Souradip Mallick, National Institute of Technology, Rourkela
The global COVID-19 pandemic caused by the novel SARS-CoV-2 is still a threat to the human population. As of February 2020, more than 102 million people globally have been infected, and over 2.21 million deaths reported. COVID-19 pandemic has a profuse impact on the economic as well as normal lifestyle and food habits of a person. COVID-19 drastically increases the rate of malnutrition on a tremendous fold which led to the double burden of malnutrition (DBM) epidemic. Low to middle-income countries (LMICs) like India, Brazil, and Mexico have the highest number of cases as well as huge post-COVID impact like malnutrition, health issues, food availability as well as job crisis. These countries had some of the highest prevalence of DBM from past which increases more during the pandemic.
Forced border closures, the inability to import foods as well as decreased production of fresh fruits and vegetables due to farm closures and worker shortages will exacerbate food insecurity and necessitate that families resort to calorie-dense, nutrient-poor foods, which have immediate negative impacts on weight and the gut microbiota.
Disruption in the supply of food systems causes some families to resort to inexpensive high-fat, low-nutrient foods and consume less meat, dairy products, fruits, and vegetables but these nutrients are essential for bone growth, immune protection, proper hormonal signaling, and gut microbiome stabilization. Thus people living in LMICs primarily rely on diets rich in carbohydrates (e.g., rice and maize) and less on fruits and vegetables, a diet that is not optimal for growth and development. This type of low-diversity, high-carbohydrate diet caused gut dysbiosis and alterations in gut physical structure leading to Non-communicable Diseases possibly through insulin and leptin signaling pathways. Moreover, diets low in fruits and vegetables lack the necessary micronutrients that act as co-factors in various metabolic pathways and fiber needed for healthy gut microbiota and host growth and development.
Shotgun metagenomics sequencing from a small cohort of 15 COVID-19 patients revealed significant gut microbiota dysbiosis. An association between several species, namely Coprobacillus, Clostridium ramosum, Clostridium hathewayi, several Bacteroides species like B. dorei, B. thetaiotamicron, B. massiliensis and more COVID-19 disease severity was observed. These species are involved in short-chain fatty acid production and anti-inflammatory capacity. Even also these species are involved in the downregulation of the ACE2 receptor in the gut. Proteobacteria, an inflammatory species dominated the gut of COVID-19 patients. Also, COVID-19 patients had reduced Ruminococcaceae and Lachnospiraceae which was also observed in malnourished individuals.
Thus SARS-CoV-2 can modulate gut microbiota structure, cause gut-dysbiosis, and also adverse metabolic consequences. It has been assumed that the gut microbiota has a significant role in COVID-19 pathogenesis and as a potential therapeutic target. Probiotics and prebiotics have been proposed as possible prevention and treatment of COVID-19.
Also read:ExSeq–Higher Resolution of Genes
[REFERENCE] – Paula Littlejohn & B. Brett Finlay; When a pandemic and an epidemic collide: COVID-19, gut microbiota, and the double burden of malnutrition; BMC Medicine volume 19, Article number: 31 (2021). https://doi.org/10.1016/j.semcancer.2021.01.008.
Bourke CD, Berkley JA, Prendergast AJ. Immune dysfunction as a cause and consequence of malnutrition. Trends Immunol. 2016;37(6):386–98. https://doi.org/10.1016/j.it.2016.04.003.
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