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The Gut Microbiome and Health: A Comprehensive Overview

Updated: Jun 12

The human body is a living landscape teeming with microscopic life forms, collectively known as the microbiome. These tiny inhabitants, including bacteria, viruses, and fungi, are crucial for our health. They assist in digestion, regulate our immune system, produce vital vitamins [1] and can even impact our mood. [2]

A petridish with intestinal tissue-like base scattered with colourful plant foods textured with characteristics of flesh, intestinal villi and microorganisms. A human-like figure stands in the centre beneath a laboratory table. The composition is inspired by Annie Liebowitz.
The food we eat transforms your gut microbiome, influencing the structure and behaviour of your gastrointestinal tract, immune cells, and beyond. Laboratory testing can identify the unique composition of your microbiome to personalise nutrition recommendations.

The microbiome is a dynamic entity, constantly changing in response to our diet, environment, lifestyle, and medication use; we can mould our microbiome and influence our health. Understanding the microbiome and its profound impact on our well-being is a fascinating journey into the microscopic world within us.

An Introduction to the Microbiome

We're at least as much bacterial as we are human if you look at cell and gene counts. Bacteria, while only a fraction of our body weight, may even outnumber our human cells by 1.3 fold [3] and our human genes 100 to 1. [4]They're vital for our immunity, digestion, and disease protection, and they start colonising us from birth.

The largest bacterial population in our bodies is in the colon. The types of bacteria that predominate change dramatically over the first 1000 days of our life, influenced by our gestation term, birthing method, early feeding and weaning patterns, and our dietary habits after weaning.

For instance, the Bacteroides species comprise up to a quarter of the bacteria in our gut due to their ability to adapt quickly to environmental, dietary and immune system variability [5].

Bacteroides are more than just passive inhabitants. They're mutualists, benefiting us and benefiting from us. For instance, certain Bacteroides strains can digest various complex carbohydrates and fibres in early weaning as the diet expands beyond milk consumption [6]. Several genes have been identified in this species that allow them to sense signals in their environment and adjust their metabolism, structure and behaviour in response [5].

This flexibility is advantageous given the changes in food and nutrition sources we consume in the first few years of life and across the seasons. As mutualists, they can do more than utilise different nutrient sources for their energy use: they even pre-digest complex sugars that other bacteria in our gut cannot digest alone, making it easier for them to get enough energy as dietary sources change. Like many other beneficial bacteria, Bacteroides can also change antigens on their surface to evade our immune response, making them valuable allies.

The gut microbiome's equilibrium and metabolites are fundamental to our health and well-being. Shifts in the balance of this ecosystem are linked to obesity [7], diabetes [8], cardiovascular disease [9], and even neurological conditions [10]. This is because the gut microbiome can produce a variety of bioactive compounds that can enter the bloodstream and influence the function of distant organs. In the following sections, we will delve deeper into the fascinating world of the gut microbiome, exploring its connection with diet, its impact on metabolic health, and its potential as a target for therapeutic interventions. We will also introduce laboratory stool testing as a tool for assessing gut health and the role of nutrition in maintaining a healthy microbiome.

The Gut Microbiome in Obesity and Metabolic Disease

The Gut Microbiome and Inflammatory Bowel Disease

Enteric Infections and Malnutrition

The Role of Nutrition in Maintaining the Microbiome
Probiotics vs Prebiotics: A Brief Introduction
Laboratory Stool Testing and the Microbiome

Plenty remains to be discovered about the microbiome, how it affects our health, and how we can optimise it through diet, lifestyle and therapeutic products. Yet even now, there are many simple, safe and exciting applications to help hone and improve our gut health.

A professional nutritional therapy practitioner like Adam Greer can help you customise and prioritise dietary changes that are most suitable for optimising your gut microbiome. If you're interested in learning about your unique microbiome, book a free discovery call to find out how nutritional therapy can help you. You can also read about nutritional therapy, which goes far beyond the microbiome to personalise your diet and lifestyle recommendations.

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