Wednesday, January 20, 2021

Irritable Bowel and COVID-19

The first symptoms of Coronavirus disease  (day 0) begin from two to 14 days after exposure to the virus (marked as day –5 in the figure below, since median time is about five days). The disease affects
different people in different ways. A recent article identified 6 distinct types of COVID-19 with different symptoms,  some of which are hallmarks of the most severe forms of the disease. SARS-CoV-2-infected patients usually first experience a fever. The fever is often followed by a dry cough or fatigue and muscle pain, followed by GI tract symptoms, if they ever occur. Some people, experience nausea or have diarrhea in the days just before the fever begins. 

Gastrointestinal symptoms are reported in about one third of COVID-19 cases, the most common is loss of appetite  - it can happen even in the mildest form of the disease. Nausea/vomiting and diarrhea are slightly less common. Abdominal pain is even less widely known in COVID-19, yet it is  - along with shortness of breath and confusion - is a potential sign of the most severe form of COVID-19. In children, having gastrointestinal symptoms was more frequently associated with severe and critical phenotype (Giacomet et al, 2020). Hyperinflammatory syndrome was presenting with both cardiac and significant GI symptoms (diarrhea, vomit, abdominal pain).

Some researchers suggest that gut dysfunction may exacerbate the severity of infection by enabling the virus to access the surface of the digestive tract and internal organs. These organs are vulnerable to infection because they have widespread ACE2—a protein target of SARS-CoV-2 for its possible routes of entry —on the surface.  ACE2 is abundantly present in the epithelia of the lung and small intestine.

Yet, even if SARS-CoV-2 reaches the GI tract, it may not cause GI problems. An inflamed leaky gut, however, may be associated with a higher risk of severe illness and the microbial imbalance of the gut affecting gut barrier integrity can allow pathogens and pathobionts easier access to cells in the intestinal lining.

Several studies have already demonstrated that, when compared with healthy individuals, COVID-19 patients present a significantly reduced bacterial diversity and higher abundancy of opportunistic Streptococcus, Rothia, Veilonella, and Actinomyces compared to depleted levels of beneficial Agathobacter, Fusicatenibacter, Roseburia, and Ruminococcaceae UCG-013. Rothia was preeviously thought to contribute to the pathogenesis of pneumonia. Critically ill patients on mechanical ventilation who were given probiotics experienced decrease in viral colonization when compared with placebo. However, the efficacy of probiotics use in COVID-19 patients and other bowel remedies remains to be proved.


La Marca A, Capuzzo M, Paglia T, Roli L, Trenti T, Nelson SM. Testing for SARS-CoV-2 (COVID-19): a systematic review and clinical guide to molecular and serological in-vitro diagnostic assays. Reproductive biomedicine online. 2020 Jun 14.

Oshima T, Siah KT, Yoshimoto T, Miura K, Tomita T, Fukui H, Miwa H. Impacts of the COVID‐19 pandemic on functional dyspepsia and irritable bowel syndrome: A population‐based survey. Journal of gastroenterology and hepatology. 2020 Nov 16.

Sudre CH, Lee KA, Lochlainn MN, Varsavsky T, Murray B, Graham MS, Menni C, Modat M, Bowyer RC, Nguyen LH, Drew DA. Symptom clusters in Covid19: A potential clinical prediction tool from the COVID Symptom study app. MedRxiv. 2020 Jan 1.

Riphagen S, Gomez X, Gonzalez-Martinez C, et al. Hyperinflammatory shock in children during COVID-19 pandemic. Lancet. 2020;395:1607–1608.

Giacomet V, Barcellini L, Stracuzzi M, Longoni E, Folgori L, Leone A, Zuccotti GV. Gastrointestinal Symptoms in Severe COVID-19 Children. The Pediatric infectious disease journal. 2020 Aug 10;39(10):e317-20.

Cholankeril G, Podboy A, Aivaliotis VI, Tarlow B, Pham EA, Spencer SP, Kim D, Hsing A, Ahmed A. High Prevalence of Concurrent Gastrointestinal Manifestations in Patients With Severe Acute Respiratory Syndrome Coronavirus 2: Early Experience From California. Gastroenterology. 2020 Aug 1;159(2):775-7.

Gu, S.; Chen, Y.; Wu, Z.; Chen, Y.; Gao, H.; Lv, L.; Guo, F.; Zhang, X.; Luo, R.; Huang, C.; et al. Alterations of the Gut Microbiota in Patients with COVID-19 or H1N1 Influenza. Clin. Infect. Dis. 2020, 71, 2669–2678.

Dhar, D.; Mohanty, A. Gut microbiota and Covid-19- possible link and implications. Virus Res. 2020, 285, 198018. 

Sudre CH, Lee KA, Lochlainn MN, Varsavsky T, Murray B, Graham MS, Menni C, Modat M, Bowyer RC, Nguyen LH, Drew DA. Symptom clusters in Covid19: A potential clinical prediction tool from the COVID Symptom study app. MedRxiv. 2020, June 16. 

Ferreira, C.; Viana, S.D.; Reis, F. Is Gut Microbiota Dysbiosis a Predictor of Increased Susceptibility to Poor Outcome of COVID-19 Patients? An Update. Microorganisms 2021, 9, 53.