Suitability of maize crop residue fermented by Pleurotus ostreatus as feed for edible crickets: growth performance, micronutrient content, and iron bioavailability

Small-scale farming of edible insects could help combat public health challenges such as protein energy malnutrition and anemia, but reliable low-cost feeds for insects are needed. In resource-limited contexts, where grains such as maize are prohibitively costly for use as insect feed, the feasibility of insect farming may depend on finding alternatives. Here, we explore the potential to modify plentiful maize crop residue with edible mushroom mycelium to generate a low-cost feed adjunct for the farmed two-spotted cricket, Gryllus bimaculatus. Mushroom farming, like insect agriculture, is versatile; it can yield nutritious food while increasing system circularity by utilizing lignocellulosic residues from row crops as inputs. Pleurotus ostreatus, is an edible basidiomycete capable of being cultivated on corn stover (Zea mays). Mushroom harvest results in abundant “spent” substrate, which we investigated as a candidate feed ingredient. We created six cricket feeds containing fermented Pleurotus substrate plus an unfermented control, measuring cricket mass, mortality, and maturation weekly to evaluate cricket growth performance impacts of both fungal fermentation duration and mushroom formation. Pasteurized corn stover was inoculated with P. ostreatus mycelium and fermented for 0, 2, 3, 4, or 8 weeks. Some 4 and 8-week substrates were induced to produce mushrooms through manipulations of temperature, humidity, and light conditions. Dried fermented stover (40%) was added to a 1:1 corn/soy grain mix and fed to crickets ad libitum for 44 days. The unfermented control group showed higher survivorship compared to several fermented diets. Control group mass yield was higher for 2 out of 6 fermented diets. Little variation in cricket iron content was observed via ICP-spectrometry across feeds, averaging 2.46 mg/100 g. To determine bioavailability, we conducted in vitro Caco-2 human colon epithelial cell absorption assays, showing that iron in crickets fed fruiting-induced substrates was more bioavailable than in unfruited groups. Despite more bioavailable iron in crickets reared on post-fruiting substrates, we conclude that Pleurotus-fermented stover is an unsuitable feed ingredient for G. bimaculatus due to high mortality, variability in growth responses within treatments, and low mass yield

Pdx1 and Ngn3 Overexpression Enhances Pancreatic Differentiation of Mouse ES Cell-Derived Endoderm Population

In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES) cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2), and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1. This combination dramatically increased the level and timing of maximal Ins1 mRNA expression to approximately 100% of that found in the βTC6 insulinoma cell line. Insulin protein and C-peptide expression was confirmed by immunohistochemistry staining. These inductive effects were restricted to c-kit+ endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions after the specification of pancreatic endoderm. Although insulin secretion was stimulated by various insulin secretagogues, these cells had only limited glucose response. Microarray analysis was used to evaluate the expression of a broad spectrum of pancreatic endocrine cell-related genes as well as genes associated with glucose responses. Taken together, these findings demonstrate the utility of manipulating Pdx1 and Ngn3 expression in a stage-specific manner as an important new strategy for the efficient generation of functionally immature insulin-producing β-islet cells from ES cells

Comparison of cricket diet with peanut-based and milk-based diets in the recovery from protein malnutrition in mice and the impact on growth, metabolism and immune function.

Some evidence suggests that edible insects could be used to treat malnutrition following protein deficiency. However, additional studies are needed to better assess the potential of edible insects as a therapeutic food supplement and their long-term impact on recovery from malnutrition. The goals of this study were to investigate the effectiveness of a cricket-based diet in recovery from protein-malnutrition in early life, and to compare cricket protein to more traditional sources used for food fortification and supplementation. Protein-malnutrition was induced by administration of an isocaloric hypoprotein diet (5% protein calories) in young male mice for two weeks during puberty, followed by a six-week recovery period using a cricket-, peanut- or milk-based diet. We examined the impact of protein-malnutrition and subsequent recovery on body weight, growth and select biomarkers of inflammation and metabolism. Protein-malnutrition resulted in growth retardation, downregulation of inflammatory markers in spleen tissue, decreased levels of serum triglycerides, and elevated serum levels of leptin and adiponectin. The cricket-based diet performed equally well as the peanut- and milk-based diets in body weight recovery, but there were differences in immune and metabolic markers among the different recovery diets. Results suggest edible crickets may provide an alternative nutrient-dense protein source with relatively low environmental demands for combating the effects of early-life malnutrition compared to more traditional supplementation and fortification sources. Additional investigations are needed to examine the short and long term impacts of different recovery diets on metabolism and immune function

Global Gene Expression Profiles Suggest an Important Role for Nutrient Acquisition in Early Pathogenesis in a Plant Model of Pseudomonas aeruginosa Infection▿ †

Although Pseudomonas aeruginosa is an opportunistic pathogen that does not often naturally infect alternate hosts, such as plants, the plant-P. aeruginosa model has become a widely recognized system for identifying new virulence determinants and studying the pathogenesis of the organism. Here, we examine how both host factors and P. aeruginosa PAO1 gene expression are affected in planta after infiltration into incompatible and compatible cultivars of tobacco (Nicotiana tabacum L.). N. tabacum has a resistance gene (N) against tobacco mosaic virus, and although resistance to PAO1 infection is correlated with the presence of a dominant N gene, our data suggest that it is not a factor in resistance against PAO1. We did observe that the resistant tobacco cultivar had higher basal levels of salicylic acid and a stronger salicylic acid response upon infiltration of PAO1. Salicylic acid acts as a signal to activate defense responses in plants, limiting the spread of the pathogen and preventing access to nutrients. It has also been shown to have direct virulence-modulating effects on P. aeruginosa. We also examined host effects on the pathogen by analyzing global gene expression profiles of bacteria removed from the intracellular fluid of the two plant hosts. We discovered that the availability of micronutrients, particularly sulfate and phosphates, is important for in planta pathogenesis and that the amounts of these nutrients made available to the bacteria may in turn have an effect on virulence gene expression. Indeed, there are several reports suggesting that P. aeruginosa virulence is influenced in mammalian hosts by the availability of micronutrients, such as iron and nitrogen, and by levels of O2

Fostering Strategies to Expand the Consumption of Edible Insects: The Value of a Tripartite Coalition between Academia, Industry, and Government.

Although many insect-based foods are nutritious and often an inexpensive option for human and domesticated animal consumption, there remains a negligible market for such foods in many countries. Several environmental and economic considerations underscore the potential value of insect-based foods, and emerging science suggests that diets incorporating such foods might also convey some genuine health benefits. However, if expanded markets for insect-based foods in cultures naïve to entomophagy are to be pursued, it will be important to develop multifaceted and coordinated strategies to 1) delineate authentic health benefits, 2) explore means of optimizing insect husbandry and food processing, 3) examine cultural barriers to acceptance, 4) formulate workable approaches to marketing, and 5) address relevant food regulations. We sought to construct a multidisciplinary coalition whose goals are to investigate the above-mentioned 5 issues. Eighteen individuals from government, industry, and academia, with collective expertise in the fields of entomology, insect husbandry, human nutrition, sustainable agriculture, entomophagy, consumer product development and marketing, food-processing technologies, food regulatory affairs, and the anthropology of food selection, convened a 1-d summit and formed a tripartite organization to integrate their varied perspectives. Collaborative efforts are underway among members of this coalition to accomplish these multiple goals. Coordinating efforts between accomplished experts in relevant fields of academia, government, and industry will greatly expand our knowledge of and appreciation for the potential benefits of insect-based foodstuffs to individuals, to society, and to the sustainability of the global food supply, and thereby inform us as to how to proceed in a judicious and intelligent manner

Fostering Strategies to Expand the Consumption of Edible Insects: The Value of a Tripartite Coalition between Academia, Industry, and Government

Although many insect-based foods are nutritious and often an inexpensive option for human and domesticated animal consumption, there remains a negligible market for such foods in many countries. Several environmental and economic considerations underscore the potential value of insect-based foods, and emerging science suggests that diets incorporating such foods might also convey some genuine health benefits. However, if expanded markets for insect-based foods in cultures naïve to entomophagy are to be pursued, it will be important to develop multifaceted and coordinated strategies to 1) delineate authentic health benefits, 2) explore means of optimizing insect husbandry and food processing, 3) examine cultural barriers to acceptance, 4) formulate workable approaches to marketing, and 5) address relevant food regulations. We sought to construct a multidisciplinary coalition whose goals are to investigate the above-mentioned 5 issues. Eighteen individuals from government, industry, and academia, with collective expertise in the fields of entomology, insect husbandry, human nutrition, sustainable agriculture, entomophagy, consumer product development and marketing, food-processing technologies, food regulatory affairs, and the anthropology of food selection, convened a 1-d summit and formed a tripartite organization to integrate their varied perspectives. Collaborative efforts are underway among members of this coalition to accomplish these multiple goals. Coordinating efforts between accomplished experts in relevant fields of academia, government, and industry will greatly expand our knowledge of and appreciation for the potential benefits of insect-based foodstuffs to individuals, to society, and to the sustainability of the global food supply, and thereby inform us as to how to proceed in a judicious and intelligent manner

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health