Interplay between severities of COVID-19 and the gut microbiome: implications of bacterial co-infections?

Abstract

COVID-19 is an acute respiratory distress syndrome and is often accompanied by gastrointestinal symptoms. The SARS-CoV-2 has been traced not only in nasopharyngeal and mid-nasal swabs but also in stool and rectal swabs of COVID-19 patients. The gut microbiota is important for an effective immune response as it ensures that unfavorable immune reactions in lungs and other vital organs are regulated. The human gut-lung microbiota interplay provides a framework for therapies in the treatment and management of several pulmonary diseases and infections. Here, we have collated data from COVID-19 studies, which suggest that bacterial co-infections as well as the gut-lung cross talk may be important players in COVID-19 disease prognosis. Our analyses suggests a role of gut microbiome in pathogen infections as well as in an array of excessive immune reactions during and post COVID-19 infection recovery period.

Interplays between human microbiota and microRNAs in COVID-19 pathogenesis: a literature review

“…Thus, the administration of probiotics may function through several signaling pathways, resulting in the prevention and treatment of various pathological conditions [ 63 ]. As microbiome dysbiosis is linked with the severity of COVID-19, the implication of probiotics in modulating the severity has been suggested as a promising weapon against COVID-19 [ 24 , 25 , 64 ]. Several studies focusing on the gut microbiome and probiotics in COVID-19 have been conducted, and several registered clinical trials have focused on the usage of probiotics in COVID-19 [ 24 ].…”

“…Moreover, recent studies have shown that COVID-19 is often associated with altered gut microbiota composition, reflecting disease severity [20][21][22][23] . As growing evidence indicates the interaction between COVID-19 and host-microbiota homeostasis, researchers have been investigating the potential of manipulating gut microbiota with probiotics to enhance the host immune system 24, 25 . The current review summarizes important findings on the direct association between SARS-CoV-2 infection and the gut-lung axis in addition to the pathological effects of dysbiosis on COVID-19 severity.…”

Covid 19: Diet Composition and Health

“…Given that SARS-CoV-2 has receptors in the intestinal endothelium, infection will reduce the expression of ACE2 in the gastrointestinal tract, and thus by various mechanisms may lead to intestinal dysbiosis [ 138 ]. The number of ACE-2 receptors in the duodenum increases with age, which suggests a potential entry mechanism for SARS-CoV-2 [ 139 ] and effects on its infectiousness and the severity of COVID-19 [ 140 , 141 ]. Research has detected the SARS-CoV-2 virus in anal swabs and stool samples in nearly 50% of patients with COVID-19, which suggests that the digestive tract may be an extrapulmonary site of replication and activity of the virus [ 6 , 142 ].…”

“…However, there is a concern about the possibility of opportunistic pathogen infections, especially in people with comorbidities such as cancer, leaky gut syndrome, or diabetes, and in organ transplant recipients [ 152 ]. Some probiotic strains take advantage of weakened immunity to transform into opportunistic pathogens, causing acute pneumonia, endocarditis, or sepsis [ 141 ]. There is a need for studies encompassing the effects of both diet and probiotics on the severity of COVID-19.…”

Anti-inflammatory effects of GLP-1 in patients with COVID-19

“…However, this imbalance in the intestinal microbiome can be associated with an increased severity of the disease in COVID-19 patients [ 42 ]. One of the responsible mechanisms could be the alteration in the microbiota with the contribution of defensive bacteria including Klebsiella, Streptococcus spp., and Ruminococcus gnavus that are associated with over-secretion of pro-inflammatory cytokines and exacerbation of the cytokine storm in infected patients [ 43 ].…”