Hypoxia: The “Invisible Pusher” of Gut Microbiota

Abstract

Oxygen is important to the human body. Cell survival and operations depend on oxygen. When the body becomes hypoxic, it affects the organs, tissues and cells and can cause irreversible damage. Hypoxia can occur under various conditions, including external environmental hypoxia and internal hypoxia. The gut microbiota plays different roles under hypoxic conditions, and its products and metabolites interact with susceptible tissues. This review was conducted to elucidate the complex relationship between hypoxia and the gut microbiota under different conditions. We describe the changes of intestinal microbiota under different hypoxic conditions: external environment and internal environment. For external environment, altitude was the mayor cause induced hypoxia. With the increase of altitude, hypoxia will become more serious, and meanwhile gut microbiota also changed obviously. Body internal environment also became hypoxia because of some diseases (such as cancer, neonatal necrotizing enterocolitis, even COVID-19). In addition to the disease itself, this hypoxia can also lead to changes of gut microbiota. The relationship between hypoxia and the gut microbiota are discussed under these conditions.

Effects of COVID-19 protective face masks and wearing durations on respiratory haemodynamic physiology and exhaled breath constituents

“…While looking at the exhalation profiles of organosulfur such as dimethylsulfide, allyl methyl sulfide and butanethiol, the effects of both face mask types are reflected in the systemic origin of these substances from microbial anaerobic methylation [ 61 ] in the lower gut. Studies have shown that effects of hypoxia act as an “invisible pusher” of gut microbiota [ 62 ]. Gut flora maintain the hypoxic balance of the intestinal environment in order to regulate nutrient absorption, gut permeability and immune response [ 63 ].…”

Hypoxia Improves Endurance Performance by Enhancing Short Chain Fatty Acids Production via Gut Microbiota Remodeling

“…Previous studies have reported that hypoxia could significantly affect the gut microbiota (Bai et al, 2018;Mazel, 2019;Han et al, 2021), but the understanding of hypoxia-induced changes in the gut microbiota is far from clear. It was widely accepted that hypoxia exposure significantly decreased the aerobic bacteria and increased the anaerobic bacteria (Mazel, 2019;Han et al, 2021).…”

“…Previous studies have reported that hypoxia could significantly affect the gut microbiota (Bai et al, 2018;Mazel, 2019;Han et al, 2021), but the understanding of hypoxia-induced changes in the gut microbiota is far from clear. It was widely accepted that hypoxia exposure significantly decreased the aerobic bacteria and increased the anaerobic bacteria (Mazel, 2019;Han et al, 2021). However, most studies have not excluded the interference of confounding factors such as genes, diet, exercise, and hypoxia exposure model (Li and Zhao, 2015;Karl et al, 2018;Suzuki et al, 2019;Jia et al, 2020;Montoya-Ciriaco et al, 2020).…”

“…In recent years, the effects of hypoxia on the gut microbiota attracted much attention (Mazel, 2019;Han et al, 2021). Short-term or chronic exposure to hypoxia can influence the composition and diversity of the gut microbiota (Li and Zhao, 2015;Karl et al, 2018;Suzuki et al, 2019;Jia et al, 2020), thus helping the hosts to adapt to the environment (Li et al, 2016(Li et al, , 2018(Li et al, , 2019Sun et al, 2019;Ma et al, 2021).…”

“…However, the interventions considerably varied with regards to the hypoxia model such as exposure time and oxygen concentration, and to the confounders such as exercise or diet. Thus, the influences of hypoxia exposure on the gut microbiota are still controversial (Li and Zhao, 2015;Karl et al, 2018;Suzuki et al, 2019;Han et al, 2020Han et al, , 2021Jia et al, 2020).…”