What is a gut microbiome?

The gut microbiome is a community of trillions of microorganisms (also called microbiota or microbes) that live in your gastrointestinal tract. This complex group of microorganisms consists of bacteria, fungi, yeast, and viruses.

Microbes house the largest part of organisms in the body and weigh around 1-2 kg, which is roughly the weight of your brain. Together, these microbes function as an extra organ.

There are more bacterial cells in your body than human cells, and up to 1,000 different species of bacteria live in the gut. Most are crucial for your health, while others may lead to disease.

Your microbiome is partially shaped at birth by the maternal vaginal microbiota. From ages 3-5 years, the microbiome increases, diversifies, and transforms into adult-like microbiota. Each microbiome is unique like a fingerprint. Once your microbiome is established, the composition remains stable, but due to environmental and lifestyle-related factors, it can change and become damaged. 

How do microbes influence the digestive process?

The presence of saliva is influenced by the microbiome as you chew your food. Hydrochloric acid (HCL) is an important component of digestion and in part controlled by the microbiome. It is released once food travels down to the stomach and destroys most of the pathogens you consume. The microbes that escape the gastric acid move down to the intestinal tract. In a healthy gut, pathogenic (bad bacteria) and symbiotic (good bacteria) microbiota coexist without problems.  

Bile, pancreatic enzymes, and cellulase (an enzyme only made by microbes) are further produced to break down and assimilate food in the small intestine. Thereafter, food travels to the large intestine and ferments where microbes convert fiber into important compounds called short-chain fatty acids, which are essential for good gut health.

How does the microbiome impact your health?

The microbiome controls the immune system, central nervous system, digestion, hormone production, detoxification, and other bodily processes. During infancy, your microbiome helps develop your immune system, and once established, it helps maintain it. The microbiome has direct interactions with the body through its immunomodulatory properties. 80% of your  immune cells reside in your gut and the microbiome controls the functionality of your immune system by communicating with these cells.  The microbiome also produces small proteins called cytokines to help control the body’s inflammatory responses. Microbes help synthesize certain vitamins, enzymes, and hormones.

With that being said, an unhealthy gut microbiome can affect your overall health and lead to diseases.

How do you know if you have an unhealthy microbiome?

An imbalanced microbiome is known as dysbiosis. This occurs when pathogenic bacteria outweigh the good microbes in your gut. An overgrowth of bad bacteria causes chronic active inflammation that may lead to deficiencies, mental health disorders, or diseases. 

As the microbiome becomes damaged, it sends signals of danger to the body, increasing inflammation and is displayed as different symptoms.

Some common symptoms include:

• Constipation
• Diarrhea
• Bloating
• Gas
• Fatigue
• Acid reflux or heartburn
• Weight problems
• Mood and anxiety disorders
• Skin issues

How to improve your gut microbiome?

A diverse microbiome is good for your health and is impacted by the food that you eat. It is important to pay attention to your gastrointestinal symptoms, particularly when they seem to follow meals. Your symptoms may be an indicator that you require dietary changes to restore your gut.

Some ways to improve your gut microbiome include:

• Eat a variety of colorful fruits and vegetables (these are rich in polyphenols)
• Eat fiber-rich foods
• Avoid processed foods
• Reduce red meat consumption
• Eat fermented foods
• Reduce stress
• Maintain a regular eating schedule
• Consider probiotic and prebiotic supplements
• Avoid sugar and processed sweeteners

References:

https://www.hsph.harvard.edu/nutritionsource/microbiome/
https://www.healthline.com/nutrition/gut-microbiome-and-health#TOC_TITLE_HDR_3
https://health.clevelandclinic.org/gut-microbiome/