Gut Microbiota Dysbiosis Correlates With Long COVID-19 at One-Year After Discharge.

BACKGROUND: Long coronavirus disease 2019 (COVID-19) in recovered patients (RPs) is gradually recognized by more people. However, how long it will last and the underlining mechanism remains unclear. METHODS: We conducted a prospective follow-up study to evaluate the long-term symptoms and clinical indices of RPs at one-year after discharge from Union Hospital, Wuhan, China between December 2020 to May 2021. We also performed the 16S rRNA sequencing of stool samples from RPs and healthy controls (HCs) and analyzed the correlation between the gut microbiota and long COVID-19. RESULTS: In total, 187 RPs were enrolled, among them, 84 (44.9%) RPs reported long COVID-19 symptoms at one-year after discharge. The most common long-term symptoms were cardiopulmonary symptoms, including chest tightness after activity (39/187, 20.9%), palpitations on exercise (27/187, 14.4%), sputum (21/187, 11.2%), cough (15/187, 8.0%) and chest pain (13/187, 7.0%), followed by systemic symptoms including fatigue (34/187, 18.2%) and myalgia (20/187, 10.7%), and digestive symptoms including constipation (14/187, 7.5%), anorexia (13/187, 7.0%), and diarrhea (8/187, 4.3%). Sixty-six (35.9%) RPs presented either anxiety or depression (42/187 [22.8%] and 53/187 [28.8%] respectively), and the proportion of anxiety or depression in the long symptomatic group was significantly higher than that in the asymptomatic group (41/187 [50.6%] vs. 25/187 [24.3%]). Compared with the asymptomatic group, scores of all nine 36-Item Short Form General Health Survey domains were lower in the symptomatic group (all P < 0.05). One hundred thirty RPs and 32 HCs (non-severe acute respiratory syndrome coronavirus 2 infected subjects) performed fecal sample sequencing. Compared with HCs, symptomatic RPs had obvious gut microbiota dysbiosis including significantly reduced bacterial diversities and lower relative abundance of short-chain fatty acids (SCFAs)-producing salutary symbionts such as Eubacterium_hallii_group, Subdoligranulum, Ruminococcus, Dorea, Coprococcus, and Eubacterium_ventriosum_group. Meanwhile, the relative abundance of Eubacterium_hallii_group, Subdoligranulum, and Ruminococcus showed decreasing tendencies between HCs, the asymptomatic group, and the symptomatic group. CONCLUSION: This study demonstrated the presence of long COVID-19 which correlates with gut microbiota dysbiosis in RPs at one-year after discharge, indicating gut microbiota may play an important role in long COVID-19.

Unraveling the Interconnection Patterns Across Lung Microbiome, Respiratory Diseases, and COVID-19.

Albeit the lungs were thought to be sterile, recent scientific data reported a microbial microbiota in the lungs of healthy individuals. Apparently, new developments in technological approachesincluding genome sequencing methodologies contributed in the identification of the microbiota and shed light on the role of the gut and lung microbiomes in the development of respiratory diseases. Moreover, knowledge of the human microbiome in health may act as a tool for evaluating characteristic shifts in the case of disease. This review paper discusses the development of respiratory disease linked to the intestinal dysbiosis which influences the lung immunity and microbiome. The gastrointestinal-lung dialogue provides interesting aspects in the pathogenesis of the respiratory diseases. Lastly, we were further interested on the role of this interconnection in the progression and physiopathology of newly emergedCOVID-19.

[Mechanism and intervention of mucosal immune regulation based on "lung and large intestine being interior-exteriorly related" theory of traditional Chinese medicine].

The "lung and large intestine being interior-exteriorly related" is one of the classical theories in traditional Chinese medicine, which indicates a close correlation between the lung and large intestine in physiology and pathology, and plays a pivotal role in guiding the treatment of the lung and bowel diseases. Modern medicine has revealed some connections between the lung and large intestine in tissue origin and mucosal immunity, and preliminarily illuminated the material basis and possible regulatory mechanism of the theory. Recently, this theory has been applied to guide the treatment of refractory lung and intestine diseases such as COVID-19 and ulcerative colitis and has obtained reliable efficacy. Existing research results show that the anatomical homogeneity of lung and large intestine promotes the correlation between lung-bowel mucosal immunity, and mucosal immunity and migration and homing of innate lymphocytes are one of the physiological and pathological mechanisms for lung and large intestine to share. Under the guidance of this theory, Chinese medicines with heat-clearing and detoxifying or tonic effects are commonly used in the treatment of the lung and intestinal diseases by regulating lung-bowel mucosal immunity and they can be candidate drugs to treat lung/intestinal diseases simultaneously. However, the existing studies on immune regulation are mainly focused on the expression levels of sIgA and cytokines, as well as the changes in the number of immune cells such as innate lymphocytes and B lymphocytes. While the following aspects need further investigation: the airway/intestinal mucous hypersecretion, the functional changes of pulmonary and intestinal mucosal barrier immune cells, the dynamic process of lung/intestinal mucosal immune interaction, the intervention effect of local pulmonary/intestinal microecology, the correlation and biological basis between the heat-clearing and detoxifying effect and the tonic effect, and its regulation of pulmonary/intestinal mucosal immunity. In this paper, we try to analyze the internal relationship between lung and intestine related diseases from the point of view of the common mucosal immune system of lung and intestine, and summarize the characteristics and rules of traditional Chinese medicine compound and its active ingredients, which have regulatory effect on lung and intestine mucosal immune system, so as to further explain the theoretical connotation of "lung and large intestine being interior-exteriorly related" and provide reference for the research and development of drugs for related diseases.

The Thrilling Journey of SARS-CoV-2 into the Intestine: From Pathogenesis to Future Clinical Implications.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a direct impact on the gastrointestinal system, as up to 50% of fecal samples from coronavirus disease 2019 (COVID-19) patients contain detectable viral RNA despite a negative rhino-pharyngeal swab. This finding, together with an intestinal expression of angiotensin conversion enzyme 2 protein, suggests a possible fecal-oral transmission for SARS-CoV-2. Furthermore, gastrointestinal (GI) symptoms are common in COVID-19 patients including watery diarrhea, vomiting-particularly in children-nausea, and abdominal pain. Pathogenesis of SARS-CoV-2 infection presents significant similarities to those of some immune-mediated diseases, such as inflammatory bowel diseases or rheumatoid arthritis, leading to the hypothesis that targeted therapies used for the treatment of immune-mediated disease could be effective to treat (and possibly prevent) the main complications of COVID-19. In this review, we synthesize the present and future impact of SARS-CoV-2 infection on the gastrointestinal system and on gastroenterology practice, hypothesizing a potential role of the "gut-lung axis" and perhaps of the gut and lung microbiota into the interindividual differential susceptibility to COVID-19 19 disease. Finally, we speculate on the reorganization of outpatient gastroenterology services, which need to consider, among other factors, the major psychological impact of strict lockdown measures on the whole population.