it establishes the efficacy of simple friction-heated, single-screw extruders for commercial manufacture of ready-to-eat wholegrain pearl millet food products by small and medium scale entrepreneurs.

Factors Correlated to Protective and Risk Dietary Patterns in Immigrant Latino Mothers in Non-metropolitan Rural Communities.

Immigrant Latinos face conditions which over time negatively impact their nutritional behaviors and health outcomes. Our objective was to evaluate associations between environmental and lifestyle factors and both protective dietary patterns (e.g., intake of fruits and vegetables) and harmful dietary patterns (e.g., consumption of salty snacks and fast food). Surveys were individually and orally administered to 105 foreign-born Latina mothers living in rural locations in a Midwestern state. Principal component analysis created composite variables for each construct and Spearman correlations were conducted to determine associations. Protective dietary patterns were positively associated with access to food and information (ρs = 0.21) and language acculturation (ρs = 0.24), and negatively associated with family challenges (ρs = -0.31). Food insecurity was negatively associated with harmful dietary patterns (ρs = -0.24). Findings suggest that rural Latino dietary interventions should be complemented with comprehensive strategies addressing environmental and lifestyle factors across ecological domains.