Today, with a dazzling array of probiotic products, lactobacilli and bifidobacteria are the two most frequently mentioned names. Many people know that they are good for the gut, but what is the actual difference between the two? What's unique about each? This article will explain it to you in detail.
1. Basic concepts: different scopes and different levels
Lactic Acid Bacteria (LAB) is a broad concept that refers to a class of bacteria that can use carbohydrates to ferment and produce large amounts of lactic acid. There are currently 18 genera and about 200 species of lactic acid bacteria known, including Lactococcus, Lactobacillus, Bacillus, Bifidobacterium, etc.
Bifidobacterium is a specific bacterial genus in the lactic acid bacteria family and one of the most representative bacterial genera among probiotics. To put it simply: all bifidobacteria are lactobacilli, but not all lactobacilli are bifidobacteria.
The conceptual scope of the two can be understood as follows: Lactobacillus (broadest range) ⊃ Probiotics (middle level) ⊃ Bifidobacterium (narrowest range).
2. Overview of core differences
Contrast Dimensions | Lactic acid bacteria | Bifidobacteria |
Classification | A common name for bacteria, including multiple genera | A specific genus of probiotics |
Cell morphology | Cocci or bacilli | A curved, bifurcated or rod-like rod |
Primary habitat | Milk, dairy products, fermented foods, human and animal intestines | Mainly found in the intestines of humans and animals, especially the colon |
Sensitivity to oxygen | Facultative anaerobic bacteria (can survive in an aerobic environment) | Obligate anaerobic bacteria (cannot survive in an aerobic environment) |
Main metabolites | Lactic acid | Lactic acid + acetic acid |
Amount in intestine | Relatively few | Hundreds of times more abundant than Lactobacilli in the colon |
3. Characteristics of Lactic Acid Bacteria
Lactobacilli are a type of bacteria that are extremely widely distributed. They can be found in nature from human food and animal feed to soil and even the natural environment.
Key features include:
Wide variety: Lactic acid bacteria include 18 genera and more than 200 species, divided into two categories: animal-derived lactic acid bacteria and plant-derived lactic acid bacteria.
Strong acid production ability: it can ferment carbohydrates and produce a large amount of lactic acid.
Wide adaptability: Strong acid resistance and can survive in a variety of environments.
Wide range of applications: often used in food fermentation, such as the production of yogurt, kimchi, miso and other fermented foods.
In terms of health effects, lactic acid bacteria can regulate the balance of intestinal flora, enhance the body's immunity, promote intestinal digestion and absorption, reduce intestinal pH, and improve the intestinal environment. Lactic acid bacteria can also secrete bacteriocins that inhibit pathogenic bacteria and produce antibacterial substances such as hydrogen peroxide.
4. Characteristics of Bifidobacteria
Bifidobacteria are one of the most important members of the intestinal flora of humans and animals and are considered to be bacteria that have adapted to the human intestinal environment.
Key features include:
Dominant intestinal flora: In the human gastrointestinal tract, especially the colon, the number of Bifidobacteria is hundreds of times that of Lactobacilli. The proportion can account for about 90% in the intestinal tract of infants, and gradually decreases to about 3% in the intestinal tract of adults.
Strictly Anaerobic: Very sensitive to oxygen and cannot survive in an oxygen-containing environment.
Unique metabolism: In addition to lactic acid, fermentation products also produce acetic acid, which is beneficial to human health.
Changes with age: The number of Bifidobacteria is highest in infancy, begins to decrease after weaning, remains relatively stable in adulthood, and decreases again in old age.
In terms of health effects, Bifidobacterium has many important physiological functions such as biological barrier, nutritional effect, immune enhancement, improvement of gastrointestinal function, and anti-aging. It can reduce the pH value of the intestinal environment to inhibit the growth of harmful bacteria and enhance the intestinal mucosal barrier function. In addition, Bifidobacterium can also synthesize beneficial substances such as vitamins and short-chain fatty acids, and affect the production of neurotransmitters and hormones through the "gut-brain axis", helping to alleviate psychological problems such as anxiety and depression.
5. How to choose and supplement
There are several points to note when taking daily supplements:
Do not take it together with antibiotics: antibiotics will kill harmful bacteria as well as good bacteria. It is recommended to wait 2-3 hours after taking probiotics before taking antibiotics.
Pay attention to the water temperature: It is best to control the water temperature at around 35-40 degrees when taking it. Excessive temperature will cause the activity of beneficial bacteria to disappear.
Pay attention to the storage conditions: Bifidobacteria are sensitive to temperature and generally need to be stored at low temperature; Lactobacilli are not heat-resistant and oxygen-resistant, so they should be consumed as soon as possible after opening.
Choose a suitable strain: Different strains have different effects. For example, Lactobacillus acidophilus can relieve lactose intolerance, and Bifidobacterium lactis can enhance the immune barrier. It is recommended to choose according to personal physique and needs under the guidance of professionals.
Conclusion
Although both lactic acid bacteria and bifidobacteria are beneficial to human health, there are obvious differences between them in terms of conceptual scope, classification, habitat, and metabolites. Lactobacillus is a large family of bacteria, and Bifidobacterium is an important member of this family that is particularly important in intestinal health. Understanding these differences can help us make more informed decisions when choosing probiotic products.
