Keeping probiotics alive until someone eats them

The number that matters is the viable count in the consumer's hand, at the end of the declared shelf life, after a supply chain that included a warehouse in May. Everything in probiotic product design follows from that.

The four enemies

• Heat, during processing and during distribution.
• Moisture, which activates cells and then kills them in an unsuitable matrix.
• Oxygen, particularly for strict anaerobes.
• Acid, both from the food matrix and from the stomach.

Choose the strain for the format

Spore-forming strains such as Bacillus coagulans survive heat, moisture and acid far better than most lactobacilli, which makes them the practical choice for baked, extruded or ambient products. Traditional lactobacilli and bifidobacteria have deeper clinical evidence but need refrigeration, protective matrices or encapsulation to hold their count.

Design the overage from data

Adding a safety overage is standard practice, but the number should come from your own stability study, not from a supplier's generic guidance. Run the study in the actual pack, at the actual storage condition, and plot the decline curve. It is rarely linear, and knowing its shape lets you set both the overage and the shelf life honestly.

Protect the powder

For sachets and capsules, moisture ingress is usually the limiting factor. Aluminium-based barrier structures, desiccant where appropriate, and controlled humidity during filling matter more than most formulation choices. A blend that is stable in a sealed foil pouch can lose a log within weeks in a poorly sealed one.

Label it truthfully

Declare the strain to genus, species and strain designation, and declare the count at end of shelf life. Products declaring 'at time of manufacture' are technically informative and commercially transparent about the wrong thing. The informed buyer in this category has learned to check.