Gut bacteria: What are good and bad gut bacteria?

Gut bacteria: What are good and bad gut bacteria?

09 Dec 2021

The digestive tract, otherwise known as the gut, is one of the body’s most unique organs. Not only is it a system of interconnected body parts, but it’s home to an impressive number of microorganisms. The digestive tract is home to trillions of gut bacteria that are responsible for several digestion processes and contribute to overall digestive health. Together with other microorganisms like fungi and protozoa, gut bacteria make up a complex internal ecosystem that keeps the gut, and essentially you, healthy (1).

However, the digestive tract is home to both bad gut bacteria and good bad bacteria. The body has a natural way of keeping the delicate balance between good and bad gut bacteria in check, a function that you can strengthen by eating healthily and incorporating proper vitamin supplementation to boost gut health.

Let’s find out how gut bacteria plays a role in your overall well-being, and why it’s important for you to contribute to keeping the population of good gut bacteria at a healthy level.

What should I know about good gut bacteria and bad gut bacteria?

The digestive tract can be understood as an ecosystem that includes both good gut bacteria and bad gut bacteria. And while the idea of flushing out all bad gut bacteria might appeal to you, the reality is that our body systems and organs—digestive tract included—will never be a hundred percent free from harmful bacteria.

We simply get them from countless sources in the environment and they have several entryways to our bodies including our mouths and the food that enters them. Fortunately, our bodies and our digestive tract in particular have functions in place to protect us from any harmful effects of bad gut bacteria that are carried out naturally each day.

For the digestive tract in particular, what you consciously eat or drink has significant ramifications on the bacteria composition in your gut. If you make smart lifestyle choices, you can promote the growth of good gut bacteria and maintain a healthy balance in the digestive tract (2). On the other hand, by eating unhealthily, not adhering to a regular eating schedule, or by drinking beverages that strain digestive processes, you may unintentionally be aiding in the proliferation of bad gut bacteria.

Individuals that have well-balanced gut bacteria will report regular and comfortable bowel movements, as well as being free of common tummy-related issues like excessive flatulence, bloating, acid reflux episodes, constipation or diarrhea, or even cramping or general abdominal discomfort. If these are issues you experience often or for a prolonged period of time, you might be facing the possibility of having too much bad gut bacteria in your digestive tract. More so, good gut bacteria typically have an anti-inflammatory effect on the body, whilst bad gut bacteria can exert inflammatory effects that are usually associated with more serious diseases (2).

Another risk of an imbalance of gut bacteria is the harm that can be caused by  opportunistic or transitional bacteria. When the digestive system is healthy, these bacteria simply pass through, to be eliminated in waste without causing damage. However, when the system is compromised in any way such as when the balance between good and bad gut bacteria is disturbed, these opportunistic bacteria take advantage and cause adverse effects.

Gut bacteria

What are examples of good gut bacteria and bad gut bacteria?

Without the assistance of a trained professional, it may be difficult to identify what kinds of bacteria have the densest populations in your gut. You’ll need to undergo tests to find out and depend on your doctor’s interpretations of results for specifics. When you understand them in more detail, it’s useful to have basic knowledge on the kinds of good gut bacteria and bad gut bacteria so you can take initial steps towards improving gut health.

Examples of good gut bacteria


Bifidobacterium is a type of good gut bacteria that’s among the first microbes to multiply in the gastrointestinal tract (3). Bifidobacteria are known as probiotics or live microorganisms that contribute to the health of your digestive system. Studies suggest that bifidobacteria can ease symptoms of gastrointestinal disorders like diarrhoea, and prevent gastrointestinal infections (3). Together with prebiotics, bifidobacteria can potentially reduce the occurrence of cancerous cells in animal studies (3).

Due to its probiotic traits, bifidobacteria are incorporated as active ingredients in fermented foods like yoghurt and cheese. Ingestion of fermented milk products has been shown to alleviate constipation and promote bowel movement (3).


Lactobacilli or bacteria belonging to the lactobacillus genus is another type of good gut bacteria. They are one of the most widely used probiotics typically found in fermented products like yoghurt, cheese, pickles, and salami. The genus, which includes L. acidophilus, L. rhamnosus, L. bulgaricus, L. casei, and L. reuteri, play an important role in food fermentation (4).

Gut bacteria

Lactobacilli have the powerful ability to inhibit pathogens or disease-causing microorganisms. Specifically, they strengthen the barrier function of the gut wall epithelium against harmful toxins and pathogens (5). In animal studies and initial research, lactobacillus has been shown to prevent and treat gastrointestinal disorders, including antibiotic-associated diarrhea, inflammatory bowel disease, irritable bowel syndrome, and even colorectal cancer (5).

Examples of bad gut bacteria


Clostridia are anaerobic bacteria, which means they can survive even without oxygen. Clostridia are usually involved in several diseases and are largely classified as an opportunistic pathogen (6). The pathogenic clostridium species produce protein exotoxins, a soluble protein that plays a role in disease development. Some clostridia strains contribute to diarrhea, while others are linked to food poisoning and a severe type of gastrointestinal disorder that affects premature babies (6).

Staphylococcus aureus

Staphylococcus aureus is another opportunistic pathogen that causes disease in both humans and animals (7). It has gained a reputation for spreading infection and several strains have become resistant to antibiotics. It is believed that S. Aureus increases the risk of intestinal infection. In animal studies, S. aureus can cross the epithelial barrier protecting the intestines and spread to the lymph nodes (7).

What can I do to get rid of bad gut bacteria while increasing good gut bacteria at the same time?

You can kickstart this process by focusing on improving your diet. The health of the digestive tract is intertwined with the quality of the food and beverages we consume, so a better diet composed of more wholesome, and less processed, foods is the foundation for a gut with a healthy bacteria balance.

Gut bacteria

Begin by adding more fibrous foods to your diet. Prebiotic fibre that passes through the gastrointestinal tract promotes the growth of good gut bacteria and can also help suppress bad bacteria. You can also stock up on probiotics like yoghurt, cheese, and pickled or fermented foods (2). Try to limit your intake of alcohol to less than 4 drinks at a time or consume in moderation (8). They’re notorious for throwing off gut bacteria balance especially when consumed in excess, as they kill off good gut bacteria, thus increasing your chances of developing or acquiring stomach-related diseases (8).

If you’re looking to support your intake of nutrients through a healthy and well-rounded diet, you can consider supplements.

What supplements can I take to improve the presence of good gut bacteria?


Zinc is one of the 16 essential minerals that the body needs to function, playing a specific role in healthy digestion. Some studies have shown that zinc has anti-inflammatory properties, but more than that, it’s also great to take this supplement to prevent dietary deficiency.

At Vitable, our zinc supplement is coupled with copper for optimal mineral balance. Taking zinc or copper alone has the potential to cancel out each other’s health-boosting effects, making a supplement formula that includes appropriate amounts of both minerals the more effective option. Our single-dose formula of this supplement can support healthy digestive system function.

Probiotics SB

Vitable’s Probiotic SB is a premium blend of three strains of good gut bacteria that’s formulated to support digestive function, especially during and after antibiotic use. Probiotics can restore good bacteria that may have been depleted due to antibiotic intake, as well as support the growth of friendly intestinal flora and efficient digestive system function in relation to this. Those who suffer from bouts of traveller’s diarrhoea or irritable bowel syndrome (IBS), or experience discomfort when using the toilet, can also benefit from this supplement. Vitable Australia’s Probiotic supplement contains Saccharomyces Boulaardi, a strain that may relieve symptoms of inflammatory conditions.

Daily probiotics

Vitable’s Daily Probiotics contains Bifidobacterium lactis, Lactobacillus acidophilus, and Lactobacillus rhamnosus which work together to support normal and healthy functioning of the digestive system. It’s also specially formulated to relieve digestive discomfort like flatulence and bloating, support healthy digestion, and maintain gastrointestinal health.


Curcumin is an active component of turmeric and gives the spice its yellow colour. But more than adding colour, curcumin has powerful anti-inflammatory properties that block or prevent inflammation through various molecular mechanisms, a benefit that people with stomach-related issues can take advantage of. In general, curcumin supports health digestion and digestive system health, two components that relate to having a healthy population of good gut bacteria in the digestive tract.

At Vitable, our curcumin supplement is blended with black pepper to enhance absorption by the body. It keeps the digestive system working optimally and supports healthy liver functioning.

If you’re looking for custom vitamin packs in Australia, Vitable has you covered. We offer a range of custom vitamin packs containing zinc, probiotics, and curcumin to support a healthy digestive system. You can mix and match multivitamin packs depending on your needs and health goals. If you’re worried about vitamin delivery, we got that covered, too!

Find out more about other areas that the above supplements can help you with:

Zinc | Probiotics SB | Daily probiotics | Curcumin

*Always read the label. Follow the directions for use. If symptoms persist, talk to your health professional. Vitamin and/or mineral supplements should not replace a balanced diet.


  1. National Institutes of Health. (2013). Gut Bacteria in Health and Disease. Accessed October 24, 2021
  2. Queensland Health. The Gut Microbiome - My Amazing Body. Accessed October 24, 2021
  3. National Institutes of Health. (2016). Bifidobacteria and Their Role as Members of the Human Gut Microbiota. Accessed October 24, 2021
  4. National Institutes of Health. (2008). Ecological Role of Lactobacilli in the Gastrointestinal Tract: Implications for Fundamental and Biomedical Research. Accessed October 24, 2021
  5. National Institutes of Health. (2008). Genes and Molecules of Lactobacilli Supporting Probiotic Action. Accessed October 24, 2021
  6. National Institutes of Health. Chapter 18: Clostridia: Sporeforming Anaerobic Bacilli. Accessed October 24, 2021
  7. National Institutes of Health. (2011). The Influence of Staphylococcus aureus on Gut Microbial Ecology in an In Vitro Continuous Culture Human Colonic Model System. Accessed October 24, 2021
  8. Government of Western Australia. Alcohol and the Digestive System. Accessed November 24, 2021