Probiotic bacteria in drinks adapt in human intestine
by Michiel Kleerebezem
Dutch research shows that the properties of probiotic bacteria in yoghurt drinks change in the human intestine. Especially the bacterial cell membrane changes. These adaptations can play an important role in the way bacteria influence the immune system in the intestine. For the first time ever researchers could measure the bacterial changes. This helps to understand the health effects of drinks with probiotic bacteria.
Within the framework of the Top Institue Food & Nutrition (TIFN), researchers led by Prof Kleerebezem of NIZO food research isolated the bacteria from the intestinal mucous membrane of five patients who suffer from colon cancer and where a part of the colon had to be removed.
The patients, who were treated in a hospital in Malmo, Sweden, were each given bacteria drinks for eight days before being operated on in the hope of accelerating recovery after the operation. The part of the intestine that was removed was investigated after the operation and bacteria were isolated. The investigation included looking at the changes in activity of the genes of the lactic acid bacteria which were drunk. As way of a control, one of the cancer patients received a drink without lactic acid bacteria.
Lactic acid bacteria stick to the intestinal mucous membrane where they adapt quickly. Genetic analysis showed that molecular changes took place, in particular, in the cell walls of the bacteria. The cell wall plays an important role in communication with the intestinal mucous membrane and the intestinal immune system.
This kind of genetic analysis has been performed on mice but never on humans. Previous research showed that lactic acid bacteria in health drinks activate the immune system in the intestine. The new study now reveals the adaptation of lactobacillus in the human intestines on molecular level.