The history of lactic ferments dates back to the origins of mankind, as it is closely related to the use of fermented foods. Various archaeological studies have shown that fermentation techniques were an established practice among many civilisations. Thousands of years ago, man accidentally experienced the fact that leaving fruit and cereals in covered containers for a long time resulted in the production of wine and beer, but nobody fully understood how and why this happened.
The process became known as fermentation, from the Latin word 'fervere' meaning 'to boil'. The term comes from observing that mixtures of crushed grapes stored in large containers produced bubbles, as if they were ‘boiling'. Through empirical observation, our ancestors then learned that temperature and exposure to air (i.e., the presence of oxygen) are crucial to the fermentation process.
In 1856, an industrialist from Lille, Monsieur Bigo, who produced alcohol from sugar beet, contacted the young French scientist Louis Pasteur to solve problems which had arisen in his distillery. Monsieur Bigo had observed that many vats of beet juice were not producing alcohol as the juice acidified instead. Pasteur examined samples from the vats containing alcohol under the microscope and noticed the presence of fat globules. However, looking at the acidified samples, he saw only 'thin, elongated particles'. Through further study, he then concluded that the acidified sample contained acetic acid or, as he described it, "it is definitely not wine!".
Pasteur discovered that the successfully fermented beet juice was an optically active compound, i.e. made up of living organisms He later observed that large quantities of yeast could be found in the samples of the vats in which fermentation had taken place. In contrast, in the vats containing acetic acid, he observed 'much smaller cells than yeast'. His observations made it possible to understand that yeast converts sugars into alcohol and that acidification was instead the result of contamination by a bacterial species capable of converting ethanol into acetic acid.
To eliminate possible bacterial contaminants, Pasteur tested a technique in which samples were heated to a specific temperature for a specific period of time and this process became known as pasteurisation. To the scientists of the time, his studies appeared revolutionary. In 1877 Moritz Traube, a German chemist, suggested that each chemical event during the fermentation process should be catalysed by a protein-like substance. Years later, this substance was called enzyme. Twenty years later, Eduard Buchner, also a German chemist, demonstrated that sucrose could be fermented into alcohol using yeast extracts and realised that fermentation was a highly complex process characterised by a series of events, with each step catalysed (i.e., brought about) by a different enzyme.
Thanks to the discoveries of Pasteur, Traube and Buchner, the foundations were laid for the birth of a new scientific discipline that would give fresh impetus to the world of research and medicine: Biochemistry or 'chemistry of life'. It is only since the 2000s that it has been possible to develop modern microbiology and research into the microbiota and milk ferments has taken off, rising from just a few hundred studies a year by 2000 to more than 8000 in 2016, thanks to new molecular biology techniques such as PCR – a technique that allows the repeated replication (or amplification) of certain stretches of DNA whose initial and terminal nucleotide sequences are known – as well as to large-scale studies to analyse the human bacterial genome, such as the MetaHit Project, funded by the European Union (https://cordis.europa.eu/project/id/201052/it),
Research goes on and the microbiota continues to be one of the most active, lively areas of research, constantly full of novelties. The goal in the coming years will no longer be just to understand where and to what extent the health of the microbiota impacts on human health, but also how the microbiota can be impacted through safe, correct, well thought-out, specific, and personalised support methodologies.