The human gut mycobiome: pitfalls and potentials — a mycologist\u27s perspective

We have entered the Age of the Microbiome, with new studies appearing constantly and whole journals devoted to the human microbiome. While bacteria outnumber other gut microbes by orders of magnitude, eukaryotes are consistently found in the human gut, and are represented primarily by the fungi. Compiling 36 studies spanning from 1917 to 2015, we found at least 267 distinct fungal taxa have been reported from the human gut, and seemingly every new study includes one or more fungi not previously described from this niche. This diversity, while impressive, is illusory. If we examine gut fungi, we will quickly observe a division between a small number of commonly detected species (Candida yeasts, Saccharomyces and yeasts in the Dipodascaceae, and Malassezia species), and a long tail of taxa which have only been reported once. Furthermore, an investigation into the ecology of these rare species reveals that many of them are incapable of colonization or long-term persistence in the gut. This paper examines what we know and have yet to learn about the fungal component of the gut microbiome, or “mycobiome”, and an overview of methods. We address the potential of the field while introducing some caveats, and argue for the necessity of including mycologists in mycobiome studies

Fungi in the healthy human gastrointestinal tract

Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are common on fermented foods but cannot grow at human body temperature), while still others have dietary or environmental sources (Saccharomyces cerevisiae, a fermentation agent and sometime probiotic; Aspergillus species, ubiquitous molds) yet are likely to impact gut ecology. The gut mycobiome appears less stable than the bacterial microbiome, and is likely subject to environmental factors

Fungi in the healthy human gastrointestinal tract

Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are common on fermented foods but cannot grow at human body temperature), while still others have dietary or environmental sources (Saccharomyces cerevisiae, a fermentation agent and sometime probiotic; Aspergillus species, ubiquitous molds) yet are likely to impact gut ecology. The gut mycobiome appears less stable than the bacterial microbiome, and is likely subject to environmental factors

Requirements and Sizing Investigation for Constellation Space Suit Portable Life Support System Trace Contaminant Control

The Trace Contaminant Control System (TCCS), located within the ventilation loop of the Constellation Space Suit Portable Life Support System (PLSS), is responsible for removing hazardous trace contaminants from the space suit ventilation flow. This paper summarizes the results of a trade study that evaluated if trace contaminant control could be accomplished without a TCCS, relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Trace contaminant generation rates were revisited to verify that values reflect the latest designs for Constellation Space Suit System (CSSS) pressure garment materials and PLSS hardware. Additionally, TCCS sizing calculations were performed and a literature survey was conducted to review the latest developments in trace contaminant technologies

Evaluating Split Nitrogen Applications and In-Season Tests for Organic Winter Bread Wheat

Achieving high grain yields and crude protein (CP) standards in organic winter wheat (Triticum aestivum L.) is challenging because ensuring that adequate nitrogen (N) is available at key periods of wheat growth is difficult in organic systems. Split application regimes and in-season N management tests may improve organic production. In field trials conducted over four site-years in Maine and Vermont, USA, N application regimes were analyzed for their effects on organic winter wheat, N uptake, grain yield, and CP. Tiller density and tissue N tests were evaluated as in-season decision tools. Eight treatments arranged in a non-factorial design differed in terms of N application timing (pre-plant (PP), topdress at tillering (T1), and topdress at pre-stem extension (T2)) and N rate. Treatments were: (1) an untreated check, (2) pre-plant N at a low rate of 78 kg N ha−1(PPL), (3) pre-plant N at a high rate of 117 or 157 kg N ha−1 (PPH), (4) T178, (5) PPL + T139, (6) PPL + T239, (7) PPH + T239, and (8) PPL + T139 +T239. Responses to N treatments were variable among site-years, however some common results were identified. The PP-only treatments increased grain yields more than they increased CP. The T178 and PPH + T239 treatments were the most effective at increasing yield and CP, compared with the PP-only treatments. Tiller density and tissue N tests were good predictors of grain yield (r = 0.52, p < and CP (r = 0.75, p < 0.001) respectively. Future work should test in-season decision tools using a wider range of tiller densities, and topdress N rates against tissue N measurements

Improving safety using HFMEA and insitu simulation prior to initiating contrast MRI studies in an ambulatory setting

The objective of this event was to test a new system for emergency response to MRI contrast reactions by ensuring staff familiarity with emergency equipment and a newly drafted emergency response protocols, and to mitigate any LST identified.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1020/thumbnail.jp

Crew and Thermal Systems Strategic Communications Initiatives in Support of NASA's Strategic Goals

NASA has defined strategic goals to invest in next-generation technologies and innovations, inspire students to become the future leaders of space exploration, and expand partnerships with industry and academia around the world. The Crew and Thermal Systems Division (CTSD) at the NASA Johnson Space Center actively supports these NASA initiatives. In July 2011, CTSD created a strategic communications team to communicate CTSD capabilities, technologies, and personnel to external technical audiences for business development and collaborative initiatives, and to students, educators, and the general public for education and public outreach efforts. This paper summarizes the CTSD Strategic Communications efforts and metrics through the first half of fiscal year 2012 with projections for end of fiscal year data

Sequence-based Methods for Detecting and Evaluating the Human Gut Mycobiome

We surveyed the fungal microbiota in 16 fecal samples from healthy humans with a vegetarian diet. Fungi were identified using molecular cloning, 454 pyrosequencing and a Luminex analyte specific reagent (ASR) assay, all targeting the ITS region of the rRNA genes. Fungi were detected in each fecal sample and at least 46 distinct fungal operational taxonomic units (OTUs) were detected, from two phyla — Ascomycota and Basidiomycota. Fusarium was the most abundant genus, followed by Malassezia, Penicillium, Aspergillus, and Candida. Commonly detected fungi such as Aspergillus and Penicillium, as well as known dietary fungi Agaricus bisporus and Ophiocordyceps sinensis, are presumed to be transient, allochthonous members due to their abundance in the environment or dietary associations. No single method identified the full diversity of fungi in all samples; pyrosequencing detected more distinct OTUs than the other methods, but failed to detect OTUs in some samples that were detected by cloning and/or ASR assays. ASRs were limited by the commercially available assays, but the potential to design new, optimized assays, coupled with speed and cost, makes the ASR method worthy of further study

Performance and Life Tests of a Regenerative Blower for EVA Suit Ventilation

Ventilation fans for future space suits must meet demanding performance specifications, satisfy stringent safety requirements for operation in an oxygen atmosphere, and be able to increase output to operate in buddy mode. A regenerative blower is an attractive choice due to its ability to meet these requirements at low operating speed. This paper describes progress in the development and testing of a regenerative blower designed to meet requirements for ventilation subsystems in a future space suit Portable Life Support Systems (PLSS). The blower assembly includes a custom-designed motor that has significantly improved in efficiency during this development effort. The blower was tested at both nominal and buddy mode operating points and head/flow performance and power consumption were measured. The blower was operated for over 1000 hours to demonstrate safe operation in an oxygen test loop at prototypical pressures. In addition, the blower demonstrated operation with the introduction of simulated lunar dust

Extravehicular Activity Systems Education and Public Outreach in Support of NASA's STEM Initiatives in Fiscal Year 2011

NASA's goals to send humans beyond low Earth orbit will involve the need for a strong engineering workforce. Research indicates that student interest in science, technology, engineering, and math (STEM) areas is on the decline. According to the Department of Education, the United States President has mandated that 100,000 educators be trained in STEM over the next decade to reduce this trend. NASA has aligned its Education and Public Outreach (EPO) initiatives to include emphasis in promoting STEM. The Extravehicular Activity (EVA) Systems Project Office at the NASA Johnson Space Center actively supports this NASA initiative by providing subject matter experts and hands-on, interactive presentations to educate students, educators, and the general public about the design challenges encountered as NASA develops EVA hardware for exploration missions. This paper summarizes the EVA Systems EPO efforts and metrics from fiscal year 2011