Gut in COVID 19-is it worth noticing

Abstract

Although much has been talked and written about the respiratory menace that Coronavirus disease causes, a close examination reveals that gut symptoms are equally important diagnostic markers for COVID-19. Almost 53% of COVID-19 patients experience gastrointestinal (GI) symptoms. The entry of the SARS Cov-2 virus is mediated through angiotensin-converting enzyme receptors which are abundant in the GI tract. The virus also affects the GI tract through the gut lung axis. In addition to the GI tract epithelium, hepatobiliary and pancreatic systems are also affected in COVID through multiple mechanisms. GI manifestations vary from relatively benign symptoms such as nausea vomiting diarrhea to rare cases of life-threatening mesenteric vein thrombosis. The relationship of the symptoms with morbidity and mortality is not clear. Anorexia is related to inflammation, and agneusia and anosmia carry a good prognosis. Psychiatric manifestations may be more common in those with GI affection, inflammation being the common pathogenic factor. Treatment is symptomatic, and proper hygiene precautions are necessary considering the possible fecal shedding of the virus, especially during endoscopic procedures on the GI tract.

Coronavirus disease 2019 (COVID-19) occurs due to an infection by a SARS-CoV-2 and WHO declared it as a pandemic on March 11, 2020.[1] Most commonly observed symptoms are fever rash, sore throat, headache, nausea, vomiting, anosmia (loss of smell), aguesia (loss of taste), dyspnea (shortness of breath),[2] along with lab indicators such as lymphopenia, increased-CRP levels, d-Dimer, ferritin, interleukin-6, lactate dehydrogenase.[3] These manifest 2–14 days after infection with the virus.

THE GUT IN COVID-19

Much has been talked and written about the respiratory menace that this illness causes, but a close examination reveals gut symptoms are equally important diagnostic markers for COVID-19. According to the literature, almost 53% of COVID patients experience GI symptoms.[4,5] The reason behind the high prevalence of GI symptoms in COVID is simple. SARS-CoV-2 utilizes angiotensin-converting enzyme (ACE)-2 as a receptor for entering the cells. High expression of ACE-2 on the surface cells of the digestive tract makes it a site for active viral replication.[6] Although faeco-oral transmission of the virus has not been proved yet, the virus has been found to be present in feces shed from a patient even after 21 days of illness.[7] The mechanism underlying the GI manifestations is not clearly established. It is postulated to be the result of intestinal mucosal barrier damage, increased production of inflammatory factors, and also gut-lung axis, causing intestinal immune damage and diarrhea.[8] In addition to this, a number of drugs used for the treatment of COVID-19 like Remdesivir, Tocilizumab, Nelfinavir are known to not only cause GI symptoms but also cause hepatic derangements.[9] Researchers from China have shown that approximately 50% of COVID-19 patients manifest with GI symptoms in the early stages of the disease and could be with or without respiratory symptoms. The most commonly observed are anorexia (40%–80%), loss of taste (2%–80%), diarrhea (2%–50%), nausea (1%–30%), vomiting (4%–16%), abdominal pain (2%–6%), GI bleeding (4%–14%).[10] In patiessnts with new GI symptoms, there is a need to monitor for symptoms associated with COVID-19 as GI symptoms may be an early indicator of the infection.[11]

COVID-19 can also pancreatic injury. COVID-19 has been observed to result in acute diabetes and poor glycemic control. This is probably because the ACE-2 receptor is abundantly expressed in the islet cells of Langerhans. As a result, SARS-CoV-2 can cause islet damage.[12] There has been a lot of discussion about the loss of taste (ageusia) and loss of smell (anosmia), which are predominant in COVID and have a better prognosis when compared to other symptoms.[13] Some rare but more worrisome GI manifestations in COVID are GI bleed and mesenteric vein thrombosis.[14]

GASTROINTESTINAL TRACT SYMPTOMS IN COVID-19 AND PROGNOSIS

The question whether gut symptoms predict morbidity and mortality in COVID-19 has been addressed in a systematic review by Dorrel et al. Comparative look at the Asian and North American studies on GI symptom-related mortality reveals conflicting results, with Chinese studies reporting increased mortality contrary to findings from north America.[15] The review concludes that according to the literature while GI manifestations of COVID-19 are associated with severe COVID-19 disease (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3–3.2), it does not affect mortality due to the disease (OR 0.90, 95% CI 0.52–1.54).

GASTROINTESTINAL TRACT SYMPTOMS IN COVID-19 AND PSYCHIATRY

In an interesting study from Italy, the psychiatric involvement in COVID-19 survivors has been found to be to the tune of 20%–40%. A self-rated survey showed the affection of at least one of the psychological dimensions in 56% of patients. The intriguing fact is that levels of anxiety and depression at follow-up was positively associated with baseline systemic immune-inflammation index.[16] As gut is a seat of systemic inflammation, this points to the possibility that COVID patients with gut symptoms could have increased psychiatric morbidity during the recovery period.

GUT IN TREATMENT OF COVID-19

The treatment of COVID-19 mainly remains symptomatic and supportive management along with antibacterial and antiviral medications. It has been reported that ingestion of lactic acid and bifidobacteria increases the production of antiviral antibodies in the body and results in quickening the elimination of viruses.[6] The maintainance of adequate hydration and electrolyte balance should be encouraged. Diet and nutrition need specials consideration to maintain a healthy gut and prevent complications.[6] Thrombophylaxis should be administered as per guidelines.[17]

EFFECTS ON HEALTH WORKERS

American Gastroenterology Association recommends that health workers performing upper or lower GI procedures irrespective of COVID-19 use N-95 masks.[18] All the three Indian Gastroenterology Societies (Indian Society of Gastroenterology, Indian National Association for the study of the Liver, Society of Gastrointestinal Endoscopy in India) recommend only to consider emergency and urgent endoscopies.[19] Infection control practices should be carefully adhered to when handling the patients.[20]

CONCLUSION

Even though the SARS-COV-2 is an established respiratory tract pathogen, it also frequently results in GI symptoms. In addition, the virus has the ability to deregulate hepatobiliary and pancreatic function. Despite hundreds of scientific research publications over the past 1.5 years, from GI standpoint no specific treatment protocol exists, management is mainly preventive and supportive. The prognosis, when detected at an early stage, remains fair. Therefore identifying symptoms at an early stage will help in early detection, slowdown of transmission, and cure. The Pandora 's Box needs detailed and careful examination. Hence, based on evidence, past researches, and experience, it would be wise to say that GI symptoms in COVID-19 is not a myth and should not be underestimated or brushed aside.

“Always trust your gut. It knows what your head hasn't figured out”

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.