How your mum's stress got into your belly

Part 1. Why does this happen

Earlier this year, I was visiting my mum and dad in Madrid. We were having some of my favourite conversations, mostly about trivia from the distant past, like: “Do you remember when you were 4, and you did [enter something ridiculous here], then run away laughing?” To which I’d respond: “No. I was 4 years of age. So no, I don’t remember!” Then both my mum and dad would look at me in disbelief and proceed to add some more detail about that same incident, completely ignoring the fact I had just said I didn’t have a clue what they were talking about… Yes, well. That kind of wonderfully endearing conversation. I found it astonishing that they could both remember seemingly nonessential events with cinematic precision but that they couldn’t answer some of the basic questions in my pre-consultation questionnaire for the ASD assessment with my psychiatrist.

Actual footage of my mum ignoring the fact I have no recollection of the event from 46 years ago she’s telling me about, just before she continues to tell me about it.

My dad is 90 and has brilliant memory. He’s sharp as! One of the questions was about whether my mum was anxious, stressed or depressed while she was carrying me. This is important for a number of reasons that I’ll discuss in a moment. In a nutshell, anxious mothers often have higher levels of stress hormones such as cortisol. These hormones can cross the placenta and affect the developing foetus, potentially influencing brain development and increasing the risk of neurodevelopmental disorders such as ADHD and autism.

My mum - who’s in her late 80s - simply said something along the lines of: “Oh, I don’t remember; it was a very long time ago.” Fair enough too. It was 50 years ago. Then my dad proceeded to add his hilariously witty bit of Andalusian sense of humour (dry and slightly dark, for those who aren’t familiar with it): “Your mum was stressed since the first day I met her.” And he’s not wrong.

All about my mother

My mum couldn’t remember being stressed at the time because, quite frankly, she’s always been stressed about something or another. She’s a survivor of the Spanish civil war who lost her dad at 3 years of age and was raised in poverty by her grandparents and her older sister. Her mum was around but was disengaged, probably as a result of her own trauma, having seen her husband get shot dead. Scientists have looked at how living in a war zone makes stress hormones go through the roof in mothers and how this situation shapes anxiety symptoms in trauma-exposed children. There’s a family rumour that my nan was never the same after the war. And although this is never discussed in detail, it does add up, doesn’t it? It’s just one of those family things. It was the days when there was shame and stigma associated with accepting that a family member may have struggled with their mental health. Luckily, things are changing. At any rate, my mum experienced enough early-life trauma to keep anyone in a state of hypervigilance into their adult years. And because life is messy, to make things a little funkier, my mum lost a 6-month-old baby to an antibiotic-resistant infection a few years before I was born. At this point, I reckon it is safe to say that she was probably freaking out about being pregnant with me - her fourth child - in her late thirties. This was the 70s, and most mothers were much younger, which would have added to her anxiety.

A cute psychedelic aside

During a recent Ayahuasca experience, I regressed to being a foetus inside my mother’s womb. I could hear my mum and dad talking as if I was underwater, which was totally surreal because I could not understand what they were saying, on the basis that I was a foetus with a brain without language skills. I could however sense my mum’s anxiety with absolute clarity, and it was palpable. I tried to explain my trip to my dad while my mum was preparing some sardines for lunch, but he didn’t quite get it. “It sounds weird!” he said. And it probably does sound weird, although it was a beautiful experience. For me, its significance was the confirmation that there are many different ways of knowing, and that they’re all valid. The beauty of psychedelics is that they can make you feel more comfortable with accepting that we’ll never have an explanation for everything, and that that is OK. What is life about if not about finding meaning in the stuff that happens to us and around us?

Stress, baby bumps, and gut bugs

We often hear how stress “gets under the skin,” affecting the brain, nervous system and hormones, as well as the immune system. That’s one of the ways stress damages both physical and mental health. Early-life stress (ELS) and adverse childhood experiences (ACEs) are two types of stress that get deeper than skin deep because they’re complex types of stress that affect you psychologically and can have even more pronounced effects depending on social factors like family relationships, economic status, and more. Psychological stress is so powerful that it gets “into the belly,” affecting gut microbes.

A slide from my recent presentation at the Integrative Mental Health Day at the IPM Congress 2023. For access to my full presentation please go to my post “The Mind-Gut Connection”. Paid subscribers will find a download link below my signature at the bottom of the post. To choose a paid plan, click here.

The scientific evidence on this is ample and documents how babies born to mums who live with stress, anxiety, or depression have reduced levels of Bifidobacterium and Lactobacillus. Studies suggest that the abundance of both Bifidobacterium and Lactobacillus in the infant gut microbiota may promote healthy neurocognitive development and that depletion of these bacteria may increase the risk for neurodevelopmental disorders, e.g. autism, ADHD, etc. You may be thinking, “Oh OK, surely this will correct itself after a few years.” Well, no. Studies also suggest that this isn’t the case and that you carry the imprint of trauma, stress, anxiety, and/or depression from your mum and/or your early life into your adult years. You may not even know you were carrying this imprint until much later in life. In fact, you may not even remember you experienced any trauma because your brain does an amazing job at hiding it in places where you’re unlikely to come across it doing something mundane, like deciding whether to order the same ASOS T-shirt in 2 different sizes, just in case you put on some weight before your holiday. It’s such a lovely T-shirt, and it’s on sale, so you might as well have it twice. You come back from your holiday and start to realise that the “chilled effect” you used to get from being away in the sun for two weeks has worn out really quickly and that your IBS symptoms are getting really bad. Then you hear some professor talking about early-life stress and irritable bowel syndrome on the radio and start putting two and two together.

Your IBS is unlikely to have just “happened.” There’s very likely a trigger that goes back to early life or even to a time before you were born.

Stressed mums and anxious babies

Being ADHD and autistic myself, finding out late in life and being a gut-brain scientist, I am literally all over the link between maternal stress/anxiety/trauma and the increased risk of mental health / neurodevelopmental disorders in babies. It is my new special interest, so I devour any literature I can get my hands on.

Actual footage of me devouring the literature on the link between maternal stress and the increased risk of neurodevelopmental disorders in babies.

The link is complex, and researchers cannot agree completely on what goes on, but there are several possible mechanisms through which my mum’s anxiety has contributed to my brain being wired differently. And off the top of my head (pun intended!), here are a few:

1. Prenatal environment: Anxious mothers often have higher levels of stress hormones such as cortisol. These hormones can cross the placenta and affect the developing foetus. The presence of cortisol in the placenta influences brain development and increases the risk of neurodevelopmental differences.

2. Epigenetics: Chronic maternal anxiety or stress very likely leads to epigenetic changes. Epigenetic changes are changes to genes that don’t actually alter the DNA sequence itself. They just alter the gene expression, i.e. the proteins that genes make. These changes are known for having the ability to impact the foetus’ developing brain, potentially paving the way to some differences in brain wiring.

3. Postnatal environment: Parental anxiety can also affect the child's environment after birth. Anxious parents - both mums and dads - interact differently with their children, which could impact the child's development. Also, children are intensely intelligent and very quickly learn to internalise anxious behaviours.

4. Genetic factors: Anxiety disorders often have a genetic component. So, it's possible that the same genetic factors that contributed to a mother's anxiety could also increase the risk of neurodevelopmental disorders in her children.

5. Gut microbiome: As mentioned earlier, maternal stress can also impact the infant's gut microbiota. Gut microbes are known to influence brain development and behaviour, so that’s yet another angle contributing to neurodevelopmental disorders.

The wabi-sabi of early-life stress and gut microbes

Wabi-sabi, the gut-brain axis, and the impact of early-life stress/trauma are completely disparate concepts, aren’t they? How the hell can they be connected in any meaningful way whatsoever? Well, as I mentioned in an earlier post, wabi-sabi is the art of appreciating beauty in the imperfect, in impermanence, and in the natural ageing process. Consequently, the framework of wabi-sabi can offer a unique perspective on early-life stress and the gut-brain axis. Let’s take a look!

What's this wabi-sabi stuff about?

Science confirms how early-life stress can have a significant impact on health later in life, influencing everything from our mood to our immune system. One of the pathways through which this occurs is the gut-brain axis, the bidirectional communication system that connects our gut and our brain. Stress can fragment and frazzle this connection, leading to both mental and physical health issues, including disorders related to mood - like anxiety and depression - as well as dysfunctional digestion.

In the context of wabi-sabi, these early-life experiences, as challenging as they may be, can be seen as part of the inherent imperfection and transience of life. They form part of our unique, personal journey and shape who we are, contributing to our individuality and to our personal growth trajectory. Applying the wabi-sabi philosophy to this situation allows us to acknowledge and accept these imperfections and changes, not as flaws but as part of our ever-evolving, natural human experience. Wabi-sabi encourages us to accept and adapt to our circumstances, to find strength in our innate resources, and to tap into our capacity for transformation.

On that basis, I believe that looking at the science of how early-life stress and the gut-brain axis are entwined through the lens of wabi-sabi can empower us to take proactive steps towards protecting our mental and physical health as adults, guiding us towards practices that enhance our wellbeing and resilience. The integration of the precision of science with the “realness” of wabi-sabi encourages not just acceptance but also understanding, compassion, resilience, and growth. And that’s precisely what I will be discussing in part 2 of this post, i.e. now that you know the “why?”, what can you do about it, in evidence-based wabi-sabi style, aka “Dr Miguel’s style” 😂

By the way, part 2 will be a paid post, so if you’re on a free plan, you can upgrade to a paid plan now and get access as soon as I publish it later this week. Take good care of yourself until then.