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In this episode, Greg Dickens and I discuss recent news on risk factors for food allergies in babies and children and on the cost of raising children in the US. We then talk about bellies - what they are, how they shape our health, and why we need to avoid sucking them in. Finally, we talk about sunscreen - does sunscreen increase the risk of cancer more than sunlight does? And what other risks might we want to consider?

* For more information on setting children up for better belly health, see this article: https://guenbradbury.substack.com/p/should-kids-suck-their-bellies-in

* For more information on setting children’s guts up for better long-term health, see this article: https://guenbradbury.substack.com/p/gut-feelings

* Interested in why children need enough sunlight? https://guenbradbury.substack.com/p/throwing-shade

My veterinary degree taught me about mammalian body systems.

My career in health research taught me about Western health and Western bodies.

Spending 18 months living with my three children in remote African and South American communities taught me about human health and human bodies in other cultural environments.

I share what I’ve learned about child physical health and development in weekly articles and podcast episodes.

Everything is free, but if you find my work useful and would like to show your support, you can now upgrade – completely optional, always appreciated.

Topics covered

* What factors in a child’s early life increase their risk of food allergy?

* How much does it cost to raise a child in the US, and at what point do parents spend that money?

* What are bellies and why should we care about their size?

* How can we set children up for better relationships with their bellies?

* Does sunscreen increase the risk of skin cancer more than sunlight does?

Recent episodes

Notes

“In this meta-analysis, the most credible risk factors associated with development of childhood food allergy are a combination of major and minor risk factors, including early allergic conditions (atopic march/diathesis), delayed allergen introduction, genetics, antibiotic exposure, demographic factors, and birth-related variables.” https://pubmed.ncbi.nlm.nih.gov/41661638/

“Average per-child investments from birth to age 18 total $502,152 (2024 USD), with overall disparities by household income and race/ethnicity of 6% to 15%. Early childhood shows the largest gaps—often over 50%—driven mainly by housing and child care.” https://www.nature.com/articles/s41467-026-70316-3

Possible Explanations for Rising Melanoma Rates Despite Increased Sunscreen Use over the Past Several Decades: https://www.mdpi.com/2072-6694/15/24/5868

In this microbiome-heavy episode, recorded on the bike, Greg Dickens and I discuss recent news on how fathers shape children’s long-term health, on how early-life stress affects the development of the gut-brain axis, and on how fecal microbiome transplants affect Autism Spectrum Disorders in children. We then talk about microbes - why they are important, why children need to look after them, and why they are like Santa Claus. Finally, we talk about how we understand repetitive behaviours in animals and children.

For more information on how to help children care for their microbiomes, see this article:

For more information on setting children’s guts up for better long-term health, see this article: https://guenbradbury.substack.com/p/gut-feelings

Topics covered

* How young men’s experiences shape their own and their partners’ health behaviours during pregnancy and beyond

* How early-life stress affects IBD, GERD, and other disorders of the gut-brain axis

* How fecal microbiome transplants affect symptoms of Autism Spectrum Disorder

* Why microbiomes are important

* How to help children care for their microbiomes

* How we understand repetitive disorders in children and animals

Recent episodes

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Notes

“Across biological and behavioural research, young men's early life course experiences have been shown to shape their own and their partner's preconception physical, emotional, and behavioural health.” https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(26)00148-0/abstract

“In humans, significant associations between maternal mental health problems and pediatric disorders of gut-brain interaction (DGBI) were observed in both cohorts, mirroring preclinical findings.” https://www.gastrojournal.org/article/S0016-5085(26)00205-2/abstract

“This novel hydrogen nanobubble water–based FMT method was safe and effective, reducing both core and peripheral symptoms of ASD and suggesting broad benefits via the gut microbiota–brain axis.” https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2026.1767346/full

“While most often described in children with autism spectrum disorder (ASD) and intellectual disability (ID), stereotypies can also present without developmental delay and persist into adulthood.” https://pmc.ncbi.nlm.nih.gov/articles/PMC5370241/

In this episode, Greg Dickens and I discuss recent news on how melatonin supplements affect children’s sleep and development, and why putting all drugs in gummies is a bad idea. We talk about early childhood caries, why it’s linked to prolonged breastfeeding, and why this may have a more negative effect in today’s society. We then talk mattresses - what they are, why they are used, and why we might want to consider other alternatives. Finally, we talk about co-sleeping bed attachments - what they aim to do, and why they may influence child and mother sleep in different ways to closer co-sleeping practices..

For more information on how mattresses affect child health, see this article:

Topics covered

* How do melatonin supplements affect a child’s development?

* Why does breastfeeding older children at night increase their risk of dental disease?

* What’s the deal with mattresses and health?

* Do co-sleepers give the same sleep-synchronising benefits of co-sleeping?

You may be interested in these other episodes:

Some of my subscribers have been urging me for a while to turn on the paid option to increase my Substack visibility. I’ve quietly turned on the paid option for this newsletter. Everything stays free, but if you find these episodes useful, you can now upgrade – completely optional, always appreciated.

Notes

“Exclusive breastfeeding for up to six months is associated with reduced ECC risk, while prolonged and nocturnal feeding after eruption of primary teeth elevates risk.” https://www.mdpi.com/2227-9067/13/1/102

“Our data suggest that the consumption of an HFCS-sweetened beverage increased breast milk fructose concentrations, which remained elevated up to five hours post-consumption.” https://www.mdpi.com/2072-6643/10/6/669

https://www.colorado.edu/today/2023/11/13/melatonin-use-soars-among-children-unknown-risks

“Due to a number of concerns regarding inappropriate use, lack of efficacy and safety data across pediatric populations and variability in actual content, melatonin should be used with caution in children and only under medical supervision.” https://link.springer.com/article/10.1007/s12519-025-00896-5

“These findings suggest a global rise in prescriptions without efficacy data on use in children with typical development, underscoring the need to identify strategies to prevent and reduce melatonin use in young children, as well as to improve adherence by pediatricians to evidence-based practice standards.” https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2843284

In this episode, Greg Dickens and I discuss recent news on how antibiotics during labour affect a child’s long-term health, on how our brains continue to develop into our early thirties, on how astringent flavours help us learn, and on how adverse childhood experiences affect fitness in adulthood. We then talk about football - why it’s great for children, why industrialised football poses some very specific risks, and how parents can navigate the risks so children can get the benefits of sports. Finally, we talk about why high-salt diets contribute to metabolic syndrome.

For more information on the long-term health effects of industrialised sport in childhood, see this article: https://guenbradbury.substack.com/p/do-children-need-protection-from

For more information on why childhood cruciate ruptures are up 2000% since the year 2000, see this article: https://guenbradbury.substack.com/p/cruciate-ruptures-are-up-2000-in

Topics covered

* How does in-labour antibiotic prophylaxis for Group B Strep affect the baby’s long-term health?

* How does your brain continue to develop into your early thirties?

* How do astringent flavours affect learning?

* How do adverse childhood experiences affect adult physical fitness?

* What’s good and bad about industrialised football?

* How does salt contribute to metabolic syndrome?

These other podcasts cover related topics:

Some of my subscribers have been urging me for a while to turn on the paid option to increase my Substack visibility. I’ve quietly turned on the paid option for this newsletter. Everything stays free, but you’d like to support my work, you can now upgrade – completely optional, always appreciated.

Notes

Intrapartum Antibiotic Prophylaxis and Child Health Outcomes: A Systematic Review and Meta-Analysis of Observational Studies: https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.70015

UK recommendations on GBS testing: https://www.rcog.org.uk/for-the-public/browse-our-patient-information/group-b-streptococcus-gbs-in-pregnancy-and-newborn-babies/

“In the United Kingdom, where universal screening is not currently implemented and the background rate is much lower than it was in the United States before screening was implemented, it is estimated that 440 women need to receive IAP to prevent 1 case of EOD, and 3000 to prevent 1 case of EOD leading to death or severe disability.” https://www.ajog.org/article/S0002-9378(22)00622-6/fulltext

Brain not sealed until early thirties: https://www.nature.com/articles/s41467-025-65974-8

Astringent FLAVOURS help you learn: http://sciencedirect.com/science/article/pii/S2665927125002266

Another big "ACEs cause adulthood dysfunction" study: https://www.researchgate.net/publication/400839476_Adverse_childhood_experiences_and_ad[…]e_Brazilian_Longitudinal_Study_of_Adult_Health_ELSA-Brasil

High salt intake causes leptin resistance and obesity in mice by stimulating endogenous fructose production and metabolism: https://www.pnas.org/doi/10.1073/pnas.1713837115

In this episode, Greg Dickens and I discuss recent news on how the artificial sweetener sorbitol affects liver health, and how gut microbes influence this. We discuss how early-life adversity affects cardiovascular health, and why it’s so challenging to really understand this. We then talk about salt - why it’s important, why it can be harmful, and how we should limit salt consumption in babies. Finally, we talk about motor milestones in different cultures.

For more information on salt consumption in babies, see this article:

https://guenbradbury.substack.com/p/how-bad-is-salt-for-babies

Topics covered

* How does eating sorbitol affect the liver, and how do your microbes help?

* Does early-life adversity affect later-life health, and how does this differ in different cultures?

* What does salt do in the body?

* Why is too much salt bad for babies?

* What foods do we need to limit for babies?

* Do babies still roll in cultures in which they are never put down on the floor?

These other podcasts cover related topics:

Some of my subscribers have been urging me for a while to turn on the paid option to increase my Substack visibility. I’ve quietly turned on the paid option for this newsletter. Everything stays free, but you’d like to support my work, you can now upgrade – completely optional, always appreciated.

Notes

Intestine-derived sorbitol drives steatotic liver disease in the absence of gut bacteria https://www.science.org/doi/10.1126/scisignal.adt3549

Early life adversity and physical health implications in adulthood: The Multi-Ethnic Study of Atherosclerosis https://www.sciencedirect.com/science/article/pii/S030645302500397X

In this episode, Greg Dickens and I discuss recent news on how young chimpanzees take risks, on how certain types of dishwasher detergents may affect the gut, and on how gaming affects university students. We then talk about the first hundred hours of life - why it’s more important than the second, what baby bodies expect, and how we can set ourselves and others up for a better postnatal period. Finally, we talk about giving fruit as gifts.

For more information on the early postnatal period, see this article:

https://guenbradbury.substack.com/p/getting-the-first-hundred-hours-right

Topics covered

* How does risk taking in young chimpanzees vary with age?

* How worried should we be about dishwasher detergents?

* What’s the effect of video gaming on university students?

* Should teens sleep in on the weekends?

* How does your gut microbiome affect your risk of cancer and your response to anticancer drugs?

* How does your weight in childhood affect your likelihood of disease in adulthood, and how does this alter if your weight changes in adulthood?

* What’s important in the early postnatal period, and what can we do to set things up for success?

* If everyone gave fruit as gifts, would it lose its appeal?

These other podcasts cover related topics:

Some of my subscribers have been urging me for a while to turn on the paid option to increase my Substack visibility. I’ve quietly turned on the paid option for this newsletter. Everything stays free, but you’d like to support my work, you can now upgrade – completely optional, always appreciated.

Notes

“We found that physical risk-taking correlated with age, peaking in infancy and decreasing gradually thereafter through juvenility and adolescence. We hypothesize that a similar pattern would be exhibited in humans if oversight were relaxed earlier in childhood, as it is among chimpanzees.”https://www.cell.com/iscience/fulltext/S2589-0042(25)02713-0

“The expression of genes involved in cell survival, epithelial barrier, cytokine signaling, and metabolism was altered by rinse aid in concentrations used in professional dishwashers.” (NB - professional, not home dishwashers)https://pubmed.ncbi.nlm.nih.gov/36464527/

“High-frequency gamers (>10 h/wk) demonstrated significantly poorer diet quality, higher body mass index, and impaired sleep quality compared to low-frequency gamers.”https://www.sciencedirect.com/science/article/pii/S0899900725003685

“Weekend catch-up sleep reduced daily depression risk by 41 % in late adolescents and young adults.”https://www.sciencedirect.com/science/article/abs/pii/S0165032725020555

“The gut microbiome is a central determinant of immunotherapy efficacy, particularly in patients treated with immune checkpoint inhibitor drugs.”https://www.nature.com/articles/s41422-025-01212-6

“Both plumper and thinner body sizes during childhood are associated with an increased risk of developing NCDs later in life. However, adherence to a healthier lifestyle in adulthood may partially mitigate these long-term health risks, especially for individuals with larger childhood body size.”https://www.nature.com/articles/s43856-025-01129-6

In this episode, Greg Dickens and I discuss recent news on how overstimulating babies with lots of toys can affect their learning, and on how vegetarian and vegan diets affect children’s health. We then talk about tummy time - what it is, why it was developed, why it’s problematic, and how babies can get similar benefits in other ways. We finish by talking about why different women have different levels of risk when birthing at home or in hospital, and why you might want to weigh up risks beyond mortality.

For more information on tummy time, see this article:

https://guenbradbury.substack.com/p/is-tummy-time-necessary

Topics covered

* How do Christmas presents affect children?

* Do vegetarian and vegan diets affect children’s health and growth?

* What is tummy time?

* Why is tummy time problematic, and what else can we do?

* Why are the risks of maternal mortality in home vs hospital birth equivalent in the UK?

These other podcasts cover related topics:

Some of my subscribers have been urging me for a while to turn on the paid option to increase my Substack visibility. I’ve quietly turned on the paid option for this newsletter with a January special offer. Everything stays free, but you’d like to support my work, you can now upgrade – completely optional, always appreciated.

Notes

“Repetition is key to early learning as parents are warned not to stimulate babies with too much information.” https://www.telegraph.co.uk/news/2026/01/02/the-secret-to-making-your-child-clever/

“In conclusion, this systematic review and meta-analysis suggests that lacto-ovo-vegetarian and vegan diets in childhood can be nutrient-rich and support healthy growth when carefully planned. These diets may confer health benefits, including greater consumption of plant foods and improved cardiovascular risk profiles, while also aligning with ethical and environmental values. However, they pose a higher risk of specific nutrient deficiencies if key nutrients are not supplied through fortified foods or supplements.” https://www.tandfonline.com/doi/10.1080/10408398.2025.2572983?

“The evidence for the global agreement on the association between the prevalence of stunting and chronic undernutrition in modern and historic populations is weak. We find overwhelming evidence to support the vision that stunting is the natural condition of human height also in the affluent and well-nourished social strata of feudal rural and urban societies.”

https://onlinelibrary.wiley.com/doi/full/10.1002/ajhb.23693

References on home and hospital birth in this article:

Hello! My name’s Guen. I’m a veterinarian by background and I’ve worked in health innovation for a decade. I spent eighteen months living in traditional villages across Africa and South America, learning from communities that raise children in very different ways. My passion is helping parents, doctors, and teachers identify small things they can do to set children up for better long-term physical health.

If you’re interested in this area, drop your email below and I’ll send you bi-weekly articles and podcast episodes with stories from other cultures and deep scientific dives on different aspects of child development and health. It’s free, easy, and you can unsubscribe at any time.

In this episode, Greg Dickens and I discuss how a baby’s experience of labour shapes their stress responses in childhood, and why that matters. We talk about how a few minutes of movement affect how children perform in school. We then talk about treats - what they are, what they could be, and how we can set them up differently. Finally, we answer a listener question about how we respond to research that suggests that we or our children might be at higher risk of health problems in the future.

To read more about creating better treats, see here:

https://guenbradbury.substack.com/p/how-to-get-kids-to-crave-healthy

Topics covered

* Does a child’s experience of labour affect their later response to stress?

* How does a few minutes of movement affect children’s school performance?

* What makes a treat?

* Why might we want to think differently about treats?

* How might we respond to research that suggests that we are at higher risk of health problems?

These other podcast episodes cover related topics:

Notes

Evolved birth physiology meets modern birth practice: Sustained effects of planned cesarean delivery on child hair cortisol in Brazil https://www.pnas.org/doi/abs/10.1073/pnas.2519365122

The behavioural, cognitive, and neural corollaries of blunted cardiovascular and cortisol reactions to acute psychological stresshttps://www.sciencedirect.com/science/article/abs/pii/S0149763416304614

Acute 3.5-minute light-intensity exercise enhances executive function and psychological mood in children: https://www.nature.com/articles/s41598-025-27358-2

Hello! My name’s Guen. I’m a veterinarian by background and I’ve worked in health innovation for a decade. I spent eighteen months living in traditional villages across Africa and South America, learning from communities that raise children in very different ways. My passion is helping parents, doctors, and teachers identify small things they can do to set children up for better long-term physical health.

If you’re interested in this area, drop your email below and I’ll send you bi-weekly articles and podcast episodes with stories from other cultures and deep scientific dives on different aspects of child development and health. It’s free, easy, and you can unsubscribe at any time.

In this episode, Greg Dickens and I discuss a set of recent papers summarising the evidence on ultra-processed food. We talk about the effect of childhood stress in rats, and how their gut microbes influence this. We then explore the problems that arise when women are transported during labour, and how this disrupts the normal hormonal processes of birth. We finish by talking about why drinking a smoothie has very different effects on the body from eating the same fruit whole, and why just focusing on the individual nutrients isn’t enough to understand the complexity of the system.

For more information on why moving labouring women disrupts their hormones, see this article:

https://guenbradbury.substack.com/p/donkeys-cars-or-boats-why-transporting

For more information on how birth should work in humans, try this talk:

https://guenbradbury.substack.com/p/veterinary-perspectives-on-childbirth

Topics covered

* What do we know now about ultra-processed foods, and what should society do?

* How do probiotics help stressed rats?

* What is physiological birth and why should we care about it?

* What can we do to enable physiological birth?

* Why is whole fruit better than smoothies?

These other podcasts cover related topics:

Notes

“The rise of ultra-processed foods (UPFs) in human diets is damaging public health, fuelling chronic diseases worldwide, and deepening health inequalities. Addressing this challenge requires a unified global response that confronts corporate power and transforms food systems to promote healthier, more sustainable diets, according to a new Lancet Series on UPFs and human health, published on Nov 19.” https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)02322-0/fulltext

Mild environmental stress inoculation promotes resilience to anxiety in female rats: https://www.nature.com/articles/s41598-025-24717-x

Processing Apples to Puree or Juice Speeds Gastric Emptying and Reduces Postprandial Intestinal Volumes and Satiety in Healthy Adults: https://www.sciencedirect.com/science/article/pii/S0022316622023586

Hello! My name’s Guen. I’m a veterinarian by background and I’ve worked in health innovation for a decade. I spent eighteen months living in traditional villages across Africa and South America, learning from communities that raise children in very different ways. My passion is helping parents, doctors, and teachers identify small things they can do to set children up for better long-term physical health.

If you’re interested in this area, drop your email below and I’ll send you bi-weekly articles and podcast episodes with stories from other cultures and deep scientific dives on different aspects of child development and health. It’s free, easy, and you can unsubscribe at any time.

In this episode, Greg Dickens and I are joined by biomedical scientist and international touch rugby player Anna Wilson. We discuss recent papers on early induction of labour, on artificial sweeteners and early puberty, on learning and hearing loss in rats, on dog ownership and teen microbiomes, and on repurposing drugs for previously fatal conditions. We then talk about the effects of early movement on child musculoskeletal development, and how simple tweaks to your home can set up both you and your children to move more. Finally, we answer a listener question on giving sugar to children when they are ill.

To see photos of our home, try this article:

https://guenbradbury.substack.com/p/come-look-around-our-high-movement

Topics covered

* Does induction of labour at term reduce the number of Caesarean sections in the real world?

* Might some artificial sweeteners affect early puberty?

* How does deafening rats at different ages affect their learning ability?

* Is living with a dog good for teens?

* Can we repurpose existing drugs for a fatal skin disease?

* How do we create a home that makes us move?

* Should we give foods containing sugar to sick children?

These other podcast episodes cover related topics:

Notes

Induction of Labor at 40 Weeks of Gestation after Dissemination of the ARRIVE Trial: https://pubmed.ncbi.nlm.nih.gov/41106401/

Deafening rats at different ages: https://www.nature.com/articles/s41598-025-26704-8

Early puberty and artificial sweeteners: https://link.springer.com/article/10.1007/s40618-025-02677-3

Effects of dog ownership on teen microbiomes: https://www.cell.com/iscience/fulltext/S2589-0042(25)02209-6

Can we repurpose existing drugs for a fatal skin disease?https://www.nature.com/articles/s41586-024-08061-0

JNK pathway signalling and fructose : https://pmc.ncbi.nlm.nih.gov/articles/PMC3523093/

Hello! My name’s Guen. I’m a veterinarian by background and I’ve worked in health innovation for a decade. I spent eighteen months living in traditional villages across Africa and South America, learning from communities that raise children in very different ways. My passion is helping parents, doctors, and teachers identify small things they can do to set children up for better long-term physical health.

If you’re interested in this area, drop your email below and I’ll send you bi-weekly articles and podcast episodes with stories from other cultures and deep scientific dives on different aspects of child development and health. It’s free, easy, and you can unsubscribe at any time.