Research on the “human microbiome” has recently exploded in the media. Talk of taking probiotics and eating yogurt, kombucha, kimchi, etc. to try and foster the “good bacteria” has become more and more common. Although this is a hot topic, the scientific research is still in the very early stages of trying to make sense of it all. However, the following is what we do know so far about the gut microbiome and how it can help you lead a healthier lifestyle.
What is the microbiome?
The microbiome is defined as all the bacteria, viruses, fungi, archaea, and eukaryotes that inhabit the human body. Sometimes referred to as the “second human genome”, the gut microbiome is now being considered a separate organ with distinct metabolic and immune activity. There are 10x the number of microbial cells in the human gut than in the whole human body, totaling roughly 100 trillion microbes.
How does the microbiome develop?
Though once thought that the fetal intrauterine environment and GI tract were sterile, the evidence of microbes in meconium suggests that the microbiome may develop sometime during fetal development. The neonatal microbiome is influenced by delivery type (vaginal versus C-section) and feeding type (breast milk versus formula) and continues to develop until age 2-3 years when the gut microbiota stabilizes and resembles that of adults.
What does the microbiome do?
Gut bacteria are involved in harvesting energy from food, balancing the good versus bad bacterial composition, manufacturing neurotransmitters such as serotonin, enzymes and vitamins, and are involved with immune and metabolic functions.
What can I do to have a healthy gut microbiome?
Diet seems to be the most powerful influence of the gut microbiome. Processed foods containing emulsifiers and detergent-like compounds may damage the intestinal lining, potentially leading to inflammation and contributing to inflammatory-based diseases such as diabetes and CVD. Fibers, including food-based resistant starch, soluble fiber and insoluble fiber, are some of the key nutrients for promoting fermentation and ensuring a diverse microbiome.
Do different people have differences in their microbiomes?
The gut microbiome of Americans and most other Westernized, industrialized populations is less diverse and dominated by different bacterial species than that of people from rural, less developed populations. Diet plays a role, but the shift away from natural environments with little exposure to soil, animals, and other environmental microbes has impacted the gut microbiome.
A wide diversity of gut microbiota is currently thought to be the healthier composition than having only a few bugs. This diversity is affected by a varied diet rich in plants, vegetables and fruit, so those who have a limited diet also have a low diversity of microbiota. Aging is associated with decreasing microbial diversity and the reduced diversity correlates with nutritional status, increased inflammation, and frailty.
Do probiotic supplements actually help?
Some studies have reported beneficial effects. However, most probiotic products that are commercially available have not been investigated for effectiveness. NY Times journalist Michael Pollan asked the top experts in the field of microbiome research about their use of probiotics. Most of these researches do not take them but cited focusing more on a whole-foods diet rich in prebiotic items and fermented foods.
What we don’t know about the gut microbiome and its contribution to health and disease is a lot more than what we do know. But one thing is for sure - this is a tremendous area of research with new discoveries and relevant cardiovascular implications. There seems to be great potential for the role of this second human genome and the role it may have in future therapeutic targets.