Growing the Next Generations (Part 2): Building the Gut
In our previous article, we explored the importance of the preconception nutrition landscape and how the health of both parents lays the foundation for the next generation.
From the moment of conception, the human body begins building two of its most complex systems, the gut and the brain. These systems develop in close partnership and will influence health for an entire lifetime.
Both are constructed from, and function through, fats. Not just any fats, but the stable, nutrient dense fats our biology has relied on for millennia, particularly those found in grazing mammals and ocean dwelling fish rich in quality fatty acids.
In this article we will look more closely at the gut, how it forms and why it matters so profoundly for long term health.
In Part 3, we will explore its closely connected partner, the brain and nervous system.
The Gut: Formation and Function
From the early weeks of foetal development, a simple tube begins to form. This structure gradually develops into the gastrointestinal tract, a living interface between the body and the outside world.
By the time a child is born, this system has become one of the most complex and energy demanding organs in the body.
The lining of the gut carries enormous responsibility. It must interact with food, microbes, and environmental exposures while protecting the body’s internal systems. To do this, the cells of the gut lining are constantly renewing themselves, turning over every three to five days.
To rebuild this protective layer continuously, the body relies on stable, high quality fats, particularly for the construction of cell membranes and structural components of the gut wall.
The Role of Maternal Nutrition
For millennia, breastfeeding has provided the primary nutritional bridge between mother and infant.
Human breast milk contains a dynamic balance of nutrients, and fat is the most variable macronutrient within it. The types of fatty acids present in breast milk closely reflect the mother’s diet, particularly long chain polyunsaturated fatty acids such as omega-3s.
In other words, the food a mother eats directly influences the nutritional composition of the milk that supports her child’s development.
This makes the quality of fats in the maternal diet especially important, as they help shape both gut development and early metabolic programming.
A Remarkably Thin but Powerful Barrier
The entire digestive tract is lined by a single layer of specialised epithelial cells. Despite its thinness, this barrier performs several critical functions that influence health across a lifetime.
1. Protection
The gut lining forms a barrier that protects the body from pathogens, toxins, and undigested food particles.
Within this epithelial layer are goblet cells, which produce mucus that coats the digestive tract. This mucus serves several roles. It lubricates food as it moves through the system, provides an additional protective barrier, and acts as a food source for beneficial gut bacteria.
This mucus layer is rich in fats and relies heavily on fat soluble vitamins, particularly vitamins A and D, to function effectively.
2. Selective Absorption
Between epithelial cells sit microscopic structures known as tight junctions. These junctions regulate which nutrients are allowed to pass into the body.
Healthy tight junctions allow the absorption of essential nutrients such as:
- fats
- fat soluble vitamins
- amino acids, the building blocks of protein
Maintaining these junctions requires significant energy and depends on a healthy microbiome and good nutritional support.
Research increasingly shows that certain chemicals common in the modern food system can disrupt these junctions. One example often discussed is glyphosate, alongside a number of additives and contaminants associated with highly processed foods, including some processed infant foods.
When tight junctions become damaged or weakened, the gut barrier becomes more permeable. This condition is often referred to as increased intestinal permeability, or more commonly, “leaky gut”.
When this occurs, larger molecules such as partially digested proteins may pass through the gut wall. The immune system may respond aggressively to these particles, which is thought to contribute to rising rates of food sensitivities, digestive disorders such as IBS, and the development of autoimmune conditions.
The types of fats consumed can also influence gut integrity. Diets high in unstable, oxidised seed oils may increase permeability of these junctions, leading to greater immune activation and inflammation.
By contrast, stable saturated fats help support the structural integrity of these cell membranes and junctions.
3. Communication
The gut lining also plays an active communication role with the immune and nervous systems.
Cells within the gut continuously send signals about what the body is encountering, identifying what is helpful and what may be harmful.
Among these specialised cells are Paneth cells, which act as local security agents. They produce antimicrobial peptides that help control harmful bacteria and support the development of a balanced microbiome in early life.
Another important group of cells are enteroendocrine cells (EECs). These cells release hormones that regulate appetite, blood sugar, digestion, and even mood.
These signals travel through the gut brain axis, often via the vagus nerve, highlighting the deep connection between gut health, neurological function, and emotional wellbeing.
Although most gut hormones themselves are peptides, the cells that produce them rely heavily on stable fats and cholesterol within their membranes to function properly.
Looking Ahead
The gut is far more than a digestive organ. It is a protective barrier, a nutrient gateway, and a communication hub that helps guide immune development, metabolism, and neurological signalling from the earliest stages of life.
The nutritional environment surrounding pregnancy and early childhood therefore plays a profound role in shaping how well these systems are built.
In the next article in this series, we will turn our attention to the brain and nervous system, exploring how early nutrition supports the development of the most complex organ in the human body.
By Susan Hendry, Co-Founder, Native Angus Beef
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