Developmental Programming in Animal Models: Critical Evidence of Current Environmental Negative Changes.

The Developmental Origins of Health and Disease (DOHaD) approach answers questions surrounding the early events suffered by the mother during reproductive stages that can either partially or permanently influence the developmental programming of children, predisposing them to be either healthy or exhibit negative health outcomes in adulthood. Globally, vulnerable populations tend to present high obesity rates, including among school-age children and women of reproductive age. In addition, adults suffer from high rates of diabetes, hypertension, cardiovascular, and other metabolic diseases. The increase in metabolic outcomes has been associated with the combination of maternal womb conditions and adult lifestyle-related factors such as malnutrition and obesity, smoking habits, and alcoholism. However, to date, "new environmental changes" have recently been considered negative factors of development, such as maternal sedentary lifestyle, lack of maternal attachment during lactation, overcrowding, smog, overurbanization, industrialization, noise pollution, and psychosocial stress experienced during the current SARS-CoV-2 pandemic. Therefore, it is important to recognize how all these factors impact offspring development during pregnancy and lactation, a period in which the subject cannot protect itself from these mechanisms. This review aims to introduce the importance of studying DOHaD, discuss classical programming studies, and address the importance of studying new emerging programming mechanisms, known as actual lifestyle factors, during pregnancy and lactation.

Intestinal paracellular absorption is necessary to support the sugar oxidation cascade in nectarivorous bats.

We made the first measurements of the capacity for paracellular nutrient absorption in intact nectarivorous bats. Leptonycteris yerbabuenae (20 g mass) were injected with or fed inert carbohydrate probes L-rhamnose and D(+)-cellobiose, which are absorbed exclusively by the paracellular route, and 3-O-methyl-D-glucose (3OMD-glucose), which is absorbed both paracellularly and transcellularly. Using a standard pharmacokinetic technique, we collected blood samples for 2 h after probe administration. As predicted, fractional absorption (f) of paracellular probes declined with increasing Mr in the order of rhamnose (f=0.71)>cellobiose (f=0.23). Absorption of 3OMD-glucose was complete (f=0.85; not different from unity). Integrating our data with those for glucose absorption and oxidation in another nectarivorous bat, we conclude that passive paracellular absorption of glucose is extensive in nectarivorous bat species, as in other bats and small birds, and necessary to support high glucose fluxes hypothesized for the sugar oxidation cascade.

Nitrogen and amino acids in nectar modify food selection of nectarivorous bats.

1. Chiropterophilic flowers secrete sugar nectar with low-Nitrogen (N hereafter) content and small amounts of amino acids, which may function to attract animals; nevertheless, the role that micronutrients have on the foraging decisions of Neotropical nectarivorous bats is unknown. 2. We offered the nectar specialist Leptonycteris yerbabueanae and the omnivore Glossophaga soricina pairs of experimental diets mimicking either the N content or the relative abundance of 17 amino acids found in the floral nectar from the main plant species visited by these bats in a tropical dry forest. We addressed the following research questions: (i) Do bats select N-containing or sugar-only nectar differently based on bats' N nutritional status? (ii) Does the presence of N in nectar affect the capacity of bats to discriminate and select other nectar traits such as sugar concentration? and (iii) Are bats able to distinguish among the flavours generated by the amino acid relative abundance present in the nectar from plants they typically encounter in nature? 3. Our results showed that: (i) bats did not consider nectar N content regardless of their N nutritional condition, (ii) the nectar specialist L. yerbabuenae showed a preference for the most concentrated sugar-only nectar but changed to be indifferent when nectar contained N, and (iii) L. yerbabuenae preferred diets without amino acids and preferred the taste of the amino acids present in the nectar of Pachycereus pecten (Cactaceae) over those present in the nectar of Ceiba aesculifolia (Bombacaceae). 4. Our results suggest that regardless of the low concentrations at which N and amino acids are present in floral nectar, their presence affects bats' food selection by interfering with the bats' ability to detect differences in sugar concentrations, and by offering particular flavours that can be perceived and selected by nectarivorous bats. We discuss the ecological implications of the presence of N and amino acids in nectar on bats' foraging decisions.

Sugar gustatory thresholds and sugar selection in two species of Neotropical nectar-eating bats.

Nectar-feeding bats play an important role in natural communities acting as pollinators; however, the characteristics that affect their food selection are unclear. Here we explore the role that sugar gustatory thresholds and sugar concentration play on sugar selection of Glossophaga soricina and Leptonycteris yerbabuenae. We offered bats paired feeders containing sugar solutions of sucrose (S), glucose (G) or fructose (F) vs. pure water, and sucrose vs. 1:1 equicaloric solutions of glucose-fructose at 5, 15 and 35% (wt./vol.). To see the effect of sweetness on sugar selection, we habituated the bats with a diet containing either sucrose or hexoses and subsequently evaluated sugar preferences. Sugar thresholds were S

Foraging behavior adjustments related to changes in nectar sugar concentration in phyllostomid bats.

Nectar-feeding bats regulate their food ingestion in response to changes in sugar concentration as a way to achieve a constant energy intake. However, their digestive capability to assimilate sugars can limit their total energy intake, particularly when sugar concentration in nectar is low. Our experimental study evaluated the effect that changes in sugar concentration of nectar have on the foraging behavior of the nectar-feeding bats Glossophaga soricina and Leptonycteris yerbabuenae in captivity. We measured foraging behavior and food intake when bats fed at different concentrations of sucrose (5, 15, 25 and 35%wt/vol.). To compensate for low-energy intake, both bat species reduced their flight time, and increased feeding time when sugar concentration decreased. Our results suggest that nectar-feeding bats in nature confront two scenarios with complementary ecological effects: 1) bats feeding on dilute nectars (i.e. ≤15%wt/vol.) should increase the number of flowers visited per night enhancing pollination, and 2) bats feeding on concentrated nectars could spend more time flying, including long- and short-distance-flights increasing food patch exploration for use during subsequent nights, and thus enhancing plant gene flow. Further studies on foraging behavior of nectarivorous bats under natural conditions are necessary to corroborate these hypotheses.

The intake responses of three species of leaf-nosed Neotropical bats.

Flower-visiting bats encounter nectars that vary in both sugar composition and concentration. Because in the new world, the nectars of bat-pollinated flowers tend to be dominated by hexoses, we predicted that at equicaloric concentrations, bats would ingest higher volumes of hexoses than sucrose-containing nectars. We investigated the intake response of three species of Neotropical bats, Leptonycteris curasoae, Glossophaga soricina and Artibeus jamaicensis, to sugar solutions of varying concentrations (292, 438, 584, 730, 876, and 1,022 mmol L(-1)) consisting of either sucrose or 1:1 mixtures of glucose and fructose solutions. Bats did not show differences in their intake response to sucrose and 1:1 glucose-fructose solutions, indicating that digestion and absorption in bat intestines are designed under the principle of symmorphosis, in which no step is more limiting than the other. Our results also suggest that, on the basis of energy intake, bats should not prefer hexoses over sucrose. We used a mathematical model that uses the rate of sucrose hydrolysis measured in vitro and the small intestinal volume of bats to predict the rate of nectar intake as a function of sugar concentration. The model was a good predictor of the intake responses of L. curasoae and G. soricina, but not of A. jamaicensis.