When pregnant animals are exposed to morphine, their babies can develop behavioral problems like depression, memory issues, and pain sensitivity. Researchers discovered that giving mothers two types of beneficial gut bacteria (Bifidobacterium longum and Bacteroides fragilis) during morphine exposure may help protect their offspring from these harmful effects. In animal studies, the probiotics restored memory problems and reduced pain sensitivity in both male and female offspring. However, the results were mixed for depression and compulsive behaviors, suggesting these bacteria work better for some problems than others. This research opens new possibilities for protecting children whose mothers may have been exposed to opioids.

The Quick Take

  • What they studied: Whether giving mothers special gut bacteria could reduce behavioral problems in babies born after mothers were exposed to morphine
  • Who participated: 48 female rats (24 exposed to morphine, 24 not exposed), plus their male and female offspring. The study looked at how the probiotics affected the babies’ behavior as adults
  • Key finding: Both types of beneficial bacteria helped restore memory problems and reduced pain sensitivity in offspring of morphine-exposed mothers. However, the bacteria didn’t help with all behavioral problems equally—results varied for depression and compulsive behaviors depending on the bacteria type and the baby’s sex
  • What it means for you: This research suggests that probiotics might be a safe, non-invasive way to protect children whose mothers were exposed to opioids during pregnancy. However, this is early-stage animal research, and much more study is needed before any recommendations for humans can be made

The Research Details

Researchers used female rats as a model to study how maternal morphine exposure affects babies. They divided 48 pregnant rats into two main groups: one exposed to morphine and one given saline (salt water) as a control. Within each group, some mothers received one of two types of beneficial bacteria (Bifidobacterium longum or Bacteroides fragilis) while others received only saline. The mothers received these treatments for 10 days before mating with drug-free males. After the babies were born and grew into adults, researchers tested their behavior in several ways: checking for signs of depression, measuring how they responded to pain, testing their memory, and observing compulsive behaviors like burying marbles in bedding.

This design allowed researchers to compare four different groups: morphine-exposed mothers with and without probiotics, and control mothers with and without probiotics. By testing both male and female offspring, they could see if the effects differed between sexes. The behavioral tests were chosen because they reflect problems that can occur in humans exposed to drugs in the womb.

This research approach is important because it tests whether a simple, safe intervention (probiotics) can prevent long-term behavioral damage from drug exposure. Using animal models allows researchers to carefully control all variables and measure specific behaviors that would be difficult to study in humans. The study also examined whether probiotics work differently in males versus females, which is important because we know drug effects can vary by sex.

This is a controlled laboratory study with clear comparison groups, which is a solid research design. The sample size of 48 animals is reasonable for this type of study. However, this is animal research, so results may not directly apply to humans. The study was published in a peer-reviewed journal focused on developmental neuroscience, indicating it met scientific standards. The researchers measured multiple behaviors rather than just one outcome, which strengthens the findings. One limitation is that the study doesn’t explain exactly how the probiotics work, only that they appear to help.

What the Results Show

The most consistent finding was that both types of bacteria helped restore memory problems caused by maternal morphine exposure in both male and female offspring. Offspring whose mothers received probiotics during morphine exposure performed better on memory tests compared to offspring whose mothers received morphine without probiotics.

Both bacteria also reduced pain sensitivity in offspring. Babies born to morphine-exposed mothers typically showed increased pain sensitivity (called nociception), but when mothers received probiotics, this effect was reduced. This benefit appeared in both male and female offspring.

For depression-like behavior, the results were more mixed. Maternal morphine exposure increased depressive-like behavior in offspring. Bifidobacterium longum successfully reduced this depression-like behavior in male offspring but did not help female offspring. Bacteroides fragilis was not tested for this outcome.

Regarding compulsive-like behavior (measured by how many marbles offspring buried), neither bacteria fully prevented the increase in compulsive behavior caused by maternal morphine. Interestingly, when mothers were not exposed to morphine, giving them probiotics actually increased compulsive-like behavior in female offspring, suggesting the bacteria’s effects depend on the context.

An unexpected finding was that probiotics given to mothers without morphine exposure sometimes had different effects than when given during morphine exposure. This suggests the bacteria may work differently depending on whether the mother’s system is stressed by drug exposure. The sex of the offspring mattered for some outcomes—for example, Bifidobacterium longum helped depression in males but not females, suggesting males and females may respond differently to the same intervention.

Previous research has shown that maternal morphine exposure can harm offspring behavior and development. This study builds on that knowledge by testing whether probiotics, which are known to influence brain function through the gut-brain connection, might prevent these harms. The findings align with growing evidence that gut bacteria influence mood, pain perception, and memory. However, this is one of the first studies to specifically test probiotics as a protective intervention against opioid exposure during pregnancy.

This study was conducted in rats, not humans, so results may not directly apply to people. The sample size, while reasonable for animal research, was relatively small. The study doesn’t explain the exact biological mechanisms by which the probiotics help—researchers can only speculate that the bacteria may reduce morphine’s harmful effects on the mother or influence the developing baby’s brain through the gut-brain connection. The study also didn’t test whether the probiotics would work if given after birth rather than during pregnancy. Additionally, the research only looked at adult offspring behavior; it’s unclear if benefits would persist throughout life or if other health measures would be affected.

The Bottom Line

Based on this animal research, probiotics show promise as a potential protective intervention for babies exposed to opioids in the womb. However, these findings are preliminary and from animal studies. No recommendations for human use can be made at this time. Anyone concerned about opioid exposure during pregnancy should consult with their healthcare provider about evidence-based interventions. Future human studies would be needed to determine if probiotics are safe and effective for this purpose in people.

This research is most relevant to pregnant individuals who have been exposed to opioids, healthcare providers treating opioid use disorder in pregnancy, and researchers studying ways to protect children from prenatal drug exposure. Parents concerned about their own prenatal opioid exposure should discuss this research with their doctor, though they should not start probiotics based on this animal study alone. This research is also important for public health officials considering strategies to address the opioid crisis and its effects on the next generation.

In the animal study, behavioral changes were measured in adult offspring (equivalent to young adulthood in humans). It’s unclear how quickly benefits would appear or how long they would last. If this research eventually leads to human studies, it could take years to understand the timeline for seeing protective effects in children.

Want to Apply This Research?

  • For users interested in monitoring gut health and mood: Track daily probiotic intake (type and amount), mood scores (using a simple 1-10 scale), memory or focus quality, and pain levels. Record these weekly to identify patterns over time
  • If recommended by a healthcare provider, users could set daily reminders to take prescribed probiotics at the same time each day. The app could provide education about which foods naturally contain beneficial bacteria and help users track dietary sources of probiotics alongside any supplements
  • Establish a baseline measurement of mood, memory, and pain sensitivity before starting any intervention. Continue tracking these metrics weekly for at least 8-12 weeks to allow time for gut bacteria to establish and potentially influence behavior. Share tracked data with healthcare providers to assess whether the intervention is working for the individual

This research is preliminary animal study data and does not constitute medical advice for human use. Probiotics have not been proven safe or effective for preventing behavioral effects of prenatal opioid exposure in humans. Anyone who is pregnant, planning pregnancy, or concerned about opioid exposure should consult with their healthcare provider before starting any new supplement or intervention. Do not use this information to self-treat or replace professional medical care. This summary is for educational purposes only.