Intestinal microbiota contributes to altered glucose metabolism in simulated microgravity mouse model

Abstract

Exposure to space environment induces alterations in glucose and lipid metabolism that contribute to muscular atrophy, bone loss, and cardiovascular disorders. Intestinal microbiota is also changed, but its impact on spaceflight‐related metabolic disorder is not clear. We investigated the relationship between glucose metabolic changes and gut dysbiosis in a hind limb‐unloading (HU) mouse model, a well‐accepted ground‐based spaceflight analog. Impaired body weight gain, glucose intolerance, and peripheral insulin resistance were found in 2–4‐wk HU mice. Reduced abundance of gut Bifidobacterium spp. and Akkermansia muciniphila was observed within 3 d of HU. The ground‐based control (Ctrl) mice that were cohoused with HU mice showed similar patterns of dysbiosis and metabolic changes. Compared with the Ctrls, higher levels of plasma LPS‐binding protein and altered transcription of Tnfa and glucose metabolism‐related genes in the liver were observed in HU mice. The supplementation of Bifidobacterium spp. suppressed endotoxemia and liver inflammation and improved glucose tolerance in HU mice. The results indicate a close relationship between dysbiosis and altered glucose metabolism in the HU model and also emphasize the importance of evaluating intestinal microbiota in astronauts and its effect on glucose metabolism.—Wang, Y., Zhao, W., Shi, J., Wang, J., Hao, J., Pang, X., Huang, X., Chen, X., Li, Y., Jin, R., Ge, Q. Intestinal microbiota contributes to altered glucose metabolism in simulated microgravity mouse model. FASEB J. 33, 10140–10151 (2019). http://www.fasebj.org

Gut Microbiome and Space Travelers’ Health: State of the Art and Possible Pro/Prebiotic Strategies for Long-Term Space Missions

“…However, it remains a fact that during spaceflights astronauts and cosmonauts eat less than on Earth, probably for several reasons, including but not limited to cultural habits (but the international coordination imposed by ISS is changing this aspect), the palatability of foods (still not comparable to what is available on Earth), space motion sickness, changes in light-dark cycle and appetite-regulating hormones, and, in general, stress (Laurens et al, 2019). Though the reasons are not entirely clear, impaired glucose and lipid metabolism, with insulin resistance and glucose intolerance, are also frequently observed in both spaceflights and ground-based microgravity analogs, representing a serious concern for the general health of space travelers (Tobin et al, 2002;Hughson et al, 2016;Wang Y. et al, 2019).…”

“…In addition to the design of balanced diets enriched in prebiotics, probiotics-based countermeasures could also be taken into consideration. For example, in a recent spaceflight analog study based on HU mouse model, Wang Y. et al (2019) have shown that the supplementation of Bifidobacterium spp. suppressed endotoxemia and liver inflammation, and improved glucose tolerance.…”

Circulating Metabolites Originating from Gut Microbiota Control Endothelial Cell Function

“…Similarly, gut dysbiosis has been reported in astronauts and experimental animals maintained in unloading conditions. Indeed, both microgravity and space radiation predispose to different space related disorders, most being accompanied by immune system dysregulation [41,42]. In fact, in healthy conditions, the GM plays a crucial role in the maintenance of the host’s physiological conditions by modulating its immunity.…”

Medicina humana espacial: Performance fisiológico y contramedidas para mejorar la salud del astronauta

“…Igualmente existen alteraciones en la motilidad, microbiota intestinal, metabolismo de glucosa y lípidos (89,90) , daño de las vellosidades intestinales e interrupción en las uniones celulares epiteliales por la expresión de la proteína proapoptótica Bax y disminución de Bcl2; alterando de esta manera su función defensiva, homeostasis y el riesgo de contraer enfermedades inflamatorias intestinales (76,91,92,93) por el aumento de citosinas y disminución de la inmunoglobulina secretora (IgA) (76) .…”