What Gut Microbiome Is and Why It Matters

The gut microbiome is the community of trillions of microorganisms, mostly bacteria, that live in your digestive tract. These microbes help break down fiber, support the lining of your intestines, and interact with your immune system.

Your gut microbiome is shaped by how you were born, what you eat, the medicines you take, and where and how you live. Some of these factors you can influence, such as eating more fiber and avoiding unnecessary antibiotics.

What Is the Gut Microbiome?

The gut microbiome is the community of microorganisms living in your digestive tract, particularly your intestines. These microorganisms include:

• Bacteria
• Viruses
• Fungi
• Other microscopic life forms

Bacteria are the best-studied members of the gut microbiome, but they are not the only ones. The term gut microbiota refers to the microorganisms themselves, while gut microbiomes can also include their genetic material and surrounding environment.

Everyone has a unique gut microbiome. Its composition can change with age, diet, medication use, lifestyle, and environmental exposure.

Why Does the Gut Microbiome Matter?

Gut microbes help digest fiber, maintain the intestinal lining, shape immune responses, and limit the growth of harmful microbes. Some bacteria break down dietary fiber and complex carbohydrates that the body cannot digest on its own.

This produces short-chain fatty acids, including butyrate, which helps support the intestinal lining. The gut microbiome contributes to several important processes:

• Digestion and nutrient processing: Gut microbes help break down certain fibers and complex carbohydrates, allowing the body to benefit from components of food that would otherwise pass through the digestive system.
• Intestinal barrier support: Microbial products, including short-chain fatty acids, help maintain the intestinal lining.
• Immune function: Gut microorganisms interact with the immune system and help shape its responses.
• Protection against harmful microbes: A balanced microbial community can help limit the growth of certain disease-causing organisms.
• Metabolic health: Gut microbes influence how the body processes nutrients and produces compounds involved in metabolism.

A healthy gut microbiome does not mean having only beneficial bacteria. It means a diverse, functioning microbial community that works alongside the body.

Changes in the gut microbiome, often described as dysbiosis, have been associated with several health conditions, including some digestive disorders and metabolic diseases. However, an association does not necessarily mean that microbiome changes directly cause a condition, and scientists continue to study these relationships.

What Shapes Your Gut Microbiome?

Your gut microbiome is shaped from birth onward by how you were born and fed as a baby, your diet, the medicines you take, and where and how you live.

Birth and early life

Babies born vaginally and babies born by cesarean section start life with different gut microbes. Breastfeeding supports early microbial development, and the introduction of solid foods brings further changes as children grow.

Diet

Fiber-rich foods such as vegetables, fruits, legumes, and whole grains provide fuel for certain gut bacteria. Diets that are low in fiber provide less of this fuel.

Medicines

Antibiotics can temporarily reduce the number and variety of gut bacteria. Other medicines can also affect the microbiome, so take medication as prescribed and discuss any concerns with your doctor.

Where and how you live in Indonesia

Studies show that the gut microbiome differs between communities in Indonesia. A 2019 study comparing adults in Yogyakarta and Bali found differences in certain gut bacteria between the two groups, which the researchers suggested may reflect different lifestyles (World Journal of Gastroenterology).

A 2025 study of communities in Bali, Borneo, and New Guinea, not yet peer reviewed, found that gut microbes shift gradually from rural to urban lifestyles, and that differences in diet between communities strongly predicted microbiome composition (bioRxiv). Sanitation, food availability, and access to medicines may also play a part.

Fermented foods

Fermented foods such as tempeh and yogurt are part of many Indonesian diets. Yogurt with live cultures contains living microorganisms.

Tempeh is usually cooked before eating, which kills most of its microbes, but it remains a good source of fiber and protein. Not every fermented food has proven probiotic benefits.

These differences are why a single diet or probiotic recommendation may not suit everyone.

Probiotics and Prebiotics: What Is the Difference?

Probiotics are live microorganisms that may offer a health benefit when taken in adequate amounts. Prebiotics are types of fiber that feed beneficial gut bacteria, found in foods such as bananas, onions, garlic, and whole grains.

The evidence for probiotics depends on the specific strain and the condition being treated. Ask a healthcare professional before using them, especially if you have a weakened immune system or a serious illness.

How Can You Support a Healthy Gut Microbiome?

You do not need a microbiome test to begin supporting your digestive health. Practical habits include:

• Eat a varied diet with vegetables, fruits, legumes, and whole grains, and increase fiber intake gradually.
• Drink enough water and maintain regular physical activity.
• Include suitable fermented foods, such as yogurt or tempeh, as part of a balanced diet.
• Avoid taking antibiotics unless prescribed by a healthcare professional, because unnecessary use can disrupt microbial communities.
• Seek medical advice for persistent digestive symptoms rather than relying on supplements or restrictive diets without guidance.

There is no single microbiome profile that defines perfect health. Your needs may depend on your symptoms, medical history, diet, and other individual factors.

Get Professional Digestive Health Guidance at Bali International Hospital

If you experience persistent bloating, abdominal discomfort, diarrhea, constipation, or other ongoing digestive concerns, a healthcare professional can help assess possible causes and recommend appropriate care.

Explore the Gastroenterology Center at Bali International Hospital to learn more about digestive health services. Book an appointment with a healthcare professional to discuss your symptoms, or contact us to learn more about available services and the next steps for your care.

Frequently Asked Questions

What is the gut microbiome?

The gut microbiome is the community of microorganisms, including bacteria, viruses, and fungi, living in the digestive tract. These microbes interact with the body and contribute to digestion, immune function, and intestinal health.

What is the difference between probiotics and prebiotics?

Probiotics are live microorganisms that may offer a health benefit in adequate amounts. Prebiotics are fibers that feed beneficial gut bacteria.

The benefits of probiotics depend on the strain and the condition.

Why is the gut microbiome important?

The gut microbiome helps process certain foods, supports the intestinal lining, interacts with the immune system, and helps protect against some harmful microbes. Researchers are also investigating its relationship with metabolic and digestive conditions.

Where do the bacteria in the gut microbiome come from?

Gut bacteria are first acquired at birth and in early life, through the type of delivery, feeding, and contact with caregivers and the surrounding environment. Diet, household conditions, geography, medications, and lifestyle continue to shape the gut microbiome throughout life.