Decoding the gut to diagnose and treat autism
Trailblazing professors aim to bring health and hope to future generations
6 October 2025
This is part three of our series in CUHK in Focus that talks to principal investigators of the six CUHK projects chosen for the second round of the Hong Kong government’s Research, Academic and Industry Sectors One-plus Scheme (RAISe+). The scheme provides a maximum of HK$100 million to each approved project to help local universities commercialise their research outcomes. Including the seven projects accepted last year, CUHK now has 13 projects receiving RAISe+ funding, the most among local institutions.
Autism was once looked upon solely as a developmental disorder of the brain. That was before Professor Francis Chan Ka-leung, Choh-Ming Li Professor of Medicine and Therapeutics and Professor Siew Ng, Associate Dean (Research) of CUHK’s Faculty of Medicine and Croucher Professor of Medical Sciences, began investigating possible links between autism and what is now regarded as the body’s “second brain” — our gut.
Through trailblazing research, they have been tracing secret, nanoscopic conversations between microbes in the gut and the brain in our head, in relation to Autism Spectrum Disorder (ASD). The government’s latest round of RAISe+ funding is enabling the two professors to take both their research and its practical applications to the next level — as well as to the global market. They have established a spin-off company, MicroSigX Biotech Diagnostic Limited, to actualise their vision.
The “gut–brain axis” refers to the complex, bidirectional channel through which 40 trillion microorganisms regulate not only digestion and immunity but, notably, mood and behaviour.
The most striking revelation from the five-year research by Professor Chan and Professor Ng at CUHK has been that communications within the gut–brain axis play a quiet but significant role in the onset of ASD.
The number of new ASD diagnoses has quadrupled worldwide over the past two decades, but diagnosis still relies heavily on a small group of psychiatrists with long waiting lists of patients. This means that many children under six miss a crucial window for early intervention. Five years ago, Professors Chan and Ng set out to break the impasse by turning to the gut microbiome in search of new answers.
Leveraging big data and AI
Their team collected 1,627 faecal samples from children with or without ASD. Harnessing big data and artificial intelligence, they identified 31 markers in the gut microbiome that are closely associated with the condition.
Building on these findings, the team developed a laboratory-based non-invasive diagnostic kit in 2024 that requires only a small faecal sample. With diagnostic accuracy of over 90%, the technology has received Breakthrough Device Designation from the US Food and Drug Administration (FDA) in the same year, which recognises it as a globally innovative and promising advance in ASD diagnosis.
The team pressed on with their research, transplanting gut microbiota from children with ASD into 15 healthy mice. Within days, 12 of them began to exhibit autism-like behaviours, such as social withdrawal, repetitive actions and heightened sensory sensitivity — further underpinning a possible causal link between gut microbes and the condition.
Professor Ng explains that in the gut microbiome of children with ASD, microbial diversity and richness are typically low, beneficial microbes are scarce and harmful strains predominate. This microbial imbalance, she explains, can lead to the release of specific chemicals that travel to the brain via the bloodstream, influencing neurodevelopment and potentially contributing to the onset of ASD.
“We then transplanted healthy gut microbiota into eight mice exhibiting autistic behaviours and observed around 35% improvement in their social interactions and behaviours in seven of them,” Professor Ng says, citing the team’s research findings.
While the causes of ASD are complex, involving environmental as well as genetic factors, the CUHK team’s findings suggest that targeted adjustments to the gut microbiome offer new possibilities for intervention. The team is now working on developing synbiotic formulae that contain both pre- and probiotics, providing microbial therapies to address the needs of individuals missing a specific set of microbiotas.
Professor Ng further envisions a future in which children receive microbiome screening as early as their first birthday, to allow early identification of those at high risk and follow up microbial treatment, potentially mitigating or even preventing the onset of symptoms.
New hope for IBD patients
The Professors’ breakthrough in microbiome testing technology has also opened new possibilities for early diagnosis of individuals suffering from debilitating inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn’s disease, which diagnosis relies on colonoscopy and histology with CT or MRI scans. The latest test developed by the team delivers a sensitivity of 88% and specificity of 89% within a few days, while costing just a tenth of conventional diagnostic procedures.
Professor Ng hopes, “If this technology is integrated into first-line clinical assessments — alongside blood tests for inflammatory markers, microbiological culture and viral screenings—it could slash the diagnostic odyssey of repeated consultations from months to just a few days. It would allow patients to receive effective treatment much earlier.”
From local to global impact
With the support of the government’s RAISE+ funding, Professors Chan and Ng, together with their team, are now further refining the diagnostic kits developed from their research breakthroughs. The number of biomarkers required for ASD testing has been reduced from 31 to just seven, with results now available within 48 hours — compared to seven days when the technology was first introduced — and at a lower cost. IBD diagnostics are following the same trajectory — moving towards fewer biomarkers, greater efficiency and lower cost.
Professor Ng says that both non-invasive diagnostic kits have reached the commercialisation phase and are expected to launch in the Hong Kong market by August 2026, with plans for clinical trials and registration in the Chinese Mainland and the United States. Meanwhile, the team is developing new synbiotic formulae that enhance neurotransmitter levels, to alleviate autism symptoms. They will conduct clinical trials in phases and plan for gradual entry into global markets.
Professor Chan says, “Hong Kong may be a small market, but if we can demonstrate success here, it could attract investment from major international pharmaceutical companies and help bring these innovative technologies and products to the Greater Bay Area, Southeast Asia, and even North America.”
By Jessica Chu
Photos by Steven Yan
