Gut Microbiota May Influence COVID-19 Severity, Immune Response By Megan Brooks January 12, 2021

14 Jan Gut Microbiota May Influence COVID-19 Severity, Immune Response By Megan Brooks January 12, 2021

Gut Microbiota May Influence COVID-19 Severity, Immune Response
By Megan Brooks

January 12, 2021

NEW YORK (Reuters Health) – The gut microbiome may influence the severity of COVID-19 as well as the magnitude of the immune response to the infection, according to new research.

“The composition of gut microorganisms (microbiota) in COVID patients, which is very different from uninfected individuals, links to disease severity. COVID patients lack certain good bacteria known to regulate our immune system,” Dr. Siew Ng of The Chinese University of Hong Kong told Reuters Health by email.

“The abnormal gut microbiota (dysbiosis) in COVID patients persists after clearance of the virus. These alterations could play a role in ‘long COVID’. Clinical management not only should aim at clearing the virus but also restoring the abnormal gut microbiota,” said Dr. Ng.

The study team obtained blood and stool samples from 100 adults (mean age, 36 years; 47 women) who were hospitalized with COVID-19 and from 78 adults (mean age, 45 years; 45 women) without COVID-19 who were taking part in a microbiome study before the pandemic.

Forty-one of the COVID patients provided multiple stool samples while hospitalized, 27 of whom provided serial stool samples up to 30 days after they cleared the infection.

The researchers found that the composition of the gut microbiome was statistically significantly altered in the patients with COVID-19 compared with non-COVID patients, regardless of whether they had been treated with antibiotics.

Several commensal gut bacteria known to influence the immune response, including Faecalibacterium prausnitzii, Eubacterium rectale and several bifidobacterial species, were depleted in COVID patients and remained low in samples collected up to one month after the disease resolved.

Analysis of the blood samples showed that the microbial imbalance found in the COVID patients correlated with elevated concentrations of inflammatory cytokines and blood markers such as C-reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase, the researchers report in Gut.

“Our results suggest that dysbiosis weakens our immune defense, thereby predisposing to more severe SARS-CoV-2 infection and contributing to ‘long COVID,'” Dr. Ng told Reuters Health. “Probiotics, if using the right combination of missing bacteria to boost immunity, may be potentially useful as an adjuvant therapy.”

Using big data analysis and metagenomics derived from COVID patients, she and her colleagues have developed a unique oral microbiome formula with microencapsulation technology to enhance the stability and quantity of live bacteria that targets gut dysbiosis associated with impaired immunity.

“Compared with patients on standard care, our pilot clinical study showed that more COVID patients who received our microbiome immunity formula achieved complete symptom resolution, showed significantly reduced proinflammatory markers in their blood, had increased favorable bacteria in their stool; and developed neutralizing antibody,” Dr. Ng told Reuters Health.

“We were also alarmed to find that 40% of Hong Kong people appeared to have significant gut dysbiosis comparable to that of COVID patients, suggesting they have potentially impaired immunity and will be at risk of infections including COVID-19,” she added.

The study had no commercial funding and the authors have declared no conflicts of interest.

SOURCE: https://bit.ly/3q9u1hb Gut, online January 11, 2021.

Reuters Health Information © 2021

Cite this: Gut Microbiota May Influence COVID-19 Severity, Immune Response – Medscape – Jan 11, 2021.