Article Text

Download PDFPDF
Post-acute COVID-19 syndrome and gut dysbiosis linger beyond 1 year after SARS-CoV-2 clearance
  1. Qi Su1,2,3,4,
  2. Raphaela Iris Lau1,2,3,4,
  3. Qin Liu1,2,3,4,
  4. Francis Ka Leung Chan1,2,3,4,
  5. Siew Chien Ng1,2,3,4
  1. 1 Microbiota I-Center (MagIC), Hong Kong SAR, People's Republic of China
  2. 2 Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China
  3. 3 Li Ka Shing Institute of Health Sciences, State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China
  4. 4 Center for Gut Microbiota Research, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China
  1. Correspondence to Professor Siew Chien Ng, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong 999077, Hong Kong; siewchienng{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

We recently published in Gut to show that gut dysbiosis persisted for at least 6 months in patients with post-acute COVID-19 syndrome (PACS).1 Murine and human studies have also reported microbial alterations associated with different PACS symptoms.2 3 With the pandemic entering its third year, PACS could potentially affect recovered individuals for over 1 year.4 It remains unknown whether PACS-associated gut dysbiosis would also linger for such a long time.

Here, we conducted a prospective study to determine long-term alterations in the gut microbiome of patients with COVID-19 using shotgun metagenomic sequencing (online supplemental materials). A total of 155 patients with COVID-19 in Hong Kong were followed up for an average of 14 months after SARS-CoV-2 viral clearance, and 155 age-matched, sex-matched and body mass index-matched subjects without COVID-19 were recruited as controls. Patients with COVID-19 were infected with the original or earlier variants of SARS-CoV-2 from January 2020 to February 2021. Consistent with previous finding that 76.4% of patients had PACS 6 months after recovery from acute COVID-19,1 we found that the prevalence of PACS was 78.7% at an average of 14-month (IQR 11–18 months) follow-up. The three most common symptoms were fatigue (50.9%), memory problems (44.5%) and difficulty in sleeping (35.5%, figure 1A). Gut dysbiosis in these patients did not fully recover. Both bacteria diversity (p=0.0036, figure …

View Full Text


  • Twitter @QiSu_123, @Iris_R_Lau, @Siew_C_Ng

  • QS and RIL contributed equally.

  • Contributors QS and RIL conceptualised and designed the study. QS conducted data analyses. RIL collected and interpreted subjects' clinical data. QL provided critical suggestions on data analysis. FKLC contributed to the study design and data interpretation. SCN contributed to the study design, data analysis and manuscript writing. All authors gave final approval for the version to be published.

  • Funding This work was supported by The Health and Medical Research Fund, the Food and Health Bureau, The Government of the Hong Kong Special Administrative Region. The authors are partially supported by InnoHK, The Government of Hong Kong, Special Administrative Region of the People’s Republic of China. R.I.L. received additional support from the Hong Kong PhD Fellowship Scheme (HKPFS).

  • Competing interests FKLC and SCN are the scientific co-founders and sit on the board of Directors of GenieBiome Ltd. SCN has served as an advisory board member for Pfizer, Ferring, Janssen, and Abbvie and a speaker for Ferring, Tillotts, Menarini, Janssen, Abbvie, and Takeda. She has received research grants from Olympus, Ferring, and Abbvie. FKLC has served as an advisor and lecture speaker for Eisai Co. Ltd., AstraZeneca, Pfizer Inc., Takeda Pharmaceutical Co., and Takeda (China) Holdings Co. Ltd. All other co-authors declare no competing interests.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.