Long before the word “microbiome” entered everyday conversation, naturopaths were teaching that good health begins in the gut. The intuition has turned out to be remarkably well founded. We now know that the digestive tract is home to trillions of microorganisms whose activity touches almost every system in the body. This guide looks at what that inner ecosystem does, how to recognise when it is out of balance, and - most practically - the whole foods that help it flourish.
The information here is educational and is not a substitute for professional medical advice. Persistent digestive symptoms should always be assessed by a doctor.
Meet Your Microbiome
The human gut hosts an enormous community of bacteria, along with other microbes, collectively known as the gut microbiome or gut flora. Far from being passive passengers, these organisms earn their keep. Research suggests the gut microbiome contributes to several important functions:
- Digestion and fermentation - gut bacteria ferment the fibres we cannot break down ourselves, producing short-chain fatty acids that nourish the cells lining the colon.
- Nutrient production - certain gut bacteria are involved in synthesising vitamins, including some B vitamins and vitamin K.
- The gut barrier - a healthy flora helps maintain the integrity of the gut lining, the selective barrier between the digestive contents and the rest of the body.
- Immune development - a large proportion of the body’s immune tissue surrounds the gut, and research indicates the microbiome plays a central role in training and regulating it.
From a naturopathic perspective, this is exactly why the gut is treated as foundational: support the terrain of the digestive tract, and you support the whole organism.
Signs Your Gut May Be Out of Balance
When the balance of gut flora is disturbed - a state often referred to as dysbiosis - the effects can be wide-ranging. While only a qualified professional can investigate the cause of any symptom, naturopaths have long associated a disturbed gut with bloating, irregular bowel habits, food intolerances and a general sense of sluggishness. Early naturopaths described this in terms of bowel “toxicity” from long-standing residues. Modern science does not support a literal build-up of toxins in a healthy gut, but it does recognise that a disrupted gut barrier and an adverse flora are associated with wider inflammatory and digestive symptoms - which is a more accurate way to understand the naturopathic emphasis on gut health, and a theme explored further in our articles on how detoxification works and food and detoxification.
Feeding the Good Bacteria: Prebiotics and Fibre
If the microbiome is a garden, prebiotic fibre is its fertiliser. Prebiotics are the indigestible plant fibres that beneficial bacteria ferment for fuel. The single most powerful thing most people can do for their gut is also the simplest: eat a wide and colourful variety of plants.
- Diversity matters most. Studies suggest that people who eat a greater range of different plant foods each week tend to have a more diverse microbiome - a pattern associated with better gut health. Aiming for many different vegetables, fruits, pulses, wholegrains, nuts and seeds across the week is a practical goal.
- Prebiotic-rich foods include onions, garlic, leeks, asparagus, oats, bananas, apples and pulses.
- Resistant starch, found in cooked-and-cooled potatoes and rice, oats and pulses, is another valuable fuel for the gut flora.
This whole-food, plant-forward approach sits naturally within Plaskett’s emphasis on building health from real food rather than from isolated supplements.
Fermented Foods and Probiotics
Where prebiotics feed existing bacteria, fermented foods can introduce beneficial microbes and the compounds they produce. Traditional cultures across the world have long valued fermented foods, and research into them continues with interest. Examples worth getting to know include:
- Live natural yoghurt and kefir
- Sauerkraut and other fermented vegetables
- Kimchi
- Miso and tempeh
Introduced gradually and in modest amounts, fermented foods are a time-honoured way to support a varied gut flora. As with any dietary change, the body responds best to a steady, gentle approach rather than a sudden overhaul.
What Disrupts the Gut
Just as some habits nurture the microbiome, others work against it. Diets dominated by refined sugar and ultra-processed foods tend to feed less desirable bacteria while starving the beneficial ones of the fibre they need. Chronic stress, too, is increasingly recognised as influencing the gut, and medical antibiotics - while sometimes essential - can disturb the flora and may benefit from a period of careful dietary rebuilding afterwards. The naturopathic remedy is consistent and unglamorous: crowd the plate with whole, fibre-rich foods, and the disruptive items lose their foothold.
The Gut and the Whole Body
Perhaps the most exciting area of modern research is the growing recognition that the gut does not act in isolation. Scientists are actively exploring the gut-immune relationship and the gut-brain axis - the two-way communication between the digestive tract and the nervous system. While much remains to be understood, this emerging picture echoes a long-held naturopathic conviction: that the body is an interconnected whole, and that caring for the gut has effects that reach far beyond digestion.
Key Takeaways
- The microbiome is a community of trillions of microbes that support digestion, nutrient production, the gut barrier and immunity.
- An imbalance (dysbiosis) is traditionally linked with digestive discomfort and a wider sense of being run down.
- Diversity of plant foods is the single most powerful lever - aim for many different vegetables, fruits, pulses, wholegrains, nuts and seeds each week.
- Prebiotic fibres, resistant starch and fermented foods all help the good bacteria thrive.
- Sugar, ultra-processed foods and chronic stress work against gut balance.
- Research into the gut-brain and gut-immune connections increasingly supports the naturopathic view of the body as an interconnected whole.
Nurturing your inner ecosystem is one of the most rewarding foundations of natural health - and a perfect illustration of how whole-food nutrition works with the body rather than against it.
Understanding the gut at this depth - its biochemistry, its flora and its role in whole-body health - is central to what students explore in our Professional Diploma in Nutritional Therapy. If you are just beginning, our Certificate in Nutrition & Health is an ideal first step into this fascinating subject.
References
- Valdes, A.M. et al., ‘Role of the gut microbiota in nutrition and health’, British Medical Journal (2018)
- McDonald, D. et al., ‘American Gut: an Open Platform for Citizen Science Microbiome Research’, mSystems (2018)
- Murray, M. & Pizzorno, J., Encyclopaedia of Natural Medicine, Simon & Schuster (2012)