Gut health is dependent on what we eat and how we are feeding our microbiome. We need to feed it with foods that support a healthy gut microbiome so that it can complete the myriad of functions to support our health and well-being. Our microbiome, made up of an enormous ecosystem of microorganisms including viruses, fungi and bacteria, and lives in symbiosis with us. As we are born, the bacteria in our mother’s body, mostly Bifidobacteria, populate our gut., unless we are born by Cesarean section. Any child born by Cesarean section will pick up bacteria from the skin instead, and this difference in microbiome population can increase their risk of dieases such as type 1 diabetes and asthma. The gut microbiome of babies is important for long term health – 10% of intestinal flora are Bifidobacteria although during breast-feeding, 95% of all bacteria in the newborn’s gut are Bifidobacteria. Bottle fed babies develop a different balance of bacteria, often with fewer Bifidobacteria, and this can affect their long-term health.
The intestinal flora changes as we grow older and develop as we are exposed to more bacteria via contact with different humans, animals and foods. Every single person has their own unique microbial footprint. So far, the Human Microbiome Project have identified about 1000 different species of gut microflora over many different phyla. Our gut microbiome is a huge ecosystem which is almost as diverse and dense as the Amazon rainforest. We have a huge influence on this ecosystem which is influenced by our actions and we need to look after this to maintain balance. This balance maintains biodiversity of the different organisms to create health and wellbeing. Diet, the environment, stress and drugs such as antibiotics can change this balance and reduce the amount of diversity of organisms, and this can make us ill!
Our intestinal bacterial flora are an essential part of our health and we share our body which we cohabit. Our relationship with the microbiome is symbiotic – our bodies house the bacteria and provide food whilst the bacteria participate in our health in several ways:
• Breakdown of complex carbohydates – our bodies lack several enzymes to degrade plant fibres freeing up the sugars that fruit and vegetables contain which we can then use for an energy source.
• Produce vitamins and minerals – the metabolic activity of intestinal flora leads to the production of vitamins K, B12 , niacin, pyroxidine and folic acid which we are unable to produce on our own.
• Produce short-chain fatty acids – our gut flora ferment fibre to produce short chain fatty acids which are both an important energy source for the cells of our colon along with regulating the immune process, healing, reducing inflammation ad protection from cancer and other diseases.
• Protect against pathogens – as the first line of defence, intestinal bacteria work by stimulating the immune response to protect against pathogenic bacteria. In addition, lactobacilli and bifdiobacteria can transform substances rich in fibre into lactic acid when there is no oxygen. Lactic acid acidifies our intestine and slows down proliferation of pathogenic bacteria.
• Train our immune system – intestinal bacteria can selectively supress the immune response so that we can tolerate some substances in our environment, which is important for preventing autoimmune disease and allergies. The bacterial genes can also regulate local and systemic inflammation.
• Support detoxification – the gut flora are able to degrade toxic metabolites formed in the liver from metabolisation of our food. These metabolites are carried by the bile to the intestine, where the bacteria can degrade and safely eliminate them.
• Regulate the nervous system – the latest research demonstrates a connection between our gut microbiome, digestive system, nervous system and brain. These interactions might influence everything from behaviour, mood, and appetite regulation.
Our gut microbiome is essential for balancing day to day body functions via both their metabolic activity and impact on the immune system. This system requires delicate balance to maintain optimal health and well-being and any imbalance could have a profound impact on our weight, health and quality of life. Imbalance of lack of biodiversity of the gut microbiome from nutrition and lifestyle choices could contribute to many diseases including including risk of cancer, type 2 diabetes, irritable bowel syndrome, cardiovascular disease, allergies, mood disorders and inflammatory bowel disease. The Human Microbiome Project analysed the human microbiome and its role in human health and disease, and the genome of the microbiomes. The results of this study were released last week and will help us to understand how the gut microbiome is involved in health, nutrition, immunity and disease and how we might use this in clinical settings, how probiotics might be used and regulated, and the efficacy of new treatments such as fecal transplants.
Peterson et al – The NIH Human genome project : Genome Research 2009; 19, 2317- 2323
Leblanc et al – Bacteria as vitamin suppliers to their host: a gut microbiota perspective: Current Opinion in Biotechnology 2013; 24, 160 – 168
Layden et al – Short chain fatty acids and their receptors: new metabolic targets: Translational Research 2013; 161 – 131-140
Ivanov et Honda – Intestinal microbes as immune modulators: Cell Host and Microbe 2012;12 – 496 – 508
Rhee et al – Principles and clinical implications of the brain-gut-enteric microbiota axis: Nature Reviews Gastroenterology & Hepatology 2009; 6 – 306 – 314