Hong Kong, Dec 13 : A team of researchers has developed an experimental new drug that has the potential to alter the gut microbiome and relieve multiple symptoms of long Covid. Long Covid or post-acute Covid-19 syndrome (PACS) affects over 65 million individuals worldwide but treatment options are scarce. The team from the Chinese University of Hong Kong found that the synbiotic drug SIM01, which contains strains of anaerobic Bifidobacterium bacteria (probiotics) and soluble fibres (prebiotics), could alter the gut microbiome and also possibly modify immune response. "Treatment with SIM01 alleviates multiple symptoms of PACS. Our findings have implications on the management of PACS through gut microbiome modulation," said the researchers in the paper published in The Lancet Infectious Diseases. From June 2021 to August 2022, the researchers randomly assigned 463 adult long-Covid patients at a single hospital in a 1:1 ratio to receive SIM01 or a Vitamin C placebo by mouth twice daily for 6 months. The median interval between infection and random assignment was 4 months. Nearly one third of patients (31 per cent) had been hospitalised during their infections. At six months, significantly higher proportions of the SIM01 group reported an improvement in fatigue, memory loss, difficulty concentrating, gastrointestinal upset, and general unwellness than the placebo group. More patients in the SIM01 group compared with the placebo group had alleviation in joint pain, ability to exercise, shortness of breath, insomnia, muscle pain, coughing, hair loss, chest pain, and mood disturbance. The treatment with SIM01, which targets gut dysbiosis and potentially modifies the immune response, was found effective in alleviating multiple symptoms of PACS. "We identified favourable changes in the gut microbiome, including increased bacterial diversity and short-chain acid-producing bacteria and decreased resistome in the SIM01 group but not placebo group after 6 months of treatment, as plausible mechanisms to account for the clinical improvement. "SIM01 is a safe and promising treatment for PACS, which is worth further confirmation in a pragmatic, multi-centre trial. Our findings on gut microbiota provided plausible mechanisms to account for the observed clinical benefits," the researchers said. /IANS