44 CLINICAL FOCUS
44 CLINICAL FOCUS
18 JULY 2025 ausdoc. com. au
| THE | WINTER SEASON SPECIAL
Therapy Update
A practical approach to the gut microbiome
Gastroenterology
Associate Professor Craig Haifer Gastroenterologist and hepatologist at St Vincent’ s Hospital Sydney, and Conjoint Associate Professor, St Vincent’ s Hospital Clinical school, school of clinical medicine, UNSW Sydney.
Consider a holistic approach to gut health, rather than focusing solely on microbiome-targeted interventions.
NEED TO KNOW
There is increasing evidence linking the gut microbiome to the development and progression of the vast majority of chronic illnesses.
With the increase in direct-to-consumer microbiome testing, along with an everexpanding nutraceutical industry, it is important to remember that patients are aware of the link and looking for ways to understand and influence it.
While there is both academic and financial interest in developing ways to target specific aspects of the microbiome in order to treat or prevent diseases, there is a lack of evidence for the vast majority of these interventions.
Be holistic in your approach. Ensure your goals align with those of your patient. Always be clear on what you are you trying to achieve with dietary or other interventions and have a plan to re-evaluate the patient’ s response to any interventions.
IN recent years, the gut microbiome has emerged as a pivotal player in human health, with profound implications for various chronic illnesses within and outside of the gut. 1
Alongside the rapid surge in academic literature shedding light on the intricate relationship between the changing microbiome and the underlying immune system, there is an even greater volume of commentary, theories and recommendations infiltrating a patient’ s world through various sources including social media. It is therefore important to have an approach to decipher the hype from the facts and provide practical, sustainable and achievable recommendation to patients as part of your routine clinical practice.
What is the gut microbiome?
The gut microbiome is a complex ecosystem comprised of trillions of micro-organisms including bacteria, viruses, fungi, and archaea, all of which play a fundamental role in maintaining gut homeostasis and influencing the systemic immune system. It is the body’ s window to the outside world and is heavily influenced by
everything around us including diet, genetics, age, environment and medication use. These organisms directly impact digestion and nutrient absorption. But the physiological effects are influenced not only by what organisms are present, but also what metabolites they are able to produce that contribute to immune regulation, metabolism and even neurobehavioural functions. 1
Recent advancements in high-throughput sequencing technologies and reduction in costs have revolutionised our ability to investigate the composition of the microbiome and understand
Emerging evidence suggests there is bidirectional communication between the gut microbiome and the brain.
its function and subsequent interaction with the body. 2 Compelling associations have been elucidated between shifts in the microbial composition, so-called dysbiosis, and a spectrum of conditions, including inflammatory bowel disease, irritable bowel syndrome( IBS), obesity, diabetes, cardiovascular diseases and Parkinson’ s disease, to name a few. 3-6
Moreover, emerging evidence suggests there is bidirectional communication between the gut microbiome and the brain, known as the gut – brain axis, influencing mental health disorders such as depression and anxiety; and functional disorders including IBS and fibromyalgia, and even neurodegenerative diseases such as Alzheimer’ s disease. 6, 7
What are the opportunities for intervention?
The widespread availability and accessibility of genome-wide sequencing in the early 2000s led to significant advances in the