During the Spring Festival, the wanderers who have left their hometown are like arrows, and the parents at home stand in front of the door and look at each other. On this occasion of reunion, in addition to the need to constantly guard against the resurgence of the new crown epidemic, there is another thing that needs special attention, that is, a sudden change in living habits.
If the Spring Festival is a "festival of indulgence" in disguise, it is not an exaggeration at all.
——Smelling the hometown food that has not been tasted for a long time, no one can resist the temptation.
——It took a long vacation, and didn't you talk all night, talk about wine, and sleep in the dark?
However, the consequences of "eating haythest" and "poor work and rest" will not be so easy to let you go – "intestinal microflora imbalance" is the most typical negative effect - diarrhea is its most common symptom.
Figure 1. Healthy people live in the gastrointestinal tract with a wide variety of microorganisms, that is, the intestinal flora. The "good" bacteria in the gut play a positive role in human health, while the "bad" bacteria promote a variety of (gut) diseases. (Image source: Pixabay)
The intestinal flora can be thought of as a group of "native inhabitants" within the intestines of a host. After the birth of the fetus, with every mouthful of complementary food and every breath, the ancestors of the intestinal flora also began to camp and grow their families. In addition to helping to digest and absorb nutrients from food, they form alliances with the gut's immune system, stimulate the latter's development, and help eliminate pathogenic bacteria at critical moments. Under normal circumstances, the various races of the intestinal flora restrict and interdependence with each other to achieve an ecological balance, and once the environment inside and outside the body undergoes a large contrast (such as work and rest and dietary factors, drug metabolism, etc.), it will lead to the destruction of its normal physiological combination and cause dysbacteriosis.
Don't underestimate the "imbalance of intestinal flora". On January 26, a new study published in Gut by the Faculty of Medicine of Chinese University in Hong Kong showed that "intestinal flora disorders" are still the main factors contributing to the "long new crown"* (long COVID)!
*"Long Coronavirus": Post-acute COVID-19 syndrome (PACS) caused by COVID-19 infection. Refers to one or more symptoms/complications that last for a long time (four weeks or more) in a patient with COVID-19 since the initial recovery.
Figure 2. Gut microbiota dynamics in a prospective cohort of patients with post-acute COVID-19 syndrome （图片来源：Gut）
This time, the team recruited 106 COVID-19 patients of different severity from three hospitals, and also included 86 non-COVID-19 patients as a control group for prospective studies. The follow-up period is from admission to the 6th month thereafter, and stool samples are collected at three time points at the time of admission, 1 month after discharge and 6 months.
According to the data, within 6 months, 76% of COVID-19 patients developed "long-term syndrome sequelae" (PACS): among the 30 most commonly reported symptoms, tiredness (31%), poor memory (28%), hair loss (21%), anxiety (21%) and sleep difficulties (21%) were at the forefront.
Figure 3. Proportion of 106 COVID-19 patients with 30 PACS symptoms developed after 3 months and 6 months (Image: Gut)
Given that diets are known to affect the gut microbiome, the researchers documented the diets of all COVID-19 patients during hospitalizations, provided standardized diets at various hospitals, and recommended that discharged patients continue to adopt a varied standard diet.
The CUHK research team found that the composition of individual gut microbes is closely related to the occurrence of PACS in the later stages.
By sequencing, processing, and analyzing a total of 258 stool samples, the researchers found that the fecal microbial community of COVID-19 patients had significant changes compared to the control group, characterized by the enrichment of opportunistic pathogenic bacteria and the consumption of beneficial symbiotic bacteria - patients who did not have PACS maintained a relatively rich and diverse state of intestinal microbiome, which was no different from the control group; and patients with PACS, whose intestinal microecology was disordered, some "good bacteria" known to have immune regulatory potential Apparently not fully expressed, such as Faecalibacterium prausnitzii and other 28 bacterial species, while "bad bacteria" were enriched in the samples, such as ruminococcus gnavus and Bacteroides vulgatus, a total of 14 species, and even 30 days after the virus clearance in the patient's body, the level of "good bacteria" was still low.
Figure 4. Association of bacterial species with different categories of PACS (Image: Gut)
1. Opportunistic gut pathogens refer to low-level bacteria present in the intestine, when beneficial bacteria are depleted, they tend to proliferate, while persistent respiratory symptoms are associated with "opportunistic intestinal pathogens";
2. Neuropsychiatric symptoms and fatigue are associated with nosocomial gut pathogens of hospital-acquired infections, including harmless Clostridium innocuum and Actinomyces naeslundii;
3. Bifidobacterium pseudocatenulatum and the above-mentioned Pseudocatenulatum are a class of butyrate-producing bacteria (BPB), which produce butyrates with anti-inflammatory and immunomodulatory functions, and which have the greatest negative correlation with PACS at 6 months;
There are indications that the imbalance of the intestinal microbiome at the time of admission is associated with the occurrence of PACS with different symptoms at 6 months, so the "intestinal microbiome disorder" is considered to be the main factor leading to the "long new crown" in the future. In addition, the study found that as many as 81 gut bacteria are associated with PACS, many of which are closely associated with two or more types of persistent symptoms.
Figure 5. Schematic diagram of the relationship between the gut microbiota and the development of PACS (Image: Gut)
The researchers say these findings provide observational evidence for changes in the composition of the gut microbiome in COVID-19 patients, and analyzing the gut microbiome of individuals with COVID-19 will help predict the risk of future PACS. Next, the researchers will further focus on investigating whether modulating the microbiome can help patients recover from the nightmare of "long new crown" in time.
Reference：
[1] Gut：Gut microbiota dynamics in a prospective cohort of patients with post-acute COVID-19 syndrome
http://dx.doi.org/10.1136/gutjnl-2021-325989
[2] Chinese University of Hong Kong:
https://www.cpr.cuhk.edu.hk/tc/press/cu-medicine-study-shows-distinct-gut-microbial-profile-associated-with-long-covid/
Written by | Xu Chuchu
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