Probiotics in Pregnancy Reduce Child Obesity

Jacob Collyer-Smith Lifestyle Writer

Research suggests that factors affecting the unborn foetus, even at the earliest stages of pregnancy, can have a significant impact on the child's health as they grow and may even affect their state of health in later life. In recent years, clinical trials have revealed how our earliest moments, such as the method of our birth, may impact the development of our gut microbiota (see Probiotics Learning Lab for more) and immune system; for example, studies have suggested that children delivered via caesarean section may have an increased risk of developing allergies and obesity in adulthood.

But this week a new study1 has revealed that probiotics, taken during pregnancy and breastfeeding, may help to reduce the risk of childhood obesity. The clinical trial, undertaken by researchers at the University of Turku, Finland, suggests that probiotic supplementation of Lactobacillus rhamnosus LGG® and Bifidobacterium lactis BB-12® may help to favourably modify genes related to obesity in both the mothers and their children. Most interestingly, the probiotic was able to positively alter the single most influential gene associated with obesity risk, known as the FTO gene.

Pregnant woman

Research suggests that factors affecting the unborn foetus can have a significant impact on the child's health into adulthood

What does this mean?

These findings are incredibly significant, as they suggest that probiotics taken by a mother during pregnancy could possibly have an epigenetic effect, meaning that they could directly affect the genes of the baby. This evidence could provide a platform on which to build strategies for helping to reduce the risk of obesity in future generations.

"Our present results suggest that probiotic supplementation during pregnancy may influence the DNA methylation of obesity and weight-gain related genes also in children." First author of the study, Sanna Vahamiko.

It's a generally agreed principle that obesity is caused by a combination of poor diet, lack of exercise, and an unhealthy lifestyle, in combination with our genetic make-up. The proportion to which each of these factors impacts our risk of obesity, however, is still hotly debated. Nevertheless, the results of these findings may still help us to understand the complexities of obesity, as well as the relationship that probiotics can play in helping to reduce its prevalence in modern society.

The study in more detail

The small pilot study of 15 pregnant Finnish women was a double-blind, randomised controlled trial. The participants were split into two groups, the first of which received the probiotic combo of L. rhamnosus GG® and B. lactis BB-12®, whilst the other received a placebo. The first doses were given to participants during pregnancy and lasted until weaning commenced, approximately six months after the birth. Blood samples were also taken from the participants before supplementation began, and then again between 6-12 months after birth. After the birth, researchers took samples from the infants at the same time.

Pregnancy bump

Could probiotics have a positive effect on the genetic development of the unborn child?

What are the future implications of this study?

The researchers also noted several other favourable genetic alterations in the probiotic group, including for metabolic and immunological processes, suggesting that probiotics could have other potential uses during pregnancy and breastfeeding; however, no other outcomes were being measured in this particular trial.

The Finnish team of researchers were incredibly encouraged by the results of their study but stressed that further larger studies were required to fully understand their findings.

"Specific trials will be needed to clarify the effect of probiotics on the developmental programming of foetus and further lifelong health effects in children... The current findings are certainly encouraging; we hope that they will stimulate further investigations to verify these observations."

Further reading:

New study finds probiotics reduce risk of post-natal depression

New study says our gut bacteria influence our weight loss

New meta-analysis recommends probiotics for neo-natal jaundice

You can find one of the strains mentioned in this article, Bifidobacterium lactis BB-12®, in Optibac Bifido & Fibre


  1. Vähämiko, S., Laiho, A., Lund, R., Isolauri, E., Salminen, S., & Laitinen, K. (2019). The impact of probiotic supplementation during pregnancy on DNA methylation of obesity-related genes in mothers and their children. European journal of nutrition, 58(1), 367–377.​