The 99 per cent
“99 per cent of the DNA in your body belongs to bacteria,” says Professor Ng Siew Chien (Croucher Senior Medical Research Fellowship 2020) of the Chinese University of Hong Kong. “Only 1 per cent is your own DNA.“
While this may sound slightly worrying, it is in fact good news.
“You can’t change the DNA that you inherited,” says Ng. “But you can change the ecology of the other 99 per cent.“
The second brain
This has far reaching implications for medical diagnostics and therapeutics. Ng’s job is precisely to work out what some of these implications are and to make them useful for the public.
She does this as director at the Microbiota I-Center in Hong Kong. The Center, a globally leading research facility in this field, is committed to developing a novel class of microbiome diagnostics and live biotherapeutics for a variety of diseases — not only diseases related directly to the gut.
“There are trillions of bacteria in the gut of every person,” says Ng. “Their role is so central to the overall functioning of the organism that they are also referred to as our second brain.“
Wide range of applications
The balance or imbalance in that ecosystem of microbiota is a factor in a wide range of conditions. This includes some forms of cancer. It also includes autism, allergies and eczema as well as obesity, depression and Covid-19.
“Most people think of Covid as a lung disease, but there are SARS-CoV-2 receptors in other organs as well, for example in the gut,” says Ng.
This finding is a key to new avenues of diagnosing and treating Covid. Ng and her team were the first worldwide to publish on this approach and started doing so as early as March 2020.
For example, taking stock of the state of the ecosystem of microbiota in the gut which can help us to predict whether a patient will develop long Covid.
Non-invasive methods
“This is non-invasive and quite simple: All we need is a stool sample,” says Ng.
In addition, the health or otherwise of gut microbiota is an important factor in explaining why some people develop severe symptoms from Covid, while others manifest only mild symptoms or none at all.
This insight can be turned to therapeutic use to the extent that doctors are capable of restoring the balance of an unbalanced ecosystem in the patient’s gut.
Making vaccinations more effective
This is, for example, pertinent to the efficacy of Covid vaccinations.
“We identified a species of bacteria in the gut that, if present, raises the antibody count after vaccination,” says Ng. “This means that when adding these good bacteria, we can increase the effectiveness of the vaccination while also reducing the likelihood of side effects.“
Methods like these, developed by Ng and her team, are already used in trials in Hong Kong. “We are currently running large clinical studies,” she says. “We expect results before this summer. If this works, it is ready for use by everyone.“
Big Data
Taking stock of and utilising the ecology of gut bacteria is not straightforward.
“We looked at the bacteria profiles of thousands of healthy people and compare these to the profiles of patients,” says Ng. “That way, we can see what is missing or where an imbalance precisely is.“
To evaluate these profiles — which consist of microbiota-populations numbering in the trillions — Ng and her team are relying to a considerable extent on big data and artificial intelligence.
There are over 200 staff at the Microbiota I-Center where Ng spends most of her time. These include microbiologists, moecular biologists, nutritionists, clinicians and veterinarians as well as experts on bioinformatics and big data.
Stool bank
Part of what makes this so effective is that Ng and her team built up a stool bank.
“This is rather like a blood bank, but with stool samples from healthy people,” says Ng. “Ours is one of the first in Asia.“
These samples can be used to extract and cultivate bacteria profiles for medical applications. Some are standardised — meaning they work for all or most patients — others are assembled for individual cases.
The bank allows the centre to act quickly and supply hospitals at a considerable scale rather than having to find individual donors for each patient.
Making it work
“We are committed to developing novel classes of microbiome diagnostics and therapeutics that will accelerate Hong Kong into a world-class microbiome biotechnology hub,” says Ng.
The work of Ng and her colleagues at the Microbiota I-Center promises to new classes of microbiome diagnostics and live biotherapeutics for common diseases including obesity, cancer, autism, inflammatory disorders and Covid-19.