Probiotic strains that support intestinal microflora balance in children


The intestinal microflora is of particular importance to the human body, helping to support digestion, regulate immunity, protect the intestinal mucosa, etc. But without proper and sufficient care to balance the intestinal microflora, this will be the main cause of dangerous diseases such as diarrhea, stomach cancer,…1

Especially for young children, balancing the intestinal microflora helps build a strong “stronghold”, protecting the body against the risks of disease caused by impacts from the external environment.

The importance of the intestinal microbiota

The human body’s intestinal microflora is formed in the early stages of life, possessing an estimated 1000 – 1150 different bacterial species, including beneficial microorganisms (85%) and pathogenic bacteria (15%). The components of the intestinal microflora change with each stage of development of the infant (related to pregnancy days, method of birth, breastfeeding method, weaning period,…) and other external factors such as antibiotic use3.

Up to now, only 8 bacterial phyla have been found in the human intestinal system, of which the most dominant are the Gram-negative bacterial phylum Bacteroidetes and the Gram-positive bacterial phylum Firmicutes, which may represent more than 90% of microbial groups in the human intestine4. However, no single intestinal microbiota composition is considered optimal because each individual’s physics will have different activity performances5.

The intestinal microflora in the human body includes beneficial microorganisms and pathogenic bacteria ​ (Photo: Freepik)

The intestinal microflora in the human body includes beneficial microorganisms and pathogenic bacteria ​ (Photo: Freepik)

Basic physiological functions of intestinal microbiota in human health:

Protects the intestinal mucosa: prevents mucosal infections by inhibiting invading pathogens, and maintaining an intact intestinal barrier.

Metabolism: digestion and bioaccumulation of nutrients, energy homeostasis, support of fat metabolism, fermentation of non-digestible carbohydrates, short chain fatty acid (SCFA) production.

Immune regulation: regulates enteric nerves, regulates mucosal immunity, maintains intestinal epithelial homeostasis. The microbiota is considered an extremely important source of immune stimulation.

Gut microbiota activity remains relatively stable as people enter adulthood, but quality varies between individuals due to genetic patterns, body mass index (BMI), exercise frequency, lifestyle as well as cultural and dietary habits7.

However, it is necessary to pay attention to the balance between the individual and the microbiota in order to optimize metabolic and immune functions, as well as prevent the development of disease8. Intestinal microbiota disorders are not only related to the intestines but are also the main cause of extra-intestinal diseases such as metabolic or neurological disorders9.

In particular, the development of intestinal microflora in the first 3 years of life is considered to play an important role. The symbiosis of intestinal microflora in infants is established from birth and gradually forms during the first few years. During this period, newborns develop rapidly, increasing significantly in height, weight, head circumference, activity of metabolic organs, immune system, digestive and nervous systems. This is the key to establishing the intestinal microflora and is also a solid stepping stone for individuals to have good health later on.

Intestinal microbiota significantly affects the maturation of the immune system, nutrient absorption, and metabolism, prevents pathogen invasion in children, and is related to disease conditions. short-term and long-term diseases of humans such as obesity, overweight, allergies, asthma, metabolic disorders, or chronic inflammatory diseases10.

Therefore, it is necessary to pay special attention to the quality of intestinal microflora activity right from the early stages of life, in order to enhance long-term health in each individual

The role of breast milk on the infant’s intestinal microbiota

In the first years of life, breast milk is an essential source of nutrition in protecting the health of the child’s intestinal microflora. Breast milk contains a variety of factors that have anti-infective properties, such as immunoglobulins (especially secretory IgA), anti-adhesion oligosaccharides and glycoproteins, and cytokines. Breastfeeding helps children avoid infections or infection-related diseases such as upper respiratory tract infections, gastroenteritis, etc. IgA secreted in breast milk also effectively protects infants from the passage of intestinal bacteria through the intestinal mucosa by coating intestinal bacteria, while blocking their interaction with the epithelium.

The intestinal microflora in the human body includes beneficial microorganisms and pathogenic bacteria ​ (Photo: Freepik)

The intestinal microflora in the human body includes beneficial microorganisms and pathogenic bacteria ​ (Photo: Freepik)

In particular, besides the harmonious combination of protein, carbohydrates, lipids, minerals and vitamins to ensure the normal growth and development of infants, breast milk also contains biological probiotics (Probiotics), with an amount of 10^3–10^5 CFU/ml of live bacteria, depending on the impact of microorganisms in the mother’s intestinal tract13.

Probiotics are defined as “living microorganisms that, when consumed in sufficient and appropriate quantities, have a positive impact on the health of the host”14. Probiotics work with many different mechanisms, capable of producing diverse substances, inhibiting both Gram-positive and Gram-negative bacteria, including hydrogen peroxide hydroperoxide, ethanol, organic acids, diacetyl, acetaldehyde,…15. In addition, they also compete for attachment sites, preventing the adhesion of pathogenic bacteria; reduce the amount of toxins secreted by them; at the same time, competing for nutrients with harmful microorganisms (for example, the growth of beneficial bacteria using simple sugars – glucose and fructose – slowing the growth of Clostridium dificile bacteria that cause diarrhea also uses simple sugar).

These probiotics have the following effects:

Antibacterial: Secretes antibacterial substances to reduce the amount of harmful bacteria; Competes with pathogens to prevent adhesion to the intestinal tract and compete for nutrients necessary for the survival of germs.

Immunity: Improves intestinal microflora, prevents diarrhea and constipation; Reduces allergies by creating an immune response.

Impact on intestinal bacteria: Regulates the metabolic activity of intestinal organisms by reducing the pH of the digestive tract, thereby hindering the enzyme secretion of intestinal organisms; Adjust the composition of intestinal bacteria, creating a temporary balance of the intestinal ecosystem; Increase lactose tolerance to avoid bloating and indigestion when absorbing foods high in lactose; Increase beneficial bacteria, reduce harmful bacteria.

Effects on intestinal epithelial tissue: Tights junctions between epithelial cells; Promotes the production of defense molecules such as mucus; Reduces excretory stimulation and the inflammatory consequences of bacterial infection.

Probiotics have an important impact on the digestive system (Photo: Nutraingredients-usa)

Probiotics have an important impact on the digestive system (Photo: Nutraingredients-usa)

Besides, Probiotics also help the human body fight allergies by providing important substances such as vitamin B6, vitamin B12, folic acid, riboflavin, niacin; reducing the risk of bladder cancer and colon cancer, slowing the growth of tumors. At the same time, probiotics also play a role in reducing serum cholesterol levels, reducing high blood pressure, and shortening recovery time when suffering from diarrhea or using too many antibiotics18.

Lactobacillus, Bifidobacterium and Saccharomyces are three strains of Probiotics that are widely used and studied. In particular, Lactobacillus and Bifidobacterium are two strains of beneficial bacteria that enhance the body’s digestion and immunity, while promoting intestinal bacteria and preventing diarrhea19.

Lactobacillus Bifidobacterium
There are more than 50 species of Lactobacillus bacteria, found in the digestive system, excretory system and reproductive system. Some bacteria found include:

Lactobacillus acidophilus, Lactobacillus acidophilus DDS-1, Lactobacillus bulgaricus, Lactobacillus rhamnosus GG, Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus casei, Lactobacillus johnsoniiLactobacillus gasseri.

There are about 30 species of Bifidobacterium, accounting for 90% of beneficial bacteria in the colon. This strain will be present in the intestinal tract for several days after birth, especially if the newborn is breastfed.

Some bacteria used as Probiotics are as follows:

Bifidobacterium bifidum, Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium thermophilumBifidobacterium pseudolongum.

Has a useful role in treating or preventing irritable bowel syndrome, diarrhea, fungal infections, urinary tract infections, skin diseases such as fever, eczema,… Plays an important role in children’s digestive system.
Mechanism of action: Produces lactic acid and other substrates, creating an unfavorable environment for putrefactive microorganisms to grow in the digestive tract. As a result, the amount of urase in the intestines decreases, and low pH caused by lactic acid hinders NH3 absorption from the intestines into tissues, promoting NH3 excretion from the blood and intestines. Mechanism of action: Produces some vitamins for the body (such as vitamin K, vitamin B).
Inhibits the metabolism of bacteria in the colon, reducing carcinogen formation in the large intestine. Helps the body digest some foods that the stomach and intestines cannot digest
Create bacteriocin, which helps kill other harmful bacteria by forming channels that change the permeability of cell membranes; Combined with lactic acid improves diarrhea and enhances intestinal motility Helps reduce symptoms of irritable bowel syndrome IBS and some other related diseases
These specific properties are beneficial for the digestive system Supports improving immune system health, limiting the growth of harmful bacteria in the intestinal tract

There are many clinical studies that have proven the use and effectiveness of applying Lactobacillus to the human body:

– Lactobacillus LB is an effective and safe treatment for children with prolonged diarrhea (>24 hours), based on clinical evidence with 80 non-dehydrated children between the ages of 3 months and 4 years old with acute diarrhea. When using this method, the group using Lactobacillus LB had shorter diarrhea duration (30.4 hours compared to 8.2 hours)20.

– Use of Lactobacillus LB produced a clinically significant benefit in the management of children with persistent non-rotavirus diarrhea, based on a randomized, placebo-controlled clinical trial in children. 10-month-old male or female with non-viral diarrhea. Results showed that children given the Lactobacillus supplement had a 1-day shorter recovery time (until first normal bowel movement) compared to children who received a placebo rehydration solution)

Applying probiotics to nutritional milk products for young children

Currently, using high technology, scientists have successfully created many nutritional products from milk that have the ability to transport good probiotics, especially fermented milk and cheese. Milk and dairy products are high in lactose, allowing Probiotics to survive and grow. Products such as fermented milk and cheese have a dense network structure and high fat content, helping to increase protection for microorganisms while moving through the digestive system, against the acidic environment of the stomach.

 Scientists have successfully created many nutritional products from milk that have the ability to deliver probiotics (Photo: Freepik)

Scientists have successfully created many nutritional products from milk that have the ability to deliver probiotics (Photo: Freepik)

Among them, milk beverage products are widely used by the Lactobacillus group. Strains L. acidophilus, L. casei, L rhamnosus and L. plantarum have characteristics suitable for the manufacturing process and production conditions, allowing the existence of Probiotics in fermented milk. In addition, Lactobacillus and Bifidobacterium bacteria are often added during or after product fermentation, especially with yogurt. Most commercial yogurt has a low cell count, so whether Probiotics survive or not depends largely on available nutrients, amount of species, incubation temperature, storage temperature, and fermentation time…23

Cheese is also a product rich in Probiotics, allowing their survival in the product until human consumption. Probiotics strains commonly used in cheese include Bifidobacteria, Lactobacilli, Lactococci, Enterobacteria.

In addition to dairy products and products, Probiotics have also been appearing in a number of other product segments such as juices, breakfast cereals, infant formula milk, fermented vegetables, chocolate, and some other solid and liquid products

New trend of Postbiotics and positive effects on the digestive system and intestinal microflora of children

Postbiotics (also known as paraprobiotics, non-viable probiotics, heat-killed probiotics) are byproducts from the metabolism of probiotics. In mid-2021, the International Scientific Association of Probiotics and Prebiotics (ISAPP) defines Postbiotics as a “preparation of inanimate microorganisms and/or possessing ingredients that provide positive effects to human health”. In other words, it is created when Probiotics eat certain fibrous molecules to grow, or hold onto structural pieces of bacteria, such as cell walls.

Below are some basic differences between Probiotics and Postbiotics:

  Definition Simplified definition Notes
Probiotics Living microorganisms, when used in appropriate doses, will bring health benefits to humans. Living microorganisms are beneficial to human health. Strain identity must be confirmed through genome sequencing. An effective dose of a viable probiotic must be stored until the end of its shelf life.
Postbiotics Preparation of inanimate microorganisms and/or possessing ingredients good for human health. Intact living bacteria or cell fragments, with or without metabolites that confer health benefits. Purified metabolites are not Postbiotics.

Postbiotics have the same health benefits as Probiotics, such as: Strengthening resistance; Has anti-cancer effects; Preventing inflammation; Antibacterial, preventing infection; and limiting the risk of cardiovascular diseases.

In particular, because it does not contain microorganisms, Postbiotics prevents complications when entering the human body. They also help secrete stomach acid and improve symptoms in patients with gastroesophageal reflux.

Probiotics are often included in products such as fermented foods (yogurt, cheese), or non-fermented foods (cereals, chocolate, smoothies), which can also come from milk or plants. However, some specific characteristics of foods such as acidity, chemical compounds, storage conditions, etc. can pose challenges to the existence of probiotics during production and storage. Therefore, Postbiotics with inanimate bacteria are also more likely to be ingredients of food products28.

Currently, food products containing Postbiotics supplements are not widely available. They usually include some type of short-chain fatty acid, most commonly butyrate. In addition, consuming Postbiotics by natural methods is also completely possible in the context of limited Postbiotics preparations. Some dietary supplements that enhance Postbiotics include:

– Foods that provide Lactobacillus probiotics: yogurt containing live probiotics or live yeast

– Saccharomyces enzyme: contains many metabolic processes, decomposing fats, carbohydrates, proteins

– Fermented aloe vera: helps detoxify, support digestion, produce beta-glucans to enhance immunity

– Spirulina and chlorella: algae that help detoxify the body, feed beneficial bacteria, and improve intestinal health

Postbiotics can contribute to improving health in general and human intestinal microflora in particular. Especially, because they do not contain live micronutrients, Postbiotics can be a safer method than Probiotics in terms of preservation and shelf life, as well as a safe alternative for children who have immunodeficiency or serious illness. In addition, Postbiotics is also an effective way to increase the impact of Probiotics on human health.

Postbiotics contribute to improving the health and intestinal microflora of the human body, especially young children (Photo: Freepik)

Postbiotics contribute to improving the health and intestinal microflora of the human body, especially young children (Photo: Freepik)

In general, with the child’s immature digestive system and intestinal health, it is necessary to fully utilize breast milk with effective probiotic supplements for at least 6 months of age, and for as long as possible. In addition, parents should let their children use products and food sources containing Probiotics/Postbiotics to strengthen the baby’s immune system and prevent diseases.


  1. Trung tâm Thông tin Khoa học và Công nghệ (Sở Khoa học và Công nghệ TP.HCM). (2015). Báo cáo phân tích xu hướng công nghệ. Chuyên đề: Xu hướng nghiên cứu và ứng dụng chủng lợi khuẩn Probiotic trong y học và thực phẩm chức năng.
  2. Rinninella, E., Raoul, P., Cintoni, M., Franceschi, F., Miggiano, G. A. D., Gasbarrini, A., & Mele, M. C. (2019). What is the healthy gut microbiota composition? A changing ecosystem across age, environment, diet, and diseases. Microorganisms, 7(1), 14.
  3. Derrien, M., Alvarez, A. S., & de Vos, W. M. (2019). The gut microbiota in the first decade of life. Trends in microbiology, 27(12), 997-1010.
  4. Wold, A. E., & Adlerberth, I. (2002). Breast feeding and the intestinal microflora of the infant—implications for protection against infectious diseases. Short and long term effects of breast feeding on child health, 77-93.
  5. Lara-Villoslada, F., Olivares, M., Sierra, S., Rodríguez, J. M., Boza, J., & Xaus, J. (2007). Beneficial effects of probiotic bacteria isolated from breast milk. British Journal of Nutrition, 98(S1), S96-S100.
  6. Yan, F., & Polk, D. B. (2011). Probiotics and immune health. Current opinion in gastroenterology, 27(6), 496.
  7. Tạp chí Công thương (2020). Đặc tính probiotic của chủng Lactobacillus gasseri SMH15 được phân lập từ sữa mẹ
  8. Bộ môn Sinh vật học – Đại học Khoa học Tự nhiên, ĐH Quốc gia HN (2018). Probiotics – Liệu pháp cho sức khỏe tự nhiên.
  9. Vinderola, G., Sanders, M. E., & Salminen, S. (2022). The Concept of Postbiotics. Foods, 11(8), 1077.
  10. Dr.Axe (2017). Postbiotics: Uses + 5 Benefits for Gut Health & Beyond
  11. Wegh, C. A., Geerlings, S. Y., Knol, J., Roeselers, G., & Belzer, C. (2019). Postbiotics and their potential applications in early life nutrition and beyond. International journal of molecular sciences, 20(19), 4673.
  12. Salazar-Lindo, E., Figueroa-Quintanilla, D., Caciano, M. I., Reto-Valiente, V., Chauviere, G., Colin, P., & Lacteol Study Group (2007). Effectiveness and safety of Lactobacillus LB in the treatment of mild acute diarrhea in children. Journal of pediatric gastroenterology and nutrition, 44(5), 571–576
  13. Liévin-Le Moal, V., Sarrazin-Davila, L. E., & Servin, A. L. (2007). An experimental study and a randomized, double-blind, placebo-controlled clinical trial to evaluate the antisecretory activity of Lactobacillus acidophilus strain LB against nonrotavirus diarrhea. Pediatrics, 120(4), e795–e803.
Maybe you are interested

Children with malabsorption of nutrients – Causes and solutions

Children with poor digestion, constant illness, non-standard weight are the worries of many families with children of nutrient malabsorption syndrome....
See more

ESPGHAN/ESPEN/ESPR guidelines on pediatric parenteral nutrition: Energy

Methods Medline search, Pub-Med search. Timeframe: publications from 2004 to 2016 were used to update the previous recommendations from 2005....
See more

ESPEN practical guideline: Home parenteral nutrition

This guideline will inform physicians, nurses, dieticians, pharmacists, caregivers and other home parenteral nutrition (HPN) providers, as well as healthcare...
See more