Delivery of probiotics and health benefits

Health value

The amount of human food products with probiotic bacteria continues to grow rapidly as more regions around the world are seeing the health value. Typically, these are in refrigerated dairy products or dry supplements. 

In pets, the delivery of probiotics into foods, treats and supplements is more complicated by food science, processing and product conditions. Many probiotics are not alive when given to the pet, but that does not dampen the marketing desire. 

Bacterium for life 

The term probiotic comes from the words ‘pro’, which means ‘for’ and ‘bios’, which means ‘life.’ A probiotic is ‘for life’ whereas an antibiotic is ‘against life’ or against certain bacteria. The nutritional approach to include probiotic bacteria in foods or supplements is based upon the positive health impact that has been reported. Life is on a delicate balance such that when these symbiotic bacteria are flourishing, there is a reduction in health disorders and a reduction in harmful, pathogenic bacteria.

It is estimated that the intestinal tract of mammals contains more than ten times more cells than are found in the host’s body. These symbiotic relationships can act as a defense barrier against invading pathogens. They can aid in digestion and energy utilization of the foods and even provide nutritional support to intestinal cells. But, more importantly, they can stimulate the development of the immune system and protect against the growth of pathogenic bacteria.

Nutrition for bacteria

In healthy animals, even the administration of Salmonella is not always deadly, but the moment an antibiotic is given – the Salmonella can become deadly as the beneficial bacteria are greatly reduced. In many digestive diseases, the growth of pathogens often mirrors the overuse of antibiotics. 

However, it is not just antibiotics that can lead to digestive upsets. Some ingredients are highly positive in supporting probiotic bacteria while others are highly negative. The key is to provide nutrition for the host animal (dog, cat, rabbit, et cetera) and also provide the nutrition necessary for the beneficial probiotic bacteria to thrive. This ‘coupled’ look at nutrition is unknown in most nutritional textbooks. 

Why not prebiotics?

In 1995, a term was launched called ‘prebiotic’, which meant ‘before life’. The definition of prebiotics was defined as ‘a fermentable ingredient that allows specific changes in both the composition and activity of intestinal microflora (probiotics) that confers benefits upon the host’s well-being and health.’ 

This over-simplified approach set off efforts to find the ‘silver bullet’ of ingredients to support probiotic growth in the intestinal tract. The theory was that a prebiotic could be added to the food and not be destroyed. 

Several good prebiotics are marketed, but they do not uniformly provide all the nutrition necessary. Again, this is over-simplified. Ultimately, the host digests and absorbs food to take care of its own nutritional needs first and the ‘leftover’ nutrition is there for the probiotic bacteria. As you can imagine, this leftover nutrition varies greatly. In my own experience, there are many ways to stimulate a healthy intestinal tract with and without adding probiotic bacteria and prebiotics. 

Delivery issues

The typical approach is to supplement a food with a cool-refrigerated, dry probiotic containing powder. Because bacteria are impeded by so many factors, their stability has been difficult to impossible to solve. I first started studying probiotic bacteria in the early 1980s and have searched for ways to stabilize them on or in foods. Bacteria are fragile in that they are heat sensitive, pressure sensitive and are induced to growth with higher water activity. Process and packaging limitations add to the problems of delivery. 

In human supplements, probiotics need to be kept from water in very dry conditions and as cool as possible. There should be an avoidance of acids in the products. Simply adding them on food products stimulates their growth immediately. Without nutrition to live on, probiotic bacteria quickly die off. 

Pet products have included probiotics for many years. Because of these issues, the products are typically dead upon arrival to the food bowl. Since bacteria counts are colony-forming units per gram (CFU/g), an occasional brand has artificially inflated their numbers to the consumer by incorrectly reporting them as CFU per pound.

Alternatives

In farm animal foods, probiotic delivery is just as complicated. Bacteria called bacillus have been used as they also provide similar end products that intestinal probiotics do. These bacillus-type bacteria are spore-formers. That is, they can survive some heat and still be viable in the intestinal tract. Is this a viable alternative for pet and human foods? Bacilli are a broad group of ‘soil-bacteria’ and include both pathogenic and non-pathogenic bacteria. There is no mistaking that they come from the soil and actually include a bacillus that causes anthrax. 

From a business point-of-view, great risk assessment should be considered before bringing a non-pathogenic bacillus into a food plant with those with open wounds or asthma. Bacterial counts can rise quickly throughout the plant and misleading in quality control. The greater risk is the explaining to consumers how a bacillus that caused anthrax is really different from the non-pathogenic form. As an alternative, others have focused on silage bacteria, which are also not intestinal in nature.

What is the solution? 

Our company has been involved with a unique discovery that protects beneficial, probiotic bacteria for long-term shelf life on the outside of food and treats. As moisture and water activity rises, dormant probiotic bacteria coated in powders will start to multiply and eventually die off quickly due to lack of food provided in coatings to sustain them. There is some loss over time, but shelf life studies have been done for a year showing long-term viability. Coating these protected probiotics on the outside of pet foods opens unique new foods and health options other than supplementation. Solutions including proper nutritional support can lead to more effective health claims in the future.