Irritable bowel syndrome (IBS) — basically, recurrent pain during digestion — is common. A new study by Italian pediatricians asked if a probiotic would help. They randomized children into two groups: active and placebo. Children in the active group were given pills with a lot of lactobacillus bacteria, which they took twice per day. The placebo was made by the same manufacturer, so it looked identical. During the study, the researchers did not know who was in each group.

There was a big difference between the groups, which took about four weeks to emerge. The active group had painful episodes less than half as often as the placebo group, and the episodes they did have were less painful.

Overall this supports my broad point that we need to eat plenty of fermented foods to be healthy. That’s not what the authors of the study concluded. They concluded:

Demonstration of the efficacy of a given probiotic for a specific therapeutic target will help clinicians choose which probiotic to use when dealing with a specific disease. We are entering the era of targeted probiotic use.

Which reveals a bad case of gatekeeper syndrome. I wouldn’t expect them to say their results support the idea that everyone should eat fermented foods — that’s an “alternative” (and therefore “crazy”) idea. But they could have said their results imply that kids with IBS should eat yogurt.

The Chinese character for sour (pinyin suan) contains a bottle-like element that is sometimes translated wine, sometimes whiskey bottle, and sometimes “the tenth of the twelve earthly branches,” whatever that means. The bottle-like element appears in the character for alcoholic beverage, the character for vinegar, and several other characters with no obvious connection to fermentation. But the connection between sour and fermentation is clear.

My belief that we need to eat lots of fermented food to be healthy began when I realized that would explain why we like sour foods, foods high in umami, and foods with complex flavors — preferences I’d never heard explained. We like those foods, I theorized, so that we will eat foods high in bacteria. Bacteria tend to make sugar-containing foods sour, protein-containing foods high in umami, and all foods high in flavor complexity. I had not previously connected sourness and bacteria — but the Chinese had. I don’t yet know the Chinese characters for umami or flavor complexity.