Using Evidence-based Scientific Research to Influence Dietary Behavioral Change: Taking a Look in the Mirror

Science can provide accurate information to society to inform decision-making and behavior. One contemporary topic in which the science is very clear, yet behavioral change has lagged, is climate change mitigation. Climate change scientists use evidence-based research to advocate to the public to adopt emission-reducing behaviors in various sectors such as transportation and food. However, scientists themselves often do not change their own behaviors according to the scientific consensus. We present a case study of a group of natural sciences PhD students, who, when presented with evidence and an opportunity for a behavioral change with implications for climate change mitigation, demonstrated defensive reactions that would undoubtedly frustrate these same scientists if they were doing public outreach about their own work. Our goal is to raise awareness that we scientists do not always practice what we preach but could perhaps overcome this by understanding the defense mechanisms that impede meaningful change.

Evolutionary history of the extinct wolf population from France in the context of global phylogeographic changes throughout the Holocene

Phylogeographic patterns in large mammals result from natural environmental factors and anthropogenic effects, which in some cases include domestication. The grey wolf was once widely distributed across the Holarctic, but experienced phylogeographic shifts and demographic declines during the Holocene. In the 19th-20th centuries, the species became extirpated from large parts of Europe due to direct extermination and habitat loss. We reconstructed the evolutionary history of the extinct Western European wolves based on the mitogenomic composition of 78 samples from France (Neolithic-20th century) in the context of other populations of wolves and dogs worldwide. We found a close genetic similarity of French wolves from ancient, medieval and recent populations, which suggests the long-term continuity of maternal lineages. MtDNA haplotypes of the French wolves showed large diversity and fell into two main haplogroups of modern Holarctic wolves. Our worldwide phylogeographic analysis indicated that haplogroup W1, which includes wolves from Eurasia and North America, originated in Northern Siberia. Haplogroup W2, which includes only European wolves, originated in Europe ~35 kya and its frequency was reduced during the Holocene due to an expansion of haplogroup W1 from the east. Moreover, we found that dog haplogroup D, currently restricted to Europe and the Middle East, was nested within the wolf haplogroup W2. This suggests European origin of haplogroup D, probably as a result of an ancient introgression from European wolves. Our results highlight the dynamic evolutionary history of European wolves during the Holocene, with a partial lineage replacement and introgressive hybridization with local dog populations.

The difference in the composition of gut microbiota is greater among bats of different phylogenies than among those with different dietary habits

Bats have a very long evolutionary history and are highly differentiated in their physiological functions. Results of recent studies suggest effects of some host factors (e.g., phylogeny and dietary habit) on their gut microbiota. In this study, we examined the gut microbial compositions of 18 different species of bats. Results showed that Firmicutes, Gammaproteobacteria, and Actinobacteria were dominant in all fecal samples of bats. However, the difference in the diversity of gut microbiota among bats of different phylogenies was notable (p = 0.06). Various species of Firmicutes, Actinobacteria, and Gammaproteobacteria were found to contribute to the majority of variations in gut microbiota of all bats examined, and Aeromonas species were much more abundant in bats that feed on both insects and fish than in those of insectivores. The abundance of various species of Clostridium, Euryarchaeota, and ancient bacterial phyla was found to vary among bats of different phylogenies, and various species of Vibrio varied significantly among bats with different dietary habits. No significant difference in the number of genes involved in various metabolic pathways was detected among bats of different phylogenies, but the abundance of genes involved in 5 metabolic pathways, including transcription; replication, recombination, and repair; amino acid transport and metabolism; and signal transduction mechanisms, was different among bats with different dietary habits. The abundance of genes in 3 metabolic pathways, including those involved in stilbenoid, diarylheptanoid, and gingerol biosynthesis, was found to be different between insectivorous bats and bats that feed on both insects and fish. Results of this study suggest a weak association between dietary habit and gut microbiota in most bats but a notable difference in gut microbiota among bats of different phylogenies.

Ontogenetic shift in diet and trophic role of Raja clavata inferred by stable isotopes and stomach content analysis in the Sea of Marmara

Trophic ecology studies on predator-prey interactions reveal insights into ecological communities and help understand a species' role in the food web by contributing to improved fisheries management and conservation capabilities. Understanding the ecological role of overexploited and endangered predators is essential to deciphering how their feeding behaviour influences food web dynamics. In this study, the authors investigated the feeding behaviour of the common and IUCN-listed Near Threatened (NT) thornback ray Raja clavata, using carbon and nitrogen stable isotope and stomach content analysis (SCA). It has recently suffered an 87% decline in reported catches from the Sea of Marmara within the last decade. These results show that thornback ray mainly feeds on teleost species, except in summer, with both methods showing this species changes its diet ontogenetically by SCA. This ontogenetic diet shift was at lengths 40-50 cm by changing group preferences from Crustacea to Teleostei. MixSIAR results showed that both adult and juvenile individuals of R. clavata feed mainly on the crustaceans, but the contribution of teleosts represented by Trachurus sp. was very low (<15%). The trophic position increased total length and was higher than other batoid species in the Sea of Marmara.

Comparative Transcriptomics and Methylomics Reveal Adaptive Responses of Digestive and Metabolic Genes to Dietary Shift in Giant and Red Pandas

Both the giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens) belong to the order Carnivora, but have changed their dietary habits to eating bamboo exclusively. The convergent evolution characteristics of their morphology, genome and gut flora have been found in the two pandas. However, the research on the convergent adaptation of their digestion and metabolism to the bamboo diet, mediated by the dietary shift of the two pandas at the gene-expression and epigenetic regulation levels, is still lacking. We therefore used RNA sequencing among five species (two pandas and three non-herbivore mammals) and bisulfite sequencing among three species (two pandas and a carnivore ferret) to sequence key digestion and metabolism tissues (stomach and small intestine). Our results provide evidence that the convergent differentially expressed genes (related to carbohydrate utilization, bile secretion, Lys and Arg metabolism, vitamin B12 utilization and cyanide detoxification) of the two pandas are adaptive responses to the bamboo diet containing low lipids, low Lys and Arg, low vitamin B12 and high cyanide. We also profiled the genome-wide methylome maps of giant panda, red panda and ferret, and the results indicated that the promoter methylation of the two pandas may regulate digestive and metabolic genes to adapt to sudden environmental changes, and then, transmit genetic information to future generations to evolve into bamboo eaters. Taken together, our study provides new insights into the molecular mechanisms of the dietary shift and the adaptation to a strict bamboo diet in both pandas using comparative transcriptomics and methylomics.

Cross-Generational Impacts of Diet Shift on Bisphenol Analogue Loads in Indo-Pacific Humpback Dolphins (Sousa chinensis)

Bisphenol analogues (BPs) are ubiquitous pollutants to marine organisms as endocrine disruptive chemicals. However, the residue contamination and the trophic transfer of BPs in the apex predator nearshore dolphins are poorly studied. Here, we measured the concentrations of six BPs, including bisphenol A (BPA), bisphenol AF (BPAF), bisphenol B (BPB), bisphenol F (BPF), bisphenol P (BPP), and bisphenol S (BPS) in the liver of Indo-Pacific humpback dolphin (Sousa chinensis) (n = 75) collected from the Pearl River Estuary during a period with significant dietary changes (2004-2020). BPA and BPAF were the dominant components of the residue ∑BPs in the liver, with a proportion of 80%. Sex, maturity, and stranding location had no significant effects on BP levels. The generalized additive models indicated that BPA levels in juveniles and adults decreased from 2004 to 2013 while increasing from 2013 to 2020. The temporal trend of BPA levels was likely driven by the shift of the dominant diet from Harpadon nehereus to Thryssa spp. The concurrent increase of BPA loads in calves and juveniles and adults over the recent decades suggested that the diet-mediated variations of maternal BPA levels could be redistributed to their offspring.

Microbiome Resilience and Health Implications for People in Half-Year Travel

Travel entail change in geography and diet, both of which are known as determinant factors in shaping the human gut microbiome. Additionally, altered gut microbiome modulates immunity, bringing about health implications in humans. To explore the effects of the mid-term travel on the gut microbiome, we generated 16S rRNA gene and metagenomic sequencing data from longitudinal samples collected over six months. We monitored dynamic trajectories of the gut microbiome variation of a Chinese volunteer team (VT) in their whole journey to Trinidad and Tobago (TAT). We found gut microbiome resilience that VT’s gut microbial compositions gradually transformed to the local TAT’s enterotypes during their six-month stay in TAT, and then reverted to their original enterotypes after VT’s return to Beijing in one month. Moreover, we identified driven species in this bi-directional plasticity that could play a role in immunity modulation, as exemplified by Bacteroides dorei that attenuated atherosclerotic lesion formation and effectively suppressed proinflammatory immune response. Another driven species P. copri could play a crucial role in rheumatoid arthritis pathogenesis, a chronic autoimmune disease. Carbohydrate-active enzymes are often implicated in immune and host-pathogen interactions, of which glycoside hydrolases were found decreased but glycosyltransferases and carbohydrate esterases increased during the travel; these functions were then restored after VT’ returning to Beijing. Furthermore, we discovered these microbial changes and restoration were mediated by VT people’s dietary changes. These findings indicate that half-year travel leads to change in enterotype and functional patterns, exerting effects on human health. Microbial intervention by dietary guidance in half-year travel would be conducive to immunity modulation for maintaining health.

Associations of staple food consumption and types of cooking oil with waist circumference and body mass index in older Chinese men and women: a panel analysis

Background

The dietary landscape has changed rapidly in China in the past few decades. This research investigates the associations of older adults’ choices and consumption of staple foods and cooking oils with obesity-related measurements.

Methods

Panel data were extracted from the Chinese Longitudinal Health Longevity Survey from 3253 older participants with 6506 observations. Ordinary least squares and ordered logistic regression models were estimated with the outcomes of obesity determined by waist circumference (WC) and body mass index (BMI), respectively.

Results

Older men who consumed wheat had wider WCs (β=2.84 [95% confidence interval {CI} 1.55 to 4.13], p<0.01) and higher BMIs (adjusted odds ratio 1.74 [95% CI 1.40 to 2.17], p<0.01) than those who preferred rice. Female participants who used animal-based cooking oil had lower WCs and BMIs than their counterparts who consumed vegetable-based cooking oil. Increased consumption of staple foods was associated with increased rates of obesity in both sexes.

Conclusion

Dieticians and nutritionists should design appropriate dietary plans to help reduce obesity and chronic diseases among older Chinese adults. Further clinical trials are needed to continue investigating this topic.

Trophic ecology and ontogenetic diet shift of the blue skate (Dipturus cf. flossada)

Knowledge of skate ecology must be improved to ensure their effective protection. This study represents the first description of diet composition for one of the largest European rajid, the blue skate Dipturus cf. flossada. A total of 346 specimens collected in the Celtic Sea from 2012 to 2015 were analysed for their gut content, with respect to individual total length, maturity stage and sex. Overall, the blue skate diet mainly consisted of shrimps and prawns, crabs and teleost fishes. Nonmetric multidimensional scaling and ANOSIM analyses revealed major ontogenetic shifts in the feeding strategy that were related to size and maturity, but not to sex. Shrimps and prawns, mostly composed of Crangon allmanni, dominated the diet of small and immature individuals, while mod-size skate primarily preyed on crabs. The prevalence of crustaceans decreased with size and maturity, and was gradually replaced by teleost fishes in large mature individuals. A concomitant increase of the trophic level with size revealed that large blue skate become a top predator within the ecosystem. These results highlight the need to include ontogenetic changes in the diet description. As individuals grow and mature, blue skates can play a fundamental role in the structure of the Celtic Sea food web.

The Changes in the Frog Gut Microbiome and Its Putative Oxygen-Related Phenotypes Accompanying the Development of Gastrointestinal Complexity and Dietary Shift

There are many examples of symbiotic and reciprocal relationships in ecological systems; animal gut microbiome-host interactions are one such kind of bidirectional and complex relationship. Here, we utilized several approaches (16S rRNA gene sequencing, metagenomics, and transcriptomics) to explore potential gut microbiome-host interactions accompanying the development of gastrointestinal complexity and a dietary shift from metamorphosis to maturity in ornamented pygmy frogs (Microhyla fissipes). We identified the possible coevolution between a particular gut microbial group (increased putative fat-digesting Erysipelotrichaceae and chitin-digesting Bacteroides and Ruminococcaceae) and the host dietary shift [from herbivore to insectivore (high proportion of dietary chitin and fat)] during metamorphosis. We also found that the remodeling and complexity of the gastrointestinal system during metamorphosis might have a profound effect on the gut microbial community (decreasing facultative anaerobic Proteobacteria and increasing anaerobic Firmicutes) and its putative oxygen-related phenotypes. Moreover, a high proportion of chitin-digesting bacteria and increased carbohydrate metabolism by gut microbiomes at the climax of metamorphosis would help the frog's nutrition and energy needs during metamorphosis and development. Considering the increased expression of particular host genes (e.g., chitinase) in juvenile frogs, we speculate that host plays an important role in amphibian metamorphosis, and their symbiotic gut microbiome may help in this process by providing the nutrition and energy needs. We provide this basic information for the amphibian conservation and managements.

Regional differences in the mid-Victorian diet and their impact on health

The aim of this study was to examine the impact of regional diets on the health of the poor in mid-Victorian Britain. Contemporary surveys of regional diets and living condition were reviewed. This information was compared with mortality data from Britain over the same period. Although there was an overall improvement in life expectancy during the latter part of the 19th century, there were large regional differences in lifestyle, diet and mortality rates. Dietary surveys showed that the poor labouring population in isolated rural areas of England, in the mainland and islands of Scotland and in the west of Ireland enjoyed the most nutritious diets. These regions also showed the lowest mortality rates in Britain. This was not simply the result of better sanitation and less mortality from food and waterborne infections but also fewer deaths from pulmonary tuberculosis, which is typically associated with better nutrition. These more isolated regions where a peasant-style culture provided abundant locally produced cheap foodstuffs such as potatoes, vegetables, whole grains, and milk and fish, were in the process of disappearing in the face of increasing urbanisation. This was to the detriment of many rural poor during the latter half of the century. Conversely, increasing urbanisation, with its improved transport links, brought greater availability and diversity of foods to many others. It was this that that led to an improved nutrition and life expectancy for the majority in urbanising Britain, despite the detrimental effects of increasing food refinement.

Lizards on newly created islands independently and rapidly adapt in morphology and diet

Rapid adaptive changes can result from the drastic alterations humans impose on ecosystems. For example, flooding large areas for hydroelectric dams converts mountaintops into islands and leaves surviving populations in a new environment. We report differences in morphology and diet of the termite-eating gecko Gymnodactylus amarali between five such newly created islands and five nearby mainland sites located in the Brazilian Cerrado, a biodiversity hotspot. Mean prey size and dietary prey-size breadth were larger on islands than mainlands, expected because four larger lizard species that also consume termites, but presumably prefer larger prey, went extinct on the islands. In addition, island populations had larger heads relative to their body length than mainland populations; larger heads are more suited to the larger prey taken, and disproportionately larger heads allow that functional advantage without an increase in energetic requirements resulting from larger body size. Parallel morphological evolution is strongly suggested, because there are indications that, before flooding, relative head size did not differ between future island and future mainland sites. Females and males showed the same trend of relatively larger heads on islands, so the difference between island and mainland sites is unlikely to be due to greater male-male competition for mates on islands. We thus discovered a very fast (at most 15 y) case of independent parallel adaptive change in response to catastrophic human disturbance.

Evolutionary adaptations to dietary changes

Through cultural innovation and changes in habitat and ecology, there have been a number of major dietary shifts in human evolution, including meat eating, cooking, and those associated with plant and animal domestication. The identification of signatures of adaptations to such dietary changes in the genome of extant primates (including humans) may shed light not only on the evolutionary history of our species, but also on the mechanisms that underlie common metabolic diseases in modern human populations. In this review, we provide a brief overview of the major dietary shifts that occurred during hominin evolution, and we discuss the methods and approaches used to identify signals of natural selection in patterns of sequence variation. We then review the results of studies aimed at detecting the genetic loci that played a major role in dietary adaptations and conclude by outlining the potential of future studies in this area.

How the mid-Victorians worked, ate and died

Analysis of the mid-Victorian period in the U.K. reveals that life expectancy at age 5 was as good or better than exists today, and the incidence of degenerative disease was 10% of ours. Their levels of physical activity and hence calorific intakes were approximately twice ours. They had relatively little access to alcohol and tobacco; and due to their correspondingly high intake of fruits, whole grains, oily fish and vegetables, they consumed levels of micro- and phytonutrients at approximately ten times the levels considered normal today. This paper relates the nutritional status of the mid-Victorians to their freedom from degenerative disease; and extrapolates recommendations for the cost-effective improvement of public health today.

Dietary Shifts in Relation to Fruit Availability among Masked Palm Civets (Paguma larvata) in Central China

The spatial and temporal distribution of food resources can profoundly affect foraging decisions and prey selection, potentially resulting in shifts in diet in response to changes in resource availability. The masked palm civet (Paguma larvata) has long been regarded as a dietary generalist that feeds primarily on fruits and small mammals. Both types of food resources may vary spatially and temporally and the diet of P. larvata is expected to change in response to variation in the availability and distribution of these resources. To address the effects of such variation on foraging by masked palm civets, we studied a population of P. larvata inhabiting a highly heterogeneous habitat in central China consisting of primary forest, selectively logged forest, logged forest, broad-leaved and coniferous forest plantations, and cultivated farmland. Available food resources included wild fruits, cultivated fruits, leaves, plant cortexes, amphibians, reptiles, birds, small mammals, molluscs, and arthropods. The abundance of these food categories varied significantly among seasons and habitats and civets altered consumption of these categories according to their temporal and spatial availability. The diversity of items consumed also varied significantly among seasons and habitats. From June to October, wild fruits were the main food of civets in forest habitats, whereas cultivated fruits were the main food in farmland. In contrast, from November to May, civets in forested habitats consumed primarily rodents and birds. Concordant with these changes was a shift from foraging in primary forest (November-May) to foraging in logged forest and farmland (June-October) that appeared to be associated with the availability of fruits. These results demonstrate the ability of civets to change their diet, both spatially and temporally, in response to changing food resources. To better understand how foraging behavior of civets varies with resource availability, similar studies should be conducted in tropical environments characterized by year-round availability of fruit.