Postnatal depression (PND) is a global public health problem.
According to the World Health Organisation, about 10% of pregnant women and 13% of women who have just given birth will experience a mental disorder, depression being the most common.
Maternal mental health disorders are treatable, but it is far better to prevent them.
Probiotics During Pregnancy Could Reduce PND, Study Says
A recent study has revealed women who are at risk of depression during pregnancy, or after giving birth, could benefit from increasing their intake of probiotics during pregnancy.
What Did The Study Find?
The data comes from the Probiotics in Pregnancy Study, funded by the Health Research Council of New Zealand and the Fonterra Co-operative Group Limited.
The study looked at the effects of giving the probiotic Lactobacillus rhamnosus HN001 to women in early pregnancy and while breastfeeding.
The researchers were primarily interested in how the probiotic could affect the rates of infant eczema and atopic sensitisation at 1 year.
They also looked at maternal outcomes, including gestational diabetes, bacterial vaginosis, and Group B Streptococcal colonisation before birth, as well as maternal depression and anxiety postpartum.
The study recruited 423 women between 14 and 16 weeks gestation. Of these, 212 women were randomised to take HN001, and 211 to take a placebo, from enrolment until six months after birth (if they were breastfeeding).
The researchers utilised modified versions of the Edinburgh Postnatal Depression Scale and the State Trait Anxiety Inventory to assess the women’s symptoms of depression and anxiety after birth.
The mothers who had been given the probiotic reported significantly lower depression and anxiety scores compared with the women who were given the placebo. Rates of clinically relevant anxiety were halved among the mothers treated with probiotics.
How Can Probiotics Affect Mental Health?
There’s growing evidence to show the community of bacteria (gut microbiota) that live in the intestine might be very important for improving mental health.
The gut-brain axis (GBA) is now generating a great deal of interest in the scientific world. The GBA is the biochemical signalling which takes place between the gastrointestinal tract (GI tract) and the central nervous system (CNS).
To take it one step further, the term ‘microbiome–gut–brain axis’ refers specifically to the role of gut bacteria in the signalling that takes place between the GI tract and the CNS.
So what does this mean? How can the gut communicate with the brain?
A study of mice found adding a strain of the bacteria lactobacillus to the gut of normal mice reduced their anxiety levels.
The effect was blocked after cutting the vagus nerve, which is the main connection between the gut and the brain. This suggested to researchers bacteria were using the communication link (gut-brain axis) to affect the brain.
To date, most of the research done on the role of gut flora in the gut-brain axis has been conducted on animals. Although limited, this study shows there’s more to understand about the way the gut microbiota influences mental health.
Researchers used gut microbiota samples taken from people with major depression to colonise bacteria-free rats. These rats went on to show behavioural changes related to depression.
There are only a few human studies that look at the effects of probiotic use on mental health. There are, however, large studies demonstrating that people who eat a healthy, balanced diet have lower rates of mental health disorders as teens and adults.
We know diet affects both the gut microbiota and mental health. More research is needed to determine whether a healthy gut microbiota maintains this relationship.
Improving the gut microbiota, through supplementation or by increasing dietary intake of probiotics, might be the key to influencing the gut-brain axis. This would, therefore, reduce the risk of women developing depression during pregnancy or after birth.
As this is the first study of its kind, the authors say more research is needed to replicate the findings. They must look at other types of probiotics to see if they have the same effect, and determine the dosage and the length of the treatment.
What Does This Research Mean For Mothers?
Most women tend to think depression during pregnancy or after birth won’t happen to them. When it does happen, the effects can be devastating.
Left untreated, maternal depression can be serious. Suicide is now one of the leading causes of maternal death in many high income countries.
Severe postnatal depression in mothers can also have severe effects on children, increasing their risk of emotional, cognitive, behavioural and attachment issues, as well as learning difficulties, mental health and addiction issues, and a higher risk of suicide.
Sadly, despite more focus on maternal mental health, there is still a stigma attached. Many women avoid seeking support and treatment for fear of being judged. They might be reluctant to take antidepressant medication while pregnant or breastfeeding their babies.
Although more research is urgently needed to determine whether or not probiotics can improve mental health outcomes during pregnancy and in the postnatal period, it is a more natural alternative many women would be ready to embrace.
The Gut Microbiota
Our digestive system is teeming with beneficial bacteria (gut microbiota). It contains tens of trillions of microorganisms, including at least 1,000 different species of known bacteria with more than three million genes.
Each of us has our own unique gut microbiota, but its purpose is the same. The gut microbiota:
- Helps the body digest certain foods
- Helps to produce vitamins B and K
- Protects against microorganisms that cause disease
- Plays an important role in the immune system
- Ensures proper digestive function (provided it remains healthy and balanced)
Our gut microbiota develops at birth and is largely determined by how we’re fed. By age three, our gut microbiota has stabilised and will continue to evolve over time. The composition of our microbiota is mostly determined by diet and environment.
Although the gut microbiota can adapt to change, certain situations can create an imbalance. This often happens when people are recommended to take probiotics.
What Are Probiotics Exactly?
It’s hard to avoid hearing about probiotics. They are often touted as the best solution for gastrointestinal problems in babies and adults. However, gut health is more than just popping a supplement or eating yoghurt every day.
Probiotics are live bacteria and yeasts that are either the same as, or very similar to, the beneficial bacteria already in your body.
There is a vast array of probiotic products on the market, however, each with different strains and numbers of active microorganisms. It’s hard to know which to use and, without having a stool sample done, you probably won’t know which strains you need.
If you want to add natural sources of probiotics to your diet, it’s a good idea to eat a variety of foods. Each food offers a different type of beneficial bacteria to help the body in a variety of ways.
Sources of probiotics include:
- Cultured vegetables such as kimchi and sauerkraut
- Kombucha, fermented black tea
- Natto, a fermented soybean food from Japan
- Yoghurt, be careful of brands high in sugar
- Apple cider vinegar
What are prebiotics?
Prebiotics are non-digestible carbohydrates. They act as fuel for gut microbiota, to improve function and allow growth of the good bacteria.
It’s a good idea to make sure your diet also includes some form of prebiotic. This will ensure your existing gut microbiota has plenty of fuel.
Sources of prebiotics include:
- Jicama (yacon), Jerusalem artichoke, and chicory root
- Dandelion greens
- Garlic, onions, chives and leeks (members of the allium vegetable family)
- Wholegrain and sprouted grain breads
- Whole wheat berries
- Apple cider vinegar (organic)
- Potato skins
Taken together, prebiotics and probiotics can overcome an imbalance in gut microbiota.
Are Probiotics Safe During Pregnancy?
Even though probiotics are considered a natural product, there are many different strains. The research into their use during pregnancy has also been limited.
The National Library of Medicine and the National Institute of Health (US) have concluded there does not appear to be any risk of probiotic use for expecting or lactating mothers.