Lactobacillus bulgaricus and Streptococcus thermophilus are two probiotic strains of bacteria that are frequently combined in yogurt starter cultures.
In dairy products, Lactobacillus bulgaricus produces amino acids from milk proteins that are used by S. thermophilus. Streptococcus thermophilus is also used in mozzarella cheese production and combined with other foods to help preserve it and add nutritional value.
Streptococcus thermophilus breaks down lactose that makes it easier to digest for lactose intolerant individuals. Both of these bacteria also produce lactic acid, helping to maintain an acidic environment in the gut, which prevents the growth of bad bacteria.
As probiotic supplements, these bacterial microorganisms are used to support digestive health as well as immune function. Lactobacillus bulgaricus produces bacteriocins, which have been shown in laboratory studied to kill pathogenic bacteria.
Clinical studies have shown Streptococcus thermophilus improves liver enzymes in nonalcoholic fatty liver disease, helps prevent BV (Bacterial Vaginosis) and helps to prevent URI’s (Upper Respiratory Infections).
Gut Health
Digestion
Immune Function- Supports a healthy immune system & microflora
- Promotes digestion & nutrient absoprtion
- Combats pathogenic bacteria; Improves metabolism
Lactobacillus Bulgaricus and Streptococcus Thermophilus
Related Topics
- What are Probiotics?
- Probiotic Benefits
- Best Probiotic Strains
- Probiotic Side Effects
- Probiotic Supplements
- Probiotic Foods
- Best Probiotic Yogurt
- Probiotics for Children
- Probiotics for Women
- Yeast Infections
- What are Prebotics?
- Lactobacillus Acidophilus
- Lactobacillus Bulgaricus
- Lactobacillus Rhamnosus
- Bifidobacterium Bifidum
- Bifidobacterium Infantis
- Bifidus Regularis
Lactobacillus bulgaricus is a probiotic bacterium that was first identified in 1905 by Dr. Stamen Grigorov of Bulgaria. It has now been reclassified as Lactobacillus delbrueckii subsp. Bulgaricus.
Streptococcus thermophilus is a probiotic organism from the Streptococcus family of bacteria, which does include certain pathogenic bacteria. However, S. thermophilus is known to have a positive effect on health and to aid in lactose digestion.
Lactobacillus bulgaricus was known to the Thracians who lived in present day Bulgaria more than 8 thousand years ago. Yogurt means hard, solid milk in Thracian.
In the early 1900’s, Russian scientist and Nobel prize winner Ilya Metchnikoff studied the health-boosting effects of yogurt with Lactobacillus bulgaricus and Streptococcus thermophilus.
This yogurt formed a large part of the Bulgarian diet and was said to be the reason why people in this region lived longer and healthier lives. It was from this research that probiotic bacteria were first identified.
Benefits of L. Bulgaricus and S. Thermophilus
Metchnikoff hypothesized that Bulgarians lived longer because of the beneficial bacterial organisms present in the yogurt they consumed. He believed that aging was the result of harmful bacteria in the gut breaking down proteins and producing toxins.
Harmful bacteria, such as clostridia, were believed to produce toxins like ammonia when they broke down proteins in foods that we consumed. This process was said to result in intestinal auto-intoxication.
Metchnikoff believed that the good bacteria (like Lactobacillus bulgaricus and Streptococcus thermophilus) could combat this process and thereby fight aging. Because both of these species produce lactic acid in the gut, they help to prevent the growth of toxin-producing bacteria that can speed up the aging process.
While Metchnikoff’s theory is not quite accurate, the belief that good bacteria can fight the growth of bad bacteria and promote health, is accurate.
Today, we know that the gut microflora is made up of approximately 400 different species of bacteria. It is important to keep the right balance of probiotic bacteria to pathogenic bacteria, both for digestive function and for immunity and general wellness.
Top Probiotic Supplements
Effects of L. Bulgaricus and S. Thermophilus
Research has explored the probiotic effects of combining Lactobacillus bulgaricus and Streptococcus thermophilus. These strains are believed to improve symptoms of diarrhea, digestive conditions like IBS, improve resistance to colds and to enhance the immune response.
A clinical study published in the Korean Journal for Food Science of Animal Resources in August 2015 showed that of the ten LAB (Lactic Acid Bacteria) extracts studied, four (L. acidophilus, L. bulgaricus, L. casei, and S. thermophilus) promoted both cell proliferating and TH1 (immunity effectors against intracellular bacteria and protozoa) cytokine production.
The clinical study concluded these probiotics could be used to maintain immunity and homeostasis for astronauts in extreme space environment as well as people in normal life. Homeostasis is the maintenance of stability of the human body’s internal environment in response to changes in external conditions.
A clinical study published in the International Journal of Food Microbiology in October 2015 showed the ability of anaerobic solid fermentation of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus to biotransform aflatoxins (poisonous and cancer-causing chemicals that are produced by certain molds) in peanut meal.
Children are the worst affected by aflatoxin exposure. It can lead to stunted growth and delayed development as well as liver damage and liver cancer. Adults have more immunity and the aflatoxins may be metabolized by the liver to become the less harmful aflatoxin M1.
- 5 billion live probiotic cultures per capsules
- Balanced blend of Acidophilus and Bifidobacterium
- Supports a healthy immune system & intestinal flora
How to Make Yogurt
Lactobacillus bulgaricus and Streptococcus thermophilus are commonly used as a starter culture to produce Bulgarian yogurt. To make this recipe, you will need 2 liters (half a gallon) of milk and ¼ teaspoon of a yogurt start.
- Bring milk to a gentle boil (212°F, 100°C) to kill any existing bacteria. Be careful not to burn or overheat the milk.
- Cool the milk to 110°F (43°C). Move milk to another processing container. Add ¼ tsp of starter and mix well for five minutes.
- Cover the container loosely with a lid and wrap it well. Allow the mixture to sit still for several hours.
- The fermentation process will continue until the milk reaches a pH of 4.7. Fresh yogurt will set in about 5 to 6 hours. If the temperature is too cool (50°F or less) the process will take 10-12 hours. The yogurt will be denser and more acidic if left to sit after it has set.
- When the yogurt is ready, then move it to a fridge or cool place for storage.
- The remaining yogurt starter can be placed in a Ziploc bag and stored in the freezer.
Safety Warning
Probiotic supplements are not appropriate for all individuals to use. Some people are warned against taking probiotics like Lactobacillus bulgaricus and Streptococcus thermophilus due to the potential risk for bacterial transmigration.
These supplements should not be used by anyone with a compromised immune system, those with open surgical wounds or those using a catheter. If you have been diagnosed with SBS (Short Bowel Syndrome), you should not take L. bulgaricus or S. thermophilus.
em>Lactobacillus bulgaricus and Streptococcus thermophilus probiotic bacteria have been used as a yogurt starter for thousands of years. Research is now looking into the health benefits of these organisms for digestion and immunity.
- Hwang EN, Screening of Immune-Active Lactic Acid Bacteria. Korean J Food Sci Anim Resour 2015;35(4):541-50. doi: 10.5851/kosfa.2015.35.4.541. Epub 2015 Aug 31.
- Chen Y, Biotransformation of aflatoxin B1 and aflatoxin G1 in peanut meal by anaerobic solid fermentation of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus. Int J Food Microbiol 2015 Oct 15;211:1-5. doi: 10.1016/j.ijfoodmicro.2015.06.021. Epub 2015 Jun 26.
- Vargas LA, Whey protein isolate improves acid and bile tolerances of Streptococcus thermophilus ST-M5 and Lactobacillus delbrueckii ssp. bulgaricus LB-12. J Dairy Sci 2015 Apr;98(4):2215-21. doi: 10.3168/jds.2014-8869. Epub 2015 Jan 23.
- Gezginc Y, Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC. J Dairy Sci 2015 Mar;98(3):1426-34. doi: 10.3168/jds.2014-8447. Epub 2014 Dec 26.
- Anbukkarasi K Preparation of low galactose yogurt using cultures of Gal(+) Streptococcus thermophilus in combination with Lactobacillus delbrueckii ssp. bulgaricus. J Food Sci Technol 2014 Sep;51(9):2183-9. doi: 10.1007/s13197-014-1262-5. Epub 2014 Feb 2.
- Gandhi A, Cell growth and proteolytic activity of Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, and Streptococcus thermophilus in milk as affected by supplementation with peptide fractions. Int J Food Sci Nutr 2014 Dec;65(8):937-41. doi: 10.3109/09637486.2014.945154. Epub 2014 Aug 6.
