LACTIC ACID BACTERIA OF FIRST, SECOND, THIRD AND FOURTH GENERATION

The efficiency of lactic acid bacteria products on the market is determined by the bacterial strain, its genus and species, the imprinting of the host from which it was taken (man, plant, or other mammal) and the technological form in which it is presented.

 

First generation technology: "naked" lactic acid bacteria

 

This is the most primitive generation. Bacteria are separated from a culture medium by centrifugation or ultrafiltration and placed on a food support (usually maltodextrin) after being freeze-dried in a vacuum. In this state the bacteria are in a very delicate situation: they must remain within a very narrow—between 2% and 5%—humidity range. If the humidity goes above 5%, the bacteria will wake up, and not finding food, they will die and if the humidity goes below 2%, the bacteria will completely dehydrate and transition from hibernation to death.
Moisture is detrimental to lactic acid bacteria and as consequence storing them in open containers or with substances having over 5% moisture content, is harmful. They also suffer with exposure to heat and sunlight, as the heat can cause the moisture level to drop below 2% and dehydrate them. Too much pressure can also be harmful to them, in fact, the pressure exerted by a table press can kill as much as 60% of them. The best way to package and store lactic acid bacteria is in gelatin capsules, or airtight, single-dose bags.

 

Second generation technology: Drug Delivery System (DDS) probiotics

 

This technology consists of protecting the bacterial contents of a gelatin capsule from the lethal effect of gastric acidity (pH 1-2) by painting the capsule itself with an acid-resistant coating based on cellulosic derivatives, or copolymers of methacrylic acid (a process known as gastro-resistant, or enteric coating). The capsule will, however, dissolve in an alkaline environment like that of the small intestine and allow the contents to empty out into the intestine. This type of delivery system is, however, reserved by law for pharmaceuticals (drugs, as the name implies), and not for dietary supplements, which is the primary product category under which lactic acid bacteria are sold.

 

Third generation technology: microencapsulated lactic acid bacteria with single- or double-layer coating

 

Microencapsulation (M.I.) consists of coating of lactic acid bacteria in powder form with a gelatinous liquid that dries and forms a shield around the grains, or granules and provides them with a nearly individual gastro-resistant coating. Microencapsulation is certainly an advance compared to “naked” delivery of lactic acid bacteria with the advantage of being legal for dietary supplements and having nearly the same efficacy as the DDS.

 

Though microencapsulation does provide resistance to acid, temperature, mechanical pressure and humidity, it has one major downside: the thickness of the coating is not completely uniform on all of the micro globules and the number of bacteria enclosed in each can vary from a few units to a few hundred. This numerical difference must be factored in when verifying the titer of colony forming units (CFU) in the raw material (bacterial powder). The micro globules are usually packaged in plain gelatin capsules, but as they are resistant to mechanical pressure, they can also be formed into tablets or pills.

 

Fourth generation technology: super strain lactic acid bacteria, "naked" but high performance

 

Through conventional genetic selection (not transgenic, but natural, as has been done in recent centuries with plants and animals) it has recently been possible to generate and reproduce particularly active, resistant strains of probiotics at an industrial level. These strains, in terms of revivability, shelf-life, resistance to mechanical stress, resistance to gastric acidity and efficacy, have become “real champions” of the lactic acid bacteria probiotic sector.
Microencapsulation is no longer needed for these high-performance probiotics and their functional ability is surprisingly good.