Giulia Enders

The South Pole is so cold and germ-free that the infants simply did not get the bacteria they needed to survive. The normal temperatures and bacteria the babies encountered after leaving the Antarctic were enough to kill them.

Every culture in the world includes traditional dishes that rely on the help of microbes for their preparation. Germany has its sauerkraut, pickled gherkins, and sourdough pretzels; the French love their crème fraîche; the Swiss have their hole-riddled cheese; salami and preserved olives come from Italy; Turks swear by a salty yogurt drink called ayran. None of these delicacies would exist if it weren’t for microbes

The process often results in the production of acid, which makes the yogurt or vegetables taste sour. This acid, along with the many good bacteria, protects the food from dangerous microbes. Fermentation is the oldest and healthiest way of preserving food.

The diversity of bacteria in fermented foods has fallen sharply. Industrialization has resulted in standardized production processes using single bacteria species isolated in laboratories.

In his book The Prolongation of Life, he asserted the claim that good bacteria can help us live longer, better lives. From then on, bacteria were no longer just anonymous components of yogurt, but important promoters of health

This took the formula-milk industry by surprise, because they had taken care to make sure their product contained the same substances as real breast milk. What could be missing? The answer was, of course, bacteria. And, specifically, the bacteria that live on milky nipples and which are particularly common in the guts of breast-fed babies: Bifidobacteria and Lactobacilli. These bacteria break down the sugar in milk (lactose) and produce lactic acid (lactate), so they are classified as lactic-acid bacteria.

Examples of bacteria that can resist being digested are Lactobacillus rhamnosus, Lactobacillus acidophilus, and the abovementioned Lactobacillus casei Shirota. The theory is that a living bacterium will have a greater effect on the gut.

These doubts are compounded by the fact that it is not always possible to know whether enough probiotic bacteria are reaching the large intestine alive. A break in the cold chain, or a person with a particularly acidic stomach or slow digestion, might kill off these microbes before they reach their intended destination. That is not harmful, of course, but it means consuming a probiotic yogurt may have no effect that a normal yogurt doesn’t also have. To make any difference to the huge ecosystem in our gut, about a billion (109) bacteria need to make it through the system and arrive there intact.

he bigger the villi grow, the better they are at absorbing nutrients, minerals, and vitamins. The more stable they are, the less rubbish they let through. The result is that our body receives more nutrients and fewer damaging substances.

Another trick is to snatch the bad bacteria’s food away (anyone with siblings may be familiar with this strategy).