In the near future, doctors may be able to diagnose and treat patients’ physical and mental health problems by analysing and adjusting the bacteria in their gut
The human body’s digestive system contains an ecosystem of bacteria, yeasts, fungi, viruses and protozoans that weigh up to 2 kg altogether and perform vital functions such as breaking down food and toxins, manufacturing vitamins and training the immune system to keep the body healthy.
In the past decade, research has also shown that anomalies in this ecosystem, called the gut microbiome, could be linked to post-traumatic stress disorder, higher levels of stress, anxiety and fearfulness and other mental health issues.
The importance of the gut microbiome on human wellness is why Dr Niranjan Nagarajan, an associate director and senior group leader in the Singapore Agency for Science, Technology and Research’s Genome Institute of Singapore, is spearheading work to better understand its development and changes.
At this year’s Vitafoods Asia 2018 conference, which will take place 11–12 September at Singapore’s Marina Bay Sands Expo and Convention Centre, Dr Nagarajan will deliver a talk, titled “Focusing on Precision Nutrition for Shaping the Gut Microbiome”, about his research and goals.
Dr Nagarajan said: “We know that diet plays a major role in shaping the microbiome, but precisely how it does so is not quite known. Ultimately, we want to create a system where we can say that: given that your gut microbiome is in state X, to get it to state Y, this is the diet that you should have for the next few months.”
To realise this system, Dr Nagarajan and his fellow scientists are pursuing three avenues of research. The first involves studying gut microbiome and diet data compiled by the American Gut Project, a global citizen science initiative founded by scientists in the US.
For a small fee, people can send a biological sample and a completed survey about their health, disease history, lifestyle and diet to the scientists and receive a report about the microorganisms living in their gut or other body part. The volunteers’ information is then anonymised and put online for free to help researchers investigating links among diet, exercise, lifestyle, microbial make-up and health.
“Although the data is publicly available, it’s just data, so we’ve been working on new methods to analyse it properly to give us what we want,” said Dr Nagarajan. “From the analysis, we can then come up with predictions, for instance that ‘Food A will affect the abundance of Microbiome Component B’, and conduct experiments to test them.”
He added that he and his colleagues have analysed the gut microbiome data of about 1500 people so far, of which about 800 had provided information about their diet.
Beyond this work, the team is also studying different types of food to find out what bacteria grows and feeds on them. “Not everything that we consume will get to our gut because we have a digestive system that kills most bacteria, but this research will give us some idea about what could be in your gut if you eat certain types of food,” Dr Nagarajan explained.
He continued: “Our third approach is to try and understand the inner workings of the gut microbiome. In addition to people’s diet providing nutrients to their microbiome, there’s also a food web in the gut where bacteria cross-feed one another. Some bacteria break down food in certain ways so that other bacteria can eat it.”
“We did a study where we looked at people who are taking antibiotics, because that clears the field in the microbiome, so to speak. Once that happens, we study how the ecosystem repopulates itself. This gut microbiome recovery process can tell us a lot about how bacteria cross-feed one another, and what the food web looks like,” he said.
He noted that the team’s work could have dividends for disease prevention and treatment. He said: “The more we know, the more we can perturb an unhealthy microbiome and shift it back to a healthy state. That could have an impact on a wide range of diseases ranging from metabolic to autoimmune ones.”
Alongside the conference, at the Vitafoods Asia exhibition, speakers at the Global Health Theatre will discuss the impact of the modern lifestyle on nutrition and diseases, and how food fortification is addressing these issues, will be discussed by industry experts.