Probiotics are living microorganisms often added to products due to their gut health benefits.  But how do they work?

Gut Actions

Probiotics have been associated with improved nutrient absorption (eg, calcium, magnesium).  This is generally considered a good attribute as it suggests that probiotics either help improve the breakdown of food (digestion) to release these nutrients and(or) the probiotics are somehow aiding the ability of the body to transport these nutrients into the bloodstream for use in the body. 

The gut is teeming with many different bacteria.  Not all of these bacteria are health-promoting.  In fact, some gut bacteria are associated with secreting harmful toxins that may cause illness in the dog.  Adding probiotics into a dog’s daily consumption is associated with improved composition of the bacteria present in the dog’s gut.  In fact, many potential bad bacteria in the gut decline in the presence of probiotics.  Probiotics also neutralize the bad behaviors of pathogens and can even influence pathogens to become beneficial.  Probiotics may improve gut bacteria composition by killing off pathogens.  Probiotics may also improve gut bacteria by secreting acids that are unfavorable to the growth of pathogens.

Probiotics have been also shown to improve gut immune function.  The body’s immune system is heavily tied to the gut since about 70% of the lymph tissue surrounds the gut.  The lymph tissue is the origin of many new immune cells.  Because much of the lymph tissue surrounds the gut, probiotics positively influence the development of immune cells.

Probiotic Relationships with other Bacteria

Even when probiotics have established themselves in the gut, their numbers are relatively low.  As a result, probiotic bacteria improve gut bacteria composition by methods other than simply crowding out other bacteria.  One way probiotic bacteria affect other bacteria is due to their “heavy influence.”  Think of probiotics as being the leaders in their environment.  When probiotics are present, they diminish the role of pathogens by killing them off or altering their function.  They become the “generals” present – instructing other bacteria to “get in line.”  Probiotics can also play a role as “the Public Relations firm” influencing the rest of the bacteria to play a beneficial role in improving gut health.

Takeaways

Probiotics are living microbes that provide health benefits such as improved nutrient absorption, improved gut bacteria composition, and improved immune function.  Probiotics may alter their environment by secreting acids that change the composition of the bacteria present.  Or they may alter their environment more vicariously through influencing the actions of fellow microbes.