Diet, Gut Bacteria and Health

We each walk around with about 10 times more bacteria cells in our guts than we have human cells in our entire bodies! In fact, there are about three pounds or so of bacteria in the human gut that are busy doing things that affect our wellbeing.

The Internet is a glut of stories about the gut bacteria right now because this is an emerging and exciting area of research. But there is still so much to learn. We do know that the gut is home to bacteria and other microbes. We have also known for a long time that microbes in the intestines synthesize vitamins, break down cancer-causing compounds, free up disease-fighting compounds from the foods we eat, defend against infections and ferment resistant starches and some other types of fibers. Scientists are now looking at ways in which the various intestinal bacteria affect disease risks and treatments, including those for diabetes, obesity, heart disease and cancers.

So Many Types of Microbes

Unfortunately, the science is too young still to identify an ideal composition of bacteria for any specific health concern. In general, the gut is home to more than 300 species of bacteria, and is not limited to only microbes with health benefits. There are also microbes that are known to cause gastrointestinal illness or those that are associated with other health problems. So pointing to the perfect mix is not likely to happen anytime soon.[i] Collectively these microbes are called the gut microbiota. And the microbiota comprise nearly two million genes, called the microbiome. The gut microbiome is at least 100 times larger than human genome. You can see why these tiny microbes potentially have a lot of influence on our health and are being researched but it’s important to remember that genes are not the only indicator of health outcomes.

We each have a different make up of microbes in our intestines. The composition of the microbiota is highly individualized and influenced by many factors, including your diet, genetics, general health, use of medications, environment and even whether you were born vaginally or by C-section.

What You Can Do

With so much unknown about how the gut microbiota influences health and what is the ideal composition, you may wonder if you have any positive control of your microbiome. You might. Studies suggest that a Western-style of eating – a diet heavy in animal protein, animal fat, refined grains and added sugars is associated with an increase of less desirable intestinal bacteria. On the other hand, dietary patterns that include an abundance of whole grains, fruits, vegetables and legumes are associated with greater protective species and more health benefits.[ii] In short then, follow what you already know to be healthful eating.

Probiotics and Prebiotics

You have likely heard of probiotics. These are live microorganisms which, when consumed in adequate amounts, provide a health benefit. Various probiotics have various benefits. Just like a specific antibiotic is needed to confer a desired health benefit, the specificity of probiotic is also necessary. For example, one type of probiotic may reduce some symptoms of irritable bowel syndrome, but a completely different product could be indicated for the prevention of antibiotic-induced diarrhea in children.[iii]

A less familiar term is prebiotics. Prebiotics are food for your gut bacteria that stimulate the growth or activity of your intestinal bacteria. Many dietary fibers are prebiotic. There are a number of foods with prebiotic fibers and compounds. A few are these:

Whole-grain wheat
Oats
Onions
Garlic
Leeks
Bananas
Jerusalem artichokes
Honey
Breast milk
Cereal bars, breads and other foods with added chicory root or inulin.

Bottom line: This is a fascinating area of research that will likely one day give greater insight to wellness and certain disease states. If you have specific questions related to the microbiota and your own health, a consult with a registered dietitian nutritionist is a smart idea.

Disclosure: Some of this information was gathered at a partially sponsored educational meeting.

[i] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983973/

[ii] Nutrition FYI, Diabetes Spectrum Fall 2016, Vol 29 (4)

[iii] World Gasteroenterolgy Organisation Global Guidelines Probiotics and Prebiotics: http://www.worldgastroenterology.org/guidelines/global-guidelines/probiotics-and-prebiotics/probiotics-and-prebiotics-english

Diet, Gut Bacteria and Health