A groundbreaking clinical trial conducted by the Chinese University of Hong Kong's (CUHK) Faculty of Medicine has demonstrated that modulating the gut microbiome using an oral microencapsulated live bacteria formula, SIM01, can significantly improve persistent symptoms of long COVID. The findings were presented at the Digestive Disease Week 2023 conference in Chicago, marking a potential breakthrough in addressing a condition that currently lacks proven treatments.
The triple-blind, randomized, placebo-controlled trial, known as the RECOVERY study, enrolled 463 patients who had recovered from COVID-19 but continued to experience at least one long COVID symptom. The study was conducted from 2021 to 2022, with participants having a mean age of 49 years, and 65.4% being female. Approximately 70% were suspected to have been infected with the Omicron variant.
Long COVID: A Persistent Challenge
Long COVID, defined as the persistence of symptoms beyond four weeks after COVID-19 diagnosis, affects approximately 70% of recovered patients in Hong Kong at the six-month mark. These symptoms can impact multiple organ systems and significantly diminish quality of life.
"Long COVID affects different organs and can be debilitating yet there is no effective treatment. There is an urgent need for clinically proven intervention to improve the physical and psychological impact of long COVID," stated Professor Martin Wong Chi-sang from The Jockey Club School of Public Health and Primary Care at CU Medicine.
Previous research by the CUHK team had established that patients with long COVID symptoms exhibited altered gut microbial signatures, suggesting that microbiome modulation could be a viable therapeutic approach.
Study Design and Innovative Approach
The research team developed SIM01 using big data and machine-learning algorithms to create a specialized microbiome formula, which was then transformed into an oral preparation using microencapsulation technology. This technology helps protect the beneficial bacteria as they pass through the digestive system.
Study participants were randomly assigned to receive either SIM01 or a placebo containing a low dose of Vitamin C for six months. The trial employed a triple-blind design, meaning that the participants, healthcare providers, and researchers analyzing the results were all unaware of which treatment each participant received.
Significant Improvements in Multiple Symptoms
The results showed that significantly more patients in the SIM01 group experienced improvements in digestive problems, fatigue, difficulty concentrating, memory loss, and general unwellness at the six-month follow-up compared to the placebo group.
Metagenomic analysis of stool samples revealed that SIM01 treatment led to:
- Increased bacterial diversity in the gut
- Higher abundance of beneficial bacteria
- Reduced levels of unfavorable bacteria
- Restoration of gut dysbiosis (microbial imbalance)
The Gut-Brain Connection
Professor Siew Ng, CUHK's Croucher Professor of Medical Sciences and Director of Microbiota I-Center (MagIC), highlighted the significance of these findings: "To our knowledge, this is the first clinical trial to show that modulation of the gut microbiome can improve long COVID symptoms including memory and concentration problems. These data support the importance of the gut-brain axis."
The researchers propose that restoring a healthy gut microbiota represents a novel approach to improving neurological symptoms. The mechanism likely involves the production of beneficial metabolites by gut bacteria that can circulate to the brain and enhance brain function.
Future Directions
Professor Francis KL Chan, Dean of Medicine and Director of the Centre for Gut Microbiota Research at CU Medicine, emphasized the complexity of developing effective microbiome-based therapies: "The development of conventional probiotics into a microbiome formula requires a lot of clinical data, metagenomics analysis, and microencapsulation technology. We will strive to develop more clinical applications of gut microbiome."
The study received support from the Health and Medical Research Fund of the Hong Kong Special Administrative Region Government's Health Bureau, underscoring the importance of this research area for public health.
As long COVID continues to affect millions worldwide, this innovative approach targeting the gut microbiome offers new hope for patients suffering from persistent symptoms and opens up promising avenues for further research into microbiome-based therapeutics for post-viral conditions.
