If you said 'Friendly Bacteria?', you're right! Insects, tasty sausage and fermented grass are all home to Lactic Acid Bacteria, a group of bacteria that, well, produce Lactic Acid.
So what are they, and what can they do for us?
LABs are in fermented things because we deliberately put them there. The acid they produce creates a hostile environment for any other bacteria that would cause food to go off, in a similar way to pickling things in vinegar. Salami, Chorizo, Silage, Sauerkraut and Cheese (to name but a few) are all made with lactobacillus, a family of LAB. They acidify the food, stopping microbes growing on them and causing spoilage. This preserves the food; Cheese lasts a lot longer than milk, salami lasts longer than sausage, silage lasts longer than grass, and so on.
It's actually the acid made by the bacteria that makes cheese (and yoghurt) the consistency they are rather than the consistency of milk! All the acid affects the structure of milk proteins like casein, and they change shape. This makes them stickier, binding together into more gloopy yoghurt or even solid cheese!
It's not just the acid that's used to preserve food though; some LABs produce lantibiotics, like Nisin. Lantibiotics are a type of antibiotic containing Lanthionine, an amino acid that gives the antimicrobial properties. These are added to food to further protect them from food-spoilage bacteria!
This is where the bees come in! Honey is antimicrobial, and it's been proposed that some of the antimicrobial properties are coming from lantibiotics made by LABs living in their tiny bee intestines!
They protect our cheese, they make antibiotics, they feed our cows through the winter, and most importantly of all (for me) they make chorizo, the tastiest of meats. On top of this, they are the friendly bacteria we eat in probiotics! And all the associated benefits of probiotics are provided by the bacteria themselves.
Lactic Acid Bacteria are awesome!