Italian research says: probiotics may not be beneficial

With antibiotics or stomach problems, many people are anxious to drink a few cups of probiotics to restore the "natural balance" of the gut microbes. Probiotics have become the fastest growing product in the food industry and are now incorporated into yogurt, beverages and children's food. However, not everyone needs probiotics to stay healthy. A new study of gut bacteria in African hunter-gatherers reveals that they do not have a key bacterial component in most probiotic foods, but they can still maintain good health. And, the only hunter-collecting tribe in the world—the Tanzanian Hadza tribe—does not have colon cancer, colitis, Crohn’s disease, or other colon diseases caused by modern eating habits in Western countries.

This project is the first study of intestinal bacteria in hunter-gatherers. Previous studies have focused mainly on industrialized countries, and their eating habits tend to be high in sugar, salt, and fat. These eating habits change the type of bacteria in the intestine - the microbiome group. Intestinal bacteria rapidly adapt to changes in the diet of the host, and the population of microbes living in rural areas and with less intake of processed foods is more diverse. Researchers also discovered a link between microbial group diversification and colon disease.

The study collected stool samples of 27 Hadza people aged 8-70 years and sent them to the University of Bologna, Italy, as a frozen or dry sample for the team to extract and sequence DNA from bacteria. The team identified bacteria through the DNA of Hadza's people and analyzed the type of nutrients in the feces, including microbial metabolites. This fatty acid is the source of intestinal bacteria's energy.

When the team compared the DNA between Hadza and Italians, it was found that the Hadza people's gut microbial ecosystem is more diversified. Moreover, compared with the bacteria in the African two groups of farmers, they found that only the Hadza people do not have the most common bacteria in the probiotic drink, Bifidobacterium, which may be due to the fact that the group does not consume dairy products.

Hadza people also have high levels of bacteria such as Treponema, which is a sign of Western disease, because different types are associated with systemic lupus erythematosus, periodontitis, and syphilis. However, Hadza people rarely have diseases related to different types of intestinal bacterial imbalances such as autoimmune disorders, obesity, or diabetes. The research results were published in Nature-Communications.