Scientists looked at 8 studies with over 1,500 pregnant women who were overweight or obese to see if probiotics could help prevent pregnancy problems. While probiotics didn’t help with most issues, they found that taking a mix of two specific types of good bacteria (Bifidobacterium and Lactobacillus) cut the risk of having a small baby in half. The researchers also used computer models to understand how these probiotics might work in the body, finding they affect important proteins that control inflammation and cell growth.

The Quick Take

  • What they studied: Whether taking probiotics (good bacteria supplements) during pregnancy helps prevent complications in women who are overweight or obese
  • Who participated: 1,563 pregnant women from 8 different studies who were overweight or obese
  • Key finding: Most probiotics didn’t help, but a specific combination of two bacteria types reduced the risk of having a small baby by 46%
  • What it means for you: If you’re overweight and pregnant, certain probiotic combinations might help, but talk to your doctor first since results were mixed

The Research Details

This was a meta-analysis, which means researchers combined results from 8 separate high-quality studies to get a bigger picture. All the original studies were randomized controlled trials, where some pregnant women got probiotics and others got fake pills, and nobody knew which was which until the end. The researchers also used computer programs to predict how probiotics might work in the body by looking at which proteins they interact with.

Combining multiple studies gives us more reliable answers than looking at just one study. The computer modeling helps scientists understand the ‘why’ behind the results, not just the ‘what happened.’

The studies included were all randomized controlled trials, which are considered the gold standard for medical research. However, there were only 8 studies total, and they used different types and amounts of probiotics, which makes it harder to draw firm conclusions.

What the Results Show

Overall, probiotics didn’t significantly improve most pregnancy complications compared to taking nothing. However, when researchers looked more closely at specific types of probiotics, they found something interesting. Women who took a combination of Bifidobacterium and Lactobacillus bacteria had about half the risk of having a baby that was too small for its gestational age. This finding was statistically significant, meaning it’s unlikely to be due to chance.

The computer analysis identified 46 different beneficial compounds that probiotics produce and 166 proteins in the body that these compounds interact with. The most important compounds included natural plant-based molecules like quercetin and kaempferol, which are known to reduce inflammation.

Previous research on probiotics in pregnancy has shown mixed results, and this study confirms that the picture is complicated. The finding about specific bacterial combinations is relatively new and needs more research to confirm.

The studies used different types of probiotics, different doses, and measured different outcomes, making it hard to compare. There were also relatively few studies overall, and most focused on different bacterial strains.

The Bottom Line

If you’re overweight or obese and pregnant, a combination of Bifidobacterium and Lactobacillus probiotics may help reduce the risk of having a small baby, but more research is needed. Don’t expect probiotics to solve all pregnancy complications.

Overweight or obese pregnant women should discuss this with their healthcare providers. Women with normal weight pregnancies shouldn’t assume these results apply to them.

The studies looked at outcomes at birth, so benefits would be seen when the baby is born, not during pregnancy itself.

Want to Apply This Research?

  • Track daily probiotic intake, noting specific bacterial strains (Bifidobacterium and Lactobacillus), dosage, and any digestive symptoms
  • Consider adding a multi-strain probiotic containing both Bifidobacterium and Lactobacillus to your daily routine after consulting with your healthcare provider
  • Log probiotic consistency, digestive health, and discuss baby’s growth measurements with your doctor at regular prenatal visits

This information is for educational purposes only and should not replace professional medical advice. Always consult with your healthcare provider before starting any supplements during pregnancy, especially if you have existing health conditions.