Covid can infect the gut and cause havoc. Covid also seems to persist there in some people, as well. It's an area our immune system has difficulty clearing.
A randomized, placebo-controlled trial of modulating the gut microbiome is successful for symptom alleviation in #LongCovid
This is the first successful randomized, placebo-controlled, double-blind trial with an adequate sample size (N=463 participants) for #LongCovid
From the study:
We did a randomised controlled trial on the efficacy in alleviating PACS of adult recovered patients using a synbiotic preparation SIM01 (RECOVERY trial). The synbiotic preparation (SIM01) is a micro-encapsulated lyophilised powder containing 20 billion colony-forming units of three bacterial strains, B adolescentis, Bifidobacterium bifidum, and Bifidobacterium longum with three prebiotic compounds including galacto-oligosaccharides, xylo-oligosaccharides, and resistant dextrin, which has been shown to promote the growth of these bacterial strains but also other probiotic strains.
The specific ratio of the three probiotic bacteria was decided based on the relative abundance of these species naturally present in the healthy Chinese population. We previously found that the relative abundance of several species, including B adolescentis and B longum, and the bacterial pathway of short-chain fatty acid production, were all significantly lower in the gut of COVID-19 patients compared with healthy individuals.
Results:
At 6 months, a significantly higher proportion of individuals who received SIM01 had alleviations in fatigue, memory loss, difficulty in concentration, gastrointestinal upset, and general unwellness compared with the placebo group, after adjusting for multiple comparisons. The relative benefit increase after SIM01 were 47% for fatigue, 56% for memory loss, 62% for difficulty in concentration, 30% for gastrointestinal upset, and 31% for general unwellness.
I think you can find the strains used in this study in over-the-counter suppliments and/or in foods like kefir or yogurt, and there are vegan varieties of both. If you have health issues from a covid infection it's worth trying.
If you have a standard US diet, high in processed foods with preservatives, it's probablly a good idea to intentionally eat more probiotics anyway.