Gut microbiota: everything you need to know

Written by: Dr Ravi Misra
Edited by: Aoife Maguire

Dr Misra studied the impact of the gut microbiome on gut inflammation during his PhD at Imperial College. He is currently studying how diet can predispose to inflammatory bowel disease.


He explains everything you need to know about gut microbiota, including its relationship with diet, medication and exercise.



What is microbiome?


The microbiome refers to a collection of microorganisms found in various environments, not limited to the gut as commonly believed. It thrives in soil, on the skin, and elsewhere. Basically, it refers to any place where microorganisms co-exist. The microbiota, on the other hand, refers to a specific community of microorganisms, often identified by its location, such as gut microbiota. This isn't solely comprised of bacteria; it also includes viruses and fungi, all integral parts of the microbial community


How important is gut microbiota?


Recent advances in next generation sequencing on the gut microbiota has unveiled profound insights, marking one of the most significant advancements in our understanding of its importance and its impact on our health. With approximately 3 billion bacteria and nearly 4 million bacterial genes residing in our gut, the complexity of this ecosystem surpasses that of our entire body's 23,000 genes. This complexity underscores the intricate relationship between us and our gut microbiota.


The byproducts produced by gut bacteria can have a significant impact on overall health, extending beyond just the digestive system, also to psychological well-being, as demonstrated by studies linking them to conditions like depression, alongside more immediate diseases such as asthma and diabetes.


How complex is gut microbiota?


Billions of bacteria in our bodies interact and undergo chemical reactions constantly, producing millions of metabolites. However, controlling this complex system is challenging due to the vast variation between individuals. Each person's gut microbiota is unique, making it difficult to predict outcomes. While products like probiotics and certain foods can influence the microbiota, responses vary widely.


We understand factors like diet, exercise, and stress affect the microbiota, but achieving complete control remains elusive. Research in this area is ongoing, aiming to deepen our understanding and eventually gain more control over our gut microbiota.


Diet and gut microbiota


Several studies indicate that diets high in saturated and animal fats elevate the risk of cancer and inflammatory diseases, while diets rich in fruits, vegetables, and fibre offer protection. A diet abundant in fruits and fibre promotes a healthy gut microbiota, reducing inflammation, whereas foods high in animal fats and sugars can induce inflammation. This signifies that adopting a plant-based or Mediterranean diet can be beneficial, as they have been linked to reduced frailty and improved cognition in the elderly. It's essential to prioritise fresh, unprocessed foods and avoid artificial sweeteners and emulsifiers, such as Diet Coke and Coke Zero have been shown to contribute to gut inflammation in mouse models.


Medication and gut microbiota


Antibiotics have a profound impact on our gut bacteria, often disrupting the balance and potentially leading to conditions like Clostridium difficile infection, characterised by severe diarrhoea. Overuse of antibiotics, especially in children, has been associated with an increased risk of immune-related conditions like inflammatory bowel disease and asthma. Therefore, it's crucial to use antibiotics judiciously to minimise these risks and preserve gut health.


Exercise and gut microbiota


Research suggests that exercise can positively impact gut microbiota diversity, reducing the risk of inflammatory responses. A study on a physically active rugby team demonstrated significantly diverse gut microbiota. While diet plays a primary role in influencing gut health, environmental factors such as pollutants may also have an effect, though this area requires further investigation. However, due to the complexity and individual variation in gut microbiota, there are currently no accurate commercial tests available for assessing and manipulating gut microbiota.


While some tests are accessible online, they are limited in scope and effectiveness, and there is no recommended test for accurately defining and modifying gut microbiota. Therefore, testing and manipulating gut microbiota remain areas of ongoing research without readily available solutions.




If you would like to book a consultation with Dr Misra, simply visit his Top Doctors profile today

By Dr Ravi Misra

Dr Ravi Misra is a highly trained consultant gastroenterologist based at St Mark's Hospital; an internationally recognized hospital in London.

His areas of expertise include the diagnosis and management of irritable bowel syndrome (IBS), bloating, reflux, bowel cancer, inflammatory bowel disease (IBD) and abdominal pain. He is an expert in colonoscopy and gastroscopy.

He qualified from Imperial College London in 2005 and undertook specialist training in the North West Thames London rotation. He has completed a fellowship in advanced endoscopy at St Mark’s Hospital and is skilled at diagnostic and therapeutic endoscopy. He took time out of his training to pursue a PhD on the impact of ethnicity on epidemiology, metabolic and microbial profiling.

Dr Misra devotes his career to research as well as highly professional and personalised patient care. He has collaborated with the Centre for Digestive Health at Imperial College to study how the microbiome changes in IBD. Furthermore, he has an interest in the impact of diet in newly diagnosed patients with IBD. His research has provided the opportunity to present at international conferences and publish articles in renowned peer-reviewed journals. 

View Profile

Overall assessment of their patients

  • Related procedures
  • Nutrition
    Food intolerance test
    Eating disorders
    Balloon enteroscopy
    pH monitoring
    Stomach reduction
    Gastric balloon
    Colon cleanse
    This website uses our own and third-party Cookies to compile information with the aim of improving our services, to show you advertising related to your preferences as well analysing your browsing habits. You can change your settings HERE.