Discovering the digestive health advancements of the 21st century
by Pearly Neo
In a time where the world faces a double burden of malnutrition for the first time, our global population of seven billion sees roughly two billion facing overweight and obesity woes, whereas on the other end of the spectrum, over 155 million children worldwide are stunted due to undernutrition.1 Where nutrition is concerned, the importance digestive system cannot be understated, and in an age where malnutrition is rife, it has become inevitable that ailments, and hence research, surrounding digestive health has increased at an exponential rate.
The human digestive system comprises the gastrointestinal (GI) tract, as well as accessory organs aiding in digestion including the teeth, salivary glands, tongue, pancreas, gall bladder and liver. Six key processes take place in this system in order to extract energy and nutrients from food, which are ingestion of food via the mouth; secretion of various fluids e.g. stomach acid, bile, saliva, digestive enzymes and more to break down food; moving and mixing food via muscular processes like swallowing and peristalsis; digestion, which requires the combined efforts of all three processes above; absorption of nutrients, water and other molecules after food has been broken down into its basic form; and excretion via the process of defecation to remove waste and indigestible substances.2
Every single component and process above plays a significant role in maintaining digestive health, and problems that occur at any point due to any imbalance in these could well affect the entire process of digestion. As a result, a galore of digestive-related diseases exist, from the more complex Crohn’s disease, gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), ulcerative colitis, and celiac disease, to the relatively more common yet insufferable constipation and diarrhoea. The relative sensitivity of the system aside, this goes to show the importance of learning as much as possible about every aspect of digestive health in order to facilitate diagnosis and treatment of the related diseases.
The importance of microbes
It is common knowledge that the gut hosts a flourishing ecosystem of microbes, which contribute to human health and disease in a variety of ways. Research from Singapore’s A*STAR Genome Institute and the Karolinska Institutet in Switzerland in 2011 has shown that gut microbiota can even influence brain development and behaviour by affecting the development of neuronal circuits.3 More recent research from the A*STAR Genome Institute, revealed that the microbe balance in the bile duct could play a vital role in the development of cholangiocarcinoma or bile duct cancer,4 a rare but often fatal form of cancer that is, disturbingly, increasing in incidence and mortality rates in Southeast Asia.
These discoveries clearly highlight the importance of understanding gut flora in order to ensure that suitable strategies and therapies can be developed to target ailments that emerge with regard to imbalances in this area, i.e. the presence of too much harmful bacteria and too little friendly bacteria. Current treatment for bacteria control in terms of medication targets side effects of this imbalance, e.g. ciprofloxacin which treats gut infections, and rifaximin that treats irritable bowel syndrome (IBS), both conditions that are commonly associated with gut flora imbalance. More commonly though, treatment is sought by patients in the form of supplements like prebiotics and probiotics which contain specific cultures of bacteria in a bid to increase the number of friendly bacteria and thus restore the balance.
Capsule endoscopy: Taking a real gut look from the inside
Considering the very internal location as well as the repeatedly folded-over shape of the gastrointestinal tract, taking a good look at one’s insides were previously only thought to be possible by one of two ways: The relatively more gruesome surgical method, or a less invasive but still less-than-comfortable endoscopy. Recent developments in science and technology have, fortunately, revealed much more palatable means of GI visioning and diagnostics: for example, capsule endoscopy which is essentially swallowing a camera.
Pillcam is a pill-sized camera developed by the Israeli company, Given Imaging,5 and allows doctors to see the inside of most parts of the GI tract via the process of capsule endoscopy, allowing for the monitoring of ulcers, tumours, bleeding or injuries, as well as the diagnosis of GI tract disorders like Crohn’s disease in order to decide the best method of treatment. Capsule endoscopy does not require sedation and is non-invasive, and the capsule will pass fully through the whole digestive system within roughly 48 hours. This technology gained some measure of fame after being featured on the BBC channel, where health reporter Michael Mosley swallowed a Pillcam and effectively became a living exhibit at the Science Museum in London when live pictures from the camera’s journey through his gut were transmitted to a screen for public viewing.6
Maintaining digestive health: Treatments and therapies
Modern treatments and therapies for digestive-related ailments are already near-innumerable, simply due to the sheer complexity of the entire digestive system – and yet, new therapies still need to be researched and trialled regularly because there are still a vast number of issues affecting digestive health that have yet to be fully understood or resolved, and many of these diseases remain in a stalemate situation of being able to be controlled, yet not fully cured.
A clear example of this is diabetes, which is acknowledged by experts to be able to enter remission, but not actually completely cured. An increasingly common driver of diabetes is obesity, and both conditions were targeted by researchers in a 2007 attempt to use electrical stimulation to treat obesity and diabetes, or essentially creating a sort of gastric pacemaker to control body weight.7 Theoretically, the plausibility of this approach shows great promise, but unfortunately till date, no such device can be found on the market.
On the other hand, several other new therapies are microbiome-based to target gut microflora as discussed above, such as the continued efforts of Hong Kong-based Civet Biosciences, which dubs itself ‘The Asia Microbiome Company’. One of its major areas of research is in the use of Human Microbiota Transfer (HMT) to treat Clostridium Difficile infections (CDI) and IBS. Principally, bacteria from the faecal matter of a healthy, rigorously tested and screened donor will be ‘extracted, cleansed and recycled’ via various levels of cleansing and purification before being transferred into the colon of the receiving patient.8 The screening is conducted by the Asia Microbiota Bank, which is also housed within the Civet Biosciences umbrella.
Many companies globally are also seeing the value and potential of microbiome therapies for GI-related illnesses and hopping onto the bandwagon, particularly those new to the market. This can be evidenced by the number of start-ups targeting this area, like drug discovery firm Second Genome which targets ulcerative colitis, Microbiome Therapeutics which focuses on insulin and diabetes, and Vedanta Biosciences which looks at autoimmune and inflammatory diseases.
Important as microbiome therapy is, more and more other novel therapies developed through the power of advanced biotechnology and biomedical science have entered the fray in the past decade. For example, scientists at A*STAR recently developed a microcapsule-protected system of delivering functional proteins to the GI tract, specifically targeting the transport of molecules that tend to break down before being able to reach target receptors.9 The protein trialled by scientists in this research was lactoferrin, which is generally degraded by stomach acids and enzymes in the adult digestive system before being able to reach the small intestine where its receptors are located, hence depriving adults of its various anti-inflammatory, antimicrobial and cancer-fighting properties in normal situations.
All in all, our knowledge and understanding digestive health today has developed by leaps and bounds far beyond the days where surgery was a taboo subject, yet due to its complicated structure and various interlinking organ functions, there is still so much more to be derived. In 2017, yet another organ has been added to the fray – the mesentery, previously thought to be a fragmented structure comprising multiple separate parts but now found to be a continuous structure that connects the intestine to the abdomen.10 This only goes to prove how many more mysteries remain to be discovered about the digestive system, how far we are from unravelling all its secrets, and how important research and science is in pushing forward for the sake of attaining true digestive health for all.
Pearly Neo is an experienced writer and editor with a particular interest in the food, travel and biomedical science fields.