You may not have heard of Bifidobacterium longum subsp. infantis, but it's already on intimate terms with your breastfed baby. Fortunately this bacteria can be your baby's lifelong friend.
The subspecies of the bacteria Bifidobacterium longum inhabits the gastrointestinal tract of your nursing infant. This particular strain of bifido isn't found in adults.
B. longum subsp. infantis aids in your baby's digestion and also offers protection against toxic bacteria. It is in a symbiotic relationship with your baby, partaking of components of your breast milk -- components that, as it happens, your baby doesn't need.
It certainly looks like the sugars that B. longum subsp. infantis feeds upon is in breast milk specifically for this purpose, to sustain B. longum subsp. infantis so that it can protect the health of your child.
Five species of bifidobacteria that occur in human beings are Bifidobacteria bididum (bifidus), B. infantis, B. breve, B. adolescentis, and B. longum.
Bifidobacteria don't get absorbed, they remain in the GI tract, sticking to intestinal mucosa. They can then keep toxic bacteria from sticking with them.
Bifidobacteria production of acetic acid and lactic acid creates an environment which is inhospitable to toxins. Immune cells (macrophages) can be activated by the presence of bifido with the result of the suppression of toxic bacteria.
B. longum subsp. infantis likes the complex sugars that are derived from the lactose in breast milk. Chains of other sugar units are added to a lactose molecule, creating complex sugars.
Lactose is the main carbohydrate that occurs in milk, a combination of sugars glucose and galactose. Alpha-lactalbumin (LALBA) helps with the process of combining glucose and galatose. Lactose production is then stimulated.
Alpha-lactalbumin will also attack tumor cells and cells infected by viruses, bringing about the destruction of these cells.
It has been rather puzzling to researchers that breast milk should contain elements like these complex sugars that can't be broken down by the human genome. Why would the milk have components that can't be utilized by the baby?