Human Health

Published: 21 November 2018

The Human Health Experiment will explore life in microgravity. Experiments can cover any of the following five suggested areas of research, in order to ensure the optimal health and safety of Astronauts during prolonged exposure to zero gravity environments:

1.     Bone cells, muscle cells and immune responses

2.     Haemopoietic System

3.     Microbiome

4.      Stability and kinetic behavior of medicines in space

5.     Gene expression

The subject of the experiments can be the study of the effects of microgravity on human health, and how to circumvent these effects to ensure the optimal health and safety of Astronauts during prolonged exposure to zero gravity environments.   

Project submissions should adhere to the following themes:

• Novelty and impact of the study directly or indirectly on human health.

• Pertaining, but not limited to, physiological effects of microgravity such as bone, muscle or blood health.

• Development of a prototype device to conduct non-invasive measurements of physiological states while in-flight.

• Submissions can be an improvement of technologies currently in use.

The project should strive to meet the following requirements:

• Project objectives, experimental design and expected results should be well defined.

• The project will consider aspects of prototype design and development, to be tested in-flight.

• Test plan should include features to be tested and test case documentation adhered to. 

Before you submit the Experiment Proposal Form for the Competition, please ensure that you select one of the following recommended tentative areas of research:      

1.     Bone cells, muscle cells and immune responses

Convincing evidence of previous studies suggest that the functional integrity of muscles and bone mass, can be affected by microgravity. One of the most serious problems induced by long-term weightlessness is bone mineral loss. Humans exposed to microgravity conditions experience various physiological changes that include reduction in bone density, muscle deterioration, and immune-deficiency. Despite many in-vivo and in-vitro studies under both real microgravity and simulated conditions, the mechanism of bone loss, muscle deterioration and immune responses are still not properly understood [Calcif Tissue Int. 2014 Jun;94(6):569-79. doi: 10.1007/s00223-014-9851-x. Epub 2014 Apr 1]. Therefore data from innovative studies on bone and muscle health, and the body’s defense mechanism, could further contribute to a better understanding of development of bone, muscle and immunity disorders under microgravity. 

2.     Haemopoietic System

Astronauts experience significant, symptomatic anemia caused by neocytolysis, a process that selectively ruptures new red blood cells. Studies have shown that blood cell volume, hemoglobin concentration, and red blood cell counts did not significantly differ from pre- to post-space flight. The percentage of new red blood cells did decrease after flight, and young cells lost viability, indicating that destruction of red blood cells occurred in space which suggests the effect of microgravity on the erythrocytes [] Asthe microgravity has also a proven effect on fluid redistribution in the body during space flight [], an in-vitro experimental study on the effect of altered osmolaric environment on the erythrocytes or other formed elements of the blood could take us one step closer to a better understanding of the reason of symptomatic anemia in space.

3.     Microbiome

Microbiomes are the collective genomes of the microbes composed of bacteria, bacteriophage, fungi, protozoa and viruses. They reside inside living beings. The human microbiota consists of the 10-100 trillion of symbiotic microbial cells. In fact, the health of the human brain is, to an extraordinary degree, dictated by the state of the individual’s microbiome- the vast population of organisms that live in the body and outnumber its cells ten to one [Brain makers, Dr. David Perlmutter, Hodder & Stoughton, Ltd, 2015].

An individual's microbiome is likely to be an important contributor to certain health disparity, diseases and conditions. Certain microbial species from the human microbiome have been shown to exert a beneficial or protective effect on health; the loss of these species can lead to an altered metabolic function and, in conjunction with reduced immune response, may increase the chance of infection by opportunistic pathogens. The study of the effect of microgravity on the composition of human microbiome, by designing non-invasive devices to collect samples primarily from the gut, the mouth, the nose and the skin, could be an innovative approach.

Maintaining the integrity of samples collected is a major challenge in microbiome research as the microbial composition of a sample can begin to change from the point of collection. Therefore, a combined device that would collect, and /or analyze the sample after it is collected could be revolutionary. In the event the on-site analysis of the sample is not possible, a proposal for a chemical preservation procedure that would stabilize the sample by maintaining its integrity from the point of collection, until and during the analysis, would ensure good reproducibility of the analysis. The proposed innovation for the continuous measurements of bacterial levels in microbiome while in space, when astronauts are supplemented with fecal transplantation, is in addition to other quantitative physiological and psychosocial components.

4.     Stability and kinetic behavior of medicines in space

The maintenance of the health of astronauts in the unique, isolated, and extreme environment of space is the primary goal for a successful space mission. Hence, safe and efficacious medications are essential for the wellbeing of astronauts. Space medication has been challenged with problems related to efficacy. Along with altered physiology, one of the possible reasons could be instability of space medications in the presence of harsh spaceflight environmental conditions. Altered physical and chemical stability can result in reduced potency, which can result in reduced efficacy. Hence, it is desired that medicines maintain the shelf-life throughout the space mission. Stability of medicines used for short term or long term space missions cannot be judged by drug stability guidelines, based on terrestrial environmental factors. Unique environmental conditions related to spaceflight include microgravity, excessive vibration, hard vacuum, humidity variation, temperature differences and excessive radiation, which may cause instability [J Pharm Biomed Anal. 2017 Mar 20; 136:111-119. doi: 10.1016/j.jpba.2016.12.040. Epub 2017 Jan 3.]

Data from experimental studies of zero, first or second-order, kinetic behavior of medications, which astronauts usually take during zero gravity space flights could contribute to the quality assurance in space medicine stability. This will enable us to project the failure rate of drugs and probabilistic risk assessment in microgravity. It can also contribute to the scientific development of innovate storage and packaging devices that could maintain/preserve the stability of medicines in space, as required.

5.     Gene expression

A site-specific bone loss of 1-2% is observed in astronauts and in-flight animals after one month of spaceflight. Experimental data suggest that microgravity alters the mRNA level for several bone-specific proteins in rat bone, suggesting that the characteristics of osteoblasts are altered during spaceflight. [FASEB J. 1999;13 Suppl:S129-34.] Since the osteoblasts themselves are sensitive to altered gravity levels as suggested by several studies, it is worth examining the dynamics of immediate and initial gene expression responses in different gravitational environments on osteoblasts in vitro through bone specific proteins. A comparison of expression profiles to identify potential gravity-regulated genes and adaptation processes could be a valuable contribution to better understand the gene expression in general and the physiology of the bones under microgravity in particular.