DR. ISLAM: Gut bacteria explained by a GI doctor

By Dr. Rafiul Sameer Islam

Did you know that tiny bacteria can have a significant effect on your digestive health?

Your gut bacteria play an essential role in health and disease. Improving the composition of your gut bacteria may be the answer to unlocking better overall health.

This article will discuss what gut bacteria are and how they can contribute to the development of certain diseases. We’ll highlight how you can take control of your health and develop a healthier gut microbiome naturally. We’ll also explore the connection between the gut microbiome and your brain. Lastly, we’ll touch on when you should see a GI doctor for gut issues.

What Are Gut Bacteria?

Gut bacteria are microscopic organisms that live inside your colon. Over one thousand different species of bacteria exist. But each gut microbiome contains only around 160 species. This means that the composition of the microbiome differs greatly from person to person.

Besides bacteria, your gut microbiome also contains fungi and viruses. Together, these microorganisms number into the trillions.

Some species of bacteria are good for your health, while others can be harmful. A healthy colon maintains a balance between beneficial and pathogenic bacteria.

Generally, the following types of bacteria are good for your health:

  • Bifidobacteria
  • Lactobacilli
  • Lactococci
  • Streptococci
  • Bacillus
  • Escherichia
  • Propionibacterium

Beneficial bacteria break down the fiber in the colon and synthesize vitamins and short-chain fatty acids (SCFAs). SCFAs regulate a variety of functions, including:

  • Immune function
  • Metabolism
  • Hormonal function
  • Brain function

Gut Bacteria and Digestive Diseases

The composition of the gut bacteria can change based on factors such as environment, diet, and genetics. Diseases can manifest when the gut microbiome loses beneficial bacteria, experiences an increase in pathogenic bacteria, or becomes less diverse.

Your immune system becomes weaker when your gut microbiome is out of balance. Abnormal immune responses can cause inflammation in the gastrointestinal tract, leading to the development of certain diseases.

Research shows that many diseases are associated with changes in the gut microbiome. These diseases include:

  • Colon Cancer
  • Inflammatory bowel disease (IBD)
  • Alcoholic and nonalcoholic fatty liver diseases
  • Obesity
  • Type 2 diabetes

New research from Harvard Medical School and Joslin Diabetes suggests that groups of bacterial genes, or genetic signatures, may predict disease risk. The study linked sets of bacterial genes to the following diseases:

  • Coronary artery disease (CAD)
  • Cirrhosis of the liver
  • IBD
  • Colon cancer
  • Type 2 diabetes

Interestingly, researchers found that CAD, IBD, and liver cirrhosis share many of the same bacterial genes. This means that people who have these genes may be more likely to develop these conditions.

How to Develop a Healthier Gut Microbiome

Logic would suggest that adding more beneficial bacteria, or probiotics, to our bodies would translate to a healthier gut microbiome. Unfortunately, that logic doesn’t usually work. This is because the composition of your gut microbiome is unique, so you may not need the same strains of bacteria that someone else does.

Luckily, there are other ways to enhance the current makeup of your gut microbiome. Keep reading to learn how you can help promote a healthy gut microbiome naturally.

Eat a Plant-Based Diet

Eating a plant-based diet can increase your intake of prebiotic fiber. Prebiotic fiber acts as food for the beneficial bacteria in the gut. This results in the production of SCFAs, including acetate, propionate, and butyrate. These SCFAs can maintain intestinal barrier integrity, reduce inflammation, and protect against colon cancer.

Good sources of prebiotic fiber include:

  • Jerusalem artichokes
  • Chicory root
  • Raw dandelion greens
  • Leeks
  • Onions
  • Garlic
  • Asparagus
  • Whole wheat
  • Spinach
  • Beans
  • Bananas
  • Oats
  • Soybeans

Limiting your intake of animal products such as red meat and high-fat dairy products can also enhance your gut microbiome. This is because animal products can increase the growth of harmful bacteria linked to chronic disease.

Practice Regular Exercise

Besides improving your quality of life, regular exercise can also help keep your bowel movements regular.

Research shows that exercise can improve the biodiversity of the microbiome and increase the number of beneficial bacteria. But long-term benefits to the gut microbiome only occur if the activity is maintained. Refraining from exercise for a period of time can reduce digestive function and slow down intestinal motility.

When exercising, it’s best to do so at a comfortable level. Strenuous exercise can produce a stress response that releases cortisol and epinephrine and reduces blood supply to the colon cells. This can damage the gut barrier, promote inflammation, and increase intestinal permeability.

Reduce Stress Levels

Managing your stress can go a long way towards boosting your digestive health. Like physical stress, emotional stress can cause inflammation in the gut and reduce the diversity of gut bacteria.

Finding healthy outlets for your stress, such as meditation, yoga, or journaling, can improve the health of your gut microbiome.

We’ll talk more about the connection between stress and the gut microbiome below.

The Brain-Gut Connection

The gut microbiome interacts with all human cells, including the brain. The vagus nerve, one of the 12 cranial nerves, travels from the brain to the gut. This allows for bidirectional communication between the brain and gut bacteria.

The brain-gut connection can influence the development of gastrointestinal and psychiatric disorders such as IBD, depression, and posttraumatic stress disorder (PTSD).

Interestingly, one recent study demonstrated the connection between the brain and gut using vagus nerve stimulation via Sudarshan Kriya Yoga (SKY). SKY is a yogic technique that incorporates deep breathing. Researchers found that practicing SKY can improve both cognition and bowel function. They also discovered that people with depression who did not respond to antidepressants experienced reduced depressive and anxiety symptoms after practicing SKY for 8 weeks.

As you can see, the health of your gut microbiome can affect much more than just your digestive system.

When to See a GI Doctor for Gut Issues

Sometimes, you may need a little more help than natural gut hacks to improve your digestion. If you experience new or worsening symptoms that don’t resolve on their own, you should see a gastroenterologist.

Gastroenterologists specialize in diagnosing and treating conditions of the gastrointestinal tract, liver, gallbladder, and pancreas. We can find the root cause of common gut issues such as abdominal pain, constipation, diarrhea, and bloating.

Often, changing the composition of your gut microbiome can benefit your condition. At Lubbock Gastroenterology, we give you the help you need to improve your health from the inside out.

If you live in Lubbock, TX, and want to find relief from digestive symptoms, you can schedule an appointment with your healthcare provider.

Sameer Islam, MD is a board-certified Gastroenterologist and Hepatologist practicing at Luin Lubbock, Texas. For an appointment feel free to contact his office at (806)-761-0747. You can get more information from his webpage (www.sameerislam.com) where you can also subscribe to his monthly newsletter. He also has a weekly Facebook Live show on Monday, 8:00 PM CST