Lactobacillus

Written by: danieldd
Published February 21, 2023

What is Lactobacillus

When patients show me a bottle of probiotics at the pharmacy counter, pretty much nine times out of ten it’s going to have some strain of Lactobacillus as one of the active cultures. Patients want to know if it’s a good probiotic, and what it will help them with. I’ve answered this question enough times – and read a lot of research on the topic – to have some awesome knowledge to share. So let’s dive in!

Lactobacillus is a type of probiotic bacteria that is often found in fermented foods, and sometimes added to dietary supplements. Lactobacillus is a type of bacteria that may have potential health benefits – for some folks. Some doctors and scientific studies have suggested that some of these possible benefits include improving gut health, boosting the immune system, preventing and treating diarrhea, helping with lactose intolerance, decreasing symptoms of atopic eczema, and potentially helping with weight management. Lactobacillus includes many different species and each one has unique properties.


Like most probiotics, not every particular probiotic species will help every individual. So even though there may be some health benefits for some people, not everyone will find that their particular health issues will improve when this particular probiotic is taken.


And remember, if you are having serious health issues, make sure to see your primary care physician.

What is the Lactobacillus probiotic used for?

Some potential benefits of Lactobacillus are:
-Possible improvement of digestive and gut health by balancing the gut microbiome and decreasing inflammation.
-May help boost and stimulate the immune system which may help lessen the possibility of infections.
-Preventing and treating diarrhea.
-May assist with lactose tolerance by helping to break down lactose.
-Some studies have shown that certain strains of Lactobacillius can help with decreasing symptoms of atopic eczema.
-Some studies have also shown that Lactobacillus can help with weight management by decreasing body fat and enhancing glucose metabolism.

What are the most important species of Lactobacillus?

Lactobacillus includes many different species, some of the most commonly found species in probiotic products are:

  • Lactobacillus acidophilus: Commonly found in the human gut and frequently used in probiotic supplements.
  • Lactobacillus rhamnosus: exists in the human gut and is often used in probiotic products to help with digestive matters and improve the immune system.
  • Lactobacillus plantarum: found in the human gut, in fermented foods, and is used in probiotic supplements to improve gut health and boost the immune system.
  • Lactobacillus reuteri: this species is found in the human gut and is used in probiotics to improve gut health and improve the immune system.
  • Lactobacillus paracasei: found in the human gut, in fermented foods, and is used in pr20iotic supplements to improve gut health and boost the immune system.
  • Lactobacillus fermentum: this species is found in the human gut and the vagina and is used in probiotics to improve gut health and improve the immune system.
  • Lactobacillus casei: this species is found in fermented foods and used in probiotic supplements to increase gut health and enhance the immune system.

Where is it found?

Beyond fermented foods, in healthy people, Lactobacillus is naturally found in the digestive tract, such as the intestines and colon, and it’s also found in the vagina in women, and it’s important for maintaining a healthy balance of bacteria in these areas.If you don’t have enough lactobacillus in your gut, it can cause an imbalance in the gut microbiome, leading to various health problems. This imbalance can lead to:

  • Digestive issues: Lactobacillus helps to break down food and keep the digestive system healthy, so a lack of lactobacillus can cause digestive issues like bloating, constipation, and diarrhea.
  • Increased inflammation: Lactobacillus helps to reduce inflammation in the gut, so a lack of it can lead to increased inflammation, which can contribute to a range of health problems.
  • Weakened immune system: Lactobacillus plays a role in boosting the immune system, so a lack of it can weaken the immune system and make you more susceptible to infections and illnesses.

Lactobacillus and women

Lactobacillus is a type of bacteria that is naturally present in the vagina of healthy women. In fact, scientific studies have established that “The vaginal microbiota of reproductive age healthy women is dominated by lactobacilli, which play an essential protecting role against genitourinary pathogens.” It plays a crucial role in maintaining a healthy vaginal environment by producing lactic acid and other compounds that help keep the pH levels (pH levels are the levels of acidity) in the vagina at a healthy and balanced level. (Note for non-medical people, “genitourinary means related to the genital and urinary organs.)

Having the right balance of lactobacillus in the vagina matters! It can help prevent and treat infections by controlling the growth of harmful bacteria and yeast – the right level of pH balance is important, and this bacteria helps maintain it. A healthy balance of lactobacillus can also help keep the vaginal area moist and prevent itching and burning.

On the other hand, if there is an imbalance in the lactobacillus levels, it can increase the risk of vaginal infections such as bacterial vaginosis and yeast infections. A decrease in lactobacillus levels can also be caused by various factors such as antibiotics, hormonal changes, and stress.

Maintaining a healthy balance of lactobacillus in the vagina is important for women’s overall reproductive and sexual health. This can be achieved through good hygiene practices, a healthy diet, and avoiding things that can mess up the balance of bacteria in the vagina, such as douching and using harsh soaps.

Why is Lactobacillus often in fermented foods?

Lactobacillus is a type of bacteria that is commonly found in fermented foods because it plays a key role in the fermentation process. During fermentation, lactobacillus eats sugars in the food and produces lactic acid – something that is (kind of strangely, tbh) good for many foods for several reasons. First of all, lactic acid helps preserve some foods. It’s also sour and gives many foods their characteristic sour flavor (think yogurt’s tang or buttermilk). The lactic acid also creates an acidic environment that discourages the growth of harmful bacteria, making fermented foods a safer and more shelf-stable option.

What foods contain Lactobacillus?

Not every product on this list will 100% contain Lactobacillus, but many popular foods such as the following contain some species of this helpful probiotic:

Yogurt
Sauerkraut
Kimchi
Pickles
Kefir
Sourdough bread (in the dough – it gets cooked out!)
Buttermilk
Cheese (e.g., sour cream, cottage cheese, and some types of soft cheese)
Tempeh
Miso

If you are trying to get the benefits of a probiotic from the foods listed above (or really, any probiotic containing edible thing, you have to be careful not to kill the probiotic when you cook or store it! You can also find this popular bacteria in foods that have been supplemented, like Goodbelly probiotic juice. It contains L. plantarum, and you can read my Goodbelly probiotic juice review – it’s actually pretty tasty.

Here’s how:

Avoid overheating: High temperatures can kill the beneficial bacteria, so it’s important to heat them gently and make sure you don’t boil them!! If you’re cooking with fermented foods, consider adding them towards the end of the cooking process, or simply using them as a topping or garnish. Totally easy with stuff like pickles, but for items like miso, pay attention to the proper directions on how to cook them to avoid killing your probiotics.
Store properly: Most fermented foods should be stored in the refrigerator to slow down the growth of bacteria, preserve shelf life and to maintain their probiotic properties. Make sure the containers are sealed tight to prevent air from getting in and to protect the bacteria from oxygen.
Don’t mix with other “deadly” ingredients: If you’re using fermented foods in a recipe, avoid mixing them with other ingredients that could have high acidity or be high in salt, as this can also kill the bacteria.
Be mindful of re-heating: If you’re reheating fermented foods, be careful not to overheat them, as this can kill the bacteria. Reheat them gently, either in a saucepan on low heat, or in the microwave on a low power setting.

By following these steps, you can help keep the good bacteria in fermented foods alive and get the health benefits of probiotics.

Lactobacillus FAQ

How is Lactobacillus made?

Lactobacillus bacteria consume sugar through a process called cellular respiration. In the case of lactobacillus, the sugar that is used is pretty much almost always lactose, and the end product of this metabolic process is lactic acid. The process is called the glycolysis pathway (side note, glycolysis is a cool word from the Greek words “glykys,” meaning sweet, and “lysis,” meaning breaking apart). The glycolysis pathway can be represented by the following equation:

C6H12O6 + 2 NAD+ + 2 ADP -> 2 CH3COCOO- + 2 NADH + 2 ATP + 2 H2O

In this equation, “C6H12O6” is the sugar molecule (again, it’s usually lactose), “NAD+” and “NADH” represent the coenzymes involved in the reaction, “ADP” represents adenosine diphosphate, “CH3COCOO-“ represents lactic acid, “ATP” represents adenosine triphosphate (the energy produced), and “H2O” is good, old water.

During glycolysis, the sugar molecule is broken down into smaller compounds, releasing energy in the form of ATP and producing lactic acid as a byproduct. The ATP produced in this process can be used by the bacteria for energy, while the lactic acid contributes to the sour flavor and preservation of fermented foods like yogurt. (Interested in how many probiotics are in yogurt? Read more here.)

The lactic acid lowers the pH of the fermented food, creating an environment that is inhospitable to harmful bacteria, preserving the food and contributing to its sour flavor.

What are good ways to get this bacteria as a supplement?

One of the most available brands, that you can probably find in pretty much any pharmacy or at Target or Walmart, is Culturelle. They are a well-respected manufacturer, and are usually available at a decent price. You can read about them in my review of Florastor vs Culturelle.

Where does the name Lactobacillus come from?

Like many scientific words, “Lactobacillus” comes from Latin. The word is a combination of two Latin words, “lacto,” which means milk, and “bacillus,” which means rod. This type of bacteria is called lactobacillus because it ferments lactose (milk sugar) into lactic acid, and it has a rod-like shape.

Pretty easy – if you speak Latin. (Pretty sure Latin isn’t really spoken much outside of a few churches, boarding schools and medical classrooms…)

Many bacteria names come from old languages like Latin and Greek, and the names are chosen based on the characteristics and behavior of the bacteria. The shape of bacteria is important in microbiology, as it can influence their behavior, growth, and metabolic processes. By naming bacteria based on their shape and behavior, microbiologists can study them better and learn more about their unique properties.

So, the name “lactobacillus” tells us that this is a rod-shaped bacteria that ferments lactose into lactic acid. And many bacteria names are chosen based on their shape and behavior to help us study them better and learn more about their unique properties.

Pharmacist Kari Raman

I’m Kari Raman PharmD, RPh, and I am a licensed, practicing pharmacist. I hold a Doctorate in Pharmacy from The University of the Pacific, and I’ve served patients in retail, compounding and hospital pharmacies.

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I hope Pharmacist Probiotics helps you find out if there is a type of probiotic that works for you!