Clinical Trial Investigates Multi-Strain Probiotics as Potential Tool for Restoring Gut Health in Long COVID Patients

New research shows multi-strain probiotics modestly improve gut bacteria in long COVID patients, though clinical symptom relief requires more study.

By: AXL Media

Published: Mar 27, 2026, 10:10 AM EDT

Source: Information for this report was sourced from Microorganisms.

Targeting Gut Dysbiosis in Post-Viral Recovery

Medical researchers are increasingly looking toward the gut microbiome as a hidden driver of the persistent symptoms associated with long COVID. According to Dr. Liji Thomas, up to 50 percent of patients who contract SARS-CoV-2 experience prolonged illness, a phenomenon often linked to a bidirectional chain of interactions between viral remnants and gut dysbiosis. The study suggests that while long-term inflammation remains a hallmark of the condition, introducing high-quality probiotics may offer a pathway to rebalance the internal microbial environment. By focusing on the gut-epithelial barrier and systemic inflammatory triggers, clinicians hope to mitigate the metabolic disruptions that characterize the post-viral state.

Selective Microbial Shifts Without Broad Diversity Changes

The recent clinical trial utilized a specific multi-strain formulation containing Saccharomyces boulardii, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum to observe changes in fecal microbial composition. Results indicated that the probiotic intervention did not alter the overall diversity of the gut, but instead induced selective changes in specific bacterial genera. Notably, taxa such as Adlercreutzia and Eubacterium, which are typically depleted during acute and long COVID, showed a marked increase following the 12-week regimen. These shifts represent a partial restoration of the microbial community, though the study emphasizes that these changes were targeted rather than transformative for the entire microbiome.

Metabolic Signaling and the Production of Short-Chain Fatty Acids

The potential benefits of probiotic supplementation extend beyond simple bacterial presence to the production of essential metabolites. According to the research team, beneficial microbes help generate short-chain fatty acids (SCFAs), which play a critical role in suppressing pathogens and regulating the host's inflammatory response. Functional prediction analysis in the trial suggested that the probiotic group experienced an uptick in bacterial energy metabolism and a potential reduction in oxidative stress. These metabolic improvements are consistent with enhanced microbial respiration, providing a biological basis for how gut-focused therapies might eventually aid in broader physiological recovery.