Page 150 - Helicobacter pylori and Gastric Cancer: From Tumor microenvironment to Immunotherapy

responses are upregulated[25, 26]. Next, we would review the causes of these phenomena and conclude that they probably do not derive from differences in the extracellular milieu[27, 28] (which would have been a possibility in view of the significant effects on the bone marrow niche due to loss of bone[29-31]), but are the result of changed intracellular signal transduction under microgravity[32, 33]. Although data are limited, the effects on signaling most like involve alterations in Rac signaling[34] and thus microgravity provides new insight into the role of Rac and especially its downstream impact on cytoskeletal architecture in immune signal transduction[29]. Finally, we shall discuss the implications for human disease. These consequences are quite impressive: both functional studies[35] and GWAS[36] suggest that at least for one autoimmune disease, in case of Crohn’s disease defects in innate immunity are causative, leading to excessive innate responses. Thus indeed it is at least theoretically possible that useful information may be obtained from space experimentation on human immunity
Microbiomes and humans
The human body is the living space of microbial symbionts which is ten times more in number than all Homo sapiens cells[37]. The expression "microbiota" alludes to the organisms that live in a particular section (e.g., the human body, the gut, the dirt, and so forth.). The cumulative genomes of the total microbiota in the human body are alluded to as the "human microbiome"[37, 38]. The microbiome impacts biochemical, physiological and immunological pathways and is the principal line of protection from various diseases. The cooperation between the gastrointestinal frontier and the microbiome give off an impression of being a complex system that helps with keeping up appropriate immune capacity in the gut[39, 40]. The intestinal microbiome shapes the gastrointestinal insusceptible framework[41, 42]. Stable and pathogenic microorganisms go after supremacy[43, 44]. A balance between useful and potentially harmful microscopic organisms is considered normal and adds to a robust and healthy human gut[44]. There is growing validation of the relationship between the changes in the balance of gut flora and several diseases[45].
Microbiomes and spaceflight
The last decades have seen growing concerns about the effects of microgravity on the microbiome of astronauts during long-duration stay in space. Various studies[51], have reported changes in gut microbiome physiology and composition. As mentioned the
Chapter 7
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