Isolated Grauer's gorilla populations differ in diet and gut microbiome

Conservation efforts tend to focus on populations that are genetically differentiated without paying attention to their ecological differentiation. However, isolated populations may be ecologically unique, an important aspect for the design of appropriate conservation measures for endangered species. Here we investigate the interplay between diet and gut microbiome in several geographically isolated and genetically differentiated populations of the critically endangered Grauer's gorilla. We find that dietary and gut microbial profiles are population-specific, likely due to geographic isolation and environmental differences. In addition, social groups within each population also differed in diet and, to a lesser extent, in gut microbial composition and diversity. Individuals at low elevation consumed a larger variety of plant taxa than those at high elevation, consistent with the notion that dietary choice is constrained by food availability that changes with elevation. Despite no detectable correlation between the diet and gut microbiome in richness or evenness, dietary and gut microbial composition covaried significantly. As we did not find evidence for an effect of genetic relatedness on the composition of the gut microbiome of Grauer's gorillas, this pattern is likely a result of long-term social, ecological, and geographic factors acting on both diet and microbiome. These results reveal that isolated and genetically distinct populations of Grauer's gorillas are also ecologically distinct, highlighting the need to dedicate separate conservation efforts for each population.

Coupled social and land use dynamics affect dietary choice and agricultural land-use extent

Dietary patterns have long been a driver of global land use. Increasingly, they also respond to it, in part because of social processes that support adoption of eco-conscious diets. Here we develop a coupled social-and-land use mathematical model parameterised for 153 countries. We project global land use for future population, income, and agricultural yield using our coupled dynamical model. We find that coupled social-and-land feedbacks can alter the peak global land use for agriculture by up to 2 billion hectares, depending on the parameter regime. Across all yield scenarios, the model projects that social dynamics will cause an increase in eco-conscious dietary behaviour until the middle of the 21st century, after which it will decline in response to declining land use caused by a shrinking global population. The model also exhibits a regime of synergistic effects whereby simultaneous changes to multiple socio-economic parameters are required to change land use projections. This research demonstrates the value of including coupled social-and-land feedbacks in land use projections.

Coeliac Disease—What is it and How Can People Deal With it?

In recent years, you have likely heard that some people are eating gluten-free foods. Have you ever wondered why? Coeliac disease is one of the main reasons for this dietary choice. It affects people of all ages from all around the world. It is a genetic disorder that causes inflammation in the intestines and results in various symptoms that can be observed in other parts of the body. Unfortunately, people often ignore coeliac disease or treat it like a simple allergy. Some people may view gluten-free dietary choices as just a trend. Some food allergies can manifest like coeliac disease, but these have different causes. Coeliac disease should be taken seriously, because it may not only lead to life-threatening symptoms, but also have a chronic impact on health and quality of life.

Serotonin signaling modulates aging-associated metabolic network integrity in response to nutrient choice

Aging arises from complex interactions among multiple biochemical and metabolic products. Systems-level analyses of biological networks may provide insights into the causes and consequences of aging that evade single-gene or single-pathway studies. We have shown that dietary choice per se is sufficient to modulate aging and metabolic health in the vinegar fly, Drosophila melanogaster. In other words, how each meal is presented, or the way in which it is eaten, is influential, independent of the amount or type of nutrients that are consumed. For example, when major macronutrients were presented separately, male flies exhibited a rapid and significant increase in mortality rate and a reduced overall lifespan relative to those fed a single medium containing both sugar and yeast. These effects are mediated by specific components of serotonin signaling, as a mutation in serotonin receptor 2A (5-HT2A) eliminated the effects of dietary choice. Here we show that dietary choice influenced several measures of metabolic network integrity, including connectivity, average shortest distance, community structure, and robustness, with the effects of the latter two restricted to tissues in the head. These changes in network structure were associated with organism resilience and increased susceptibility to genetic perturbation, as measured by starvation survival. Our data suggest that the behavioral or perceptual consequences of exposure to individual macronutrients, involving serotonin signaling through 5-HT2A, qualitatively change the state of metabolic networks throughout the organism from one that is highly connected and robust to one that is fragmented, fragile, and vulnerable to perturbations.

Drosophila serotonin 2A receptor signaling coordinates central metabolic processes to modulate aging in response to nutrient choice

It has been recognized for nearly a century that diet modulates aging. Despite early experiments suggesting that reduced caloric intake augmented lifespan, accumulating evidence indicates that other characteristics of the diet may be equally or more influential in modulating aging. We demonstrate that behavior, metabolism, and lifespan in Drosophila are affected by whether flies are provided a choice of different nutrients or a single, complete medium, largely independent of the amount of nutrients that are consumed. Meal choice elicits a rapid metabolic reprogramming that indicates a potentiation of TCA cycle and amino acid metabolism, which requires serotonin 2A receptor. Knockdown of glutamate dehydrogenase, a key TCA pathway component, abrogates the effect of dietary choice on lifespan. Our results reveal a mechanism of aging that applies in natural conditions, including our own, in which organisms continuously perceive and evaluate nutrient availability to promote fitness and well-being.

Assessment of genetic divergence of Sesame seeds based on biochemical parameters

The assessment of genetic divergence plays a significant role to identify promising genotypes to initiate crossing programme for crop improvement. The sesame being a nutritious oil seed crop containing various biochemical constituents used as a good dietary choice. The biochemical analysis was done taking freshly harvested seeds of eight (8) parental genotypes and twenty one (21) advance lines. The studies revealed that all the genotypes differed significantly among themselves for all the biochemical parameters including moisture content, oil content, its iodine number and saponification value, both crude and soluble protein, some mineral matters – Ca, P, Mn, Zn, Cu & Fe and Carbohydrate and ascorbic acid content. Mahalanobis generalized genetic distance using D² statistics for the assessment of genetic divergence amongst 29 genotypes based on biochemical parameters. All the genotypes were grouped into eleven distinct clusters. Maximum intra cluster divergence was noted against cluster IX with advance lines having black coloured seeds as its constituents. With regard to inter-cluster distance values the cluster X was mostly divergent from all other clusters and cluster II as the less divergent one from the rest. Cluster X with parental genotype B-14 was identified as superior cluster for the biochemical parameters on the basis of securing higher position for maximum number of characters. Constitution pattern clustering was independent of eco-geographical isolation. Promising segregants with higher oil yielding potentially may yield from inter se mating of advance line 14 and HT-1 with T-12, R-9 or advance lines 10, 14, 20.

Serotonin 2A receptor signaling coordinates central metabolic processes to modulate aging in response to nutrient choice

It has been recognized for nearly a century that diet modulates aging. Despite early experiments suggesting that reduced caloric intake augmented lifespan, accumulating evidence indicates that other characteristics of the diet may be equally or more influential in modulating aging. We demonstrate that behavior, metabolism, and lifespan in Drosophila are affected by whether flies are provided a choice of different nutrients or a single, complete medium, largely independent of the amount of nutrients that are consumed. Meal choice elicits a rapid metabolic reprogramming that indicates a potentiation of TCA cycle and amino acid metabolism, which requires serotonin 2A receptor. Knockdown of glutamate dehydrogenase, a key TCA pathway component, abrogates the effect of dietary choice on lifespan. Our results reveal a mechanism of aging that applies in natural conditions, including our own, in which organisms continuously perceive and evaluate nutrient availability to promote fitness and well-being.

NIH Workshop Report: sensory nutrition and disease

In November 2019, the NIH held the “Sensory Nutrition and Disease” workshop to challenge multidisciplinary researchers working at the interface of sensory science, food science, psychology, neuroscience, nutrition, and health sciences to explore how chemosensation influences dietary choice and health. This report summarizes deliberations of the workshop, as well as follow-up discussion in the wake of the current pandemic. Three topics were addressed: A) the need to optimize human chemosensory testing and assessment, B) the plasticity of chemosensory systems, and C) the interplay of chemosensory signals, cognitive signals, dietary intake, and metabolism. Several ways to advance sensory nutrition research emerged from the workshop: 1) refining methods to measure chemosensation in large cohort studies and validating measures that reflect perception of complex chemosensations relevant to dietary choice; 2) characterizing interindividual differences in chemosensory function and how they affect ingestive behaviors, health, and disease risk; 3) defining circuit-level organization and function that link and interact with gustatory, olfactory, homeostatic, visceral, and cognitive systems; and 4) discovering new ligands for chemosensory receptors (e.g., those produced by the microbiome) and cataloging cell types expressing these receptors. Several of these priorities were made more urgent by the current pandemic because infection with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease of 2019 has direct short- and perhaps long-term effects on flavor perception. There is increasing evidence of functional interactions between the chemosensory and nutritional sciences. Better characterization of this interface is expected to yield insights to promote health, mitigate disease risk, and guide nutrition policy.