In addition to their rapidity and cost-effectiveness, in vitro models provide many advantages that cannot be achieved by any other means. First of all, they allow simultaneous screening and ranking of multiple product candidates, process modifications or management practices, their dosages and their combinations, which is not practical in authentic systems. Secondly, real life processes typically result in high variations due to uncontrolled factors, while simulation systems can be controlled to achieve a low coefficient of variation, allowing detection of empirically small, but economically huge, effects. Furthermore, validated simulations are more likely to reveal the mode of action of the test compounds and system interactions than trials in the authentic system, since more interventions are possible in in vitro trials than in vivo. Authentic systems cannot be subjected to extreme conditions for ethical and financial reasons while simulation systems are designed to reach to extremes. Last but not least, simulation studies may reduce the number of animal and human studies needed with significant ethical and financial consequences.

Markets for laboratory models

Most industries truly benefit from in vitro models, as shown by the examples below:

• In vitro models reveal the amount of food-borne pathogens present in food stuffs and demonstrate how to prevent the pathogens from growing, ensuring hygiene quality
• Mode of action of a prebiotic is revealed in a simulation model mimicking the processes in the human or animal gastrointestinal tract
• Salmon gastrointestinal tract fermentation models anticipate the effects of different feed raw materials on the microbial community prevailing in the intestine
• Systematic product screening of pharmaceutical compounds based on their true effects on intestinal microbiota enhances development of new types of medicine
• Ensiling can be optimised for each crop using the silage model
• More efficient microbial control in process industries is achieved through in vitro models mimicking the habitats with the most intensive fermentation in the system

Our view on in vitro simulation models

• In order to be reasonable, a simulation model must be able to reliably rank product candidates using valid indicators
• Relevant simulators mimic the essential chemical, physical and biological characteristics of the authentic habitat as accurately as is possible or practical. To achieve satisfactory agreement, authentic materials are used for both substrate and microbial inoculum
• Simulation is always a model of the authentic system, developed for a specific purpose, as a 100% identical system would not be a model
• Benefits and limitations of the model have to be acknowledged

Alimetrics has developed and validated simulation models for a wide variety of environments that include:

• Digestive tract of humans and a variety of animal species
• Food and feed manufacturing processes based on microbial fermentation
• Bioenergy
• Hygiene management, shelf-life and prevention of spoilage and pathogen contamination
• Industrial processes with microbes prevailing or even multiplying in certain sites

The simulation platform allows us to rapidly expand to new animal species as well as new biotechnological and industrial processes.

The most relevant techniques are described in more detail in the following sections. However, as in all projects carried out by Alimetrics, the in vitro models are always tailored according to clients' needs.