Women who take probiotics during their first trimester of pregnancy may be less likely to suffer from the most unhealthy form of obesity after giving birth, according to research.

A study by scientists at the University of Turku in Finland suggests that manipulating the balance of bacteria in the gut may help to fight obesity.

Probiotics are bacteria that help to maintain a bacterial balance in the digestive tract by reducing the growth of harmful bacteria. They are part of the normal digestive system and play a role in controlling inflammation.

Researchers have for many years been studying the potential of using probiotic supplementation to address a number of intestinal diseases. More recently, obesity researchers have investigated whether the balance of bacteria in the gut might play a role in making people fat.

Kirsi Laitinen, a nutritionist and senior lecturer at the University of Turku, said that the results of the study, presented today at the European Congress on Obesity, were an encouraging sign of the impact of a diet supplemented with probiotics on adiposity. Adiposity, or central obesity, is a particularly unhealthy form of obesity associated with fat bellies.

“The women who got the probiotics fared best,” she said. “One year after childbirth, they had the lowest levels of central obesity as well as the lowest body fat percentage.

“We found [adiposity] in 25 per cent of the women who had received the probiotics along with dietary counselling, compared with 43 per cent of the women who received diet advice alone.”

In the study, 256 women were randomly divided into three groups during the first trimester of pregnancy.

Two of the groups received dietary counselling consistent with what is recommended during pregnancy for healthy weight gain and optimal foetal development. They were also given food such as spreads and salad dressings with monounsaturated and polyunsaturated fatty acids, as well as fibre-enriched pasta and breakfast cereal to take home.

One of those groups also received daily capsules of probiotics containing Lactobacillus and Bifidobacterium, which are the most commonly used probiotics. The other group received dummy capsules.

A third group received dummy capsules and no dietary counselling. The capsules were continued until the women stopped exclusive breastfeeding, after up to six months.

The researchers weighed the women at the start of the study, which was funded by the Social Insurance Institution of Finland, the Academy of Finland and the Sigrid Jusélius Foundation, a medical research charity.

At the end of the study they weighed them again and measured their waist circumference and skin fold thickness.

Central obesity — defined as a body mass index (BMI) of 30 or more or a waist circumference over 80 centimetres — was found in 25 per cent of the women who had been given the probiotics as well as diet advice.

That compared with 43 per cent of the women who got dietary counselling alone and 40 per cent of the women who got neither diet advice nor probiotics. The average body fat percentage in the probiotics group was 28 per cent, compared with 29 per cent in the diet advice only group and 30 per cent in the third group.

Ms Laitinen said that further research was needed to confirm the potential role of probiotics in fighting obesity. One of the limitations of the study was that it did not take into account the mothers’ weight before pregnancy, which may influence how fat they later become.

She said that she and her colleagues would continue to follow the women and their babies to see whether giving probiotics during pregnancy had any influence on the health of the women’s children.

“The advantage of studying pregnant women to investigate the potential link between probiotics and obesity is that it allows us to see the effects not only in the women, but also in their children,” she said.

“Particularly during pregnancy, the impacts of obesity can be immense, with the effects seen both in the mother and the child. Bacteria are passed from mother to child through the birth canal, as well as through breast milk, and research indicates that early nutrition may influence the risk of obesity later in life. There is growing evidence that this approach might open a new angle on the fight against obesity, either through prevention or treatment.”

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